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SpiffyDog
05-19-2007, 11:23 AM
I created a sign that is 10" x 23", with a 90 degree V edge route set to .375" deep. After each pass, the bit would go a little deeper, as expected. However, the measurement of the board on each pass was off by about 3/16" on the length. It's as if the whole board would shift 3/16ths after each pass. I also keep the machine vacuumed during machining to keep the debris from causing any interference. The pictures are of the edges at each end. Any ideas before making the call to CW support?

DocWheeler
05-19-2007, 11:32 AM
Spiffy,
It sure seems like the machine is losing track of where it is, how long is the board you are carving? Is it "rocking" a little as it travels from one X extreme to the other? Or, is there a Cup in the board that would allow it to "skim" the sensor?

What part of the State of Ohio are you?

Ken

SpiffyDog
05-19-2007, 11:40 AM
Ken,

The actual board is 31" x 11 1/2". The design board is 24" x 11 1/2". The sign outline is 10" x 23". The board is poplar which was planed prior to machining. Also, the extension panels are level with the drive belts. As I was observing this, I thought I would attempt to "manually adjust" while it was on the last two passes by applying a bit of pressure (pushing) in the direction of offest. This did not affect the cut path whatsoever.

I'm located in Circleville, which is about 20 minutes due south of Columbus on SR 23.

Keith

DocWheeler
05-19-2007, 12:27 PM
Keith,
While eating a bite of lunch, I realized that my first thoughts were off-base since it does the same thing on both ends. My next thought was that it was thinking that it had a "different" angled bit than it actually had, but since the corner in the Y direction starts off right - that can't be the problem.
The only thing that now makes sense to me is that the X position sensor got progressively looser as the carving progressed. But that increase each time would have been 3/8" which would be way too much for what I was thinking.
But, somehow the board is moving in the X direction without sensing it. Since the error seems so uniform, it must be something mechanical rather than random "skipping". My... I got to rambling.
Be sure to post the cause and solution when you get it figured out.
Seems you are the closest to me of anyone I've found so far.

Ken

SpiffyDog
05-19-2007, 03:21 PM
Ken,

That is a great assessment. This is quite frustrating as I had planned on spending my weekend filling a few orders on home signs and now that plan's shot. I had to change plans and get out and mow the lawn, which is good therapy, since it takes me about 4 or more hours to do. After thinking about it a bit (cooling off period), I'm now off to take a peek at the machine. Not sure what to look for but I'm going to peek anyway.

I looked on the map to see where Waynesville was. I was close to your area many times as my daughter attended Miami U and the drive over took us close.

Keith

DocWheeler
05-19-2007, 03:49 PM
Keith,
If the raster carving still works OK you could still do the signs, just cut them out with another tool.
Also, I PM'ed you.
Hope you can get this resolved.

Ken

John
05-19-2007, 04:28 PM
On the beta machines there is a little brass roller between the feed trays on the control side of the machine. It is the board sensor (I think) and keeps track of where the board is. It needs firm contact all along the edge of the board to give consistent results. If the bottom edge of the board has any defects, ie. knot hole, etc. the readings will be off. On the beta machines the spring wasn't strong enough to get proper pressure against the board and a small piece of rubber tubing was used as a "shock absorber" to increase the pressure. I had similar problems you are describing when I replaced my feed trays and didn't put the little piece of rubber hose back in place. It was laying on the workbench when I got everything back together, but I hadn't a clue where it came from.

Hope this helps a little as I am sure there are probably a number of other things that could be causing your problems.

SpiffyDog
05-19-2007, 06:13 PM
I had similar problems you are describing when I replaced my feed trays and didn't put the little piece of rubber hose back in place. It was laying on the workbench when I got everything back together, but I hadn't a clue where it came from.

Hope this helps a little as I am sure there are probably a number of other things that could be causing your problems.

John,

What rubber hose are you specifically talking about on the feed trays? I've had to replace the belts twice but do not remember seeing anything like that. But that doesn't mean that I somehow lost them.

