Speed Grove = Frustration and I don't know why

[1reason]

When I try to spin a tire on an axle with a speed grove the tire becomes unstable (sometimes VERY quickly) and comes to a total stop right away.

Even the axles without any prep allow the tire to spin for longer and without the massive instability.

If I don't add the speed grove and simply polish up the axle it seems fine. I have no idea what I'm doing wrong and/or what is causing the tire to be unstable. As hard as I look at the axle I'm not seeing "it".

Any ideas? I'm tempted to forget the speed grove, but really hate the idea that "I can't do it" -insert really bad words here-

I've seen groves on axles on ebay etc.... and I understand where the grove should be located and I'm not even going very deep (maybe taking off 20-25%)

I've even placed the axles in a straightener before and after making a grove. This has been a problem for me for years and before I thought it was because I was taking too much material off when polishing, but this happens before the polish

Also, there's no crimp marks on these new nails so I'm not taking a file to the nails at all other than the speed grove.

 

[GravityX]

What is the axle diameter? I don't think you can avoid the "wobble" if you are using a small diameter axle like an .089" and then turning it down some. Of course a large diameter wheel bore and small diameter axle is likely a disastrous combination anyhow.

 

[1reason]

What is the axle diameter? I don't think you can avoid the "wobble" if you are using a small diameter axle like an .089" and then turning it down some. Of course a large diameter wheel bore and small diameter axle is likely a disastrous combination anyhow.

Thanks, I'm not sure. using standard cup scout axles (without crimp marks).

But it makes me feel better if I'm over-worried about the wobble. I just didn't want to actually make the axle worse than out of the box....

Is there a list anywhere with the sizes of the wheels and the number inside so I know what wheels are best to use?

 

[GravityX]

This is an area that BracketRacer may be able to help you out with. I've heard the #8 mold has a good bore but not sure on the size.

 

[bracketracer]

This is an area that BracketRacer may be able to help you out with. I've heard the #8 mold has a good bore but not sure on the size.

Paul, I think what I said was the #8 wheels are good for the NDFW! lol! The 8's I've looked at had too much lateral runout for me.

Someone posted this earlier: Wheel Bore Chart

 

[GravityX]

This is an area that BracketRacer may be able to help you out with. I've heard the #8 mold has a good bore but not sure on the size.

Paul, I think what I said was the #8 wheels are good for the NDFW! lol! The 8's I've looked at had too much lateral runout for me.

Someone posted this earlier: Wheel Bore Chart

OK, that was for a good laugh! I can't remember everything...

 

[Kinser Racing]

I think you're making the grove to big, width wise. That's why it wobbles to a quick stop. Cut a bad wheel in half and see where your groove lies in the wheel.

 

[bracketracer]

This is an area that BracketRacer may be able to help you out with. I've heard the #8 mold has a good bore but not sure on the size.

Paul, I think what I said was the #8 wheels are good for the NDFW! lol! The 8's I've looked at had too much lateral runout for me.

Someone posted this earlier: Wheel Bore Chart

OK, that was for a good laugh! I can't remember everything...

It's OK buddy! lol!

 

[1reason]

I think you're making the grove to big, width wise. That's why it wobbles to a quick stop. Cut a bad wheel in half and see where your groove lies in the wheel.

Thanks, I thought of that, but I'm not any wider than others for sale

 

[Kinser Racing]

It never hurts to check. I do.

 

[davet]

I've had the wobble with the groove when I haven't gotten the groove square to the shaft. I put my axle in a drillpress and square up the table both ways (side to side and front to back). I lay a file on the press table alongside the hole on the table. I raise the table until the file lines up with the 3 crimp marks on the axle. Tighten the table and recheck that the file will still hit all 3 crimps marks. I spin axle and pull file into the axle to make my groove. I slide the file on the table so it hits the axle from the side then from the back.

I found a bad wobble was caused by not square file and then found my table wasn't square. No problems anymore.

