Livingston - West Lothian Starters Group

Help and advice for those starting in, or converting to P4 standards. A place to share modelling as a beginner in P4.
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Allan Goodwillie
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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Mon Aug 01, 2016 4:49 pm

Marking out - in this case we are only going to cut a shape from metal to show the cutting technique. So this does not require quite the same precision. Normally when cutting out I would use a metal scriber for marking out as James has suggested, but to make lines more easily seen by the camera I am using a permanent marker with a fine point

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The first thing I have established is a clean edge to do my measuring from and I have marked it clearly using my marker and steel rule.

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The next thing is to put the material in a vice to give proper support to the metal when using a file. The vice I am using has plain jaws so as not to mark the surfaces of the sheet when working with it. You want the line and a little bit of metal below the line to show above the jaws of the vice. If you were taking a larger amount away using a file, you may want to take it down in stages using the support of the vice. You do not want to bend the sheet during the filing process. Note the angle of the cut-do not cut straight across, the cut on a file is meant to work correctly when the file is used at this angle.

The blade of the file should not scream :evil: at you as you are cutting. Use your thumb and finger/s to give further support when filing as in the following image. I have started with a fairly large flat file and finished off using a flat needle file. Keep looking to see where you need to take material off. You should aim to get the file going down level with the line and use long strokes from one end of the material to the other and do not force. There is a tendency for beginners to take out material from the middle, but make sure you are taking it out equally for the full length of the material. And get down low and work n a good light so that you can see properly what is going on. :)

DSC05896.JPG


When you get down to the line or, near to the line, make final adjustments and once you are happy that the line is just showing all the way along its length, take it out from the vice. It may still have a few rough edges so mind your fingers. :cry: A rub down with a little fine wet and dry paper will take these off without removing much material.

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Finally mark the good edge that you are going to be measuring from. You can use the mark shown, but any mark that is recognisable to you is all that matters. :thumb

DSC05899.JPG

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Allan Goodwillie
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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Mon Aug 01, 2016 6:43 pm

Looking through the fourum, there are a few areas of specialist knowledge explored for those of you in the group new to the fourum. There is a tools and their uses section which covers some of the more specialised issues, but nothing as basic as what we are doing here. There is much useful advice including how to look after tools as here http://www.scalefour.org/forum/viewtopic.php?f=7&t=3465 and I would suggest having a look in this section when certain problems arise from time to time.

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When marking out I use a steel ruler with nice clear markings, we were taught not to measure using the end of the ruler as that is where most ware occurs. :idea: Here I have been marking out the metal for cutting using a steel ruler and a small model makers square.

DSC05901.JPG


The areas to be cut are marked out with hatched lines so it is clear what is going to be cut away. Maybe not really necessary with such a simple piece, but you can imagine with lots of areas to be cut out there may be quite a lot of confusion possible, especially if a sheet has a number of pieces to be cut and pierced.

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I have taken my centre punch and marked positions for drilling holes. One area I will take out using a junior hacksaw and the other will use the piercing saw. There is a little distortion here, should have done this on the anvil of my vice, but it can be flattened later.

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Allan Goodwillie
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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Mon Aug 01, 2016 7:03 pm

I have a basic work block made from a piece of spare ply wood and some MDF strip along two edges. The strip stops the metal turning when drilling a hole. It does not take long to make and can be turned upside down to fit on top of the vice to act as a work surface to take the worst marks and preserve the workbench. It also allows the work to be held in a higher position and also allows for clamping etc. It's not pretty, but very useful none the less.

Here the metal strip sits ready for drilling, the vice is being used as a clamp to hold it on the the workbench.

DSC05904.JPG


Next I am drilling the holes - perhaps a little big for what is needed, but I am assuming you may not have many drills at your disposal yet. The aperture I want to cut with the hacksaw is the one with several punchings.

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As it turned out using a bigger drill meant only two holes in each, but that is OK the same problem may occur when you are doing this, in fact you may only have a much larger drill. A number of small holes in a row is best, but as you will see two will be fine. The view below shows the work sitting on my cutting block.

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The cutting block is made up from another piece of plywood with a v cut and a block of wood screwed and glued on to the underside to allow it to be held in the vice as below.

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The underside of the cutting block, simple to make.

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Allan Goodwillie
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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Tue Aug 02, 2016 8:08 am

I am going to use the piercing saw to cut out the first aperture. The metal is placed on the v cutter so that the metal can be supported and the thin blade of the piercing saw travels up and down in the v. Cut leaving the line and a small margin for filing to shape later.

