Ralph's workbench

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ralphrobertson
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Ralph's workbench

Postby ralphrobertson » Sun Apr 26, 2020 2:49 pm

Since we are all constrained and tied to our home and with me being fed up of making buildings I decided to resurrect one of my old projects that I have had on the go for 2 or 3 years (or probably more actually). This isn't my oldest project, like most people I have quite a few more some of which date back 30 years or so but this one doesn't have anything to do with buildings so it seemed a good project to carry on with.

A few years ago I purchased a Craftsman L&Y 0-6-0 A Class loco kit and soon after I inherited one from the estate of one of our departed members who planned to make one for Slattocks Jnc too. It seemed logical to make 2 at the same time so with this in mind I started to get things together to do it. At the time the Manchester club had a pantograph engraver so masters were made for the mainframes and tender frames and parts were cut not only for myself but for a couple of others too. The mainframes were cut based on Brassmasters sprung hornblocks but my attempts weren't that good so I ditched that idea and decided to produce my own etch for this loco.

At the same time a visit to Dick Petter's house generated a lot of interest in trying to adopt some of Dick's techniques into the build of these locos. Those who have seen Dick's locos run know the superb running qualities of his locos and it was interesting to learn how he does it and to see if I can get somewhere near doing something similar myself. One of Dick's techniques is to get weight down into the chassis so I started by making the tender chassis the way he does them by building it up around a block of brass which is milled to the right profile. Drawings were produced which set out the required dimensions and cutouts for both tender chassis. One was to be made with beam compensation and the other as a CSB.

A class loco and tender.pdf
(52.83 KiB) Downloaded 57 times

The tenders were built up and both were pulled around Slattocks to make sure they worked ok. They both seemed to work as planned and then the project was put to one side and work started on other things like the mill.......

Anyway, at the start of the lockdown the project was picked up again and recommenced. The loco chassis weren't yet started and these were intended to be made up using High Level hornblocks and gearboxes. You may notice in the drawing little holes in the hornguides that line up with the High Level hornblocks, well these proved to be a perfect match and all the hornblocks were soldered up using thin wire to line them up before tacking them in.

Fellow member Richard Dunning who has made a lot more locos than me suggested I do a tender drive so that I could load the loco with weight so never having made a tender drive loco I went for it. Hmmm...... I did have the bits in stock, 2 pairs of Ultrascale universal joints so it should be easy. Well, a couple of weeks down the line I managed to get it all working and yes there is plenty of space for weight. I need to see how these locos run on Slattocks before I go much further with the chassis or maybe I will have to set up my layout Gt. Jackson St. up and get that working again to test them out but they do seem to traverse a yard of track without too much effort.

Here is where I am at today, still a lot of work to do.

20200426_131307.jpg


Summary of bits - Craftsman kit, own chassis etch, Gibson wheels, High Level hornblocks, High Level Roadrunner 40:1 gearboxes with Drive Stretcher, Mashima TA12 motors, Ultrascale universal joints (well one part of them, the universal shaft is home made).

Ralph

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PeteT
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Re: Ralph's workbench

Postby PeteT » Sun Apr 26, 2020 9:12 pm

ralphrobertson wrote:Ultrascale universal joints (well one part of them, the universal shaft is home made).


Thanks for sharing Ralph - looks like an interesting project! I noticed in the photos that the UJ sockets looked like the Ultrascale ones, but that the ends of the shafts werent. I'm in the process of getting my J39 up and running, and have been disappointed by the length of the Ultrascale joints, mainly caused by that plastic moulding and that followed by a brass sleeve, before you can try and thin it down.

I've assumed that the way they work is that the plastic ball helps centre the rod, but allows the rod to be thinner and so still move in X & Y as the loco traverses curves and inclines. I see the end of your shafts have the same ball effect, can I ask what diameter tube was used? (Is this the same as the Ultrascale ball diameter?). Drilling the hole for the cross wire directly centrally sounds difficult - but other than that I like the concept.

