perfect, easy canted drill 1st time

[bracketracer]

VK, why don't you clamp a machinist's square to the bottom of your block so you have a hard stop for the tool? Then when you move it just keep it tight to the stop and reclamp it. That would have to be better than eyeballing it?

 

[Vitamin K]

VK, why don't you clamp a machinist's square to the bottom of your block so you have a hard stop for the tool? Then when you move it just keep it tight to the stop and reclamp it. That would have to be better than eyeballing it?

Good thinking. I like it!

(While I don't have a machinist's square, it does give me some ideas for stocking stuffer requests... /images/boards/smilies/biggrin.gif)

I bet you could do the same with a good quality metal ruler, too!

 

[GravityX]

This might be the ideal square for the job.

 

[davet]

It seems like we could MINIMIZE reclamping misalignment problems by starting out by choosing one side of the wood block to be our reference edge and drawing, perpendicular to that edge, a line across the block at the spot where the edge of the axle guide would rest. Then, we clamp on one side, with the spacer, and drill our canted hole. Then, when the time comes to move the spacer and reclamp the guide, we refer to our perpendicular line, trusting it to line up the axle guide, as opposed to the other edge of the wood block.

This is what we did. I'm also assuming the block is machined and drilled straight and parallel. My boy had an accident with the router while cutting on our block so we drilled another one the same way with good results. The second time we used a razor blade to make the mark across the block instead of a pen or pencil in hopes of being even more accurate.

Wish I had seen the above post about clamping the square to the block as a stop for the tool before we cut the second block. That would've been better yet I think.

 

[ugotkevin]

Sorry for bringing up an old thread. I think I'm going to use this, but why did you use a #45? If I did my math right that's a 4.8%, wouldn't you want to use a #55 which would be closer to the 3%?

 

[B_Regal Racing]

Check your math (or check mine). A #45 bit should yield about a 2.7 degree cant angle.

degree of cant = ATAN (drill bit thickness / 1.75)

A #45 drill bit is .0820 inches

 

[davet]

I used a protractor to make a 2 degree and 3 degree angled line on paper. These appeared close to the axles I bent with a 2.5 degree bend done with railrider tool.
I stuck those 2.5 bent axles in a block of wood and started drilling canted holes alongside them and installing straight axles. When I found the hole that gave me the angle that matched the 2.5 bent axles I used that one.

IIRC I have since seen a chart that showed cant with that bit as a spacer to be about 2.78 degrees. I would have to go back and look at some notes we made. I hope I didn't say #45 by mistake. It may also be that we are clamping it against the wood block which could introduce some compression of the wood.

The cant seems good with just a hair of light visible under the outside edge of the wheels when resting on flat surface. We ran a 2.90XX at Districts on 42' BestTrack with track record with this car and this drill, including 4 LED lights and a 3v battery.

I have no idea how that would compare with the fast guys here though. It's just working for us.

 

[W8NONU]

Here you go...

http://www.stanpope.net/camdrill.htm

 

[ugotkevin]

Man, I was way off my math...I was actually good at trigonometry at one point, true story. #43 is the right one.

 

[davet]

We used the smaller one in case we had to make a slight axle bend due to a bad drill. We don't risk the whole block that way.

 

[Pacfanweb]

I've been doing this with a Pro Body tool for years. Works fine for Cub racing.

It's not perfect by any means, but it's about the best way to get canted rears without a Block or Goatboy tool. (or a drill press)

I'd never bother trying it for league or Mid-America racing, though.

 

[davet]

It can work.

1st Place Webelos II in the nuclear arms race that is the NorthernStar Council with this drill method, 4 LED lights and a 3v battery. 3.7509 seconds average on 64' track.

It was not, however, the fastest car at the event but it took us as far as we could go.

I think if I were to get into league racing the money for the new SB Pro tool would be worth it.

 

[davet]

One of the reasons we were told our method was flawed was because it relied on the block being perfectly square. Isn't the SB PRO doing the exact same thing we did but without the reclamping?

 

[LightninBoy]

Yes - but "without the reclamping" is a critical difference. Actually, its *the* critical difference.

 

[davet]

Yes - but "without the reclamping" is a critical difference. Actually, its *the* critical difference.

Thank you Sir!