Back to Back Adjustments

Hi all,
I have a need to adjust the back-2-back distances on the wheels of most of
my RTR stock, and I was wondering if there are any good tools available for
doing such? I know of back-2-back gauges, but what about a tool to do the
job accurately? I find adjusting the distance by hand can produce poor
running (wobbles, etc).
Ian J.
Reply to
Ian J.
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Excellent question. When I got fed up with the constant derailing of my rolling stock, I went in my local model shop and asked if I could get one of those back-to-back gauges that I'd been reading about on this very group. The shopkeeper looked at me strangely and the reply went something like "Oh *no*, Sir! Such things are not for the likes of thee..."
Cheers, Steve
Reply to
Steve W
Mainly trains have varoius back to back guages if asnyione is looking for one, very handy if not essential tool for quality running with todays rtr wheelsets.
Reply to
Piemanlarger
"Ian J." wrote
Ian.
Be Warned! Setting the back to back (B2B) of a wheelset is not the ultimate answer and can in fact make matters worse - often apparently inexplicably - as you seem to have found!
A recent thread I started ("Does anybody know Iain Rice") evolved because I have finally managed to understand the whole issue of wheel settings vs. flangeways and I wanted to get his view of a possible workaround for the lack of enforced standards in OO before our club starts work on a "finescale" restoration project.
In a nutshell B2B is a myth. The critical dimension is actually the "Checking gauge" or "Wheel Check Gauge" which is measured from the BACK of one flange to the FACE of the other.
A B2B gauge only sets the distance between the BACKs of the flanges.
The truly critical dimension - WCG - includes the thickness of one of those flanges as well.
Clearly, if you take 2 dozen identical wheelsets and set the B2B then the wheel check gauge for all wheels will be the same.
However, if you take 2 dozen wheelsets of varying ages from more than one manufacturer (and made in more than one country) and set the B2B then you will wind up with wheelsets set to a number of different Wheel Check Gauges because each WCG includes the thickness of one flange in the wheelset, and there is no guarantee that those flanges will be the same across all wheelsets. I know at least two people who have gone down the route of buying a B2B gauge believing it was the ultimate Holy Grail, and have eventually thrown it away before grumpily announcing that achieving good running on finescale track in OO is not possible.
If you want to go down the B2B setting route then you need to work out what the B2B needs to be for each type of wheelset you have in your fleet to achieve a consistent WCG that works on your layout, and you need a B2B gauge for each of those types of wheelsets, and you need to mark each axle to identify which B2B gauge should be used on it, and that is a lot of work and expense.
Over the next few months I am going to try setting WCG by taking under performing wheelsets out of stock and visually inspecting how they cross the common crossing of the points they are failing to get over, and then going "in a bit, out a bit" until we can see the flanges going through the flangeways the way they should. It sounds crude but my ultimate intention is to develop some sort of "Rig" to hold the wheels while we do this and a plasticard measuring device that measures true WCG which we can be used in place of a B2B gauge. The reference book I have used to arrive at this plan is "An approach to building finescale track in 4mm" by Iain Rice; ISBN 1 874103 003 published by Wild Swan.
I would like to say "I hope this helps" but I have a nasty feeling I may have just ignited another flame war.
Elliott
Who thinks "Publish and be damned" is as good a motto as any.
Reply to
Elliott Cowton
Elliott,
First let me say I agree with you on the principle of 'WCG'. But in my original post, I was in fact asking for a b2b adjustment tool, not a b2b gauge - an adjustment tool would need to be able to be set to whatever b2b measurement a person might need, thus allowing for WCG to be set accurately as well. I have an idea in my head for how such a tool might look and work, but I don't have the skills or tools to construct one myself, nor the skills to make up accurate drawings for it so a precision tool making company could manufacture it.
So I am trying to find out if any such tools might already exist...
Ian J.
Reply to
Ian J.
GW Models (and no doubt others) make a wheel puller, not sure if anyone makes a wheel 'pusher'. I've had the same problem trying to re-gauge my EM stock to OO (long story...), my particular problem being sore fingers more than 'wobble'. I finished up making a whatsit to go in the vice, basically two bits of flat brass plate shimmed to the same thickness as the protruding length of the pinpoint axle, each with a 2.5mm hole drilled in it. These go either side of the wheelset with the BtB gauge in between, then the whole lot is squeezed gently in a vice fitted with hard rubber pads on the jaws. In the end it was a lot more hassle and no more reliable than twisting the wheels in a bit by hand.