Cut towards the first hole. You can cut either clockwise or anti clockwise. It does not matter as you are always going to be cutting away from yourself. The change to right angles is achieved simply by turning the metal. I tend to hold the metal using my free hand, not easy to show when holding a camera! You will quickly get a feel as to how the metal is cutting by the feel of your fingers and hands. No forcing, :evil: if you want to,
:idea: add a slight touch of oil when you are cutting, some also use a little touch of saliva just to ease the blade along.

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Here we have reached the first hole and the material is being turned on the cutting block, very easy if you have drilled a couple of holes. Even without holes it is still possible to change direction with the blade as it is a narrow blade and will cut curves, if necessary, like a jig saw.

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Once the second hole has been reached make your final turn and work back towards the edge. Nothing to it! You can see however that pre-drilling holes makes it easy and if you were cutting an odd shape,say, not from the edge, but from the centre of the material when making a chassis - quite a common occurrence with the shape well within the material, it is an easy technique to undo one end of the saw, place the blade through one of the holes and cut out the material - not something you could do with a hacksaw :!:

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Well that is the first cut made - I have left enough of the line to see it OK and now it requires cleaning up with a nice flat needle file.

:idea: I have two sets of needle files. The first is a set of really good ones for use on materials like metal which will not clog the teeth.(Individuals can cost as much as £10 a go)-so you would not want to mess these up! The second set is a set of cheap ones for filing solder and white metal and any other material which will clog up the teeth. I do have a couple of brushes which I use for cleaning them one is steel , the other a brass brush - probably originally a hush puppy brush, both of which are reasonably effective.

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Allan Goodwillie
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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Tue Aug 02, 2016 8:36 am

Now to the junior hacksaw. This requires a slightly different technique and is only of use when cutting materials from the edge. It is a saw developed for cutting thicker materials at a quicker rate. A large hacksaw does have its uses on larger projects - aluminium baseboard frames for example, which we will look at when we get around to alternative baseboard construction. The junior saw does have many applications in loco building and is often used when cutting out frames and cutting along longer edges which would take a long time using a piercing saw. It is also easier perhaps to keep cutting in a straight line due to its thicker blade.

The technique is much the same as before, support and cut in from the edge up to the hole.

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As you are cutting keep the blade at an angle rather than cutting down vertically as you would with the piercing saw. You will find it easier to start the penetration of the metal if you do this - especially if it is a thin sheet as here. Cut in to the second hole same as the first.

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Do not attempt to turn the metal at right angles as you will find that the blade will not cope with that. You will need a pair of flat nosed pliers for the next part. Take the piece to be removed out by carefully folding the metal back and forward along the line of holes. With the two larger holes here that is enough for this fairly small piece of metal.

:idea: If you have a small drill it is preferable to have a number of small holes rather than two larger as it puts less stress on the metal that is left.

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Working the metal gently one way then the other will create a fracture caused by metal fatigue between the two holes. Do not be tempted to take the material out all the way up to the line as that is a much stronger material - you are using the weak point to do the business. You will be left with a ragged edge, but at least you can clean up to the edge with a flat file.

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Now clean out the material from your cuts by placing the material in the vice and filing with a good needle file. There will be less to file using the piercing saw, but the time taken is much the same with the hacksaw as it cuts quicker, but requires more filing to achieve the same result.

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Allan Goodwillie
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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Tue Aug 02, 2016 8:58 am

While we are with the saws it would be useful to mention the fitting of piercing saw blades. Sometimes when you buy them there are no instructions which can be a problem for someone just starting up. So I have photographed the instructions here just to help. Fitting junior hacksaw blades is a similar technique and follows similar principles. There are no wing nuts, pressure on the frame will allow for one blade to come out and for another to be put in.

The instructions on "How to insert"

1 Loosen wing screw at both ends of the frame.

2 Insert one end of the blade into the top of the frame in such a way that the teeth face outward and point downward. Tighten screw. (See Illustration A)

3 Firmly hold frame against workbench edge, and press it to insert the other blade end. Tighten screw, then release pressure slowly. Pluck the blade to check tautness; it should make a sharp whistling sound. (See illustration B)

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So I know it is basic, but then again some of you have not needed to use these tools before, so I hope that helps chaps. :thumb

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Will L
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Re: Livingston - West Lothian Starters Group

Postby Will L » Tue Aug 02, 2016 3:03 pm

Allan Goodwillie wrote:..add a slight touch of oil when you are cutting, some also use a little touch of saliva just to ease the blade along.


A Jeweller would rub a candle along the blade, but I agree spit does the job and is readily available, just don't try licking the blade.

Allan Goodwillie wrote:While we are with the saws it would be useful to mention the fitting of piercing saw blades. Sometimes when you buy them there are no instructions which can be a problem for someone just starting up. So I have photographed the instructions here just to help. Fitting junior hacksaw blades is a similar technique and follows similar principles. There are no wing nuts, pressure on the frame will allow for one blade to come out and for another to be put in.


