27 replies to this topic

[utfan98]

Looking for a company/part number for the tightest, straightest, and hardest 3/32" stock. 

What are you guys using?

[Cheater]

Define 'stock,' please.

Brass rod, tube, or plate? Or steel piano wire?

[chasbeeman]

McMaster-Carr, S7 is best for axles.

[utfan98]

Axles.

[utfan98]

Thanks, MC has several options, S7 was one of a few I was looking at.

[chasbeeman]

Heat treating for hardness is probably a good idea if you have access to do so.

[MSwiss]

Koford M623R.

It's made for slot racing.

Super-straight. Perfect sizing for bushings and ball bearings.

And most important, the correct temper, so it won't snap in a bad wreck.

[havlicek]

Tight, straight, hard 3/32" material still leaves a lot on the plate. Axles that are too hard means brittle (as mentioned above), and you don't want the "hardest" material, you want a material that's hard enough, but not too hard. "Tight" is another vague thing and there are variations between different "3/32" axles. A thousandth or so here or there can mean the difference between a sloppy fit, a slip fit, and an axle that is bound.

 

The McMaster-Carr stuff is most likely fine, but it's not meant for slot car axles, but general machine shop type stuff. The Koford material has been spec'd and selected for the purpose. 

 

If you still go for the McMaster Carr, I'd go slow and try one before ordering more.

[Mark Proppe]

I've ordered the McMaster-Carr stock slightly oversize to solder bushings in. Tighter fit, better alignment, then use Koford to race. Works every time.

[Steve Deiters]

Do a search for "mold ejector pins." That is what I have been switching to. They don't bend and will break before they do. I haven't broken one yet.

[Geary Carrier]

Koford M623R

 

Mike,

 

How would this axle work as an armature shaft running in ball bearings?

 

Thanks,

 

g

[gotboostedvr6]

Bill has the best axles.

[MSwiss]

I've ordered the McMaster-Carr stock slightly oversize to solder bushings in. Tighter fit, better alignment, then use Koford to race. Works every time.

 

That's a common way machinists who race install their bushings.
 
Rather than risk getting the axle stuck in the bushings, or BB's, I use the below technique. It's is a great way to use any straight axle to install your bearings.

It simulates a tight axle, by pulling the front, hard, up against the front of the bushing or bearing bore.

 

 

Do a search for "mold ejector pins".  That is what I have been switching to.  Don't bend and will break before they do.  I haven't broken one yet.

 

If you are racing for the win, bending your axle is much more preferable to breaking your axle, or even worse, breaking your ball bearings.
 
With a bent axle you can limp to end of the heat, and change it, during intermission.
 
Guys were trying to use some super-hard drill blank for F1 front axles.
 
Both Noose and J.J. talked about snapping them, and winding up out of the race with an F1 tricycle.
 

 
How would this axle work as an armature shaft running in ball bearings?

 

Great, if you had lams with the correct bore to press them into, and of course, have a pinion with the correct bore.

And the motor setup would have to be able to accept the 3/16" OD ball bearings on both sides.

[Geary Carrier]

Thanks, Mike.

[Bill from NH]

Mike,

 

Explain the use of a rubber band during chassis setup as shown in your post #13 photo.

 

Thanks.

[MSwiss]

It wasn't originally in the post, but I added it.

It simulates a tight axle, by pulling the front, hard, up against the front of the bushing or bearing bore.

[Upfront slot cars]

Koford has the best axles!!!

[munter]

I am always looking at a cheaper option for this and that when scratchbuilding...

These may not be the hot ticket for racing but hopefully will be OK for my 1/32 scratch cars using lo-po motors and urethane tires under resin scale bodies.
 
I am aware there are axles and then there are other axles.
 
Steel round ground bearing shaft 2.38mm 3/32" × 304mm long
 
I will buy from anywhere if it suits my needs

[Cheater]

It simulates a tight axle, by pulling the front, hard, up against the front of the bushing or bearing bore.

Of course, as I have mentioned before, my favorite technique to align bushings is to use machinist gage pins to be that "tight axle," selecting the appropriate pin sizes to fit the bushings with as close to zero play as possible.

FWIW, most of the oilites bushings sold to the slot car hobby do not have very consistent bores diameters. One exception is the Slick 7 machined bushings.

When you get the bushing bores nearly exactly parallel and co-axial, the difference in spin is very noticeable.

[Ecurie Martini]

Different cars/classes/loads will have different requirements but for 1/32 cars, the loads are so low that the bearing surface of the typical oilite is overkill. I chuck mine in the lathe and counterbore with a 1/8" end mill to reduce the width of the bearing surface to about 1.5 mm. After installation I pass a 3/32" hand reamer through both bearings.  

 

I find that this works well for the drill blank axles I typically use.

 

EM

[Bill from NH]

Pappy's Jiggy and Magna Jiggy also work well for getting bushing bores parallel and coaxial.

[Cheater]

Not in the way I meant, Bill...

 

Correct me if I am wrong, but the only way to get two bushings to have bores parallel and coaxial is to install them on a shaft/axle that fits both bushings with near zero clearance. Without such a shaft, a jig can't do that.

[Bill from NH]

In order to use the jigs, one needs accurate jig wheels and good shafting. Like most chassis jigs, they don't do anything by themselves.

[Dave Crevie]

Cheater's method of using gage pins is the ultimate method, and the one I often use.

On a car I am entering in a big race, I use M-42 cobalt high speed drill blanks. They won't bend, and won't break in any wreck that wouldn't destroy the bracket anyway. Theyrun about $2-3, but are usually only sold in packs of six. Most industrial suppliers have them.

[Pappy]

I use Avid ball bearings and they work well with about any axle or drill blank other than Slot.it. So if you want a nice tight fit in your oilites for alignment you might try a Slot It axle.