What causes this?

[jonathan68]

I found that if I have to carve several circles in a row - they always end up like this? I don't know if it's just when I do this type of carve or if it's just more apparent? As you can see the cutout shape become oblong and they don't carve out centered? It gets worse as you move down the line?

I just calibrated the machine a few days ago. I'm using the heavy duty rollers and the Rock chuck. I'm carving in MDF.

Any thoughts?

[dbfletcher]

Are you using maskingtape ont he bottom on the brass roller side? MDF is pretty slick and hard, so the masking tape will greatly help the brass roller get a good "grip" ont he board as it passes.

Doug Fletcher

[jonathan68]

Actually, no. I have read about that but never seemed to have a problem before. Can you use painter tape? Do you line it up on just the bottom edge leading up the board edge?

[AskBud]

I found that if I have to carve several circles in a row - they always end up like this? I don't know if it's just when I do this type of carve or if it's just more apparent? As you can see the cutout shape become oblong and they don't carve out centered? It gets worse as you move down the line?

I just calibrated the machine a few days ago. I'm using the heavy duty rollers and the Rock chuck. I'm carving in MDF.

Any thoughts?

sorry, but the picture of the carve does not match the designer image.
(look at the stud position on each view) They are not in the same position as they are in the design.
The ones in the photo of the bad carve are all moved to different positions in the circle. This is not so in your posted design.

My guess is that you need to re-load the design to the card.
Also, make sure that your actual board is at least 7" longer than the design board and "Stay under rollers".
AskBud

[cnsranch]

Doug's right for sure.

MDF is slippery, and since the cut out's done last thing, the machine's losing track of where the overall carve is.

Masking tape along the key pad side will help, but I'd use tape under the whole board (MDF can slip on the belts, too).

Bud's right about the ptns not lining up, that's a weird one - I'd guess he's right about the 7".

BTW, you may want to take 3 passes on the cut-outs - shown below - not so much with MDF, cause it is somewhat "soft", but you do take the chance of breaking a bit cutting thru .75" in one pass...

[jonathan68]

Carving with the painter's tape now on the front edge. Ever since I upgraded to the heavy duty rollers, I've had no problems with the board slipping but it makes sense that the brass roller would.

I have the cutout and the mpc right in front of me and don't see any difference? Outside of the poor alignment. . .

Jonathan

[dbfletcher]

Carving with the painter's tape now on the front edge. Ever since I upgraded to the heavy duty rollers, I've had no problems with the board slipping but it makes sense that the brass roller would.

I have the cutout and the mpc right in front of me and don't see any difference? Outside of the poor alignment. . .

Jonathan

I think what Bud is refering to is that in your MPC the pins/studs (whatever you want to call them) are all at 12,3,6,9 oclock positions. In the picture you posted, it looks like the circles may have been rotated after you carved this.

Thanks,

Doug Fletcher

[jonathan68]

Oh, lol

I actually popped them out and put them back in for the photo. They were right to begin with. Sorry about that. . . .

[cnsranch]

That was gonna be one of the great mysteries :mrgreen:

[jonathan68]

Do you guys use painter's tape? Does something else work better?

[cnsranch]

As Al Who says - bottom shelf, cheapest you can find, etc.

Beware, however, that the cheapest isn't the stickiest - sometimes I have to double it up - not a bad idea anyway, gives the roller more grip.

[Digitalwoodshop]

I think everyone hit the nail on the head... The Brass Roller slipped when the board moved to the new location....

I use bottom shelf cheap painters masking tape.... Blue Painters tape is more expensive. You just want to give the brass roller something to bit into.... The Smooth wood is the problem....

AL