The whole process of using a pearcing saw, and the correct way of fitting a blade was covered extensively on this thread quite recently.

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Allan Goodwillie
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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Tue Aug 02, 2016 4:12 pm

Thanks Will, :D

Thanks for pointing out the other thread as it ties in nicely with this one. I am keeping everything together here and exploring different challenges as they come up within the starters group and very basic use of some tools was inevitable at the beginning. It can be a bit bewildering as there is so much on the forum for someone coming to it for the very first time, so this is producing a focal point for the group and I hope that they will also go off and explore further from here. Your direction indicated some further uses for piercing saws where multiple shapes can be created by soldering several sheets together and then cutting using the saw and some interesting diagrams concerning changing blades all of which I would recommend they have a look at.

I am going on to suggest things they can consider getting ready before we get together one to one or one to two over the next month, but by putting it here on the forum it means the information is here and ready to hand - maybe not all that useful to others using the forum necessarily but another possible way of using the forum as a useful teaching aid others getting a starters group going may consider doing the same thing and may even want to use some of the material. For those of us using tools on a day to day basis it may seem obvious how you use them, but I am happy to take everyone at whatever level they are starting on and work from there much as I did in my Art teaching days.

You know I had forgotten all about using a candle :o - which I did do when I did silversmithing at Art College - but of course a good technique.

You yourself are very good at passing on information and tips and I am not surprised to see you pointing up information already on the forum, which I confess I had missed. Thank you again Will for showing an interest in this little bit of the community - I was a little bit worried about putting really basic stuff up here. in case some of our number would feel that it was a bit too basic, but I am starting with where people are in their development and hoping to bring them up to speed. There are of course areas for more advanced working elsewhere on the forum so it should be possible to cater for all levels in our society, once the members of the group get used to coming here and posting in public then I am sure they will also be happy exploring the richness of the forum.

Needless to say we welcome others like yourself with a friendly voice who may take an interest and who don't mind helping out those who are really just starting to do similar things, it is much appreciated. I am sure there will be other areas that will tie in and if there are further examples of things which tie in that I may have missed, but you know about so please let us know. ;)

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Allan Goodwillie
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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Wed Aug 03, 2016 10:12 am

Preparation for chassis assembly.

Most of the group are starting by using a chassis kit of some kind. Some are ancient kits :| , some more modern, however we will look at progress as we go along and tackle any problems that may arise - as this is being done in real time almost, it will give others who are just starting some hope that any problems can be overcome and even if you are not a member of our little group still feel free to add to the conversation, you may prefer to place comments etc. in the parallel stream that has been set up for this.

This part will cover what is required by members before coming along for individual sessions over the next month/6weeks, by then I hope those taking part will all have one working chassis at least and will have tried out the jigs etc. and feel comfortable with them.

Lets start with the chassis parts. I have covered how to go about scratch building chassis elsewhere, but everyone has some sort of kit chassis they want to assemble. Most of the chassis consist of chassis sides and spacers of one sort or another. Some chassis come with additional details like springs already etched as part of the chassis.

Elsewhere I have recommended using a form of keeper plate and we have already had some discussions at previous meetings about the usefulness of designing a loco which is easy to dismantle and to maintain - so with this in mind I will take as an example a Comet models chassis. They design and make nice straightforward chassis that give a reasonable modicum of detail, without requiring a huge amount of time to assemble. They are easy to adapt and are aimed at the average modeller who wants to improve the quality of their locomotive and not require years to do it. There are some beautiful kits on the market which are meant for modellers stretching for something top end and who want to take the pleasure of building such over a lengthy period of time. It is intended to give fulfilment in the getting there even more than the final product.

However this group is about building complete layouts within a reasonable time and building one or two locos is just part of what we are doing.
So lets look at the chassis sides. The loco chassis can be used for either a Jubilee/Scot or Patriot. the engine will find its way on to our Grayrigg layout at home when completed. :) This engine once built will do a lot of work over the next few years.

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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Wed Aug 03, 2016 11:17 am

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Here we see the instruction sheet with a chassis side. A few comments may be put in here, in that if your particular chassis is an old one, the spacers may only be provided for OO If that is the case I will provide spacer material when you come over. Even some of the Comet kits come with OO spacers only, although they have been very good at updating their kits by adding in EM and S4 spacers. If no S4 ones are available then EM ones will do. but your EM ones will give you an outer frame width of 13.5mm, which will look to most eyes OK. What they will also give you is more sideways movement of the driving wheels and therefore more flexibility on your curves. In the case of the Jubilee I am building I will be using S4 spacers which Comet provide. This will bring the chassis out to a width which will allow a motor with 14mm width to pass out from the frame still attached to its gearbox and wheel set. The spacers themselves are a small fraction over 14mm.

