cut keeps increasing depth any Ideas.

[srrutle]

I have tried cutting 2 different projects both times the cutting depth has increased I created a simple 1X6X0.025 cut region saves to project (Test one) and cut it. it started at a depth of 0.04 and ended up at 0.129, on the larger projects the depth increased by 1/4 inch. any help would be appreciated.

[AskBud]

I have tried cutting 2 different projects both times the cutting depth has increased I created a simple 1X6X0.025 cut region saves to project (Test one) and cut it. it started at a depth of 0.04 and ended up at 0.129, on the larger projects the depth increased by 1/4 inch. any help would be appreciated.
There are many possibilities!
Before you tear things apart, try these items.

1) Level Head:
Take a piece of stock 3/4" or thicker, about 15 inches long, that is known to be truly flat.
Saw it into 2 pieces, lengthwise.
Place each piece on the sandpaper belts, one on the keyboard side and the other on the opposite side.
Using 4 strips of paper, place one piece on the board under each roller so it extends out of the machine.
Lower the head until the rollers begin to just touch the paper.
Now, tug on each piece of paper to determine the tension/resistance. They should all be the same feel. The paper is your "feeler gage"!

2) Is the bit tight in your chuck? What chuck do you have? If you have a CarveTight Chuck, are you using the new carving bit with the pressed on sleeve?
3) Are your belts rolled on the edge?
4) Others may add more.
AskBud

[srrutle]

1: lowering the head it touches down on the corner by the switch first then moving the crank handle about 1/2" it holds all 4 of the papers
2: It is a CarveTight Chuck and new bit with sleeve.( Problem started after installing CT )
3: The belts look new no curling tears or any signs of age.

Thanks.

[unitedcases]

Definitely sounds like your head is out of level. I would also blow out the back of the encoder on the z-motor just to be on the safe side. I dont know how many hours you have but it doesnt take much to get dust in there.

[bjbethke]

I have tried cutting 2 different projects both times the cutting depth has increased I created a simple 1X6X0.025 cut region saves to project (Test one) and cut it. it started at a depth of 0.04 and ended up at 0.129, on the larger projects the depth increased by 1/4 inch. any help would be appreciated.

Looks like it may be an encoder problem, it is easy to check. Use the Keypad to check the position of the Z and Y positions.

Depth change in the length of the carving is in the Z truck. Move the truck to the top and record the reading, then move the truck to the bottom and record the reading.

Then move the truck up and down several times these two reading should not change.

If you have a problem I find it is best to remove the Z motor to open the encoder; there are two bolts that hold the cover and the nuts that hold the bolts are loose, it is very easy to lose the lower one.
Your MPC shows the board size is 36x9 is that the size board you are using to make this test? Is the board flat?

[Digitalwoodshop]

Looks like it may be an encoder problem, it is easy to check. Use the Keypad to check the position of the Z and Y positions.

Depth change in the length of the carving is in the Z truck. Move the truck to the top and record the reading, then move the truck to the bottom and record the reading.

Then move the truck up and down several times these two reading should not change.

If you have a problem I find it is best to remove the Z motor to open the encoder; there are two bolts that hold the cover and the nuts that hold the bolts are loose, it is very easy to lose the lower one.
Your MPC shows the board size is 36x9 is that the size board you are using to make this test? Is the board flat?


One more step to moving the head up and down..... The Whole Reason is to look for a bad FFC Cable.... Moving the FFC Cable WHILE you are moving the head up and down will point out a bad FFC Cable as while moving the head it will loose pulses resulting in a new reading at the top and bottom.

And if I read your problem correct, the new 1/4 inch depth is uniform left to right on your board, not tapered left to right? Tapered = un level head, Uniform = FFC or Encoder Cable Problem.

AL

[liquidguitars]

Generally I think this is a factor of the need to replace the z pack motor assembly.

[srrutle]

any Idea what the z pack motor assembly cost is ?

[Digitalwoodshop]

With Post 6 I need to back up and look at this... Any chance this happened because the Bit is loose in the QC.... You do have a Quick connect? With Bit Holders.... Bits are very often loose in the Bit Holders and move up or down while the project is cutting... Every Bit Holder should be checked for set screw tightness....

Did this happen with more than 1 project? If you opened a new board and draw a 2 inch circle and made it a carve region then set the depth to .25 and let it cut... what happens... Any chance this is a Art Problem.....

I am trying to exhaust all options before buying a motor..... A FFC Cable is more likely to fail..... The big flat cable....