Stuart.
Reply to
Stuart.
A lathe does a reasonable job!
The correct adjustment is not "back-to-back" but "flange/tread junction to flange back". Even quite dissimilar profile wheel-sets will operate satisfactorally with that dimension set to a common measurement.
Regards, Greg.P. NZ
Reply to
Greg Procter
Ian J. said the following on 05/01/2006 21:13:
GW Models make a wheel puller that may well do you. This (as it's name suggests!) will pull the wheels out, and you can use a vice to push them in. You will still need to ensure that the all-important wheel check gauge is correct, as mentioned previously.
Details at
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Paul Boyd
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Reply to
Paul Boyd
I manufacture and distribute such gauges as time and whim allow me to. My product is in the form of a turned gauge with a maximum/minimum step - they get a bit boring to make but I seem to have no problem selling every one I get around to making. Alternatively I make a 1/2" turning with a milled slot - drop the wheelset in and press the wheels against the gauge - rather more time consuming to make and I NEVER have any remaining in stock.
Regards, Greg.P. NZ.
Reply to
Greg Procter
either use the Alan Gibson B2B gauge or use a clock vernier which I find more accurate and quicker.
Reply to
Richard Willcox
My B2B wheelsetting gauge comes close for wagon wheels. A precise setting machine would not only set the spacing between the wheels but also the length of axle extending beyond the wheel. Such a machine would be complex and therefore expensive. Quite simply, the eye is good enough to set the axle extensions as it is only the eye that will judge the result. We therefore come back to the flange base to wheel back dimension. You need one gauge for each wheel profile in your collection within the circa 0.5mm tolerance.
If you use a block gauge with an axle slot, the wheels can be pressed with simple tools (eg big drill press) against the block gauge to get vertically concentric wheels (99%) Throw away the 1% failure, it's cheaper than the required press required for 100% accuracy.
Regards, Greg.P.
Reply to
Greg Procter
Most engineering vices have a slight but discernable taper to the jaws - use a big cheap drill press!
Reply to
Greg Procter
Elliot,
I know that the content of your message implies it, but could we just clarify that your statement really only holds good for UK 00 standards - or more accurately, lack of standards. If you work with track and wheel standards which are maintained to a proven specification, then a B-to-B gauge is a quick and accurate method of setting wheels to gauge, since all the flange widths are within spec, therefore the check gauge is within spec.
Jim.
Reply to
Jim Guthrie
"Jim Guthrie" wrote
Agreed! It is the lack of a recognised and enforceable standard that makes it difficult for those of us who don't want to (or can't) go the whole hog to EM or P4.
In circumstances of properly laid down wheel and track standards a B2B gauge is a very simple answer to the problem of accurately setting WCG.
Elliott
Reply to
Elliott Cowton
"Ian J." wrote
Ah! that will teach me to read the original post properly won't it! When others started telling you where to get gauges from my alarm bells rang, although looking at one or two of the other posts I have probably done some good by reminding everyone what the problems are with r-t-r OO stock.
As to a B2B setting tool, I question whether one could be possible given the massive variations in both wheel construction and dimension we have to work with.
I am about to be given something approaching the gadget Greg Proctor has described in another part of this thread, its actually a spacer from somewhere inside the fuel system of a Sea King helicopter and being an "aviation" part it is machined to incredible accuracy whether its needed or not. Luckily, it just happens to equate to the B2B required to make the wheels on Bachmann goods wagons run over Nictun Borrud's points. Whether it could be adapted to commercial use or not I don't know; the problem is, as others have stated, getting the wheels evenly spaced about the centre line while pushing or pulling them into place. A big pair of pushers/pullers based on the design of a pair mole grips with an adjustable spacer in the middle might work although this would be very difficult (and expensive) to manufacture so that it could accommodate all known variants of r-t-r wheel design.