Thanks,

shipbadger
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Joined: Sun Jul 20, 2008 3:00 pm

Re: Ralph's workbench

Postby shipbadger » Mon Apr 27, 2020 8:06 am

Pete,

Don't forget the old trick of using 7mm scale handrail knobs as the ball end for UJs. Saves drilling holes through the end for the wire.

Tony Comber

davebradwell
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Re: Ralph's workbench

Postby davebradwell » Mon Apr 27, 2020 8:18 am

I see in all those fine looking bits that the drive shaft has the pins at right angles - they should be in-line in order to achieve a constant velocity drive and minimise wear. See https://www.beldenuniversal.com/universal-joint-phasing or others.

Regarding sourcing of shafts, has there been any news of NWSL coming back on stream yet?

DaveB

David Catton
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Re: Ralph's workbench

Postby David Catton » Mon Apr 27, 2020 8:58 am

https://nwsl.com/ but I don't think the full range is yet back.

HTH

David C

ralphrobertson
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Re: Ralph's workbench

Postby ralphrobertson » Mon Apr 27, 2020 9:36 am

I see in all those fine looking bits that the drive shaft has the pins at right angles - they should be in-line in order to achieve a constant velocity drive and minimise wear. See https://www.beldenuniversal.com/universal-joint-phasing or others.


That's very useful Dave thanks, I can easily change my shafts. I went on the information published by Dave Goodwin of Adavoyle fame many years ago when he stated that he had no idea what was correct but right angles worked so they used that.

Pete, I too was put off by the Ultrascale female part of the coupling. Far too long and that is why I ditched it. I also initially attached the Ultrascale parts with Loctite 601 but in the end I put them in a vertical drill and tapped them 12BA to give me some flexibility both in taking them on and off and also adjusting the length of the shaft.

The revised part I made from some brass rod. First drilled a hole in the vertical drill and then drilled in from the end in the lathe before turning it down. I used the Ultrascale rod for the shaft, the rod in my pack was 0.9mm diameter and i used this for the cross-shaft too. I did look at using 7mm handrail knobs but the ones I had in stock were tiny but I know others used them very successfully including Dave Goodwin for the Adavoyle locos.

I have the Adavoyle articles somewhere but I seem to remember that they used piano wire for the shaft. I have some of that too but a quick measurement of what I have to hand made it 0.8mm thin so I stuck with the Ultrascale silver steel. If I did this again I would make all my own bits, it isn't that difficult with a lathe but you could probably do it using various diameter tubing too. If anyone is interested in the dimensions I will knock up a drawing.

Dave Goodwin gave me some notes he and Tony Miles produced in October 1980 which came to 15 pages and pre-dated their Railway Modeller articles of 1982 on the same subject. They used Airfix Slimline motors with Romford 30:1 gears and achieved superb running with their techniques. All locos were sprung I might add but not using springy beams, the notes do make interesting reading especially for 4-4-0s.


Ralph

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PeteT
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Re: Ralph's workbench

Postby PeteT » Mon Apr 27, 2020 9:44 pm

Thanks Dave for the clarification on in-line UJ pins - I had got as far as thinking that it would be one of the other... so this saves a 50/50 guess being invariably wrong.

One benefit of the UJ system being in parts is that I can do my initial proving with the Ultrascale parts provided, and once happy can do something nicer cosmetically with the shaft, while being in the position to see whether it is the cause of bringing in noise or performance issues. Thanks Ralph for info on the bits you have used.

I hadn't heard of the 7mm hand knob idea actually Tony! But it does sound feasible, if they are course enough. Another of those things exhibitions are useful for, to actually see the relative sizes from different manufacturers.

Anyhow, I look forward to seeing the A class' develop.

ralphrobertson
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Re: Ralph's workbench

Postby ralphrobertson » Fri May 08, 2020 5:09 pm

Things have progressed since the last post and a lot of detailing has taken place. One loco is running perfectly, the other still needs some tweaking which is tomorrow's job. Need to get a couple of brass whistles and some chequer plate for the fall plate. Getting there.

