one wavy line of text on 3 line carve

[Wood Art 1]

The last line to carve on these plaques wanders above and below the line. Centerline. plaque is 8" tall x 5.5" wide. Using a Bergerud fixture so all that pieces are a precut size. The "May 3" were the last two to come off the CW. The other 8 came off last week. I have about ten examples with the same font and layout that came out OK inbetween last week and the May 3 cuts. Driving me totally nuts - it's only a short drive.
Is this a font style issue?

[bergerud]

That is curious. They are off in the same way. I wonder what the cutting order of the letters was. I this 1.187?

[Wood Art 1]

version 3.1. This is the last line to carve. The 0 is first, M is 2nd. 2 is third...walked away frustrated at that point.

[myshop1044]

Jerry it looks like the wood is moving, is it tight in the jig?

[bergerud]

Jerry it looks like the wood is moving, is it tight in the jig?

Perry may have a point. The board is only under one roller when the text is cut.

Jerry, do you have sand paper grip strips on the rails?

You might also check the head pressure.

[Wood Art 1]

Dick, I lubed the guides and got the pressure to 75-77 lbs. the fixture will not move in the CW until I crank up the head when removing the fixture after carving. I will do another test and hold my hands on the fixture and belts to determine if there is any slippage. The Plaque does not come out of the fixture until I loosen the side clamp. I will try some more tests with the attachment @ .51, .52 etc to see if it continues. I will try another font at .5 attachment and etc. to see if it continues. I have about ten examples of the same font at .7 attachment that all came out straight, between the United States and the May 3 examples.

[bergerud]

You know, my theory of poor tracking has to do with vibration confusing the tracking encoder. It is very hard to test as it would only happen for certain resonant frequencies. I bet the UHMW transmits vibration to the tracking roller more efficiently that wood does. I wonder, as an experiment, if you could try a few more layers of masking tape.

[bergerud]

I was thinking of embedding a strip of hard rubber under the base rail for the tracking roller.

You know, with your repeated runs of the same project, and since you already have the clamping, you should consider the procedure:

http://forum.carvewright.com/showthr...253#post249253

[Wood Art 1]

Dan, my apologies for hijacking your fixture. Have used this fixture for about two years. Replaced the bottom rails once and sanded them smooth to eliminate tracking roller groove a couple of times. Always use masking tape. ALWAYS tighten side to prevent slippage. Only use the end stop when board length gets close to 19" max fixture length. If the 8" plaques are all cut from the same board - I set the board into both ends of the fixture to set the base fixture width to match board width. Then I set the top of the board slightly less than 1/8" proud into the fixture, using a handmade gauge - setting the board at both ends to tighten the rails. Move the board to the center - approx - and squeeze the board into the fixture.
The wingnuts at the bottom of the fixture prevent the bottom from squeezing in. Only the wing nut in the rails is used to tighten the piece into the fixture. Approximately one turn tightens the board.
Therefore every board that goes into the CW gets measured by the CW.

[Wood Art 1]

Dan. no evidence of belt shift. and since in most cases prior to these tests, I had a line 2 at the top and two more lines of text (same font) at the bottom of the plaques that ALWAYS turn out OK. Hard to believe that It would only screw up on the last line. Top of board may still be a factor.
Still love the UCB concept, even if I don't use it right. I haven't put a board on the belts in months. When you were first working on the design a couple of years ago, I picked up the concept. As I mentioned I've replaced the bottoms with Ultra-High Molecular Weight Polyethylene UHMW. I still use masking tape. Be interesting to see if these pieces survive the brass roller better. I've seen UHMW pieces 8"x8"x1" used in conveyers get folded to 90 deg and when they return to the inspection port, they are straight again. Tuff stuff!
Thanks Jerry.