To jig or not to jig

[David B]

I have just spent a most enjoyable and productive weekend at Missenden Abbey in what might be termed the 'light engineering' department under the watchful eye of Tim Watson. Light engineering as in our room were any number of aids such as pillar drills, hand drills and cutters and chassis jigs being used by 4mm (several working in P4) and 2mm modellers.

The chassis jigs drew much attention in the room, both the Hobby Holidays and Avonside types. The starting prices (for 4mm) are similar - Hobby Holidays from £165 and the Avonside from £170 through Eileen's. I mention starting price because there are extras that can be bought which can bump the price up further.

There are a number of pros and cons, not least the price and cost effectiveness. At the weekend, a couple of beginners spent the whole time plugging away, carefully reading instructions whilst others whipped up their creations. Against this, one Mark Taplow showed off his chassis and how perfectly aligned the axles were as it gently slid down over the pegs under gravity.

With so many excellent aids available to help us achieve better models, is a chassis jig a reasonable investment to make? Are they something that is bought in enthusiasm only to find challenging to use effectively and end up in a dusty cupboard? Does one really need a jig - there are any number of guides to 'building the perfect chassis'. They are not something you just pop down the road to buy like a pot of paint.

If you have flirted with the thought of buying one, how far have you got? If you already have a jig, what are your experiences and thoughts? Would you go back to building chassis the 'traditional' way? Will you be putting it on eBay and converting it into another kit? Have you encountered problems? Are they straight forward to use? There are only two types of product available; is there a preference?

David

[allanferguson]

Frame Jig 3.JPG

My version. This was my first go. Later I tapered the ends of the rods (in the lathe) to suit the coupling rods. Not as pretty as Hobby Holidays or Avonside, and I need a new one for every loco, but I can build a hundred of these for the cost of one of the others.

The rods are forced with a drill press into holes drilled 3mm, using the coupling rods as a jig, to ensure perpendicularity.

You might gather that I have something of an obsession about not spending money on expensive tools!

[John Bateson]

I have long been tempted by the Avonside apparatus and nearly got one at Wakefield a couple of years ago. Careful reflection v. state of bank balance at the time militated against it though.

I think it depends on the models or kits you want to build. Most of the older kits, revitalised kits or just plain awful kits, or indeed scratch builds where you start with a flat frame would benefit from one of these, no question about it.

However, where a kit has fold up parts which would lock the parts into place within a small part of a millimeter there is probably little advantage to be gained. Such kits would have the two frames and the spacers as a single part on the etch. An alternative to the frame with lots of fold up parts are where the frames are locked into place with CAD generated SLOTS in the frames and TABS on the spacers, which should be have at least two planes preferably at right angles. Both these are quite unlikely to need such as the Avonside apparatus.

Or if you can drill the holes accurately enough then Allan's solution may be the answer.

And it won't help at all with the diesel or electric bogies.

I could be wrong though - and it does come in a very nice box - and I am intending to be at Wakefield again this year...

John

[Mark Tatlow]

Three observations (since I am quoted!):

- I find that making a truly smoothly running coupled locomotive the hardest part of finescale modelling - much, much harder than compensation or springing. Therefore anything that makes that task easier gets my vote.

- yes it is a lot of money, heading for the same as a full strength loco kit when you consider the cost of wheels/motor etc. So, if it saves one irredeemably messed up loco kit, it has paid for itself (and yes I have in case anyone asks!).

- the jig in itself is not the end of the story. I find that there is an issue with setting it up (I use the Avonside one) and I therefore do so very carefully. I find that once you have set the spacings, the act of tightening in place with the allen key restrainers will change them a bit. This stands to reason when you think about it – there has to be a little looseness in the bars that hold the false axles to enable them to move. Therefore, when they are loose there is bound to be some tolerance in the settings, which can make itself visible when it is tightened. I over come this by using vernier callipers to check that the spacing, once clamped in place, is exactly the same as the centres of the coupling rods that I have used to set it out from. If it is not, then I adjust it until it is (this took an hour on Saturday to get to an acceptable standard).

On the basis that

[Tim V]

My methods are detailed in my workbench thread, I see no need to buy a jig.

The money is better spent on machine tools, like a lathe, which are more versatile and using which you can construct chassis' accurately.

There have been various article over the years on these methods.

