Skipped Carve Area?

[flyingemt]

Has anyone seen anything like in this image? This was a simple test in pine to check sizing for flush mounting a couple of coins.

Symptoms:

1. Check Tracking Roller Error on measurement.
2. Board is 1/2" longer than programmed, 18 1/2" long, measured out at 16.845"
3. At 64% complete, I notice this skip


In researching, I can think that I need to elongate the mounting holes for the Brass Roller as I do have the rubber belts. Should this correct this as shown below?

Flying...

[bergerud]

Push the brass roller down with you finger and see how close to it comes to the rubber belt. If it touches, you may be right.

[fwharris]

How close is the brass roller to the belts when you have the head cranked down? It should not be touching the belts. In the belt install instructions the test to see is to place a sheet of paper between the roller and the rubber belts. Crank down the head on a board and see if there is any drag on the paper when you pull it out.

Was this measurement error just with this board or is it consistent on all boards?

Is the rubber damper spring under the brass roller bracket?

The skip looks to be a loss of contact with the brass roller. It could be an un even edge on the board, warped board, raised out feed trays.

[lynnfrwd]

Does the skip measure 3.5" from edge of board? Check feed tray height and add 7" to actual length of board.

[lynnfrwd]

Feed tray too high, it lifted board off roller.

[lynnfrwd]

Okay, I'm more asking then telling. I could be wrong.......

[liquidguitars]

Almost looks like the bit is slipping...

[Digitalwoodshop]

It's all about the Brass Roller... The board lost contact with the brass roller then moved the board in X until the brass roller finally gave the correct reading. BUT due to the los of contact with the brass roller the board moved out of position. Since the board continued to carve CORRECT after the board moved, that tells me the Brass Roller is working properly.

So now it comes down to one of the many reasons why the board lost contact with the brass roller....

The number one reason that the board looses contact with the Brass Roller is designing a project that lets the board be held by one roller at ANY TIME. Unless the board is being held flat to the table by both rollers it can tilt UP loosing contact with the Brass Roller.

The Tilting up can be caused by many reasons... One like posted above, the in or out feet table adusted TOO High causing the board to be Lifted UP off the Brass Roller.

The 7 inch Rule of Wood that the machine likes... Since the Cutting Bit is "About 3.5" inches from each roller, designing a project that leaves WOOD under the 3.5 inches is very important in my opinion.

As a side note... The bottom of the board where the Brass Roller rides needs to be good with no missing wood. That is where the use of masking tape helps, it gives the brass roller something soft to bit into and leaves a sort of rack and pinion on the bottom of the board.

So I see you designed the project and used a board with "Frugal" board use in mind... I design projects with a 4 inch DEAD area on the Right Side of Designer where I draw a box then place the artwork to the left of it.

When it comes to the actual board, sometimes I just use the source board for the 4 inches and after the project is done I cut off the 4 inch good wood and save it to cut a Bear Pattern to sell to Tourist. BUT I have been known to just use masking tape to add a Scrap Wood Blank to the end of the source board.

I also Always design my projects with Place on End... it saves Servo Time as Center Board measures the board twice..

Good Luck...

AL

Some ways I solve the FRUGAL Board Use in MY Favor. In the second to last picture I placed SCRAP wood on BOTH sides of the source wood to have the board held by both rollers. In the last picture I flipped the board and moved the scrap to the other end...