I did examine the brass roller and it does have the rubber ring as mentioned. It appears to be OK as it's does not seem loose. I also took a board 47 inches in length and had the machine measure it several times, each time positioning the board in a different location. The measurement was always within .01. However, this is not really a good test since the board is not moving back and forth. I'm sure that the machine finds the end, sets the X position and then finds the other end and calculates the distance.

Keith

Kenm810
05-19-2007, 06:17 PM
Keith,

I seem to recall a few posts referring to the step action a little similar to your problem. I'm not sure if this will help. but it sounds close. Search for Jon Jantz's post 1-02-07 "cut path problem"

SpiffyDog
05-19-2007, 06:33 PM
Keith,

I seem to recall a few posts referring to the step action a little similar to your problem. I'm not sure if this will help. but it sounds close. Search for Jon Jantz's post 1-02-07 "cut path problem"

Ken,

Thanks. After reading that post, I'm a bit intrigued about the board roller sensor. Although the piece of wood I was working with had enough material to stay under the rollers, the piece was long enough that it could possibly affect the roller pressure. I did find that one of the fold out trays came out of adjustment and was a 1/16" lower than the board. I'm not sure if that is enough to cause this problem but I'm going to re-adjust and try again using a test piece.

A project for tomorrow...I'll keep everyone posted on the results.

Keith

Kenm810
05-19-2007, 07:21 PM
If you get a chance check the "O" ring, It probably is not the case but few of the guys had damaged to the "O" ring or lost it altogether while carving a project.

Board Tracking sensor=brass roller left center.
It should have an O-ring captive and be springy up-down

John
05-19-2007, 09:35 PM
If you get a chance check the "O" ring, It probably is not the case but few of the guys damaged to the "O" ring or lost it altogether while carving a project.

Board Tracking sensor=brass roller left center.
It should have an O-ring captive and be springy up-down

I would say it should be a "stiff" springy. The little piece of rubber tubing is/was 1/4 inch o.d. tubing about 1/4 long placed on end under the "hinge" that holds the brass sensor. Probably/hopefully the compucarve spring was upgraded so the "shock absorber" isn't needed.

SpiffyDog
05-20-2007, 06:59 AM
I would say it should be a "stiff" springy. The little piece of rubber tubing is/was 1/4 inch o.d. tubing about 1/4 long placed on end under the "hinge" that holds the brass sensor. Probably/hopefully the compucarve spring was upgraded so the "shock absorber" isn't needed.

The O ring is there and I checked it for nicks. It looks good. Also, as pointed out, this sensor is firm but flexible. It didn't seem to have a spring, though.

SpiffyDog
05-20-2007, 06:26 PM
So, after adjusting the fold down support trays, thoroughly cleaning the machine, checking the brass roller and O ring, etc, etc, etc...I tried the same sign project as before, but this time I only did the outline to save time.

Drum roll............Same thing. Rats! :mad:

So...I'll be calling support tomorrow. Maybe they have something up their sleeve.

benluz
05-21-2007, 07:12 AM
I created a sign that is 10" x 23", with a 90 degree V edge route set to .375" deep. After each pass, the bit would go a little deeper, as expected. However, the measurement of the board on each pass was off by about 3/16" on the length. It's as if the whole board would shift 3/16ths after each pass. I also keep the machine vacuumed during machining to keep the debris from causing any interference. The pictures are of the edges at each end. Any ideas before making the call to CW support?

Hello,did you use the v-bit for the whole carving?.I'm not sure if the cw supports Mutilple pass v-bit carving at this time.
Ben

SpiffyDog
05-21-2007, 07:30 AM
Hello,did you use the v-bit for the whole carving?.I'm not sure if the cw supports Mutilple pass v-bit carving at this time.
Ben

Ben,

The project required the V bit to carve down .375" and then do the cutout. At the start of the project the machine asked for the cutting bit and then the V bit. I stopped the project before it got to the point it needed to cutting bit.

