bogieman

I don't see a problem, as you're quartering the wheelset against against the other wheelset, not relative to the chassis. Therefore any slop in the axle holes (and we are talking about 0.1mm here) won't affect the quartering.

 

 

I don't have a quartering tool, but I do have a lathe, a few minutes work produced this tool which is mounted in the tailstock and a dividing/indexing tool (Unimat). A slot is cut in it for the crankpin to fit through, you can just see the slot on the right hand one (right hand leads). The tailstock chuck is given bias with the key to ensure it stays in the same place. Using the tailstock wheel, I can push the wheels towards each other, checking with the back to back gauge as it advances.

Neat! I'm not that talented an engineer though. I presume you have to make a set for each diameter of driver?

My first attempt at Jinty conversion with fixed chassis and no "slop" runs down to 15secs for 10 inches which I make about 6 scale mph. How much will a "sloppy" one run down to? Walking pace or less I guess and then I'll be depressed because I don't really want to unsolder the crankpins and brakegear now! Maybe I'll just leave it in a siding or sell it and start again.

And I like Richards's polishing idea particularly as you have to do something similar to remove the paint from the tyres if you spray paint the drivers.

Axle holes reamed to 1.5mm then carefully enlarged by twisting a 1.6mm drill in all three axle holes. Then the Simpson springs put on. There is a sheet about it on the VAG, plus an article in the magazine. Jerry Clifford (Queensquare) put me on to it.

 

Electrical pickup was the problem, it ran smoothly enough. Haulage power not ascertained as I don't have any other stock!

Thanks for that I'll see if I can find the sheet on the YAG I must have missed it. Will also look up article.

The problem I foresee is quartering. Dead easy when there's no slop in axles as the etched rods are so accurate. But add in the axle slop and you're into a completely different game with possibility of jerking wheels as coupling rods "rotate" if quartering not spot on and you've lost one of the ways of it happening naturally. Just a thought.

Just stripped mine down, as I wasn't satisfied with its performance. Fitted Simpson pickups in enlarged axle holes as recommended. Having the removable motor and gear was a boon.

 

Running transformed, hoping to sneak it onto a 2mm layout in the near future....

Could I ask

("enlarged axle holes as recommended".) how large?

("I wasn't satisfied with its performance.") was that speed, pulling power, ultra slow speed or reliability at not stopping due to loss of electrical contact?

("enlarged axle holes") was that all axles, front and rear or just centre?

Thanks

Tony,

 

I don't know which tables you were following. The 100DP tooth counts you list are not standard shop items.

 

These centres come from the 2mm website "gear mesh calculator", which I wrote and am reasonably certain is accurate.

 

64DP 14T to 18T, theoretical perfect mesh 6.35mm, with running clearnances = 6.48mm

M0.4 14T to 18T, theoretical perfect mesh 6.40mm, with running clearance = 6.53mm

100DP 18T to 31T, theoretical perfect mesh = 6.22mm, with running clearance = 6.35mm

100DP 20T to 30T, theoretical perfect mesh = 6.35mm with running clearance = 6.48mm

 

Gears, gear mesh calculations and related items are discussed in a pair of articles by Denys Brownlee and Henk Oversloot in a 1990's 2mm Magazine, which is in the archive CD set.

 

 

- Nigel

The figures I used are from a gear mesh calculator on the internet, don't remember now from where, but I copied all the figures out and kept them as a Excel file for all the 100DP gears readily available in small sizes (shop ones are in bold) i.e. 14 15 18 20 21 24 28 30 31 34 37 39 42 44 45

52

I did check them against various books and other internet sources as well as working them out as best I could mathematically to check them. However I'm no mathmetician or engineer so I could have slipped up on one or two. The figures for the 64DP amd M0.4 and 100DP shop available ones certainly match the figures given in the Year Book tables.

And you're right I haven't just stuck with the 2mm SA shop tooth sizes as I have a small stock of other tooth sizes also from places like Branchlines or Ultrascale so that I can play about with gear spacings and ratios.

Certainly when I work with the figures in my composite chart things seem to run ok which for a non engineer is to me the ultimate test.

Common sense says that introducing a bit of slop on 100DP spur gears could be more problematic than 64DP/M0.4.

 

I would have thought either springing only the centre axle or all six would be stable combinations. Never spring the outside ones without the centre one, that would create the dreaded rocking action.

