Whats on your 2mm Work bench

[Chris Higgs]

One more coreless concern - I recall that the original advice when coreless motors first started to be used was that their bearings were not strong enough to allow a worm to be mounted without some additional bearings. Is this still true? Is that why the Maxon (for example) has such a short shaft?

 

 

There are many many models with this arrangement. However I have heard that the Lawton coreless motors being much cheaper do not have very robust bearings to resist end thrust. The Maxon is generally considered the strongest of all. The short shaft merely reflects the kind of application it is most used in, which is certainly not model railways.

 

 

Chris

Edited December 6, 2013 by Chris Higgs

[Donw]

With any worm drive the force back on the worm will be perpendicular to the angle of the gear teeth/worm thread so there will be a side thrust as well as a fore and aft thrust. However in our small models the forces must be fairly small. I am not aware of any measurements of the train load from 2mm models. However if the mechanism is binding sufficient to cause a stall it would increase the side thrust. So it could be the case that where there has been trouble with mounting a worm on the shaft, the cause could have been elsewhere in the mechanism.

As to what kind of controller will suit a coreless motor. I find a simple emitter follower type circuit produces smother running but at slow speeds the low voltage is more affected by dirt. The use of feedback  or pulse width can produce problems if the controller characteristics are such that the motor tries to follow the resulting waveform giving lumpy running. I have not been in a position to run models for long enough periods to be able to judge whether the use of square waves or  variable mark/space waveforms is detrimental to brush life It would be interesting to hear if anyone has experience of coreless motors failing in this way.

Don

[Izzy]

I have an old AMR which I still occasionally use, but I would never use it with more modern motors of any type. It isn't so much that it will fry the motors but that the feedback is just too severe for the more efficient motors that now exist compared with the past, whether they are coreless or not. All that usually happens is that a loco will jerk and spit it's way along the track as the bemf over-reacts. This is despite Len Rich trying to 'turn down' the feedback for me when coreless motors first became popular all those years ago. None of my current Farish or Dapol locos are happy running under it.

 

As far as the Nigel Lawton motors go, the one I would suggest is the 8x16mm. This is quite powerful, with a rare earth magnet, and is fairly slow running. The main bearing is fine, probably half the motor length. But, in common with many coreless designs there is no end bearing in the end cap to take/absorb end thrust of the kind generated by putting a worm on the shaft. However, all you need to do is be careful when fitting a worm to ensure that excessive pressure isn't used to force the worm on, and ensure that endplay is minimal.

This last requirement is to prevent the commutator finger brushes being crushed/distorted by any end thrust. This is how coreless motors usually get damaged/wrecked.

 

Izzy

[D869]

Thanks all. I've ordered three motors today - the Association can and the mini and midi from Nigel Lawton (I think that's everything that's been suggested bar the Maxon), plus several of his adapter sleeves so we'll see how things go once these arrive.

 

In other news... after a lengthy (and finally successful) session trying to find a coupling rod that had vanished unseen to a far corner of the room I now have both rods fitted and the chassis rolling freely down a slope.

 

Regards, Andy

[Steve Sykes]

The South Western brake van is pretty much finished; just needs the DGs putting on now.  Next up is an LSW elliptical-ended open, one of the ones without a sheet rail.  If anyone has any ideas on how to model a Williams patent sheet rail that isn't horribly fragile, I'd be grateful for suggestions.

 

 

[queensquare]

Just giving that a like Steve isn't really adequate, that's a little jewel of a brake van.

 

Jerry

[Donw]

Jerry is quite right about the van a real beauty. If you are planing to run the wagon with a sheet on, a piece of plastic card fixed between the rail and the floor would give it support.

Don

[IanLister]

That looks amazing in the close up pics Steve. It must look even better 'normal size'!

Ian

[John lewsey]

I like that. Steve lovely model

John

[cornish trains jez]

Hi Everyone,

 

Further to my last entry on my china clay wagon, I have decided to jump the gun a bit this afternoon and have a go at making my first "hood" using some tissue paper which I found on amazon. The colour is almost spot on and with a little weathering should look convincing enough.

 

First of all, a removable "tent" was made using 1.5mm thick card which will be the main former for the tissue paper. As tissue paper is quite thin, I decided to carefully glue two sheets together and then formed it around the tent, the main sides being first, and then wrapping around the ends and trimming to the right length. Having studied a good number of photos of these vehicles in service, the end sections of the hood tended to have the hood a bit bunched up with the sides looking quite tight which I hope I have managed to achieve with the wagon.

