cutting pattern out not working

[bamaman315]

While cutting out pattern the with cutting bit the bit is making stair step cuts what causes this?

[cestout]

If you are cutting it in several passes, the tracking is not precise.
Clint

[AskBud]

While cutting out pattern the with cutting bit the bit is making stair step cuts what causes this?Without seeing the MPC, it's not easy to give firm advice.
That being said, it could be how the machine sees the ends of the board or how the brass roller tracks on the wood. Combine these things with the hardness or slickness of the wood and the sharpness (or lack thereof) of the cutting bit. Many times we use the "Max-pass-depth" setting to ease the pressure on the cutting bit, which can eliminate the stepping (if it is just a pressure issue). The harder the wood the more you need to consider the max-pass-depth usage.

Again, seeing the MPC and a photo of the board involved could really help with the best solution(s).
AskBud

[TerryT]

If the stair stepping is on the ends of the board the two most likely scenarios are;
1. The board is loosing contact with the brass roller due to cupping, bad edge or warping.
2. You may not be using the 7 inch rule and your board is comming off the brass roller as it moves end to end during the cutting pass.

[lawrence]

If you are cutting it in several passes, the tracking is not precise.
Clint

I'm not sure what you're saying here Clint-if you are saying that the machine tracking isn't precise, I use multiple passes all the time and it works great for me. I do, however, always use jointed boards, tape, and an extra 8 inches. Bamaman, maybe your machine needs to be calibrated.

Lawrence

[bamaman315]

How do I calibrate the machine? I have another machine and it cuts out fine, the pattern is the coin bank from the carvewright store.

[bergerud]

If your board is not slipping and your bit is not dull, then you must have something mechanically wrong. Defective tracking sensors seem to be rare. I would take a look at the x drive system. You may have a missing tooth on an x drive gear or the x drive might be bogged down with sawdust in the rollers. There have been many posts on this problem. Maybe you should data mine the forum with a search for "stair stepping".

edit: check for a rolled over sandpaper belt near the brass roller.

[cestout]

Lawrence,
What I am saying is that if the roller slips even a teeny bit (the O rings do ware) then subsequent passes will not line up with the first.
Clint

[Digitalwoodshop]

OK, everyone is correct..... And "It's All About the BRASS ROLLER"..... IT is loosing contact with the board during the cut and causing the stepping. Since I own Stock in a Masking Tape Company I really push everyone to place a strip of masking tape on the under side of the board where the brass roller makes contact. This gives the Brass Roller something to BITE into and makes the board and brass roller into a sort of Rack and Pinion....

SO things that can make the board loose contact with the brass roller....

1. Too Short of a Board.... IF at any time the board comes out from under the rubber roller it can tip UP and at that moment loose contact with the brass roller. Since the machine is doing a Multi Pass Cut Path.... It is moving... So the board will keep moving until the brass roller catches again and the Brass Roller Encoder reads the correct number.... But since the board was moving and the brass roller was NOT.... The the difference is Stair Stepping.... IF you plan your project with 4 inches of WOOD on either end of the carved or cut area then the board will be held down by both rubber rollers flat to the table and the brass roller will NOT loose contact by not tipping up. I have even used masking tape to add 4 inches of dead wood to the end of the board..... See Pictures.... I use Place on END for my projects and plan for a 4 inch blank area on the right side of designer AND I leave my boards LONGER.... and cut them off later... That keeps the rear roller under wood....

2. A Rolled Under Belt, under the Muffler side, at the Brass Roller.... This is VERY hard to SEE.... And will raise the board up OFF the Brass Roller by doubling the belt... I cut a 3/4 inch strip of belt away at the brass roller and see silver. Works GREAT.... No Silver... Rolled up belt....

3. A missing area of WOOD on the Brass Roller Edge of your Board....

Good Luck,

AL

[lawrence]

Not sure how to calibrate.... never had to do it. I do hear folks mention it though. I think the others with more experience are probably spot on with it being that something is affecting the roller

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[bamaman315]

Ok I did a compairision with my other machice, the problem starts from the measurement of the board, the board is supposed to come out from under the rear roller to measure the board , that is whenn I am getting the possible board removal error message. does anyone one have a fix for this?

[AskBud]

Ok I did a compairision with my other machice, the problem starts from the measurement of the board, the board is supposed to come out from under the rear roller to measure the board , that is whenn I am getting the possible board removal error message. does anyone one have a fix for this?This would indicate that the board needs more support that the outer roller can handle (probably it's longer than 24 inches) or it has a ding on the bottom where the brass roller makes normal contact. If it tiltrs away from the brass, it aborts! many times all you need is an exter set of support rollers.

Needless to say, the board should be free of dings, warps, and such. Masking tape along the path of the brass roller is also a good idea.
AskBud

[bamaman315]

that is the first time I have had this problem and the board is 24 inches long , I will try puttting a support roller and try it again, i will let you know the out come. I am carving same pattern in my other machine and it is work fine.

[bamaman315]

I tried that same problem as soon as the board comes out from under rear roller it gives me the message

[AskBud]

I tried that same problem as soon as the board comes out from under rear roller it gives me the message1. Try a different board.
2. If that fails, I would check to see it the traction belts and support rollers, on the machine are level. Lay a flat bar (ruler, clamp bar, long level, etc) on the belts and roller wings to make sure everything is in contact.
AskBud

[bamaman315]

bud wouldit be ok if I gave you a call?

[AskBud]

bud wouldit be ok if I gave you a call?Check your private messages.
Bud