Axle holes and locks

[Owens Racing]

As a follow up to Johns warning about forcing axles, I figured I'd share the process I've been using for drilling/reaming axle holes with an integrated axle lock. I grabbed a few random pictures I had on hand to try and show what I do.

I start with a 3/16" OD by 1/4" high aluminum standoff that's tapped 4-40 through it. I drill 3/16" holes in the body perpendicular to where the axle holes will be drilled.

Here are the standoffs being epoxied in when I laminate the bottom cover and Divinycell foam to the body.

Here's a close-up of some nylon standoffs I tried once. They didn't work as well as the aluminum ones did.

Bottom cover after trimming with a router and drilling through the bottom cover to be able to install 4-40 set screws to lock axles.

Bad close up after top cover was laminated and trimmed.

Holes are drilled slightly undersized and then reamed about .0005" larger than the axles while the body is still in the block.

What I end up with is a perfect slip fit for assembly and dis-assembly but the 4-40 set screws lock the axles in solid. The aluminum doesn't wear out like the wood, so the axle position is perfect no matter how many times you assemble/dis-assemble.

 

[Owens Racing]

One additional note. You should drill the holes with a carbide bit or run the risk of the drill walking when it hits the aluminum.

 

[Crash Enburn]

Wow. I have the sudden desire to curl up into the fetal position...

 

[cozybldr]

What drill press is that? It's not a Proxxon, but I notice the digital readout. It looks similar to the Proxy.

 

[Owens Racing]

What drill press is that? It's not a Proxxon, but I notice the digital readout. It looks similar to the Proxy.

It's the variable speed model from Micro-Mark.

 

[Guest]

If you don't mind answering. Where did you buy the integrated axle lock nuts and screws. What is the size of lock and screws that you used? thank you so much/images/boards/smilies/smile.gif

 

[Owens Racing]

If you don't mind answering. Where did you buy the integrated axle lock nuts and screws. What is the size of lock and screws that you used? thank you so much/images/boards/smilies/smile.gif

I originally used 3/16x1/4" 4-40 standoffs, but could only find them at Mouser Electronics. I've used 1/8x1/4" 2-56 standoffs on my last two cars. You have to be a little more precise with you standoff/axle hole placement, but I like them better. And, they are available from McMaster Carr.

Also, I tried to respond to your PM but it looks like you have PM's blocked.

Jimmy

 

[Guest]

Sorry, I didn't realize I had the PM blocked. I think my works network was blocking it. Thank you so much for the reply I really like your idea of the interlocking post. Brillant, I hope to try it in a few weeks.

 

[DerbyDad4Hire]

How did I miss this thread??? Wow, that is very cool.

 

[cygnus]

You are a maniac machinist Jimmy! I love it!! Keep up your awesome contributions to this sport/hobby.