It's interesting that you mentioned that, though. After looking back, the V bit did carve down deeper than it should have. It never requested the cutting bit. Hmmm?

Keith

Jeff_Birt
05-21-2007, 07:59 AM
There are a few other things that you might try.

#1: Construct a square in Designer, say 6" on a side and use the cut out tool, do you still get the same 'stair step' effect? This is just a simple test of a vecotr cut.

#2: Check your down pressure, do a quick search for specifics, I think that when you place bathroom scales under the rollers you should have #80-90.

Charles M
05-21-2007, 08:19 AM
Keith,

For longer boards I found that I have to use roller stands to augment the built-in supports or I get the same stair steeping effect. Seems the board is not held down on the roller when the board is at one end or the other and the machine can't measure the location properly. Also, I just sent my machine in for service because it was cutting too deep like you describe.

SpiffyDog
05-22-2007, 05:50 PM
I went back and designed a smaller sample as Jeff suggested. The design did have some arcs and corners as the original pattern had. I ran the project and all went well. :) At this point, I can only think it could be two possible reasons: 1) the board needs extension rollers to offset the weight, or 2) there is a measurement problem on an extended length cutout design specific to my machine.

I'll need to get a bathroom scale yet to check the roller pressure. So, for now, I'll try the original project again using extension rollers, as suggested, and post the results. Thanks everyone for your help so far.

Jeff_Birt
05-22-2007, 09:31 PM
Strange, I had something similar to this tonight on a two sided carving. I had a 27" x 7.5" project (in Designer) on 3/4" MDF, cut on a 4' piece of stock (support by a roller stand). The back side went fine and the raster portions of the front went good too. When it started the vector portions (the cut outs and drilling) it was WAY off and had the stair-step effect in some area.

It sure looked like the all the saw dust (even though I vacuumed it during operation) may have been causing the problem by wedging against the pressure rollers and allowing some board slip. I'm going to try just one section of this carving tomorrow, both front and rear, and see what happens.

Jeff_Birt
05-23-2007, 08:26 PM
I tried one section of the four on the two sided project that I had problems with last. The carving drilling and cut out operations worked perfect on both sides, no stair stepping and no offsetting. I would have to conclude that the problem is related to the size (weight) of the board and/or sawdust build up. I always use a roller stand, althhough it's a cheap one. I guess the thing to do now is finish my downdraft/air blast set up to get rid of the sawdust accumulation and look at some of the roller skate (or roller ball) stands that someone mentioned the other day.

cycollins
05-26-2007, 11:07 AM
I think the fact that the miniaturized project worked better is a smoking gun. I did a very simple rectangular cutout repeatedly on a project that was too big to stay under the rollers. I had EXACTLY the same observation you did - namely that each iteration of the project (that is, each time it passed on to and off of the board-tracking sensor), the entire project seemed to "slip" along the x-axis by ~ 1/16". Find a way to stay under the rollers. Use a sled of some kind if you have to and you should be right as rain.

DCC

dominulus
08-19-2007, 09:31 PM
I purchased my CW in June, and just discovered the piece of rubber tubing underneath the board tracking sensor. Does this mean I have a Beta machine? (See John's post below from 5/19)

pkunk
08-19-2007, 09:39 PM
I purchased my CW in June, and just discovered the piece of rubber tubing underneath the board tracking sensor. Does this mean I have a Beta machine? (See John's post below from 5/19)
Nope, they all have 'em. It's a spring.:p

Gman_Ind
08-20-2007, 09:03 AM
I had the same stair stepping vector cutting the outline of a Lyptus sign. The raster detail in the middle was perfect but the vector cutout stair stepped. I stopped the machine for fear the 1/8 bit would snap under the increasing load. I finished the sign with a bandsaw and figured it was a fluke due to the complex shape the machine was cutting out. My piece was 12" tall by 18" long, x 4/4 thick. It weighed about 5-7# it is heavy wood.