Re: Tim V's workbench - latest shenanigans

[Tim V]

Yes.

The project 45XX on this thread used Ultrascales, and I did cut the boss off the back.

[David Thorpe]

Thanks, Gordon. I've in fact got some of these, but haven't used then on my latest loco. The centre section of the S4 Stores axle is 10.00mm wide. The High level gearbox I am using is 9.75mm wide. I can't, I'm afraid, guarantee the necessary precision to ensure that the live section of the axle will never short against the gearbox, which I would like to keep isolated. There's also the problem of hornblocks getting in the way, not to mention an anxiety that the axle, once assembled, might not be entirely true. However, your reminder has given me cause for thought and there should be a way round it, possibly by using thicker insulated washers between the sections of the axles combined with slimmer hornblocks. I'll try to give it a go with the next loco, but still feel that these axles are a poor substitute for the Bill Bedford type.

As for lobbying the manufacturers, all I want is some 1/8" steel tube with a sufficiently large internal diameter to accomodate a hard steel rod covered by some suitable insulating material (BB recommended sewing thread, wound round the rod and then smeared with Araldite). You just push the insulated rod into the tube, wait for the araldite to set, cut the axle to length, and then cut the necessary insulating gaps wherever you want them in the tube (but not, of course, in the rod).

DT

[martin goodall]

DaveyTee's post confirms my current misgivings.

I am entirely convinced as to the advantages of split-frame / split-axle current collection, and I purchased a good stock of split axle components (both for two-part and three-part axles) from the Stores at Scaleforum a couple of years ago, but I still haven't taken the plunge, largely for the reasons I mentioned in my previous note and which DT has reinforced.

I am, however, grateful to Tim for confirming that the boss on the back of the Ultrascale wheels can just be sliced off to fit the 'shorting' wires (or strips).

Provided I can be sure that the insulated middle section of the driven axle is comfortably wider than the gearbox [High Level, or Portescap in my case], then I see no problem. If there is any risk of the gearbox moving about on the axle (unlikely?) then I see no difficulty in packing it with fibre washers to ensure that the gearbox can't stray off the insulated section of the axle.

BUT - if the axles I have do not have a wide enough central insulated section, then I have a problem. The prospect of making my own split axles does not fill me with joy, although they would be needed only for use on the driven axle, and the commercially available ones can no doubt be used on the other axles.

[David Thorpe]

I note that High Level's Slimliner gearbox is 6.3mm wide at the point of the driven axle. Given that the centre section of the Society's split axles are 10mm wide, this may be the answer. I think I shall acquire one at S4North and give it a shot.

DT

[Paul Willis]

I note that High Level's Slimliner gearbox is 6.3mm wide at the point of the driven axle. Given that the centre section of the Society's split axles are 10mm wide, this may be the answer. I think I shall acquire one at S4North and give it a shot.

I've been very satisfied with the SlimLiner box. It makes a problem scenario NotAProblem

At risk of egg-sucking, don't forget to pick up at the same time some 1/8th fibre washers for spacing the gearbox from the frames/axleboxes...

Flymo

[hollybeau]