 

The ends still need a little tidying up but should look okay once this is done.

 

Here are a couple of pics, any comments, good or bad, would be greatly appreciated before I attempt the rest.

 

 

 

 

Best regards,

 

Jeremy

[Rabs]

I'm certainly no expert, but it looks a little tall to me. Maybe it's just a trick of perspective on those photos.  I know on most GWR wagons the height of the rail was such that, when folded down, it was about the same width as the wagon (so that it wasn't out of the loading gauge) - so a pitch of about 45 degrees would follow.  

[Chris Higgs]

Hi Everyone,

 

Further to my last entry on my china clay wagon, I have decided to jump the gun a bit this afternoon and have a go at making my first "hood" using some tissue paper which I found on amazon. The colour is almost spot on and with a little weathering should look convincing enough.

 

First of all, a removable "tent" was made using 1.5mm thick card which will be the main former for the tissue paper. As tissue paper is quite thin, I decided to carefully glue two sheets together and then formed it around the tent, the main sides being first, and then wrapping around the ends and trimming to the right length. Having studied a good number of photos of these vehicles in service, the end sections of the hood tended to have the hood a bit bunched up with the sides looking quite tight which I hope I have managed to achieve with the wagon.

 

The ends still need a little tidying up but should look okay once this is done.

 

Here are a couple of pics, any comments, good or bad, would be greatly appreciated before I attempt the rest.

 

PC080007.JPG

 

PC080011.JPG

 

 

Best regards,

 

Jeremy

 

Are there photos of the real thing anywhere? The ten itself looks good to me, but is it the right total height?

 

Chris

Edited December 8, 2013 by Chris Higgs

[cornish trains jez]

Hi guys,

 

I thought that maybe the pitch was a little too high. I think I may need to shave about 1-2mm off the height to get it right. Thanks for the feedback.

 

Best regards,

 

Jeremy

[Paul-2mm]

I have a high regard for "motors that came out of the ark" as Chris puts it. The very similar Tenshodo has a shaft that can be pushed along in the armature, making it a single ended motor, enabling this:

 

http://www.zen98812....uk/060chas.html

 

These motors are very robust and run just as well as coreless motors.

I have been very impressed with the capabilities of the Mashima 9/16 motor especially once the magnets have been chopped down to size as required for some of the Fence Houses kits.

 

Here's a short video of a J27 chassis I'm working on, it hasn't run in 4+ months, hasn't been oiled, is only picking up from the tender and I didn't clean the tender wheels prior to recording the video. At one point I turned the controller down a little too much and you can see the motor briefly stall.

 

There's still work to be done as there's a couple of tight spots but I'm very happy with how things are going.

 

[Etched Pixels]

IMO there's a lot of scaremongering concerning coreless motors with a worm affixed directly to them

 

I wouldn't worry about it personally and I'm sure others would agree

 

Paul A.

 

I didn't worry about it on my B4. The Lawton motor bearings broke a couple of months later

 

So I would worry about it. It's only a case of having something each side of the worm to take thrust.

[Ian Smith]

I have been very impressed with the capabilities of the Mashima 9/16 motor especially once the magnets have been chopped down to size as required for some of the Fence Houses kits.

 

Here's a short video of a J27 chassis I'm working on, it hasn't run in 4+ months, hasn't been oiled, is only picking up from the tender and I didn't clean the tender wheels prior to recording the video. At one point I turned the controller down a little too much and you can see the motor briefly stall.

 

There's still work to be done as there's a couple of tight spots but I'm very happy with how things are going.

 

Paul,

 

I think you need to file a flat on the top of pound coin tender so that it will meet the loading gauge  

[John lewsey]

That's really impressive Ian

[Paul-2mm]

I think you need to file a flat on the top of pound coin tender so that it will meet the loading gauge  

Unfortunately it was the only coin I had, have you ever tried stacking £50 notes on a 2mm chassis?

Edited December 12, 2013 by Paul-2mm

[Donw]

Unfortunately it was the only coin I had, have you ever tried stacking £50 notes on a 2mm chassis?

Just pass the notes and I will be happy to try

Seriously that is very impressive. The cardan shaft looks very whippy but does the job. What sort of wire did you use.

Don

[Paul-2mm]

Just pass the notes and I will be happy to try

Seriously that is very impressive. The cardan shaft looks very whippy but does the job. What sort of wire did you use.