AL

[srrutle]

I have checked the Z Truck travel raising to top of travel turning on option 0 7 down to Y Z moving Z down travels from 0.000 to 2.943 and holds there moving along the y axis to exercise the FFC cable and repeating with light upward then downward pressure on FFC cable top and bottom remain at 0.000 to 2.943

I have rechecked the bit it is still has pressed on sleeve tight up to the CarveTight Chuck

I have rechecked the head for level using 2 3" extruded aluminum channels 20" long the 4 papers all slide and stop at the same time.

I will try the cut with a 2" circle hopefully this weekend.

Thanks....

[Digitalwoodshop]

Your way ahead of me.... Good Job !!!!

The Circle test will tell us the health of the system...

AL

[DickB]

Did you check for dust in the encoder?

[srrutle]

I attempted to do a 6" circle just to make it easier to see the issue, I got called away child got hurt ( child is OK ) but cut went deep and broke the bit.
As for the encoder I got about 1/2 teaspoon of dust out that was before the circle test.
I called support they said Z motor probably going to get the Z motor assembly ( FFC Cable motor and circuit board all together. ) I will update after I get parts and install and test.
Thanks for all your help.

[srrutle]

I replaced the Z pack assembly 2 circuit boards FFC cable and motor.

no good same issue.

This image should be a 2" hole at a depth of 0.100" from start of drill it went from 0.100 to 0.334 in a diameter of 1.08" I stopped it before I lost another bit.

Reminder this issue started 1st carve after Carve Tight change.

any other thoughts?

[jaroot]

Just a shot in the dark. Have you tried reformatting the card?

[Digitalwoodshop]

Could be a bad encoder or dirty Z Encoder where the retract of the Z is not working properly.... OR

Looks like a X Direction problem as the cut ends without completing the circle.... I would remove the X Gear Box Cover and blow the sawdust out of the X Gear Box. Look for a broken single tooth.. I had that...

Remove the Y Motor and inspect the Y Gear Box looking for bad 5 x 11 x 5 mm bearings and possible worn big plastic gear shaft.
http://www.vxb.com/page/bearings/PROD/5mm/kit768

AL

[srrutle]

I formatted the card 2 times.

I stopped it in the middle of the 2" cut so it would not break another bit as it got deeper. machine only has 25 hours on it.

when I carve a pattern the pattern carves a clean pattern it just has a slope to it as the depth increases.

[want2learn]

have you recalibrated your machine after changing to the carvetight?? and also make sure the board edge sensor wire harness is not pinched as mine was causing the bit to go thru the board at times [the wire harness runs up the z truck guide rails covered by a plastic cover]

[srrutle]

I measured a board and the thickness was only off by 0.001 and the width was only by 0.004 so I did not run the calibration and when checking the Z Truck belt for support I broke one of the wires on the sensor wire and replaced it currently I am waiting for LHR to send a Z motor support had me send the replacement for exchange I had send it before they would ship a replacement for the refurbished one I bought. If replacement dose not work support says it will have to be sent in for troubleshooting.

[srrutle]

Well I put in 2nd Z motor and carve depth still increasing S _ _ T!!!

Sweet while considering where to sink the machine as a boat anchor,
I thought about some of the things I did and at one point I while putting the Z truck back on I had the bearings to tight and the carving started going the other way up in the air. taking the pressure off the bearings the cut went back to going deeper. then I thought about the tension on the Z Belt on the Z truck so I backed off the tensioning shoulder screw about 1 1/2 turns giving the Z motor belt a little slack (not loose just not banjo tight)
and now cutting depth stays level YAHOO (not the .com emotional out break )
If all else fails trash the instructions....

2. Re-assemble the new Z-motor pack. Insert the protruding belt pulley on the Zmotor
pack through the slot in the Y-truck and into the top loop of the Z-truck belt.
Replace and fully tighten the Z-truck motor pack tensioning shoulder screw and
spring with the 4mm Allen wrench (See Figure 12).

I thought I was going back to mallet and chisels... but I am back

Thank you all very much for the Help and input.

[unitedcases]

I just reread this again. Did you ever change the ffc cable. Everytime I have this type problem that is what it is. Make sure if you do to follow the instructions to the letter. And buy extras. I keep at least 3 or 4 on hand.

[gashawk]

Try checking the drive belt on the z truck. It may be torn. It measures the starting depth, then the drilling action pulls the bit down.