Help on Ruff edges

Michael Vendryes · Post by **Michael Vendryes** » Tue, Apr 03 2007, 3:38AM

I'm very new to the cnc world and recently had a couple of book cases made as test pieces before going on to build for customers, when I received the pieces back all the edges were very ruff and hairy and I had to sand them all down, is this normal?
any suggestions?

Mark Hesketh · Post by **Mark Hesketh** » Tue, Apr 03 2007, 6:06AM

what type of cutter bit are you using? upcut? downcut? if you are using a downcut, you may find the bottom edge turning out rough. if you use an upcut, the top edge will be rough. we use a combination up-downcut bit and that gives us the best edges.

another place where you might get rough edges is if your part overhangs your spacer board at all. if the cutter bit is cutting the material where there is nothing underneath it to support that edge, it can give you a rough edge.

hope this helps

Ryan Hochgesang · Post by **Ryan Hochgesang** » Tue, Apr 03 2007, 7:52AM

Michael,

As Mark has mentioned, type of cutter will make a differance in the cut quality; cut feeds and speeds can also have some affect on the quality of cut. If a cutter has excessive wear and is dull, this could also be another factor.

David Hall · Post by **David Hall** » Tue, Apr 03 2007, 12:22PM

In addition to the other excellent cut quality suggestions, this is the \"Normal\" result of climb cutting many veneer core materials.

\"Suggestions?\" ... yes, See your Private Messages

Regards,
Dave

Rob Davis · Post by **Rob Davis** » Tue, Apr 03 2007, 3:40PM

Dave, if their private messages have the answer, why not tell all of us?

David Hall · Post by **David Hall** » Tue, Apr 03 2007, 4:58PM

Rob,

The \"answer\" is to not climb cut VC material.

My \"suggestion\" was non-technical and less than complimentary so I chose to keep it out of a public discussion.

Regards,
Dave

Forrest Chapman · Post by **Forrest Chapman** » Tue, Apr 03 2007, 7:35PM

As David suggest conventional cutting will leave more and more fuzz as the bit loses its edge. While the downside to cutting conv. is when the bit leaves an lipped edge on skinned parts. Hopefully Thermwood will help us resolve this issue by allowing a roughing pass or multi directional outline cuts. I hope you get your problem figured out.

Forrest

Ps. David, are you as crazy busy as I am? I haven't seen you on the forum lately.

David Hall · Post by **David Hall** » Wed, Apr 04 2007, 8:12AM

Hi Forrest,

I believe you meant to say climb cutting will leave the fuzzy edge.

Yes, we're very busy. Busy is good; but doesn't leave much time for the fun stuff.

Regards,
Dave

Forrest Chapman · Post by **Forrest Chapman** » Wed, Apr 04 2007, 8:48AM

Dave,

Thanks for the correction. Yes, no fun stuff here either.

Forrest