Ralph
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20200508_121411.jpg

nberrington
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Re: Ralph's workbench

Postby nberrington » Fri May 08, 2020 5:16 pm

Something very handsome about a Victorian 0-6-0!
With those huge motors in them you could pull a horse.

Nice work Ralph!

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iak
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Re: Ralph's workbench

Postby iak » Sat May 09, 2020 1:15 pm

Gorgeous beasties Ralph :thumb
I don't suffer from insanity, I enjoy every minute of it....

Perfection is impossible.
But I may choose to serve perfection....
Robert Fripp


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ralphrobertson
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Re: Ralph's workbench

Postby ralphrobertson » Sat May 09, 2020 3:53 pm

Thanks for your encouragement guys. The second loco is now running much better after stripping down the tender, the tender wheels were dragging on the sideframes so did a bit of thinning down and now it runs well.

Moved on to my good old 4F. Now this has a long, long history. It is a real combination kit, Alan Gibson loco body and an LMS Society tender both combined with a Bill Bedford sprung 4F chassis. It has been on the go for over 30 years and since we all seem to have plenty of time right now it seemed sensible to finish it off. It is painted and numbered and just really needed the chassis sorting out but for one reason or another it just never seemed to get to the top of the pile. Well it has now.

I decided to get one of Chris's new High Level coreless motors and use this in the 4F so the first step was to hook this up to the Roadrunner+ gearbox in the loco. First problem! The gearbox was so old that it only had motor fixings for 10mm spacing and the new motor has 8.5mm and I can't see any way to change it so..... I have a spare Roadrunner+ gearbox 54:1 ration which is possibly slightly too low for what I want for this loco but until I get it running I reserve judgement.

Next problem..... The 54:1 Roadrunner+ gearbox I have has a worm for 2mm and not the 1.5mm that the coreless motor has. How to get around that without either phoning Chris and getting his help or turning up a sleeve? It seems that most of the older type Mashima motors I seem to have collected have a 2mm shaft, that is the TA10 and TA12 which I seem to have quite a collection of. The newer style Mashima motors have a 1.5mm shaft and although I do have quite a few of these I wanted to use the coreless motor to try out in this loco. So before phoning Chris I took a look at the gearbox box.

Digging through all the High Level boxes I have there was no solution, either they were the wrong ratio or the wrong worm diameter. I do have though a Porters Cap gearbox. Remember those? They were the fore-runner of High Level and I think it was a joint collaboration between Chris Gibbon and Pete McParlin of Backwoods Miniatures - it certainly goes back many years. Anyway, this gearbox happened to have a 1.5mm worm that matches the 54:1 gearwheel so I used that.

More details and a photo to follow.

Ralph

davebradwell
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Re: Ralph's workbench

Postby davebradwell » Sun May 10, 2020 8:25 am

Your perception of a suitable gearbox ratio is interesting and barely overlaps mine - 54:1 is the highest I would dream of using and only in shunters like the J72. Anything that pulls coaches gets 30:1. This reduces noise at a stroke and also passengers like to travel at a reasonable speed. Slow speed running should still be good, if not a decent feedback controller is the answer or, better still, dcc with a "silent drive" decoder. The controller should do what its name implies - get a grip of the motor and make it rotate smoothly at the speed you set.

You may have seen the common improvement to the fine Roadrunner+ gearbox - by adding a spacer to a shaft to prevent the gears rubbing on each other noise is further reduced. PeteT mounted his tender motor resiliently and this seems to have been successful. Once you get rid of the high speed motor noise such things become worth doing and you shouldn't be able to hear the motor, even in a small room, when running at line speed.

With apologies if you feel you've suffered from my campaign for lower gear ratios.