[David Thorpe]

the jig in itself is not the end of the story. I find that there is an issue with setting it up (I use the Avonside one) and I therefore do so very carefully. I find that once you have set the spacings, the act of tightening in place with the allen key restrainers will change them a bit.

I found this too and in fact raised it on this board - viewtopic.php?f=7&t=1708 . I haven't actually tried any of the suggestions to resolve the issue, primarily because when i last used the jig everything was perfect first time! As you rightly say, however, it isn't always like that and patience is undoubtedkly needed. I wouldn't like to be without the jig though.

DT

[David B]

The money is better spent on machine tools, like a lathe, which are more versatile and using which you can construct chassis' accurately.

I am sure you are right, Tim, if you have acquired the necessary skills. I have not and a lathe could be lethal in my hands because of this. I could acquire those skills at a cost, which added to that of a lathe would make it very expensive indeed.

A jig, though, strikes me as being accessible to anyone as no particular (specific) skills are required other than the ability to solder.

- I find that making a truly smoothly running coupled locomotive the hardest part of finescale modelling - much, much harder than compensation or springing. Therefore anything that makes that task easier gets my vote.
- yes it is a lot of money, heading for the same as a full strength loco kit when you consider the cost of wheels/motor etc. So, if it saves one irredeemably messed up loco kit, it has paid for itself.

Very valid points.

I wouldn't like to be without the jig though.

The acid test?

David

[Paul Townsend]

The money is better spent on machine tools, like a lathe, which are more versatile and using which you can construct chassis' accurately.

I am sure you are right, Tim, if you have acquired the necessary skills.

He isn't always right, only usually but will have the chance to kick me tonight!
I have a lathe and a jig and use both for chassis building now.

- I find that making a truly smoothly running coupled locomotive the hardest part of finescale modelling - much, much harder than compensation or springing. Therefore anything that makes that task easier gets my vote.
- yes it is a lot of money, heading for the same as a full strength loco kit when you consider the cost of wheels/motor etc. So, if it saves one irredeemably messed up loco kit, it has paid for itself.

Agreed, you should see my collection of abandoned crap chassis that predate acquiring the jig, on second thoughts no you shouldn't. I also find it a time saver.

I wouldn't like to be without the jig though.

="Davidb"
The acid test?

You are supposed to wash the phosphoric acid off after use

[Terry Bendall]

Since a chassis jig is not something that most people use frequently, one solution is for an area group or a small group living near to each other to agree to fund the purchase of a chassis jig jointly which can be shared amongst the group.

Terry Bendall

[Tim V]

A jig, though, strikes me as being accessible to anyone as no particular (specific) skills are required other than the ability to solder.

David

Yet courses are offered in both lathes and jigs, therefore someone thinks that both are difficult to use. You still need more skills to build a chassis than the ability to solder, how about pressing the wheels on square, making axles the right length, cutting gear shafts to length, all tasks the jig won't help with. I will admit I have a George Watts quartering jig.

There is a learning curve for a jig, the same as a learning curve for a lathe.

[martin goodall]

When I looked back and reflected on the dodgy loco chassis I had produced in the past, including one that was quite literally banana-shaped (and went straight into the Black Museum), I had no hesitation in buying an Avonside Chassis Squared Pro.

It has only been used once in anger so far, for correcting an exisitng chassis, but I expect to use it more in future.

Without any reliable jig or fixture to use in the past, I have no idea how I ever managed to get loco chassis together at all.

[John McAleely]

However, where a kit has fold up parts which would lock the parts into place within a small part of a millimeter there is probably little advantage to be gained.

This is a yes, but in some cases no thing. In my limited experience, the Highlevel 03 chassis appears to meet these requirements, but quite deliberately uses hornblocks/guides that float within the design, and therefore I benefited from the use of the jig while assembling it.

My second build seems likely to meet all the necessary criteria (The Bradwell A1), and so I have assembled the mainframes without the jig. I did still use it to build the coupling rods (that may prove to have been excessive caution on my part), and I do plan to double check my work by putting the result on the jig.

From my vantage point (beginner, also looking around the room at Missenden), any kit (or scratch build) which is being modified to have horn blocks or other floaty bits added will need some method to ensure it is true, and the jig (I have the ChassisPro) is a good balance between skills needed, time invested, and probability of success while still learning. My first chassis (built while learning to solder) appears to be a success.