Note that there is already a pivot hole already provided in the etching to allow the front two driving axles to be compensated. The back axle can be fixed and the drive put on that as the simplest solution towards a compensated engine. Some may prefer to have the motor drive on the centre axle - so we will have a look at that as well later. Brake hangers come with the kit, which is useful and there are already fixing holes provided - all very useful. If using an early kit you may find that there are no representation of brakes at all! - If so do not worry I will suggest solutions. Although the instructions suggest using a W&H cylinder block I would maybe re-think that, again I have a kit that comes with the complete chassis kit that Comet have produced and it looks very nice indeed. :)

It is not entirely clear from the initial instructions whether the area that you have to take out for the W&H cylinder block needs to be taken out for the Comet one. So I am going to do what a good number of innocent beginners do, which is to build using the instructions as provided and reading as I go along, building stage by stage.

Now those who have been building for years will know I am saying this tongue in cheek, as we all know that many kits have been issued over the years and the one weakness is instructions! Things being written in after the event, or written before a first build has been executed, etc. as well as important things being left out. So what I am saying is that this cut out may not be necessary and may provide us will an interesting diversion later.

What I do suggest is that you read all the instrucions first and try by examining diagrams and components to go through an assembly in your minds eye.

Even then I remember in the old days when most of us thought nothing of getting our hands dirty and mending our own cars, having to deal with the removal of my first hub bearing. The Haynes manual made it all seem straightforward - a nice exploded diagram showing all the components and an order to take them off, which I duly did one by one. Then it finally came to the hub bearing itself where it simply stated "Now remove the hub bearing." -No mention of the fact that the proper tool to use was a hub puller - a somewhat specialised piece of equipment which was absolutely necessary. After a great deal of time and frustration, broken tools and damaged fingers.

I had to give up and reassemble what I had! :cry: :evil:

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Allan Goodwillie
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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Wed Aug 03, 2016 2:45 pm

Now to the work, I will do this using photos with captions. :)

To begin with, separate the chassis sides from the fret. Do not be tempted to separate all the parts from the fret as the fret has the useful role of keeping everything together and identifiable until needed. This can be done in a number of ways - a pair of tin snips or sharp scissors can be used if the material is thin and part etched through, another possibility is to use a small metal chisel and hammer on a metal block, or again a Stanley knife and mat. All methods work fine, just be careful not to distort the metal during the operation. :!:

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The two sides are going to be cut together - one of the techniques suggested by Will. The already marked out side is the lower one and the upper frame side has also been cut from the fret. The upper frame's surface that will be soldered to the lower one is being cleaned using a glass fibre brush. We are only cleaning the surface other cleaning methods can be used. Fine wet and dry or a cleaning dip can be used. I would not use Brasso as it leaves a protective film after being cleaned which does not like solder. The underside of the lower side should also be cleaned in the same way.


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Get used to cleaning both surfaces before soldering anything - cleanliness is everything for a good joint, even if temporary. Here I have painted on some green flux and melted a thin layer solder on to the areas I want to join. Note I have not added solder everywhere I have placed it wherever I am going to make cuts and also at the ends of the chassis to maintain alignment.


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When soldering the two sides together I have simply added a little more flux along the ends between the two pieces of metal. I held the frames using paper to stop the fingers burning. Lining everything up I touched the edge with the soldering iron. This allows the solder to melt and flow on to the other surface as the flux allows it to. I then go and solder the other end making sure that everything is straight and in line. If it is not then re-heat and separate by putting a small screw driver blade in between the two sheets and giving a gentle twist. Reset and follow the procedure as before. If all is well go ahead and solder the opposite end in the same way.


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a similar technique is used on the areas to be cut particularly along the bottom edge. The technique is slightly different in that you can put flux on from the edge and it will work in using capillary action after that just a touch of solder on each and these parts will also hold. (Note there is not too much additional solder showing on the outside when finished.)


So now we have the two sides soldered together ready for cutting by a piercing saw and V cutting block. :thumb
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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Wed Aug 03, 2016 3:12 pm

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I have started by cutting away pairs of springs to create a flat chassis bottom. The springs will be kept for fitting to the keeper plate later, if I decide to use them. Remember when cutting to leave the line showing.


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Once all the springs have been cut away I place the sides in the vice and file carefully down to my marked line.. If any of the areas become unsoldered you still have the ends to keep things in line.


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Finish with a fine file.