I have been using split frames/axles for some time and although it is not without its problems, once solved, there is no going back. I use the Branchlines two and three-part axles for which you need to buy their perspex jig to assemble them while the epoxy is going off. Try and avoid the modern "rapid" epoxies as I find they go off too quickly to allow you time to assemble the axles - particularly if you are doing three axles or more. Branchlines do the axles in 1/8" and 2mm variants but only the 1/8" are available as a three-part suitable for mounting a gear wheel or gearbox upon.
The first problem, as others have recounted, is that the width of the middle axle is not sufficient to span between most gearboxes, and certainly not a Portescap. I have solved this by cutting off small lengths of 1/8" tubing (sold by Exactoscale - can't remember what for) and soldering these to the middle axle. You can do one small section on each side or a longer one on just one side. To ensure concentricity (not having a lathe at the time) I drilled a 1/8" hole in a piece of hardwood on my pillar drill, pushed the half axle inside and dropped the sleeve over it. It was then a question of soldering in the resultant void. I then upturned the "lengthened" middle axle, popped it into the pillar drill and dropped it gently onto a fine file to get the length of the middle section to my liking and ensure it was round. This has worked well.
More recently I have sourced some 1/8" stainless steel tube (available here - http://cgi.ebay.co.uk/30-Stainless-Stee ... 3a6486ced5 ) (usual disclaimer). Mine was sold as 1/8" but it now only seems to be available as 3.2 or 3.3mm. Either way it may need turning down a tad. The beauty of this material is that it will maintain its concentricity. Wrap a steel (or are they iron?) nail of a suitable diameter with cotton, impregnate with superglue, sand down if necessary when dry and then insert into the tube with more superglue/epoxy. When set the insulating sections can be cut wherever you like, filled with epoxy, cleaned up and then cut to length. So far I have made one axle (see below) and results are promising to date. You do need a lathe however to do this properly.
One problem I do have and have yet to solve to my satisfaction is wheel wobble resulting from either the etched commercial shortening strips or the use of 5 amp fuse wire. Recently I had some success with putting the wheel on first and then with a small drill in a pin chuck drilling a hole between the hub and the axle from the outside. This drills mainly into the wheel but partly into the axle. Pop the wheel off, solder the wire on, clean up and put the wheel back on. Most of the "bump" from the soldered wire is now let into the axle and any remaining fits into the groove in the inside of the wheel. It needs Loctite and letting dry overnight in a George Watts quartering jig but this method looks promising. It also has the benefit of pinning the axle (but not as elegant as Tim's solution). There is however some wobble even with this method so I am currently investigating the use of electrically-conductive silver paint. I did use a product called Elecolit many years ago with mixed results but with modern motors taking so little current and the paint having evolved this may yet prove to be the simplest/easiest method yet.
Sorry to have rambled on. For those yet to put their foot into the water of split axles come on in - it is worth it never to have to bend those pick ups back into place again. The photo's of Tim's uncluttered chassis should be enough to convince anyone. Keep up the good work Tim - you are an inspiration to us all.
If I can manage the uploading of photos I have attached a few of some Kirtley and Johnson locos I have built and one of the stainless axle (with "iron" insulated core) about to be split on the lathe.

Bryan

[David Thorpe]

Thanks for that, Bryan, very interesting. I looked rather longingly at the tubing you found on ebay, but as you say it is 3.3mm OD, ie 0.13 inches, fractionally but crucially bigger than the 0.125 inches required for most 4mm axles. Not having a lathe, I do not think that i could reduce its diameter with anything like sufficient accuracy. I've also heard that stainless steel can be a poor electricity conductor, and wonder if you'd found that?

Brass tubing in 1/8" is readily available, but I have been strongly advised not to use that for axles, particularly when the wheel bearings are also brass. I had thought of substituting the Branchlines centre axle section with a longer length of 1/8 brass tube, and then making up the axle in the usual way using their outer axle sections and the plastic jig, but that would presumably come up against the same problem of the brass section of axle having to revolve in the brass bearings on the gearbox. Whether that is going to make any real difference on my small layout is perhaps doubtful - the locos don't exactly cover a lot of miles! There is also the prospect of High Level producing nylon versions of their standard 1/8in axle bushes - whether brass + nylon is any better than brass + brass I don't know.

In any event, having had my usual struggle to fit effective yet also unobtrusive pick-ups on my latest loco, I shall definitely be ging split axles a shot for the next one.

Sorry if we're hijacking your thread, Tim!

DT

[Tim V]

No problem.

I have though pointed out, it isn't absolutely necessary to have a three part axle, I've used two part successfully.

One thing needed is a dimensioned sketch of the various split axle kits out there, so informed decisions can be made. Has someone got these kits who could measure them?

[hollybeau]

DT - according to the Exactoscale web site their new driving wheels have stainless steel rims and hubs and if it is OK for them.... As for the size I recall Iain Rice commenting many years ago that it you had a true 1/8" axle and put it into a true 1/8" bearing it would be a very tight interference fit and the whole thing just wouldn't work. Iain didn't use a 1/8" parallel reamer as I suspect most of us do but a new 1/8" drill bit to clean his bearings out and he reckoned that gave just the right amount of working clearance (or should that be "slop"? ).
The battery in my digital vernier calipers has just decided to die on me but when I get it replaced I will measure some standard Gibson/Ultrascale axles (or maybe someone out there could do that) to see how near they are to the magical 1/8". My suspicion is that there will be variation. At the end of the day what matters is that the axles fit the wheels and have a nice running clearance in the bearings. It could be that further research into the availability of stainless steel tube of other diameters will turn one up that is just right. Failing that I don't mind having a go at turning some down for you Dave (or making them to your requirements) but let me undertake my own trials first to see if they work as well as they promise.
Tim - My only concern with a two part axle on a gearbox is that the latter becomes live to one side of the chassis. This is fine with a plastic bodied loco but with whitemetal or etched bodies and axles moving inside on springs/compensation there is a risk of the body becoming live which in turn could result in a short through the buffers/couplings (particularly AJ's which tend to get soldered to metal wagon substructures).
Good idea about posting the various sizes of split axles. I have no experience of the items from stores but will measure the Branchlines ones I have when my new battery arrives.