DaveB

ralphrobertson
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Re: Ralph's workbench

Postby ralphrobertson » Sun May 10, 2020 9:11 am

That is very interesting Dave. The Slattocks group have some Black 5s which were built using Hornby bodies with a Comet chassis, Mashima motors and Roadrunner+ 40:1 gearboxes. Whilst they ran perfectly the speed at which they ran with a passenger train was, in our view, far too slow so the ratio got changed from 40:1 to 30:1 which made them perform at the right speed. Those 40:1 gearboxes are now in the L&Y locos I am now building.

One thing that we discovered that not many might know is that by changing the worm and the top gear (the one with a larger and a smaller gear on it) you can change the ratio of the box without putting in a completely new one. This discovery was made too late for the Black 5s I am talking about, fortunately for me as I managed to use the spare gearboxes.

The other thing is that all these locos are running on DCC so if the top speed is too fast it can be reduced by setting CV values. One of the advantages of DCC I guess.

At the moment I am thinking that for passenger locos I will use 30:1 and for everything else 40:1 and try to control the speed range using DCC. That is going to mean changing gears in most of my gearboxes.

Ralph

davebradwell
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Re: Ralph's workbench

Postby davebradwell » Sun May 10, 2020 7:53 pm

I must admit that when things needed to go faster I just turned up the volts on the dcc system, although some decoders have quite a modest Vmax so care is required. The lower ratios were to keep the noise down although, of course, higher geared locos are painfully slow at any reasonable voltage. Just as we use springs for quiet running, although they do keep the wheels on the track as an added bonus, a gear ratio can be chosen for the same end and the drive electronics made to work for its living. Your Slattocks locos have ended up with the same ratios as our group uses so we must all be right.

They may be able to improve speed within the decoder as the feedback types hold a few volts in reserve. Certainly the Zimo enables this to be phased out above a certain speed step so almost full voltage is available.

DaveB

ralphrobertson
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Re: Ralph's workbench

Postby ralphrobertson » Wed Jun 03, 2020 10:12 am

Been a while since I posted but I have been beavering away with things. The L&Y locos have had their chimneys changed and now, thanks to John Redrup and help from L&Y Society boys sending me in that direction, they now have brass lost wax castings which are a bit more circular than the cast ones that came with the kit.

I moved on to continuing with my 30+ year old 4F and managed to get it running with a new motor but I just don't like the motor and gearbox combination position and am pondering what to do with it. There is going to be another delay until I resolve it but in the meantime I picked up another 4F from the cupboard.

This 4F is an Alan Gibson kit together with a scratch built tender which came from the estate of one of our old friends. Now Colin was very precise in what he did and when he decided to build something before he started it he religiously collected absolutely everything he would need to make that model, the sad thing was he never finished any. As a result the box usually contained most bits including things like number plate, shed plate, works and tender plates (Kings Cross range) as well as motors, wheels and gearboxes, hornblocks, crankpins etc. So a complete set of parts ready to go. What was even better is that Colin made the tender from scratch and a damn fine job he had made of it too. A Stanier 3500 gallon tender fully rivetted by hand.

20200517_103406.jpg
Scratchbuilt Stanier 3500 gallon tender

20200517_103416.jpg


In the box there were 2 or 3 sets of frames for both the tender and the loco, another set of fully rivetted tender sides, another spare set cut out and marked up waiting to be rivetted and an assortment of bits needed to detail the tender.

20200517_103501.jpg
4f chassis in the background is the 30 year old one


The first thing I needed to do was to open the tender up so that I could use the inside space so I made an opening with my Dremel with the cutting disc. I have a battery Dremel which I find absolutely invaluable and I would recommend to others, no cables makes the job easy. Also Dremel have this superb device called Speedclik https://www.dremeleurope.com/gb/en/dremel%C2%AE-ez-speedclic-starter-set-348-ocs-p/ which is worth its weight in gold, the cutting discs don't shatter and last forever, I am still on my first metal cutting wheel after many years and although it is getting smaller it still cuts easily. Their locking system is well thought out and the wheel never comes loose.