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Cut out the apertures for the compensating/springing units to go into using the technique as shown before and clean out to the etched lines using files as before. You may also want at this stage to clean the cusp off the etches after all it is only doing the work once when the sides are still stuck together, here is an opportunity to save some time, but care should be taken not to mess up the profile as it will be a mistake twice over. The photo has been taken using helping hands, but the work should be done in the vice. If using a small file like this to finish off and you have completed the first edge use the plain edge of the file against the already finished edge when preparing the next and so on. (Assuming you have all read James's bit on files and their uses.


This is, I hope, all straightforward so far. :)

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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Wed Aug 03, 2016 3:48 pm

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What was not clearly marked for the camera were the cuts to be made to the frames for the rear axle. Bushes could just be fitted, but since the axle is intended to be removable with the motor/ gearbox unit a couple of slots in the chassis will allow this to happen.


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The rear axle bushes being checked for fit. Looks fine. If the hole has to be enlarged a little use a large broach, if not, use a large needle file,(or rat Tail file - looks as it sounds!) but file and take care to open up the hole equally. This probably will not be necessary. It is noticeable here that there are already cleared slots in the etched lines to allow for the turning of the saw when cutting out.
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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Wed Aug 03, 2016 4:06 pm

Here I will show, as an alternative, the use of a junior hacksaw

The cut out for the cylinders can be taken out before de-soldering by cutting in from the edge as demonstrated earlier. The use of a pair of pliers to remove the material is fairly straightforward. Please note where the etched line is compared to the top of the vice. In this case the etched line is the weak part, even without holes, although there are the two etched through leads at either end. Taking the pliers, the metal is simply bent back and forward until the metal breaks along its length. Cleaning up again required files as before. This action can, of course, be done using a piercing saw as I have done with the other apertures.

Here are the stages-

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Allan Goodwillie
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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Wed Aug 03, 2016 4:19 pm

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Heating one end and forcing in a small screwdriver will allow the pieces to come apart gradually as heat is applied to each area of solder. Eventually all will separate and the solder should be removed using some wet and dry, it should be only a small amount and easy to remove.


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Smooth any surface flaws. All surfaces are now cleaned to remove any solder and any roughness around the cut edges can be removed using a file if necessary.


Job done, chassis sides ready for assembly.

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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Wed Aug 03, 2016 8:31 pm

Compensation or springing units.

Along with the chassis sides it is possible to make up the compensation or springing units so that they too are ready for assembly. The ones I am using for this loco are the MJT compensation units. MJT sprung and Gibson sprung units are all very similar to make up. Although some kits require springy beams and come with springy beam units to make up the simple solution and quickest to get running for the beginner is a compensated chassis. I am not against springy beams and have some locos now running on them, but suggest not going down that road for one's first attempt. There is nothing to making up the MJT ones - just go easy on the solder is what I would recommend - so here goes.

The MJT units are very simple. They come as a sheet of etched brass and a number of square style axle bearings.

:idea: If you have not had to fold etched lines before always fold so that the etched line is to the inside of the fold.

Any pair of flat nosed pliers will do for bending. A small square can also be used to check for right angles. Although the etchings are designed to make sure that all is square when the parts are fitted without too much fiddling. :)

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The first photograph shows one of the bearing guides folded at right angles along the half etched lines.


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Here we have a photograph showing from left to right the bearing, a backing plate, and a backing plate with the bearing guide fitted.


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You may find that you have to take a small amount off the tabs on the guides using a flat needle file as occasionally the slots they fit into can be a touch under size.


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Here we see the rear of the backing plate with the three tags now fitting through the guide is nice and snug against it without any gaps and all ready for soldering.


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When soldering hold the two parts together on the work surface using a pair of tweezers thus.


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Use a small amount of liquid flux and a very small amount of solder on the end of the iron and attach the guides on the back surface of the plate. I normally do the horizontal one first and with tiny amounts I do both sides once I am sure that everything is sitting correctly. Note the solder on the horizontal is taken right up to the top edge of the backing plate - this will prepare it for soldering on to the chassis sides later - it is just a thin tinning coat.

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Allan Goodwillie
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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Wed Aug 03, 2016 9:04 pm

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If we turn the backing plate over to see the other side you can see that the soldering job, although fairly neat, could do with some solder taken off the running surfaces. This can be done using either a steel scraper if you have one or an old needle file to remove anything showing on this side. Do not worry about the discolouration, this has been caused by the heat.


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I would also take off any excess solder from the back of the unit, but be careful not to make the joint too fragile.


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A small fillet of solder is fine in this position on the outside of the guide, as it will add to the strength of the unit.


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Prepare your bearings using a large broach to take off any burr that may be just on the inside edge, either side of the bearing and try an axle through each one to make sure that the axle will pass through each one without any friction. Avoid taking any more off than a tiny amount at the edge - you don't want a tapered hole!


