Help cutting narrower traction tires

[mmagliaro]

Anyone got a good method for slicing an existing rubber traction tire so it is narrower?

My scratchbuilt 0-6-0 uses Kato Mikado tires, that I sliced a little narrower so they would fit into my grooves.
All I did was stand a tire up on end, then kind of squish it flat with a steel straight edge, and slice with a sharp Xacto blade.
It works, but it isn't really all that perfectly uniform.

(I could make the grooves wider in the drivers, but then I would have to cut the flanges a little thin, or make the drivers
wider, and I really didn't want to do that).

Is there a neat trick for somehow slicing a tire a little narrower and getting it perfectly square and even?

[davidgray1974]

I wonder if an adjustable Hand Mandoline slicer would work?  Not sure of the exact thickness these can cut but may be worth a try.
http://www.bedbathandbeyond.com/store/product/sharper-image-3-in-1-stainless-steel-adjustable-hand-mandoline-slicer/1044496951?skuId=44496951&mcid=PS_googlepla_nonbrand_kitchenfoodprep_&adpos=1o1&creative=43742640829&device=c&matchtype=&network=g&gclid=CIqij-PrysoCFdgVgQodcUUJvQ

Or maybe "The Chopper" that they sell at MBK.
 http://www.modeltrainstuff.com/NWSL-The-Chopper-p/nwsl-49-4.htm

David

[wazzou]

Fit the tire onto a bit of appropriate diameter, make sure it is aligned properly under rotation.  Then, while spinning, hit it with a new single edged razor blade?

That's what I'd try anyway.

[narrowminded]

If you have or could make a snug fitting, shouldered for squareness, arbor that you could chuck up in your mill then clamp a knife blade in the vise you just might get what you're after.    Maybe a little soapy water or just... dare I say it.... spit on it.   Problem with too much oil, especially if it gets under the tire, it could all go silly.  Then if there is no lube the blade might grab it and get all silly the other way.  Just have to feel your way through that one.  I'd even try spinning it by hand in neutral with some soapy water applied with a finger every few rotations.  I trust you'll get.  You've accomplished much more difficult things.

[Lemosteam]

^^^^This, without the lube.^^^^


Make sure the mandrel stretches the tire a little.
See if you can clamp an exacto in a tool holder and keep the blade at a very low angle to the surface (tangential) of the material and apply light pressure. 

[TVRR]

You might try doing them mounted on the driver, just invert, apply power and slice off the excess  with a razor blade or scapel.

[peteski]

The problem with a spinning tire and a knife held by hand is that unless the knife blade is not perfectly perpendicular to the tire, the knife blade will skew to the side while it bites into the soft tire material.

[Doug G.]

I would fit it onto a mandrel of some sort mounted in a drill or whatever and just turn it by hand while cutting with a new razor blade. No high speed spinning.

Doug

[mmagliaro]

I appreciate all these ideas, folks.  I am mulling them over. 

I sure wish there was such a thing as cheaply available square-cut, very-thin-wall precision O rings
(that you didn't have to buy 1000 from at an industrial supplier, that is).
... in a variety of widths and thicknesses, of course!

[OldEastRR]

How did your NeoLube business turn out? You get all your money back? Do you still have any to sell?

[Kisatchie]

Hmm... I'd just whack
the traction tires with
an ax...

[mmagliaro]

How did your NeoLube business turn out? You get all your money back? Do you still have any to sell?

Thanks for asking.
Yes, I did manage to get all my money back out of that and I do have a little left (I think maybe 15-20 jars).
So yes, if I sell more, I will actually make a little money for all my trouble, which is nice.
(of course, if you counted the hours I put into it, hunting the stuff down, jarring it up, going to the Post Office
a bunch of times, I actually made nothing... )

Every once in a while, I get a message from somebody wanting a jar.  So the stuff will probably trickle
out of my house over the next few years.

[narrowminded]

I appreciate all these ideas, folks.  I am mulling them over. 

I sure wish there was such a thing as cheaply available square-cut, very-thin-wall precision O rings
(that you didn't have to buy 1000 from at an industrial supplier, that is).
... in a variety of widths and thicknesses, of course!

You can take this a little further and your mill might be just the tool.  Rubber can be ground.  If you get a piece of vacuum hose with an ID somewhere near your need and an arbor that it fits snugly on, then rig your Dremel type tool into your machine so you can control it with the machine tables, you're well on your way.  The hose also is more stable, has more support within itself to hold shape than an already narrow and thin tire requiring a squaring shoulder and having little support for any outside force that engages it.  Make sure the arbor is running true (as the mill is capable of) as it IS your inside dimension and controls the uniformity of the wall thickness.  Start with your known dimension, advance the grinding/ sanding wheel a little with the compound, and then run the hose up and down across its face with the quill.  Measure, repeat, measure, repeat, until you have the thickness required.  Then get your packing knife blade appropriately mounted in there and part off tires to your heart's content. 

A few further details:  Use neoprene if you can.  It has all of the properties (well, the best set of properties) for your purpose.  The three key ones are its resiliency, abrasion resistance, and adequate resistance to oil, alcohol, and the types of chemicals it may normally encounter in this service.  When I say resiliency, I mean the resistance to relaxing under tension, taking a "set", as all of these materials will do to some degree.  It's just less prone to that than other typically found hose materials.  Buna is another pretty typical resilient and is good on the oil resistance but isn't AS good on the "set" and abrasion resistance.  That wouldn't preclude using it but if you can get neoprene, it'll be slightly better suited to the service.

If you make the arbor you might consider making it to the same dimension as the wheel it's going on.  That way your dimension as ground will be the actual dimension of the final product.  Make life easier, intrinsically correct size (or at least the size you measured, correct or not) , no compensation in width or wall required.  Also, if you can only find fiber reinforced hose you can probably still use it as you will grind through the outer and reinforcement layers getting down to what you're after.  Getting just vacuum hose might save the mess of strings getting wrapped up as you break through that layer but...

As a hose it may make stretching it on to the arbor harder, especially if it's fiber reinforced.  Two shots at it, one smaller arbor to rough it in and then assembled to the final slightly larger finish size arbor.  Once thinned, especially if it's fiber reinforced, it will be more willing to submit to your will.   And as hose therefore more of it, harder to stretch, a soapy lube may be helpful with either type of hose.  The lube will displace if left on the arbor a little while before to start working on it.

Clean the machine BEFORE you start so it's easier to clean up when you're done because you'll get a lot of dust.  Most won't hurt anything but I guess some abrasive will be in it so best to contain it and make it easy to clean up when done.  Hate to get grinding materials on a machine tool in places they don't belong.

Good luck!

[narrowminded]

Add:  How much stretch?  I'd go for at least 10% and up to maybe 30% for this service.  That's from the cuff but should be safe.  Enough to stay in place and not so much that the material would fail, be near its tensile.  If you wanted to be more specific in that do some searches but you'd also need to know for sure what your exact material and details were.  Probably won't know that nor need it.  If in service it gave you troubles, that's where you'd have to go look.  That's the beauty of this kind of work.  When it's not quite right it can be a little frustrating at worse but nobody gets hurt and you didn't shut down a $70,000 per minute assembly line.  And those aren't Z scale dollars.

[Doug G.]

Related: I used to make traction tires from Aurora Model Motoring tires mounted on a wheel and filed down. It worked well and I do believe a couple of my old locos still have them on although most of them have been replaced by silicone tires since. I think the idea was an MR "Helpful Hint" or in an Rx column.

Doug