Bryan

[Tim V]

The large prairie was causing some problems at Ally Pally, I had a look at it tonight and this was what I found!

IMG_1112.JPG

The sticky stuff in use to support the motor has found its way onto the middle axle! I wonder what other horrors await my further investigation.

[hollybeau]

I now have a new battery and have been doing some measuring of the various axles (of nominal 1/8" diameter) that I have in stock. These include various modern Gibsons, some Ultrascales, one Sharman (from 25 years ago) and some Kean Maygib. I was expecting some variation but I can report that within a thou they all came out at 0.120 inches i.e. some 5 thou less than a true 1/8". I should add that my digital calipers are of the cheap and cheerful variety and have not been calibrated against a known length but since this was a relative rather than absolute test there should be reasonable confidence in the outcome. So does this tell us anything useful? Probably not but I would suggest that our hornblocks/bearings etc are made to a fairly accurate 1/8" internal diameter and the axles are deliberately made thinner to allow them to revolve. This is only my assumption you understand based on some rather crude testing and am prepared to be shot down or put right by those in the know. It does of course allow the bearings to be reamed out by an 1/8" parallel reamer. (The corollary being that if the axles were a true 1/8" and the bearings slightly larger then we would need an "1/8 and a bit" reamer and I don't see many of those listed in the tool shops).
As it happens the 1/8" stainless steel tubing I am using to make my split axles also came out at 0.120" so should be a "perfect" fit on the wheels (Gibsons as it happens).
I have taken a photo (apologies for the quick lash up and poor sketch) showing - at 1 the Branchlines two-part perspex jig for holding the axles while the epoxy goes off. You will note that it can accomodate both 1/8" and 2mm axles. At 2 are the components of a three part 1/8" Branchlines split axle with the sketch showing the dimensions (all in millimetres but for the conversion to imperial of the axle diameter - slightly fatter than "standard" axles). You will note that these end up being way over length - even for outside cranked locos. Assuming the middle land is kept central I find that cutting the axles to length results in the ends looking like a swiss roll. At 3 are the two split axles I have made for my next loco (yes it is for an 0-4-0T!) One is a straightforward 50-50 split, the other in three parts to electrically isolate the gearbox. Because I can put the splits where I like you will see that it is wider than the 8mm of the Branchlines version. If using High level Gearboxes the latter can only really be used with the Slimliner boxes (6.3mm width). Remember also that there will be some residual lateral "float" between the worm wheel and the bearings and this needs to be factored in although even in the worst case scenario of the 'box moving sideways and bridging the split it is of course moving away from the other end. Since my earlier post I have given up on using suitable nails as the inner core as they turned out to be anything but suitable being of inconsistent diameter and prone to bending when put under end load in the lathe. I am now using high speed steel (actually some old 1.8mm dia twist drills) which so far have proved fine. The helical part gives a good key for the araldite/cotton mix although the fluted end looks even worse than swiss roll when cut to length. No 4 is simply a standard axle included for comparison.
The next task will be to try the silver paint down the backs of the wheels and will report back as to its success or otherwise.
Finally, I was speaking to Len Newman on the Exactoscale stand at Scalefour North and he confirmed that their three-part axles are indeed "natural" split axles. They would just need a means of shorting out between the hub and tyre. Easier said than done of course and rather expensive if a mistake is made. Let's hope the silver paint is the solution.
My apologies again for hijacking Tim's thread. If this and other similar posts takes us off into a split axles/frames discussion then perhaps Webmaster Keith can give it a life of its own. Here comes the photo:

[Tim V]

I'd agree that this may need a separate thread.