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Try to fit your bearing in to its guide. What you are looking for is a good sliding fit without too much slop. The slot in the bearing may be a tight fit on the guide flanges and some filing of the flanges may be required to allow it to slide properly.File equal amounts from both sides and all the way up to the top of the guides.


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As you can see in this photograph There must be maximum movement available for compensation.


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To help the glide as it were I would also polish the bearing sides. Once you have a good sliding fit then use a small piece of wire or resin cored solder to tie the two parts (the guide and the bush) together as a pair. You will mark them later when fitting to the chassis and from now on they will be considered as a pair

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Allan Goodwillie
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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Thu Aug 04, 2016 4:45 pm

I would like at this point to point the members of the group in the direction of all the good work that has been done by many over the years to bring together the digest sheets. There is a sheet on the MJT compensating units which is worth looking at and explains a few extra things.

Since we are building engines at the moment it would be worth looking again at Jim Smellie's Digest 40.1.1 as there is a pretty good article on building brass etched kits and some of the techniques involved. Since we are concentrating on chassis at the moment, it would be worthwhile studying how to go about constructing the bodies since most of you will want to have the fun of doing that by yourselves without too much input by myself. Jim explains and describes various techniques for soldering very well. He also has suggestions about quartering, however using my jigs should make that particular problem less so.

Digest section 41.0 is also well worth reading at this sage as it is all about methods of compensation and springing of locos. All the theory is there for you to consider. Other sections of 41 are also worth looking at and perhaps relevant for your particular loco.

What we will do here is follow actual cases and problems as they arrive. I would ask everyone to consider what is written and said as you add information about what you are building. I am unlikely to slate anything myself in terms of the products that are manufactured for our use. We already have had a discussion on this and how some kits are meant for the more advanced modeller and it is perfectly possible to make a complete pigs ear of them just due to inexperience and not being up to speed with techniques. We already have one errant gearbox which will need looking at to solve a problem, yet it is a pretty good gearbox, Interestingly I have had the same problem with a similar gearbox recently on one of the locos I built for Burntisland all these years ago. We will be looking for possible problems at as everyone gets down to making their gearbox/motor combinations.

Which brings us to the next bit of homework which can be tackled just by following instructions and working away at the bench at home.I thought we could have a look at the different makes of gearboxes that are on the market and their strengths and maybe their slight weaknesses. Notice I am saying slight as most are well engineered and will give good results when fitted. This is one area which has been much improved over the years giving a good selection where good results are pretty much guaranteed. Some systems are more flexible and some are more suited to small prototypes or in some cases large locos requiring a higher rate of haulage than the average.

I am hoping that doing this review of the different makes may help you make decisions about what will suit your own engine. One thing that comes to mind at this time is the possible demise of Mashima motors in all their forms. They have had a number of gearboxes designed to use them and many loco kits also use these as standard. There are already suggestions for alternatives, but I personally use them almost exclusively now, although I use quite a wide range of gearboxes - all those I am covering I have used in at least several locomotive with success. :)

:idea: If buying a gearbox I would make sure I buy a matching motor to go along with it.

There may be quite a few people going out trying to get replacements for favourite locos requiring possible replacement motors.

The Mashima range is quite large and has strength and quality in depth.

We will look at how to choose the right combination later.
Last edited by Allan Goodwillie on Thu Aug 04, 2016 7:07 pm, edited 1 time in total.

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Allan Goodwillie
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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Thu Aug 04, 2016 7:06 pm

At first there seem to be quite a range of gearboxes, but they break down into three groups.

A) Those using an idling gearwheel to allow modellers to place the motor above and clear of any axle.

B) Those having a flexibility allowing various combinations of geometry and placing of the motor.

C) Those already assembled ready for use, some already connected to motors.

DSC05614.JPG


They all look very different and cannot all be seen properly in their respective packaging. Their packaging gives little hint as to what they look like assembled, nor are the assembly instructions on show. We shall start with the Markits two stage layshaft gearbox, which will be assembled and fitted to a Mashima motor.

DSC05638.JPG


You can see some of the necessary information you may need to select a particular combination. In this case we can tell the following:

First,what does it tell us? Followed by Comments :thumb

Gearbox first - it is a set of gears for 4mm
-that's us!

It is a gearbox and motor mount
-there is provision on this gearbox for attaching the motor

It includes a 38:1 set of gears
-the gear ratio is important for the transmission of power and speed and we will look at that later in more detail

It is a two stage gearset
-this is telling us that there is an idling gear in the system which will allow the motor to sit in an elevated and level position within the body.

the worm gear which fits the motor shaft requires a motor with a 2mm diameter shaft

this tells us that we need a motor with the same diameter of shaft - in this case a 2mm one. Some motor sizes only have say a 1.5mm shaft in which case we either find a gearbox with a worm gear having a 1.5mm hole or alternatively, find a sleeve which will bring the shaft up from 1.5mm to make it 2mm. (A good reason for simply matching and buying both at the same time.)

it includes the layshaft and bearings
-the idling gear has a layshaft provided to allow it to work and there are bearings provided in the pack to make the gearset have a long life and give improved running characteristics.