Having learned chassis building with the jig, it will effectively defer the day when a lathe &c will be useful to me, allowing me to focus time and budget on learning other tools and skills I need.

FWIW, I think the learning needed to use the jig is much less than that for a lathe - most of the time I spent on the course I was on while first using it was learning general skills for chassis building (such as troubleshooting minor binds) which presumably apply with or without my particular choice of jig.

[Paul Willis]

If you have flirted with the thought of buying one, how far have you got? If you already have a jig, what are your experiences and thoughts? Would you go back to building chassis the 'traditional' way? Will you be putting it on eBay and converting it into another kit? Have you encountered problems? Are they straight forward to use? There are only two types of product available; is there a preference?

David

Well, as one of those having an equally enjoyable time at Missenden *with* a chassis jig, I certainly wouldn't be without one. Mine is the Avonside version, and seems to do all that I need.

Mind you, it did take me around 18 months to commit to buying one, as the price of them is quite daunting. However, as mark has said and others have echoed, compared to the cost of another loco kit (particularly one gathering dust in the pile in the cupboard!) then a tool that you may use a couple of times a year is not a bad investment - and it will last a lifetime.

I was convinced by a practical demonstration by John Brighton, who showed me just how easy it was to set up frames and hornblocks with it, and what to be looking for in terms of tolerances and "fit" when building a chassis. This has given me a baseline to be confident to build to, rather than having to grow this experience over a number of locos myself, by trial and (mostly) error.

So I would strongly advocate anyone that is wavering about getting a jig to find a friend (perhaps in your area group, or come to Missenden for the Autumn Course?) and see one in action.

Yes, there are *slight* problems with the jig - as has been mentioned, the setting blocks can move slightly when tightening the screws to lock them down, although Mark's way of checking them is sound. I adopt an approach of just repeating the loosening/tightening process until it is spot on.

Or you can get lucky - as happened to me at Missenden. After assembling the coupling rods on my Y5, I had the chassis set up on the jig, and the hornblocks neatly in place all in the space of twenty minutes! Okay, this was only an 0-4-0, but it shows that even someone ham-fisted like me can do a proper job easily when using the right tool.

And yes, the instructions are very comprehensive, and for the Avonside jig well worth watching (they are on a DVD) as they give some other uses of the jig, such as setting up footplates and bufferbeams square.

I like mine - I wouldn't be without it.

Flymo

[Paul Willis]

My version. This was my first go. Later I tapered the ends of the rods (in the lathe) to suit the coupling rods.
...
The rods are forced with a drill press into holes drilled 3mm
...
You might gather that I have something of an obsession about not spending money on expensive tools!

Hmmm...

Out of interest, what is the purchase cost of a decent lathe, and a decent drill press?

Just wondering if I can sell my Avonside jig, and have any loose change left after buying both of those

Flymo

[allanferguson]

[quote="Flymo748

Out of interest, what is the purchase cost of a decent lathe, and a decent drill press?

Just wondering if I can sell my Avonside jig, and have any loose change left after buying both of those

Flymo[/quote]

Fair point. But I mostly use the lathe for other things. The first jig I made with pointed rods, I put them in the mini drill and filed them. Then I thought "I'm in the Scalefour Society; I should do this properly......"

The drill press is necessary to ensure the rods (and the holes for them) are true to the surface of the MDF. Mine came from B & Q for about £30.

I take the point about modern self locating frames, but my modelling is of much older prototypes for which these aids are not available.

What I needed was something to help me erect two frames in line, with the appropriate spacers, and with the axleboxes truly in line.

And I still have problems getting mechanisms to run smoothly, but at least I know it's not misalignment of the axleboxes that's the problem. Misalignment of the brain cells, possibly.....

Allan F

[John McAleely]

What I needed was something to help me erect two frames in line, with the appropriate spacers, and with the axleboxes truly in line.

FWIW, I think the version of your fabricated jig with pointy bits of some sort to build/align coupling rods looks equivalent to the other jigs under discussion. So if one has (or wants) the skills & tools to make them, then I would see no reason to buy one of the proprietary jigs.

[HowardGWR]

Hugely interesting thread, thanks gents. Allan seems to have found the egg of Columbus as far as cheap jigs go, but it was pointed out that truly vertical drilling was a must. Not only that, but the block of wood must be perfectly 'square' too, must it not?