If you have an idea for something to do this job try to find a tame tool maker or watch repairer and explain the problem to them. Our club's retired tool maker come watch repair expert is very good at putting other people's ideas into practice and this is probably the best way to go. Asking a precision tool making company to do it would be prohibitively expensive unless you can guarantee to sell one to every OO modeller in the UK - which you might just be able to do...
HTH
Elliott
Reply to
Elliott Cowton
More precisely: the back of one flange to the _root_ of the other. NB that a properly designed wheel will have a small fillet between tread and flange.*** The root of the flange is the centre of this fillet (which should lie above the theoretical intersection between flange face and tread face.)
The NMRA gauge incoporates a go/no-go pair of slots for checking wheel sets: gauge, flange depth and thickness in one operation. Since the slots are sized for RP25 flanges, they automatically also measure back-to-back and check gauge. RP25 dimensions. IIRC, they are working on a fine-scale vesrion of the gauge, based on the proposed fine scale standard (which appears to be based on Proto-87, which appears to be similar to P4 except for gauge.)
[...] *** PS: in the late 50s, NMRA ran an exhaustive series of tests on different wheel profiles, done for them both by modellers with large layouts and by clubs. They found that for reliable tracking a sharp edge on the rail head required a fillet on the wheel, whereas a rounded railhead (as in tinplate track) required a sharp corner between tread and flange. They also tested exact scale wheels, and found that if the track was well built, and trucks/loco frames were equalised (compensated), these wheels were as trouble free as the overscale ones we are used to. This finding was IMO one of the motivations for Proto-87 and Proto-48, but I'd like to hear from one of the developers of these standards.
Reply to
Wolf Kirchmeir
Hi Ian.
Pretty difficult to get your question answered I see. :-)))))
If the wheelsets are for coach or wagon I usually hold each wheel with two fingers from each hand and twist in opposite directions to break the 'seal' whilst at the same time pulling or pushing the the wheels apart or together until the B2B gauge fits.
For deisels with plastic bogies, either remove the wheels and 'twist' os use a wheel puller.
Steam locos are a little bit more tricky.
One wheel can often be 'slid' along its axel until the gauge fits by using a flat bladed screw driver between the wheel and chassis, but levering from a point as near the axel as possible. Don't try it on Bachmach steamers as they are glued in place.
What is realy needed os some sort of forked instrument that fits each side of the axel to give an even push.
It's worked for me.
Reply to
David Smith
In message , Jim Guthrie writes
Have you tried it with stock produced by Walthers? These have metal wheels on plastic axles, and not all the axles are straight.
Reply to
Jane Sullivan
First of all, thanks to everyone else for their replies, even though most haven't quite answered what I'm looking for. The wheelpuller is out, as I believe these can remove the tyre from the wheel centre. And also, as has been pointed out, the b2b gauge alone isn't capable of addressing variable WCG.
I have used the 'flat blade screwdriver levered against the chassis' method, and that's what's gotten me into trouble (my Bachmann 08 wobbles a lot!). I've even managed to use the technique on Bachy steamers, but not wholely successfully.
My idea is not unlike a pair of pliers, only instead of them pivoting on a connection in the middle like scissors, the two halves actually roll against each other (when you clasp the handles, the nose end opens). Then there is a 'calibrated' rod for measurement, and a threaded rod connection between the handles, with a threaded wheel on it to act as the stop at the right gauge (adjustable to suit gauge required). The nose end of the pliers are flats with a 'axle diameter-sized' slot in them (possibly with collars to account for different axle diameters). The flats will push against the backs of the wheels when the handles of the pliers are compressed, but only so far as the threaded rod connection setting will allow. Now, I haven't quite solved the problem of how to hold the centre of the axle firm so that both wheels will move evenly outward, but I believe some kind of grip could be integrated to bite the at the centre of the axle, thereby prevent uneven wheel movement.
I'd draw a diagram, if only I was skilled enough to do something that looked reasonably like what I have in mind...
Ian J.
Reply to
Ian J.
Note that this is no longer the 'proposed finescale standard' it has been ratified and is now the published NMRA Proto:87 standard, see
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Unfortunately they have got very old and/or died, you will have to settle for reading their published works which you will find here:
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Keith
Reply to
Keith

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