Having opened up the tender body and seeing the success I had with the L&Y locos with their tender drives I decided to do this on the 4F too. I also wanted to try out the Adavoyle way of working which was a sprung tender with split axles so set about using the frames with some fibreglass copperclad as a base. I found some 2mm Perseverance hornblocks and bearings and used these in the frames and managed to make up a running tender.

20200521_153357.jpg


At this stage the tender is not weighted and it bounces along very freely, once weighted the drawbar will weigh down on the back of the loco. In some ways making the tender first makes it difficult to test but I prefer to make tenders before locos if I can, it always seems to be a pain to have to make a tender once you have finished making the loco, a bit like making coach interiors when you have finished the rest of the model.

Of course, one of the tender wheels wobbled so what to do about it? After a few thoughts I rifled through the box of wheels and found a set of old Studiolith wheels which were pre-mounted on stub axles. To me that seems like a great idea, someone else squares the wheels up for you and that got the grey cells working to see if I could do something similar.

20200525_104716.jpg


So far I have spent a few days trying to make up a device that squares wheels. First it was a 3D printed jig but I found that wasn't accurate enough once it was printed on the Photon but currently I am working on a resin cast version which is much more accurate. I will post more on this once I have manage to perfect it - I am sure others find wobbly wheels a pain in the proverbial like I do, the always seems to be one set of wheels which never go on square and don't mention Sharmans!

Ralph

triumph3
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Re: Ralph's workbench

Postby triumph3 » Wed Jun 03, 2020 11:26 am

Excellent work Ralph.
Have you thought about selling your jig for putting wheels on square?

Colin Wrangles is sadly missed, but I have one of his locos, a conversion of a Hornby B5 which I have now renumbered and fitted a double chimney and DCC decoder. When we next visit Slattocks I will bring it along.

David

ralphrobertson
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Re: Ralph's workbench

Postby ralphrobertson » Wed Jun 03, 2020 12:25 pm

Thanks Dave.

Have you thought about selling your jig for putting wheels on square?


Yes, I did but so far the reject rate has been pretty high so for now it is a non starter. Once I have got a working version you will see what I mean.

Colin Wrangles is sadly missed, but I have one of his locos, a conversion of a Hornby B5 which I have now renumbered and fitted a double chimney and DCC decoder.


I never knew about that, but I bet it wasn't finished was it? We have a big stock of models from his collection to build all of which are totally relevant to Slattocks.

Ralph

ralphrobertson
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Re: Ralph's workbench

Postby ralphrobertson » Tue Jun 30, 2020 2:03 pm

Its been a while since I wrote anything but I have been busy. I decided to stop work on the sprung tender chassis for the 4F and change it to a different design along the lines I used for the A Class locos. These have a milled brass block chassis which gives low down weight in the tenders and make it much easier to test the running of them. The sprung version a la Adavoyle was bouncing all over the place and it would have been difficult to test without hitching it to the loco which has not yet been started.

So, putting the sprung chassis to one side I milled up a block of brass to use and found a Bill Bedford 4F chassis kit which I could use. Instead of using this as a sprung chassis I changed it to use beams so it was easier to make the brass block and it runs fine. This will be a tender drive so I made up a universal to attach to one of Chris Gibbon's new coreless motors.

20200620_122226 resize.jpg


I am playing around with wheels and axles at the moment and trying to find a way of getting square wheels onto axles using stainless steel tubing. This tender is the first test of this and the front two wheels have some 2mm tube with a 1.5mm internal diameter. A length of 1.5mm silver steel rod has been glued into the centre of the tube. The rear axle is 2mm tube but with a 1mm internal diameter. I didn't have any steel rod to use on this one so it has been left open. I am doing this with tubing to see if I can find a way to make split axles easily using this method with some form of insulating material - watch this space.

The motor mount is temporary and adjustable until I can get the right angle for the driveshaft once the loco chassis is built.