Currently on the workbench is a Heljan Hymek diesel, that had two speeds - fast and stop. On the layout, it is required to pull 25 wagon trains up 1:60 gradients. no matter what I did with the decoder settings, it didn't get any better. Poor motor performance was pointed at.

First step measure up what was there, along with how far away from the motor the UJs were placed. That 28.5 was a mistake (measure twice cut once - I wasn't paying attention), it was 18.5.

IMG_1265.JPG

I worked out that an 18:33 motor would fit and as I like the Canon, that was chosen.

IMG_1263.JPG

I don't believe in bashing flywheels off with large hammers - as I've seen done on models, it was when I saw them being bashed onto the new motor I really cringed.

I used a George Watts wheel puller to get the flywheel and all important Universal Joint off.

IMG_1264.JPG

[Tim V]

I'd decided that the flywheels were superfluous as I use DCC. The UJs could be glued onto the motor shafts, after they'd been shortened.

IMG_1266.JPG

And I could hack the moulded rubber motor mounts to fit the bigger motor quite easily with a sharp knife.

IMG_1267.JPG

And here is the new motor nestling in its home. After brief testing, I pronounced it done. I put a spot of UHU to prevent the motor from turning in its mount.

IMG_1268.JPG

Now to persuade Mr Ashton to get on with the new continuous test track, so I can put it through its paces.

[David Knight]

Tim,

Is there a flat on the shaft of the Cannon motor or is it a trick of the light?

Cheers,

David

[Tim V]

Yes, I was surprised to see it when I bought it. Doesn't seem to have affected the trueness of running.

[Tim V]

An update, the Hymek was running round at Scaleforum, where it was a transformed engine, able to run all day without overheating.

On this thread I discussed what I'd done with the High Level Tenderiser viewtopic.php?f=20&t=1323&p=9728#p9728 Regrettably, I was only able to use the gears. Due to the design of the box, I was unable to use it, soldering the box would have melted the gears, as they had to be assembled onto the shafts before final assembly.

So here is my use. That Canon 18:33 should give my ROD some grunt

IMG_2385.JPG

[Tim V]

What was on the workbench today was my own test track. It has been creating some limitations, and I have been needing to get a handle on shunting. So here is the rebuilt test track, double the length of the previous one.

IMG_2408.JPG

It has a length of Peco on the right, with ordinary C&L P4 flexi track on the left with a point at the nearer incomplete end. The track leads into a 3' radius curve at the far end. Total length of 8'.

[Mark Tatlow]

................and I imagine there is another loco awaiting conversion to P4 on the shelf too?

Do Ultrascale do drop in wheelsets for Duck?

[Philip Hall]

Mark Tatlow wrote:
Do Ultrascale do drop in wheelsets for Duck?

Not sure, but Thomas might appear at Clutton one day to make up a threesome! Maybe P4 tyres on Romford wheels. Don't ask...

Philip

[Mike Garwood]

Mark

I don't think that's Duck, I think it's Percy...I'll get me coat.

Mike

[Mark Tatlow]

Nope, definately Duck!

Percy is no 6 and is a saddle tank.

http://en.wikipedia.org/wiki/Duck_the_G ... ern_Engine

Getting it all right takes on an additional meaning.....................???

[Andy W]

Do the Branchlines split axles (and indeed the home made ones) need some cotton wrapping around the male section to prevent shorting? Or does the epoxy provide enough insulation on its own?

[craig_whilding]

Mark

I don't think that's Duck, I think it's Percy...I'll get me coat.

Mike

Its Duck's day out at the wheeldrop clearly . I guess you could say you can get a drop in set for it too if you use the Bachmann chassis..

Nice test length Tim, I really must nail down the various bits I have lying around into one myself though i'd use individual chairs and a 3-point for the curved bit to represent the layouts the stock will run on.

[Tim V]

That Duck is a push along one I've inherited from my son, and stands as much chance of being converted as the Hornby Tinplate engines also seen up there that no one has commented on! Both are massively oversized for 4mm.

The split axles are made as per MRJ 19. No need for any cotton, as there is no loose section of axle.

[Mike Garwood]

That Duck is a push along one I've inherited from my son.....Both are massively oversized for 4mm.

Ahhh, a purist ! I once looked at motorising a Percy for my son...I'll get me hat this time..

Mike