Bumps on profile cuts

[CNYDWW]

By the way, what brand bit are you using? I've used the same style and size bit before and had the exact same thing happen. It was a cheaper bosch bit.

[asteude]

It's a Bosch bit, wouldn't you know it.

What do you use instead?

[shoeshine]

Andy, I would definately recommend getting bits that are designed for CNC. if your tolerence is tight. They have slightly different geometry than plain old router bits for general woodworking. There are plenty of brands out there (different people swear by different companies) Centurion, Amana, Onsrud are ones I've had good luck with.

[beacon14]

Always worth checking the simple stuff first. Also check that the pinion gear is on the shaft tight if you have play in only one axis.

[asteude]

Thank you all for your input! I'll post when I get a chance to implement all of these tips and get some results.

Andy

[CNYDWW]

It's a Bosch bit, wouldn't you know it.

What do you use instead?

I don't usually do to much more then a typical 1/4 or 3/8 dia spiral bit will handle so i actually usually just run to lowes and pick up the very same bit. Let the other guys that run into this more often give you recommendations. Onsrud is always a good choice however.

[asteude]

Andy, I would definately recommend getting bits that are designed for CNC. if your tolerence is tight. They have slightly different geometry than plain old router bits for general woodworking. There are plenty of brands out there (different people swear by different companies) Centurion, Amana, Onsrud are ones I've had good luck with.

I found a Whiteside bit that'll work. The part #'s for their CNC bits appear to start with "C" and are otherwise the same as the handheld router bits. So, the bit I ordered, C1072, is the CNC equivalent of the regular 1/2" diameter, 2" cutting length, 1/2" shaft bit with part #1072. I found the best price on www.carbideprocessors.com.

[jerry_stanek]

Hartville tool gas a Whiteside 1072 for $22.19 with free shipping. I am not sure if you can join the router bit club that after you purchase so many bits you get to choose a free one. I belong but I go to the store and pick them up.

[asteude]

Hartville tool gas a Whiteside 1072 for $22.19 with free shipping. I am not sure if you can join the router bit club that after you purchase so many bits you get to choose a free one. I belong but I go to the store and pick them up.

That's a great price for that bit! I don't see the CNC version on their site though (C1072.)

[asteude]

I made the following changes:

1. Climb cut first followed by conventional cut
2. used onion skin instead of tabs
3. got rid of leads and used spiral plunge instead
4. used a specialized CNC bit (Whiteside C1072)

I didn't tighten the step motors yet. I may still do that if I run into problems down the road. For now, I'm a little worried about overtightening them.

The first cut I tried was perfect... until the part broke loose because the material thickness was off and I cut all the way through the material. I'm now changing the "onion skin" to, perhaps, an "elephant skin" to be able to absorb a little variance in material thickness.

Thanks for your help, everybody!!

Andy