The stories of these expensive fancy jobs moving about under tightening frightened the financial life out of me. I've only ever used the Rod Neep thingy and it has not worked for me.

[Paul Willis]

The stories of these expensive fancy jobs moving about under tightening frightened the financial life out of me. I've only ever used the Rod Neep thingy and it has not worked for me.

What I would say is not to be scared by the fact that there is this slight creep in the jig axles on tightening.

It is fairly inevitable on tightening any sort of screws up to the final tightness. The key thing is that it is readily known, and easily identified. You can do it with a set of digital calipers, or just by very careful observation of the tightness of the rods.

You are literally talking about a movement of a hundredth of a millimetre. It's the difference between making the rods slip over the pins, and pushing them on because they are tight.

See if someone in your nearest Area Group has either the Avonside or Hobby Holidays jig, and see what you think. I was also sceptical until one was demonstrated to me.

Flymo

[Philip Hall]

it was pointed out that truly vertical drilling was a must. Not only that, but the block of wood must be perfectly 'square' too, must it not?

I don't think the block of wood needs to be square, merely that the face of it is perpendicular to the drill. MDF is usually of a consistent thickness, so when placed on the drill press, the holes will be perpendicular. It will be important that the rods are inserted using the press as well. An alternative would be a thick block of Tufnol or paxolin. It would also be important that any turned down ends of a jig axle are truly concentric with the axle proper. Whether you can do that will depend on the accuracy of your lathe.

If this is beyond you for one reason or another, then the proprietary jig is for you!

Philip

[David Thorpe]

All I can say is this. When my wife was good enough to buy me the Avonside jig as a big birthday present, I also invested in a GW Models wheel quartering jig. Thanks to these two, for the first time in my life I was able to produce a chassis that ran sweetly at once without any tweaking. OK, the tightening up procedure on the jig can be a bit of a pain, and wasn't something I'd bargained for, but it doesn't happen every time and when it does it can be resolved with a little bit of patience.

DT

[David B]

Thank you, fellow modellers. I agree with Howard that this is a hugely interesting thread. Of course, there is a learning curve as Tim points out, but I don't think it to be as great as that of using machine tools like a lathe, and with the Avonside jig, there is the well publicised problem with tightening the jig up which Mark and Davey have referred to. Knowing about this means that one has to take time and particular care, but it is not insurmountable.

I notice, however, that no-one has referred to the other jig, available from Hobby Holidays. Does anyone own one; has any-one used both to draw comparisons?

The price has been a recurrent theme and sharing it between friends or in a club as Terry suggests is a solution. Mark made a very good point about the cost of an imperfect chassis and 'lost' model compared with that of a jig. There are many more tools available to us now that help us make better models and comments made here certainly indicate that a jig would increase the success rate in producing chassis that fulfil their purpose reliably. What struck me were the comments from Davey & Paul that they would not like to be without their jigs now and, to me, that speaks volumes.

There are other means to achieve the end - Tim with a lathe, Allan's budget version and Iain Rice with his rods and grids - and the jig is another tool which can take a lot of the inaccuracies out of the build, given care and patience. Like Mark, 'anything that makes that task easier gets my vote', so I think I may be salting the pennies away and perhaps converting surplus and redundant bits and pieces into cash. I have seen the results first hand at the Missenden weekend before which, like Paul, I was sceptical, but seeing them used in the flesh and reading the helpful comments on this thread has convinced me. Any doubters amongst you could do no worse than to see a demonstration, and then decide whether it is for you, you and friends, or not at all.

Further comments on experiences with jigs will be welcome, I am sure, to those who come after us wondering if a jig will 'cut the mustard' - and to anyone left a legacy by the unknown relative!

David

[Will L]

I'm a kitchen table modeller myself, and as machine tools don't feature in our kitchen, I've always used jigs of one sort or another for assembling chassis, or at least I have since I started to do so successfully. This is a feat I put down to the influence of one Mike Sharman who understood that that it is more important that dimensions matched than that they were prototypically accurate to the nearest very small bit of a millimetre. To be honest I have been managing quite happily with a set of jig axles with pointy ends which will do the trick nicely once you've mastered them. You also need a flat surface to assemble the frames on and a set square to ensure that they are. The thing you need to rememberer is that so long as the axle spacings in the frames match the crank pin spacings in the rods the chassis should run OK. Absolute flatness isn't vital, unless you still insist on building rigid chassis, nor do the axles need to be perfectly parallel. One of my early OO efforts had axles that were visibly out of parallel to the naked eye, but the rods matched the axles spacings on the side they were on and it ran very nicely thank you.

