what's down with pocket cuts?

[Adrian]

I'm no expert on the Shark Pro but the basic design is very similiar to my old machine. Although it would move at 100ipm there's no way it would cut at that sort of speed.

I'd try a run at half the speed and/or as an aircut and see if it's ok then.

From the file you posted I'd say overlap percentage is very low for a pocket toolpath. I'd normally run at 40% rather than 10%. That wouldn't be causing you any problems other than the cutting taking a lot longer than it needs to.

[spinningwood]

Steve - The shark has stepper motors, not servos. This means that the shark doesn't really know whether the cutter is moving or not. It just assumes that it is. If something happens to stop the cutter from moving in a given direction you will lose steps which looks like it is suddenly offset by that number of steps (aka inches in your case).

The two most likely culprits in your case are

(a) the drive mechanism is binding (dirt on the lead screw or a failed bearing or something else. If this is the case you need to contact Tim Owens at Nextwave and figure out a solution.

or

(b) you mounted your project so that the area to be cut is outside the area the shark actually can cut. When it hits the max limit it will make a grinding noise and lose track of where it is. This will end up looking like it suddenly offset.

With respect to Dan's question about your cutting speed: You are running a 1/4" end mill at 100 ipm with a 0.03" depth of cut and a 0.025" stepover. I run with a 100 ipm setting and much more agressive cuts without any problems on my shark. I don't see why yours would be less capapble, but Dan's suggestion to try a slower run as a test is a good one. If the problem goes away at a slower speed with a 0.03" depth of cut and a 0.025 stepover then either you are using a really dull cutter or something is wrong with the machine. In my opinion anyway.

Since the problem seems to be getting worse, it sounds like some sort of machine problem rather than something you are doing. You can get Tim's contact info off the nextwave website.

Ed

[Tony Mac]

Ed, Thanks for your reply. It's an ongoing problem. I chose a simple project that stopped also. It's also in Vcarve tooling now. Not just pocket. It's my 1st attempt to send a file. So I guess I didn't send everything. Let me retry. Sorry for the mix-up scramble communicating.
Also about "noise" yes, it makes a noise. Meaning when it stops, heading into the 2nd pass, it hums while stopped for approx 5 seconds then changes it's bearings. Stays on the same course, but offset by inches off. HELP!

Steve,

Sounds like a mechanical issue and I would recommend talking with the manufacturer,
or discussing this issue on the CNCShark Forum > http://www.cncsharktalk.com/

Tony

[kauffwoodproducts]

Thanks Adrian, I've done an Air run. Awhile ago. I'm thinking it's could be mechanical with the sharkpro. I'm going to start at a different point. Stay away of the area I think. See if if runs problem free, like it should. Run something small I guess.
I'll keep posting with any new details.Thanks, Steve

[kauffwoodproducts]

Thanks, Ed and Tony. You guys beat me to it. I'll give Nextwave a shout. ..Steve

[kauffwoodproducts]

It must be a faulty bearing. I grabbed the pause button when it stopped and humming. went out of program and back into control panel, moved the router down the X+ path and caught the noise again. It's mechanical. Problems that are hit and miss, are for the real pros. Thanks for everybody's help. With everyone's ideas, helps bring on new directions to solving problems! ...Now to get on the phone with Nextwave.

Also sending a vid clip might have been to easy. But could that ever be a option? ..course not youtube, that wouldn't be right for sales. But someday on this forum?

Steve