It has a suggestion of some sort of suitability
-but I would suggest that this is something which you will have to decide for yourself as there are a number of factors involved more to do with the motor than just the gears on their own. Again we will look at that later.


Now the Motor It is a Mashima
-Well we know the make

it is 14 x 26
-this indicates the size of the motor giving width (or diameter if it is a round one) first and the length of the body second in Millimetres

it is a flat can
-this is telling you that it is not a round motor shaped like a "can" but that it has flat sides which have a maximum width of 14 mm

it is for 12v DC
-the maximum voltage that it is intended that the motor should take in normal running. It uses direct current to operate in opposite directions

it is 5-pole
a 5-pole motor has better running characteristics than say a 3-pole motor and generally most model railway motors are 5-pole nowadays (again more on this later)

there are attaching screws
-As the packaging in this case is clear we can make out the screws inside and that the driveshaft sticks out either end of the motor to allow for a flywheel

What we are not told here and we might like to know, are the following - ;)

Gearbox - what type of gears are actually used - different gears have different characteristics in running and transmission of power. What materials are used. How are the gears fitted on to the motor shafts,layshaft,axle (Do they need glue or are they screwed on) What kind of efficiency do they have? Are they quiet in running? Will they be suitable for a heavy locomotive pulling 40+ wagons fully loaded up gradients of say 1in 60 or just a small loco and two 6 wheel coaches on a short level branch layout?

Motor - What is the shaft diameter? What speed does the motor like to run at? What is the torque or pulling power? What weight of train will it pull ? Is the motor conventionally wound or is it scuew-wound? (A scew-wound motor is made in such a way that it gives almost perfect even pulling as against a conventional motor which gives a slightly variable output particularly noticeable at slower speeds when it is said to "Cog" (Two cylinder locomotives did this anyway - you can be too perfect.) I have a BR standard 2-6-0 which runs with a bit of a role at speed which was just like the real thing when it was needing treatment at the works - so I have never tried to change it - I like it that way. NB Atlantics should thrash about at the back and K3's as well, but sorry I am starting to digress. :P.

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Allan Goodwillie
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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Fri Aug 05, 2016 8:57 am

:idea: Before we start I would emphasise that the half etched fold lines must remain on the inside of the etch.The reasons for this are twofold. Firstly if bent the wrong way the components of the gearbox will not match up properly and if you have to bend the etches the other way to fix matters you may find that the folds may break leading to other problems. :evil: So you have been warned :!:

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This gearbox comes with instructions on the inside of the label as we can see here.

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I have cut out the main part of the etching using a knife and mat, leaving other parts until they have to be dealt with.

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Care should be taken in cleaning up not to take all the tags off as they are used during the assembly to fit into the slots provided -the half etched ones that have secured the gearbox within the fret can be taken off using a small pair of scissors as below.

DSC05642.JPG


The instructions say to fold into the 1/2 etch lines which will be in the inside of the box when folded. I suggest using a steel ruler to help fold the first side at right angles. The second side I have used a pair of flat nosed pliers. The half etched lines should fold without too much difficulty - try not to get any distortion in other areas of the box - fold carefully and gently, until both sides are at right angles to the back of the box.

DSC05643.JPG


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So far so good :thumb

Any slight distortion can be taken out just by gently squeezing between the jaws of the pliers.
Attachments
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Last edited by Allan Goodwillie on Fri Aug 05, 2016 9:34 am, edited 1 time in total.

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Allan Goodwillie
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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Fri Aug 05, 2016 9:24 am

Before moving on check at this stage that the work so far is correct and that the etched lines are on the inside and that the two sides have been bent at right angles to the back - I use a small right angle to check, but there are any number of ways of checking.

DSC05646.JPG


Now use the pliers to fold down the top - make sure that the tags are going to fit into the slots on the tops of the sides.

DSC05647.JPG


Now do the same for the bottom of the box.

DSC05648.JPG

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Allan Goodwillie
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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Fri Aug 05, 2016 9:27 am

Now back to the instructions

Looking at the instructions they are fairly minimum at this stage and I would say that perhaps they assume the modeller has already put together a gearbox before - It suggests fitting the gearbox to the motor at this stage, this assumes you know how your motor is going to fit within the body and which motor you are going to use. We will look at this as we go along. It also says fit bearings, gear and worm and that the "bearing flanges inside box against Gear" - not entirely clear.