Don

The cardan shaft is a real bodge job, I haven't perfected the technique for making them so as soon as I made one roughly the right length I popped it in so I could play! The wire is from a guitar string (top E) I've had it years, bought on a recommendation from Andy Calvert to use as handrails on N gauge locos.

[nick_bastable]

Been working on getting this running reliably

 

 

 

Body is a Ultima 3d print with a few extra bits added

 

Chassis is scratch built association 6mm tender wheels driven on one axle  by 21:1 gear set  ( the only one that would fit) and a Nigel Lawton  pulley drive given a ratio of about 80:1  

 

 

 

Getting it weighted is a  problem and in retrospect I should have driven both axles, still tweaking it hence the loss of paint   although it probably runs better than the original

 

 

Edited December 23, 2019 by nick_bastable

[garethashenden]

Can you extend the shaft that the worm is on to reach the other axle and then have another worm and gear there?

[nick_bastable]

Can you extend the shaft that the worm is on to reach the other axle and then have another worm and gear there?

not really would be quicker to start from scratch again although I do plan to do a double ended drive for the Ultima   Southern/WCPR Railcar Number 5 printed body on the same belt drive principle only this time using thick brass as frames to get the weight up 

 

it manages to pull its self along and is slowly been tweaked to be better and is certainly   better than my steam chassis 

Edited December 19, 2013 by nick_bastable

[DavidLong]

There doesn't seem to have been much modelling done chez Long in recent months and output has been slow even by my usual snail-like standards. However, just to show that I haven't completely ground to a halt I recently took a few snaps which are reproduced below and there is a theme.

Over the last few years there has been some excellent work done by the likes of Bob Jones and Chris Higgs to produce a range of etched chassis', marketed by the 2mm Scale Association, with which to enhance both kit and RTR bodies. The wagons below are of both types and are still to reach the paint shop, a move which I confidently predict may happen by 2015 or 2016 or 2017 . . .

 

 

 

These two are closely related, the first being an LMS D1927 Double Bolster and the second, its successor design, a D2067 Double Bolster. The latter was the last wooden bodied double before switching to the steel-sided version. They both utilise Chivers bodies allied to Higgs underframes. The bolsters are plastic strip and, if you look carefully, you may just be able to make out the holes for the chain shackles at the bolster ends. The shackles have been made but are stored safely until required. D1927 has some scratch-built 2-rib buffers while D2067 has some early trial white-metal buffer bodies with separate steel heads.

By the mid-1960s both of these types would have been looking the worse for wear so the painting and weathering should be amusing.

 

 

The next is a B.R. Diagram 1/069 Conflat which has a Bachfarish body with an etched B.R. 8-shoe fitted underframe. I like this style of underframe, so much more interesting than the usual 4-shoe type. The body is a very decent rendition of the type and deserves the subtlety than an etched underframe provides. The buffers are some more pre-production samples, this time of the Dowty hydraulic type.

 

 

A couple of Medfits this time. The left-hand one is another Bachfarish body of LMS diagram D1927 while the right-hand one is a Parkwood body of B.R. diagram 1/017. Both were built unfitted and have been vacuum-braked by B.R. in the late-1950s, hence the 4-shoe vacuum brake gear with associated tie bars. I will be using them as engineers stock for carrying spent ballast as they would have run in the mid-1960s.

The buffer beams are Evergreen U channel strip as Association etches are to 2mm scale and lack a little in width for N scale bodies. D1927 has also acquired Dowtys but 1/017 is stuck with simple spindle types.

 

 

 

The last one is a bit of an oddity, apart from having no wheels and also having got as far as a blast with primer. It is an example of a batch of 32 wagons built to diagram 2/072 in the 1950s and lettered Flat ED. I photographed one at Bridgnorth a few years ago and I believe that a number have survived at preservation sites. They utilised an LNER eight-shoe style underframe but with B.R. style axleguards. By chance this is the same type of underframe used on some B.R. plate wagons and is available as an etch from the Association. The only real challenge with the scratch-built body was creating neat squares along the edge of the floor and then filling them with representations of the lashing rings. A simple enough wagon but also something a bit different. No idea what I'll use it for though . . .

 

David

[-missy-]

Hello.

 

I was just going to click the like button but I thought that wasnt enough. They are brilliant David!

 

I totally agree with you in regards to etched chassis having a finesse about them which you just dont get with the regular moulded types. It would be great if you could let me know the shop codes for them too, then I could give some a go as well. I dont think I could get anywhere near the quality of your work though but I would be happy giving it my best shot...

 

Missy