 

[1reason]

I've had the wobble with the groove when I haven't gotten the groove square to the shaft. I put my axle in a drillpress and square up the table both ways (side to side and front to back). I lay a file on the press table alongside the hole on the table. I raise the table until the file lines up with the 3 crimp marks on the axle. Tighten the table and recheck that the file will still hit all 3 crimps marks. I spin axle and pull file into the axle to make my groove. I slide the file on the table so it hits the axle from the side then from the back.

I found a bad wobble was caused by not square file and then found my table wasn't square. No problems anymore.

Wow, that may be it!!! Thanks, I just heppened to check a couple of days ago and noticed it wasn't dead on (the drill press), but didn't think it would matter for anything. I bought a silver bullet and will use it to square it off

Thanks

 

[davet]

Just to clarify. First put a drill bit in the chuck and square the table to that. Make sure the bit is big enough (I use 1/4") just to make sure it doesn't flex when you put your square against it. Then put the nail/axle in the chuck.

As far as where and how big to put the groove I have found that the side of my file is just a hair wider than the group of 3 crimp marks. I set it so the file will take out the 3 crimp marks in one shot and that has worked well for us.

We use the stock kit BSA axles with axle head burrs and crimp marks. The diameter of the axle is oblong in the area where the wheel rides. They are .082 on narrow side and up to.091 on high side. They still ride smooth with a groove that is square.

***** The other problem I had with more of a very bad vibration that I never did get fixed was when I used the Revell axles. They were round, straight and had nothing to file off so I thought they were the ticket. I prepped 8 of those axles, some with grooves and some without. Every single one caused a very bad vibration. I tried ones without prepping too and got the same thing. Take the same wheel and run it on a BSA axle and smooth as silk. Didn't matter if I used the Revell wheels or stock BSA wheels with the Revell axles. I couldn't get them to run smooth without lube, with oil or with graphite. Good luck.

 

[Kinser Racing]

If you chuck up the pin supplied with the Silver Bullet and use the Silver Bullet as a square it is extremely accurate to square up your table. That's part of the versatility of it.

 

[GravityX]

+1 Kinser I agree with the versatility of the Silver Bullet, I use it often to square things up. Like checking the squareness of the rear axle holes using Silver Bullet and some extended axles. I also use it to square up the wood block onto the X-Y table on the mill, just to name a couple uses.

 

[Pacfanweb]

Don't know about everyone else, but I like those Revell axles if you can't buy some from DD4H.

The few I've used were straighter than the Grand Prix axles from the BSA store, and as mentioned, no crimp marks. They are shinier, so less polishing.

Used them on my son's car this year, it was easier polishing for him, and he won District.

No wobbles, so I don't think that just having the Revell axles is your problem.

 

[1reason]

I would guess this is not an issue, but with so many things, what I guess and what I'm told here are very different. I bought a axle straightener at Michaels and haven't really read much about them one way or another here. http://www.revell.com/pinewood-derby/rmxy8667.html

Anyone else use it, and what is the group's thoughts?

One thing I do know about the one I bought, if I try to taper the head by pounding directly on it (it's supposed to allow this I believe) the axle is ruined (100% failure) because the taper is uneven.

 

[Kinser Racing]

Go with good axles if you can. If you just can't. File the edges where the nail point is squeezed off. They'll chuck up much cleaner. Go to "How it's made" on Netflix or somewhere else and watch the nail episode, you'll see why there are raised points when they squeeze them off into a point.

 

[Guest]

+1 to Kinser and Pack fan.
The Chinese axles are way better than the American counterparts.
The American ones are all over the place in terms of being circular too.

 

[B_Regal Racing]

I would guess this is not an issue, but with so many things, what I guess and what I'm told here are very different. I bought a axle straightener at Michaels and haven't really read much about them one way or another here. http://www.revell.com/pinewood-derby/rmxy8667.html

Anyone else use it, and what is the group's thoughts?

I bought one 24 months ago. You can have it (really, I'll ship it to you) - I stopped using it 23 months ago. I just buy 50+ BSA axles and look for straight ones because I love the challenge -OR- you can buy axles from DD4H and be done with it.