 

You could try adding the springs just as pickups, without enlarging the holes. Although it has now been done for so many years, it is questionable as to using bearings as pickups, which is what the split frame design does, is totally wise, given that oil might get in there.

 

Which combination of 100DP gears did you use? None of the available combinations seem to match the mesh centres used for the M0.4 gears, so I think you took a bit of a risk there?

 

Chris

Well Chris I'm no engineer so you can perfectly well say I'm mad or stupid and I won't mind but according to the gear meshing tables the centres for gears are quoted as follows:

64DP 14T to 18T = 6.35mm

M0.4 14T to 18T = 6.40mm

100DP 18T to 31T = 6.35mm

100DP 20T to 30T = 6.35mm

I tried the 3rd and 4th options and they both work perfectly well with apparantly good meshing but decided on 18/31 and it has survived testing under load for three days continuous running on a shuttle circuit.

My rationale is that 100DP gives you a greater number of ratio options and ability to have a bigger ratio thus enabling the loco to run more slowly and with better control for shunting. Which is what I prefer.

Tony

The recommended size for axle holes when using 'SImpson springs' is 1.6mm. These are nothing more than pieces of very thin phosper-bronze wire which bear onto the axles in the gap between the inside of the frames and the muffs and act as springs/pickups - in reality mostly the latter. Your chassis already has extra holes etched into it to locate the ends of these. You can buy such wire at Eileens emporium of use N gauge coupler springs straightened out.

 

The coarseness of the gears used in the design mean it's OK to have a little bit of play even on the driven axle in this case.

 

But I would not totally rule out the possibility of other issues. Running on wires attached to the motor, double check that it really rotates smoothly without any tight spots in the rotation. Causes for this could be quartering issues or irregularity in the gear teeth. It's possible these might not stop the loco when running on such a test, but will when it has the extra effort of moving its own weight along the track.

 

Chris

Thanks for that Chris yes I had noticed the extra holes (talking of extra holes what are the holes for in the etching of the springs in the 57xx?)

• Do they need to be on all three axles?
  
• I've used all100DP gears and not 64DP but assume they could still be used
  
• I was reluctant to open up the holes to 1.6mm when it ran perfectly well at 1.5mm
  
• Yes it runs fine on wires connected direct to motor at very slow speeds and with hardly a flicker from a milliammeter needle as drivers slowly rotate.
  

After running it in some more on a little shuttle unit the pickup problem now comes down to just the front pair of drivers which is strange given that the centre drivers are up a hairsbreadth.

I found your coupling rods so accurate that when the second side slides onto crankpins easily I know the quartering is correct. That why I preferred no slop in the axle bearings or the crankpins holes.

And I'm reluctant to take it apart now that all the brake gear etc is on and everything painted. And fortunately it is getting better with running in on the shuttle rather than on rollers or against the buffers.

Unless you use wires on the axles in generous axle holes to give the chassis a bit of flexibility, it may indeed be that the chassis is not dead flat. In fact on an 0-6-0 it's better to have the middle axle a touch high. The old trick is to put the mechanism on a mirror and look / feel for any gaps or rocks between the glass surface and the wheel tyres. If there are gaps then firmly take hold of each end of the chassis and bend / twist it in the right direction to at least make the middle wheels off the ground (only a gnat's whisker of course). I have done this Uri Geller trick on many chassis, especially Farish 0-6-0s and it helps considerably. If this prospect is too frightening, then determine which wheel set is too low and file out the axle bearings vertically to allow its upward movement to bring it into 'flatness'. This axle should then have two light phosphor bronze springs on it. This adjustment must not be done on the driven wheel, of course.

 

As much weight as possible and seriously polishing the wheel rims is also a good idea.

 

Tim

Axles in generous axle holes - how generous?

It may indeed be that the chassis is not dead flat. In fact on an 0-6-0 it's better to have the middle axle a touch high. - The chassis is dead flat on testing with mirrow and the centre axle by luck is marginally up by a hairs breadth.

This axle should then have two light phosphor bronze springs on it.- Do you mean on the centre slightly raised axle?

This adjustment must not be done on the driven wheel, of course. - sadly the centre axle is the driven axle!