Clearly one's ego demands things are done a little better than that these days, but it is worth remembering what is nice to have and what is absolutely necessary! I'm sure Tim's reliance on a battery of machine tools produces some very nice and dimensionally accurate models, but, no matter how accurately he produces the bits, I would have thought getting them to fit together so it all works as intended was still jig country.

Yes some of the nice fold up etched chassis we have available these days may indeed fold up accurately and need no special attention to produce a square and accurate result. But I would still be inclined to jig them up against the rods to ensure
1. I had managed to bend the folds in exactly the right places
2. The built up rods do in deed match the frames
3. The axle blocks are accurately drilled down the middle.
Though quite what you do with such a thing if any of the above proves not to be true I'm not rightly sure. You will at least know why you can't get it to run properly.

So jigs are us, and despite a fondness for my fairly basic tool set, I do possess an nice orange plastic case containing the Avonside product. The reasons for this are more to do with my relationship with my now dear departed father, rather than a burning desire on my part to own one. However I have used it, and the truth is that it does make chassis assembly easier. I also discovered you need to pay attention to how the axle pins get set up, but this is really is only a question of knowing how to get the best out of the tool to hand.

So my final verdict on these super jigs is... not necessary but nice to have.

Will

[LesGros]

Flymo wrote

...I was convinced by a practical demonstration by John Brighton, who showed me just how easy it was to set up frames and hornblocks with it, and what to be looking for in terms of tolerances and "fit" when building a chassis. This has given me a baseline to be confident to build to, rather than having to grow this experience over a number of locos myself, by trial and (mostly) error...

I too, was shown the benefits of using the avonside jig by John Brighton. I also asked him about the Hobby Hols jig. He said that he uses both in his model making business, also that some of his colleagues prefered one and some the other, for himself would use whichever was available when he needed to use it. For me that was pretty convincing that the chassis jig is a valuable tool. In the hands of the professional it saves time and reduces error. I tried the HH jig and managed to achieve a slightly twisted frame, with parallel axles. Due to my own hamfist, I am sure. Being unsatisfied, I dismantled the frames and started again, but with an avonside, which I found a little easier to hold the frames square by using the fences as shown in the video.

I judged that the price for a jig was worth the peace-of-mind, and that I would be less likely to waste expensive loco kits through ineptitude.

As to which is the best, there is not much to choose, The Avonside has vertical axle pins, and fences to align the top edge of frames; The Hobby Hols Jig has horizontal pins, so spilt fluxes drip clear of the mechanism, and it can be fitted with a set of rolling road bearings. Both can cope with a variety of bearing diameters.
Idealy, as others have already said, try to see both in use before deciding, but ultimately, it is down to an individual's preference

[dcockling]

http://www.scalefour.org/forum/viewtopic.php?f=28&t=1932

Chris Yates has a Hobby Holiday's jig for sale, see the link above.

All the Best
Danny

[HowardGWR]

Of course, if one has the Perseverance jig, one already has the lathe turned down temporary axle ends to which Philip and Tim refer (always assuming that these were reliably prepared square anyway ). That's what attracts me to Allan's implementation, which I think I will try.

I think my observations on later problems have had more to to with Perseverance frames themselves being a bit more 'flexi' than was sensible (very thin nickel silver), for keeping the distances between axles square. You can take a typical Perseverance (I appreciate newer entrants to the hobby will be non-plussed) frame and can easily slightly bend it, in handling, even after all is soldered up.

At the time in the eighties when Iain Rice was extolling virtues of Mike Sharman's techniques, the Rod Neep designed 'chassis' were state of the art, and I bought a bunch.

The results stare at me from the bench, having been rebuilt several times, (40xx and 2301 classes) without ever getting first time starting every time, all the time. For me it's Pendon reliability or nothing. So it's nothing.

I think I may take them apart again and laminate them or cut new ones out. Any other experiences with Perseverance (how well named) to share?