Poor carve quality, ideas of what the problem is?

[dehrlich]

I am having a problem with poor carve quality on some stuff. See the attached pic. That is on "best" with a new bit on hard maple. It should be carving a lot smoother than this. I'm using a 1/2" rock chuck, bit is tight, doesn't seem to be slipping. Everything seems to run smooth and quiet. Need some ideas of what to check. Calibration maybe? I would appreciate some help here. Thanks!

68519

[bergerud]

My first thought is z rollers. Ether dust under them or in them or too loose or to tight. Next would be dust in the z belt and sprockets.

[mtylerfl]

My first thought is buy a CarveTight spindle. ;)

Seriously, Dan made some good suggestions. Hopefully it's something simple like that. AL may follow-up with more. He uses the Rock himself and may be able to give you some more tips.

[fwharris]

It is hard to tell what your project is but I do see some cross lines that look to be evenly spaced down the board. Did you set bit optimization? How are carvings on other woods? It might be just the nature of that piece of wood.

As Dan said start with checking the Z bearings. Also check the compression rollers and your drive belts (sandpaper or rubber) for any dust build up.

[unitedcases]

I am having a problem with poor carve quality on some stuff. See the attached pic. That is on "best" with a new bit on hard maple. It should be carving a lot smoother than this. I'm using a 1/2" rock chuck, bit is tight, doesn't seem to be slipping. Everything seems to run smooth and quiet. Need some ideas of what to check. Calibration maybe? I would appreciate some help here. Thanks!

68519

I've had a dull bit do this. Almost like it grabs in spots and let's itself go in spots. Dirt can get back on the Y rather too and hide around the dust sweep area too. Looks like it should sand right off though.

[FWMiller]

Mine does that but I believe it's because I don't have good dust collection set up yet. If I am able to babysit the carve and stop and vacuum a lot it mostly goes away. I think in my case it's from dust getting stuck in the z pulleys teeth. I've had the exact same carve come out perfectly flat on the bottom and the next one bumpy and the only difference I can determine is how clean the machine is.

[cnsranch]

Take a close look at your Y roller bearings - mine were just a tad loose and I was having problems.

[cestout]

I was going to say check the rollers, but I would look at the Y rollers. Grab the base of the bit and try wiggling it. Use you 12mm flat wrench to adjust the roller cam.
Clint

[dehrlich]

I checked all the rollers, lubed the rails and blew everything out. As mentioned the bit is brand new. Question; would a cut motor that is on it's last legs cause a vibration that could be translated to the bit? I haven't tried another actual carve to see if it's the same... since I didn't find a problem I assume that I may have the same issues...

[mtylerfl]

Vibration 'from the cut motor' could possibly be something amiss with your flexshaft core. Have you had it out recently? Fairly common for folks to not re-insert properly - not saying that's you, of course, but worth asking about "just in case". Check to be sure the core is fully engaged at both the cut motor and spindle ends and that the ends are not worn which could lead to "bad spin" of the flexcore. Might also check the overall condition of the core by doing the "twist" test (video is in the CW support section of the website).

[fwharris]

I checked all the rollers, lubed the rails and blew everything out. As mentioned the bit is brand new. Question; would a cut motor that is on it's last legs cause a vibration that could be translated to the bit? I haven't tried another actual carve to see if it's the same... since I didn't find a problem I assume that I may have the same issues...

Have you tried a test carve on some scrap wood to see if this repeats? Maybe even a test on the same piece of wood also to compare to. I've seen different carve quality results on the same type of woods before.

[lynnfrwd]

Sometimes it's not the machine, but the project. Good to rule that out.