Problem drilling axle holes

[BulldogRacing]

When I follow all directions using the silver bullet I will only get about one in four car bodies where the rear wheels migrate to the axle heads when I test froward and backward. Usually it;s the left rear wheel that won't migrate out when I roll forward, yet when I test backward it works. When I do get a car right I hollow out for the weight pockets and the body and then I re-test and it's all screwed up. My car gets out of wack and the rear wheel don't consistently migrate out. Should I drill after weight pockets are fabed? I'm stuck on how to do this well. I'm getting some good times on my 42' best track but 3.01 3.00 and 2.99 is not good enough to really compete with you guys. How do I drill a consistent block Without messing it up? Thanks for all your help!

 

[Guest]

It does help to remove the weight pockets first to release any stored tension in the block, also making sure the table doesn't budge when it's pressed on can make a world of difference.

 

[DerbyDad4Hire]

THat is right, chances are you have a high spot on the table, you are letting the block rock or slide side to side when drilling or possibly having an issue with your test wheels and axles. There is always a sneaky little issue that is causing the problem and once you find it then you are good to go.

 

[speed bump]

It does help to remove the weight pockets first to release any stored tension in the block, also making sure the table doesn't budge when it's pressed on can make a world of difference.

. Make sure your pin is in the middle of the of the block. If its on one end or the other end it will rock if u place your hand on the opposite end of pin. I use a 1/8 tungsten tig rod. It's is just as long as the block

 

[ngyoung]

My plan for drilling was to get all the pockets as well as any extra pockets to reduce weight, add weights, drill axle holes, test, cut the profile, check weight, take out any extra wood, and test again. I will be doing one block's pockets today with a router so hopefully everything goes as planned. The end mill bits I ordered on Amazon won't be here till tomorrow and I am too impatient to wait. I cut about 12 blocks from a board I got at a local lumber supplier all sorted by weight so I will have plenty to try out.

I like the idea I read on here about wrapping the tungsten cubes in tape before gluing in so that I can cut them back out to use in a different car without destroying the old one.

 

[DerbyDad4Hire]

It does help to remove the weight pockets first to release any stored tension in the block, also making sure the table doesn't budge when it's pressed on can make a world of difference.

. Make sure your pin is in the middle of the of the block. If its on one end or the other end it will rock if u place your hand on the opposite end of pin. I use a 1/8 tungsten tig rod. It's is just as long as the block

I personally don't like the long pin. i center the pin under the point I am drilling and make sure and keep pressure there. With the long pins you have more of a chance of table imperfections effecting the drill. That is just my opinion though. The long pin would make it easier.

 

[MOFAST]

What about two short pins, one on either end? I have 2 pins from McMaster and this prevents the rocking.

 

[DerbyDad4Hire]

All I can say is whatever you are comfortable with and is producing good results.

 

[pony express]

If you use the long pin method be sure to mark one end to use as the end where you will be drilling. Use the same end under the drill site. It minimizes error in the long pin. The longer the rod the more likely there will be an error in how round and precise the rod is.

 

[quadad]

Couple of typical things to check:
- How plumb is your table ? When going from an unknown setup, my first check is with a 1/4" diameter reamer blank and a machinist square. Then I check further with a dial indicator. There are some pictures here of simple jigs for this.
- One other issue with the long pins is that you have more exposure to debris from drilling the previous hold. Because your error appears consistent though, odds are good that it is something that is always present.

You can also practice without using the pin by drilling flat axle holes in some scrap material. While it is tougher to get the wheels to migrate, this eliminates one possible error source and you can flip the wood upside down and check forward/back that way too. Pretty soon it becomes obvious where your problem is.

Before you drill, make sure your wood plank is flat on the bottom though. Place the wood on your DP table or something else very flat. Push on each corner. If it raises up from any of the four corners, flip it over and try again. If both sides are bad, don't even use it. Whichever way works well is the position you want it in on your silver bullet.

If your table can not be shimmed you can have it milled or try placing something that is flat on top of it (which may need to be shimmed).

I think all of this is more important right now than worrying about whether you should mill the weight pockets first. Do that AFTER you have the basic drilling working. From what I understand, you check your drilling right away and see problems. This has nothing to do with weight pockets..

 

[BulldogRacing]

Thank you very much for all the input. I will go check for humps in the table next. Thanks for all the great help here, my boys took 1,2,3 at their local race, no district so I'm bummed. They raced against 26 cars, the stuff I learned here is amazing. Thank you to all and DDFH equipment is unbelievable. I used cheetahs and 92 axles and tungsten, built my own fenders. I think I'm going to order his fenders next, well happy building!

 

[The Iceman]

My Problems came from the drill speed not fast enough!