RC10Talk - The Net's Largest Vintage R/C Community

Here's a topic I haven't really seen discussed...I picked up some JPS front wheels that closely match a nice set of rears that are meant for old-style Kyosho taper-fit axles. The wheels are machined to accept bearings. Now here's the weird-ass thing: the wheel bearing hole diameter is just about 9.5mm. To my knowledge, no metric RC bearing exists in that size. However, that's pretty much the outside diameter of a 3/8" Standard-sized bearing; ~= 9.525mm. Problem is, I'm using 5mm axles.

I've already discovered that using the closest standard-sized axles, 3/16" = 4.763mm, are too small for 5mm I.D. bearings, even only a quarter of a millimeter is too much play.

So, other than filing or grinding the 3/8" aluminum wheel bearing holes a bit wider to accept the 10mm bearing, and keeping the 5mm axles, is there anything you can do with a 5 x 9mm bearing to make it just big enough to snugly fit inside the 3/8" hole? Of course, I've never seen a bearing that has metric 5mm I.D. and SAE 3/8" O.D. or else I'd buy some.

wrap a piece of tape around the outside? piece of shrink tube?

Shrink tube might do the trick. Thanks, I'll give that a try. I'd rather do something to the bearings than modify rare aluminum wheels.

I have used aluminum foil for the same situation in bearing races in aluminum tranny cases that eventually get wallowed out from normal use. I have had good luck with it.

What about borrowing steering knuckles from another car, or modifying your existing steering knuckle to accept 3/16" axles?

Phin wrote:What about borrowing steering knuckles from another car, or modifying your existing steering knuckle to accept 3/16" axles?

That's not an option considering I'm already using off-brand front end parts that were carefully chosen just so that they'd work together. The last thing I want to do with this car is run ANYTHING Standard-sized, if at all possible, because then I'm not just replacing the knuckles, I'm replacing the carriers and possibly the arms & hinge pins too, not to mention anything threaded into the parts like ball studs that would be 4-40 instead of 3mm, etc., etc...and have to go through a long process of trying to find new parts that will all fit together.

Another option: go on Ebay and buy a small tube of Loctite 270 (or 271 - same thing). It is designed to act as a bearing grip for worn bearing holes. It acts like an adhesive, but also it expands as it sets, gripping the bearing like a vice. I have some here in case I ever need it. Threadlock may be similar, but this product is designed specifically for bearing use.

you can also buy shim stock in the appropriate thickness. it's called feeler gauge stock and comes in 1ft lengths. I typically cut a length and width with scissors and wrap as desired. You can get it in .001" increments.

jwscab wrote:you can also buy shim stock in the appropriate thickness. it's called feeler gauge stock and comes in 1ft lengths. I typically cut a length and width with scissors and wrap as desired. You can get it in .001" increments.

I like that idea even more as it probably wouldn't wear as fast as rubber/tape. Where would you buy that stuff? Never even heard of it until now.

Coelacanth wrote:

jwscab wrote:you can also buy shim stock in the appropriate thickness. it's called feeler gauge stock and comes in 1ft lengths. I typically cut a length and width with scissors and wrap as desired. You can get it in .001" increments.

I like that idea even more as it probably wouldn't wear as fast as rubber/tape. Where would you buy that stuff? Never even heard of it until now.

I'd take scissors to an aluminum can and cut a strip the width of the bearing. You can wrap it around once, and another time if that ain't enough. Any beer or soda is fine, just not light or diet

Coelacanth wrote:

jwscab wrote:you can also buy shim stock in the appropriate thickness. it's called feeler gauge stock and comes in 1ft lengths. I typically cut a length and width with scissors and wrap as desired. You can get it in .001" increments.

I like that idea even more as it probably wouldn't wear as fast as rubber/tape. Where would you buy that stuff? Never even heard of it until now.

Here's some peelable shim stock. They use this kind of thing at the Lazy B, where I work.
http://www.accutrex.com/accupeel_laminated_shims.html

Marc,

I've been there before. I bought some brass tubing that was 3/16 in diameter. I then cut a piece that was the same length of the axle...and then cut a channel down the entire length. You can then fit it over the axle and it will take up the slack so you can use the 5mm bearing. If it's still a little thick, you can reduce the diameter by sanding/filing it.

Regards,
Roger

highwayracer wrote:Marc,

I've been there before. I bought some brass tubing that was 3/16 in diameter. I then cut a piece that was the same length of the axle...and then cut a channel down the entire length. You can then fit it over the axle and it will take up the slack so you can use the 5mm bearing. If it's still a little thick, you can reduce the diameter by sanding/filing it.

That's a great idea for those bearings with a little too much I.D.

You could use some 3/8 OD tube, with a suitable wall thickness, that will enable you to use a more common bearing size, such as 8mm x 5mm (Tamiya 850)..

A quick search and I found this tube http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXPL68&P=7

With its 3/8 OD. and wall thickness, I have roughly calculated the ID. to be approx 8.1mm..

If you have sufficient length in the stub axles, you could use 8mm x 5mm flanged bearings.. The flange would hold the "spacer" in place, and also hide (to some extent) the spacer from view..

Mark.

aluminum soft drink can is about .004" so it will work if you need to make sometime bigger by multiples of .004".

mcmaster-carr carries feeler gauge stock not sure if they sell to canada. but any industrial place should have it.

for example:
http://www.mcmaster.com/#feeler-gauge-stock/=mdhc4j

see if that works and you can see the table of feeler gauge stock.