And in answer to Jerry's questions,

are you testing it with the body on? - yes on and off makes no difference and I've tried loading it with a large piece of lead sheet wrapped over the loco.

have you used any additional means of pickup eg. Simpson springs? - I've looked up Simpson Springs but cannot find a picture showing exactly what is meant by this.

do all the wheels sit squarley on the track - yes the front and rear ones do but the centre ones are ever so slightly raised

adding very fine conventional wiper pickups - both back and top acting.- Please can you point me to a diagram or picture so I know what you mean exactly. (sorry to be dense!)

I've just built my first etched chassis (for the Jinty) and it runs ok and reasonably slowly too provided it's on electrical leads direct to motor (Faulhaber 10/16).

Problem is it's not very happy on the track and keeps stopping if I run it too slowly. When this happens turning up the power does nothing as it requires a slight nudge to restore electrical contact at wheels/track.

I've tried:

• Running it in on rollers
  
• Running it in against the buffer stop
  
• Cleaning the tyres
  
• Cleaning the track
  
• Adding weight
  
• Different controllers such as Pentroller, Gaugemaster, old fashioned transformer/rectifier/variable resistance
  

But nothing seems to help. Any suggestions other than the bin and start again!

I bought myself a set of drills with very small increments: 1.5mm, 1.51, 1.52 etc. These I can run into the muffs until I reach the desired size.

 

A general comment on the muffs - they are made tight as it's relatively easier to open them out than fill them in! Tolerance reasons on them and the wheel axles mean we cannot make them exactly to a certain tightness of fit. A significant proportion would then have to be discarded as too loose. Plus each loco builder has his own preference of how tight he wants them to be.

 

Chris

That sounds interesting idea Chris. But where do you buy drills in 0.01mm increments? And when I do find some what do you recommend going up to - 1.54 or more or not so far?

Tony

On the subject of etched kits/chassis can someone advise me as a beginner on using the 2mmSA black axle muffs.

They seem so tight as to be almost impossible to press the driver's stub axle into them without giving one cause to fear bending or damaging the delicate etched chassis or ending up with a bent and wobbly wheel.

So my question is should the hole be eased in some way and if so how without making them intolerably loose.

I've tried using a 1.5mm hand reamer but it removes no material from the hole and certainly does nothing to ease fitting them.

I'm building a couple of 57xx Panniers and the Jinty all at once using these Chris Higgs etched chassis. I'm writing it up as I go hopefully to get it published in 2mm magazine as I'm using the more radical approach to the bodies.

Because they have same size drivers, are all 0-6-0Ts and use the same gear ratio I'm hoping to compare the results of using three different motors.

My problem is that at this late stage I have just realised the Panniers have identical cabs styles, when I had planned to make one of each version (earlier 1929 Churchward 57xx style cab and later 1933 Collett 8750 style cab).

Mine are both the later Collett 8750 cab types with rectangular spectacles, in fact a spare I have is also of this type!!

Does anyone have a Grafar body of the earlier cab version with circular spectacles they would be prepared to swop or sell? Even just the cab alone as it's a separate plastic moulding that slides upwards and off.

Many thanks

I wasn't happy with the unsupported motor, plus I didn't like assembling the worm wheel inside the frame, so I've made these slight modifications.

A simple L piece of scrap nickel is soldered to a base plate which is screwed to the frames, using the existing spacer and 14BA screws.

The motor can be removed for setting up the wheels etc.

I feel the same about motors/worm mounting (and indeed about the whole chassis assembly with brake gear etc) but in discussion recently somebody asked, how many times have you taken a chassis apart for repair once built and nobody could give a single example. Is it possible we are being too cautious?

Thanks for the blog url Andy most useful.

Thanks for the answers offer Richard, sounds like machining the body is going to be a pain!

Tony

Tony,

 

The June 2011 2mm Magazine has an article by Rich on the test builds of the 57xx and the 14xx chassis.

 

If you can't find your copy let me know as I have a pdf copy.

 

Andy

Thanks Andy, got it in front of me but not read it yet but will shortly. "Double Heading, a trial run" pp44-47.

Somewhere on RMWEB (or its previous versions) Richard Brummitt had details of the test build he did for me, which was of the rear axle drive.

 

Chris

That's useful to know although my searching hasn't found it yet.

Hi Richard! Any ideas?

Maybe if it's no longer available on the internet you've still the photos on your computer? You already know my email address.

