Does not cut parallel to squaring plate

[dbfletcher]

I started to design a cut some pieces for a video arcade cabinet and in the process I have discovered that my machine doe not cut true. I took a piece of .75 x 11.25 x 48" MDF that I verified was prefectly square and true to start. Then I drew to parellel lines lengthwise on the board at 5" and 4.75". I used the 1/8 straight bit to cut a .10 in groove at 4.875" on the board. The groove was appox. 1/8" off from one side of board to the other. Am I expecting too much of this machine? Is there a simple adjustment that can be done to true this up? I have attached my project if any of you care to run it on yourmachine and report your findings.

According to the specs of the machine on the website, it seems it should be far more accurate that this. Any suggestions would be appreciated. This is my fourth machine since June. The first three died with Z stall errors after a few hours of carving. The fourth also did that but I sent it back to the factory for repair instead of returing to the store for replacement. It has been carving fine since I recieved it back, but this accuracy thing is causing me greif now.

[Digitalwoodshop]

I had a little trouble when I cut this project and it ended up being worn sand paper belts.

Try it with new belts. You can always use the old one's later if it turns out to not me that.

Also I found loading the board that I sometimes had the board 1/8 of an inch away from the front guide near the keypad. I always place my finger tips to feel this gap front and back. A board starting out 1/8 of an inch out does strange stuff.

Also put masking tape on your board where the brass roller hits.

Good Luck.

AL

[dbfletcher]

I forgot to mention.... I first noticed this problem when I was performing the joining function on a board. I knew the board was perfectly square, but the 3/8 bit would cut pretty deep on one side, and either just skim the other side or not hit the board at all.

[dbfletcher]

Using the terminology on page 14 of the manual.... if it slide the guide place as close to the squaring place as it slides, the distance between the two on the right side (front) is 1.46". The distance on the left side (rear) is 1.52". Could this be the cuase of my problems? Can someone measure thier machine and see if theirs are dead parallel... or is .06 reasonable and not the cuase of my problem.

[dbfletcher]

Can anyone measure there machine and let me know??? Is your guide place perfectly parallel to the squaring plate or is there a variance?

Thanks,

Doug

[BobHill]

Since the sliding "guide" really isn't a true guide and shouldn't be so tight to the wood that it can bind the travel, that's not as important as having the head perfectly perpendicular to the inside wood true guide. That's what should be measured. Place a true square against the inside guide, lower the bit to just touch the square and move the head across to see how true it is. That should work for you.
Bob

[dbfletcher]

Excellent suggestion. I did as you suggested. The head is pefectly perpendicular to the squaring plate. One thing I did notice.... and I know the slide plate should not be so tight that it causes drag, but when I feed a long (6ft) board from one side all the way to the other, becuase I have that .06 gap on the left side... the board starts flush to the squaring plate... but after it is moved back and forth... it migrates over to the slide plate on the left side and is no longer directly against the squaring plate on the left. The right side is both agsit the slide plate and squaring plate. I guess that makes sense becuase it was the smaller measurement. So does that mean the sand paper tractors are not pulling the board thru the machine perfectly perpendicular to the cutting head? Are there any adjustments that can be made?

[BobHill]

Your long wood sliding might well be due to the belt not running true. Have you been having any problems with the belt folding under on either side of it's drive rollers? If so, you need to true the rollers (check the manual for this). That's what it looks like to me.
Bob

[Jeff_Birt]

With long stock you care going to need some axillary out feed rollers to help support the stock. Also you need to properly adjust the out feed rollers on the machine itself. If they were too high in the front that would encourage the stock to work to the back.

[dbfletcher]

Thanks. I do have aux rollers. But I typically don't use long stock. I first noticed the problems on a 20x10x.75 peice. I just used to long stock to more clearly prove the problem to myself. I have looked thru the manual and troubleshooting guide, but I don't see where that talk about trueing the rollers. Do you happen to have a page reference?

[dbfletcher]

I read the pdf for replacing the traction belts and this paragraph caught my eye:

Before you tighten the screws on the sliding plate put a board in the machine that you know has parallel edges. Slide the sliding plate up against it then tighten the screws. This just makes sure that your sliding plate is parallel to the squaring plate.

I loosened the screws, made sure the guide plate was parallel to the board, put my straight board back in and ran the project again. Guess what!!! No more drift! So it looks like at least part of the problem as indeed that the guide plate was not parallel to the squaring plate.

Now my only concerns is that I watched the right belt very closely while it measured the board. When the board travels left to right, the belt slide towards the front of the machine. When it travels right to left, the belt slides to the rear of the machine. Over the lenght of this 6ft board, the belt slide appox. 3/16 of an inch. Is this something to be concerned with? Search the forum, it seems other people had this issue, but it didn't look like it was user correctable. Thoughts?

[BobHill]

Did you try the Built in function for Jointing and Squaring (p. 21 of CW manual)?
Check the CarveWright manual: p 37, Check Sandpaper Belts for Tears or Roll-up. note the belt alignment with the Squaring plate (wear marks also should show travel angle). Do a Search and somewhere you should find a PDF on changing the sandpaper belts. There is a chance that the rollers aren't reseating properly with their springs.
Bob