The worm wheel is long and narrow and fits the motor shaft, it is made of steel and has a grub screw. There are two brass gears one for the layshaft. The layshaft is also part of the kit.The other brass gear fits the driving axle - so I suggest finding the axle you intend using as your main driving axle - there is a modification you may wish to make when this is fitted into the gearbox.

You will need a small set of screwdrivers, a small flat file and perhaps a large reamer, or alternatively a round needle file.

DSC05649.JPG

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Allan Goodwillie
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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Fri Aug 05, 2016 3:02 pm

The first thing I had to do was to ream out the holes for the bushes first one side then the other - took out only a tiny amount and checked the bushes would fit. Care should be taken not to take out too much - the bushes should fit perfectly without any slop otherwise the gears may not mesh properly later.

DSC05650.JPG



Here we see the first bush in place - note the thick flange is in the inside - this should clarify the instruction.


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It is an idea to hold the first in place using a small amount of blutack while the other bush is being placed. Note that very little of the bush shows on the outside. This is because the gearbox is designed to be able to go between 00 chassis sides which are much narrower than S4 - there are some advantages in S4 - here we have extra room.

DSC05652.JPG

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Allan Goodwillie
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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Fri Aug 05, 2016 3:42 pm

Here we see both bushes, flanges on the inside and fully into their respective holes.

DSC05653.JPG



I have taken the motor I was thinking about using and tried it in the body cavity to see how much room there was.

DSC05654.JPG


One advantage of this particular gearbox is the fact that it allows more than some others the opportunity of using a wider range of motors. It has outside lugs (left and Right) which can be used for attachment (Easier to get at the screws when motor and gears are in place), or it does have other hole positions at the back for attachment of the motor. It depends on which motor you want to use. In this case the motor will not drop between the frames, but can be taken off the engine if necessary by unscrewing both the motor and the worm wheel.

DSC05656.JPG


Here we see the other fixing holes in the back end plate. On some designs difficult to get in and out if the sides and top are solid and the worm in place. This gearbox, however, allows access both from the top and from the sides to allow unscrewing of the worm wheel as well as demounting of the motor. The photograph below shows just how easy it is for access. (An advantage over some other types.)

DSC05659.JPG


As a temporary measure the worm can be slid on and the layshaft slipped through the bushes and the smaller brass gearwheel placed on that to see what the fit is like between the worm and the idle gear. It is quite a common practice to try in a piece of cigarette paper between the two a temporary tightening of the grub screws on both the worm and the idle gear will allow for the turning of the motor and will give an idea what the mesh id like between the two parts of the gear. With any luck they should mesh fine as was the case here. Note when fitting the motor it is offset to the left,this allows the gear wheel to mesh correctly as the gear wheel is also offset as shown below. The worm should be set for the centre of the brass gears drive again as shown below. The tweezers are useful at this stage and will also hold the gear wheel as the layshaft is passed through one side, then the gear wheel and out through the bush on the other side.

DSC05660.JPG

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Allan Goodwillie
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Re: Livingston - West Lothian Starters Group

Postby Allan Goodwillie » Fri Aug 05, 2016 4:23 pm

You can temporarily try in the other bushes for the axle in the same way as the ones for the layshaft. While doing that, the final gear wheel can be fitted on the axle and the gears checked for correct meshing. The upper gear wheel should transfer the movement from the worm down to the driving axle. If all is OK take off the gears and perhaps the motor before you tackle the soldering. If the mesh is OK between the gears then next comes the soldering of tags and slots as well as soldering the bushes into place, using the same technique as before.

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I would tend to put some solder on the inside folded joints to give the box structure some strength. (You can see why it is necessary to remove gears etc. at this stage - they do not like flux or solder as both can do them harm. :thumb

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Also at this time solder the bushes in place on the outside - tricky, but I hold the bush in place on the inside using a wooden coffee stirring stick.

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Here we are, bushes in place and all joints soldered to give strength to the gear box. Time now to go and give it a wash in some nice hot soapy water. Keep water well away from the motor! You will note that I have removed the motor with which I had held the gearbox during the previous operation :o

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The remainder of the operation is just re-assembly, except that when putting in the lay shaft you may want to add some thin washers to help keep the gearwheel in the correct running position and eliminate any slop. You may also want to file a small flat on the axle to allow the grub screw a space to fit in so that when tightened it does not have to be ultra tight - which can be a problem. Something similar could be considered for the layshaft. If the grub screws are too tight on plain shafts they certainly will not come off, but they make the gears slightly off the centre of the axle and when the locomotive is running this can be seen as a slight slowing and speeding up over a revolution of the wheels. It can only be eliminated by doing as suggested - no amount of tweaking other items on the chassis will counteract this phenomenon. It is ready for testing.

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