I'm currently thinking of building both chassis types from the one etch to try things (different motor fittings and amounts and sites of metal removal etc.) although I realise I'll only have enough parts to completely finish one that gets chosen to use. Then I could write up an article with the answers to my original query.

Thanks Tony

That all sounds pretty difficult but I might still try the rear axle drive just to try to get the improved appearance. There's some nice photos of the chassis and motor on centre axle in the instructions and earlier in this post, does anyone have (a) similar photo(s) of the rear axle build?

I decided that the amount of metal to remove to fit the motor in did not justify the extra work. After all, the loco is light enough anyway. And it's pretty awful metal to do anything with.

That's very interesting as I hadn't realised the metal removal was to fit the motor. I had been under the mistaken impression that it was a cosmetic exercise to give a clear view under the boiler. What therefore is the biggest motor one can fit after say minimal removal of metal?

And does it mean that even with the drive on the centre axle for this conversion you had to remove metal to fit the motor? I'd appreciate knowing what size motor you managed to use or that one can get in?

It would be useful to have comments from others who has done it one of either ways and the difficulties involved in removal metal to get a motor in..

Many thank for advice.

With the 57xx etch chassis conversion now available can anyone summarise the pros and cons, advantages and disadvantages or just the difficulties of using the rear axle drive compared to the centre axle please.

I'm just about to start and would appreciate guidance on which to use.

Many thanks

Please does anyone have a Chris Higgs 57xx Grafar chassis etch they're not planning on using for a while, could thus wait until they are in stock in the shop again and would be prepared to sell to me?

I've finally managed to locate a 57xx body at a reasonable price but now find the etch is out of stock! I have wheels, gears, motors the whole set up but thought stupidly that the etch would be easily available when everything was ready to go.

I wanted to use it's building to write an article on some ideas I had for building one, although my ideas might not work out of course.

Many thanks

 

An etched GWR tender is already in the pipeline. Could be a long pipeline though

 

Chris

About how long? Weeks, months or years?

Despite being out of period for what I would like to portray I have succumbed to the offer of a 2251 bodyshell. Those that did likewise will also need a tender.

 

I have whitemetal tenders from Langley, P&D Marsh and GEM kits but none of them posses the fidelity that an etched one could/should/would have. It might be a plausible proposition for one of the greats in 4mm to reduce one of their kits, or a stand alone kit in 2.06mm, if there is enough demand.

I'd join you in this with order for two etches al least but only if 2mm not 2.06mm!! Sorry about that Richard. The relative standardisation of GWR tenders is very useful for modellers I always think.

 

Yes, although I haven't done the instructions, when they do a parts list will be included. And normally the instructions or at least the parts list will be online so you can get all at once.

 

Often, and it will be the case here, there will be a recommended motor, but others may choose something different, inclduing from another source. And there will I know be at least some the chassis where a choice of wheel sizes can be made - either a set which are full scale size but perhaps quite tight inside the splashers, or use the next size down and have a bit more leeway.

 

Chris

Chris

Any current information on possible date for availability of these (48xx and 57xx) etches?

Has anyone tried "The Greenwich Coupling CPL1 00/H0 NG coupling" for narrow gauge railways ?

As an alternative and at the risk of starting a spate over the various options, what is the "best" 2mm scale coupling (i.e. neat, unobtrusive, reliable, easy to fit and adjust) coupling for a beginner?

 

Are these plain (3-106) or flanged (3-107)? I've only ever used the latter. They have always been a nice sliding fit up to the point where the flange meets the spoked face.

 

I've done both. I was advised not to linger with the iron if soldering, I presume because there is a risk of disturbing the tyre. Gluing with epoxy also proved successful. Using superglue will stink when you heat the crankpin later to solder the retaining washer for the rods.

Thanks for your help. I have 3-106 that have a head 0.5mm high so they stick out of the back of the wheel quite a bit. Sounds like I have bought the wrong crankpins! Maybe I should get some 3-107, I guess the flange goes at the front on these too saving having a washer. Are they soldered from behind also?

Could I ask a new question as I'm building my first 2mm scale loco and I've met a snag. It's about the 2mm SA loco drivers and crankpins.

How does one fit the turned brass crankpins into the drivers?

The head of the crankpin sticks out from back of driver so do I countersink the hole, or file the head down? And if the latter do I do it before or after fixing in the wheel?

Also how do I fix the crankpin in the driver? With glue or solder?

Many thanks for any advice,