Work continues......

ralphrobertson
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Re: Ralph's workbench

Postby ralphrobertson » Tue Jun 30, 2020 2:04 pm

At the same time I have been playing around with static grass and some test pieces for Slattocks. I will post on the Slattocks thread for that.

Ralph

ralphrobertson
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Re: Ralph's workbench

Postby ralphrobertson » Tue Jun 30, 2020 3:30 pm

Having gone through a mammoth workbench tidy up I thought it would be useful to have a stand to hold some metal sections in so I drew up a design and cut this out on my laser cutter. 2mm MDF which is a pain on the Emblaser cutter but after a few hours work a suitable stand came out. I passed the idea over to Andy Goodman and it is possible that it may appear in his online shop although the design might come out slightly different from mine to fit in with his product range. https://www.ebmahobby.co.uk/
20200630_115625.jpg

davebradwell
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Re: Ralph's workbench

Postby davebradwell » Wed Jul 01, 2020 9:02 am

I've also found inside framed tenders try to wobble when they house the motor and normally use outside wagon type springs. Perhaps Adavoyle stock had more damping and possibly softer springs so it would have more effect. A sagging csb might be a better set-up as the wire would slide in the supports a tiny amount which might calm it down a bit. Mine all have separate springs curved upwards which means the ends have to rub on the supports - just a touch - and the bearing carrier plate has quite an area in contact with the inside of the frame. Normally there's steel springs front and rear with phos bronze in centre as this gives the thing a better sense of level. You might also have tried changing the weight as there may have been a resonance at a particular speed. Anyway, I'm sure that's for another day now.

You'll be able to watch the difference in ride between the sprung loco and compensated tender, my first P4 loco was done like this.

DaveB

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Will L
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Re: Ralph's workbench

Postby Will L » Wed Jul 01, 2020 12:28 pm

I agree with DaveB that some sprung systems are better at damping out oscillations than other's. For CSBs the fiction between spring and fulcrums will be paying its part as will friction between axle block and the horn guides (if we can call them that). Practice says I have never seen a CSB chassis that does oscillate. I did once build a wagon with two rocking w irons connected by a torsion spring which was only attached to the wagon in the centre. That wasn't a good idea and did oscillate badly, because there was very little to prevent it. The more usual wagon individual sprung axle boxes do have the the bearing carrier rubbing against the W iron and I think that is usually enough to dampen out any oscillation.

A tender drive presents special problems for a sprung tender chassis, as the torque going down the drive shaft will make the springs compress more on one side than the other. Whether enough to produce a visible body tilt is another thing. If the torque varies in a rhythmic way (e.g. a non consent speed UJ?) you might theoretically set up an oscillation if sprung without much damping. However I've never built one so I have no idea how real a problem this may be. I am sure any driven sprung chassis will have torque derived suspension events. Just like the real thing, my CSB locos will lift a little at the front when pulling a heavy load although you will be hard put to observe it directly.

davebradwell
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Re: Ralph's workbench

Postby davebradwell » Thu Jul 02, 2020 8:28 am

It would seem, on reflection, that by sticking a couple of bits of lead flashing inside each side of a Gresley 8w tender, I've probably created perfect condition for an inside-sprung tender to wobble - it's almost a large balance wheel. A loco with it's more central lump of lead is perfectly stable. I make motored tenders heavy to minimise any tendency to lean under power but have never seen any effect. The logic is that a light tender would have light springs which would be more easily deflected by the torque.

DaveB

Andy G
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Re: Ralph's workbench

Postby Andy G » Tue Jul 14, 2020 10:01 am

Following on from Ralph passing the idea for the material stand over to us, we've been doing some development on it and have started a new thread in the Products area - https://www.scalefour.org/forum/viewtopic.php?f=40&t=7044

Cheers
Andy
https://www.ebmahobby.co.uk
Cheers
Andy
EBMA Hobby & Craft
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