What caused this?

[JuicyCarp]

Carvewright should come with a 100% money back guarantee to turn your hair grey! I recently replaced the Z motor after the encoder disk broke. After replacing the motor I started a carve, got about 30 minutes into the carve when the machine stopped and I got the all too familiar clean your Y rail message. I took the whole thing apart, cleaned every bearing I could find, cleaned every rail, had the machine looking like new, and started a carve. The carve took 1 hour and 30 minutes, I had no issues, except these little lines carved throughout the carving. What did I do wrong?


My thinking is:
1. Possibly a loose bit?
2. Perhaps a loose Y bearing?

62254

[RogerB]

What type of belts. It could be belt tracking or a twist in your wood.

[bergerud]

I would recheck the tension on the y and z rollers. (It should be hard to make the rollers slip on the rails.)

[Digitalwoodshop]

Since it happened near the end of the board I wondered if the board was being held by only 1 roller and was lifting due to the weight of the other end of the board.

It could also be a loose Z Truck bearing.

It could also be a loose Z Truck BELT as in the screws into the back of the truck are loose... Was a past problem with Replacement Trucks.

Could be a loose screw in the Z Motor or Gearbox.

WAS the board under both rollers all the time? Or only under one when this problem happened. DID the problem start 3.5 inches from the physical END of the board? IF YES... Then the 1 Roller Pilot Error.... The Board was allowed to LIFT and DROP as the board was cutting making lines... 2 Rollers ALL the time will solve this.... Remember Tips and Tricks and the use of Carrier Boards, Sleds, and taped on 4 inch blocks of wood would solve this.... As in designing your projects with a 4 inch NON carved area on the end of the board to artificially stay under both rollers AND flat to the table.

AL

[JuicyCarp]

Thanks for the help fellas, let me see if I can answer a few questions...

The board was under both rollers during the whole carve. I loaned out my saw, so I just carved in the center of the board, with about 12 inches of hang over on each end.
The problem was not isolated to just the ends of the board, but occured sporadically throughout the entire carve. There would be a couple inches with the lines, then several without, then a couple with lines...so on.
Tension on the belts could be the issue. When I put everything back together I just pulled everything a bit snug, I will double check that.
I have the upgraded belts.
I am going to just go through and snug things down a bit and give it another go, see how this turns out!

[lynnfrwd]

Check that nothing is loose on the z-truck (including bit) and check that your z-belt is not loose.

Re-check the installation instructions of the Z-Motor Replacement just to make sure paying particular attention to this part:

2. Assemble the screws holding the Z-truck motor pack. Replace and tighten the
two screws (with lock washers) that secure the Z-truck motor pack to the Y-truck
(See Figure 12). Tighten these two screws as tight as possible by hand. Check
again and make sure that the Z-truck motor pack tensioning shoulder screw and
spring are in place and tight before tightening these screws fully with a screwdriver.
Failing to tighten these screws AFTER the Z-truck motor pack tensioning shoulder
screw is tightened will result in an incorrect belt tension. Also make sure that all
wires are clear of the area. It is possible to pinch the wires coming up from the
board sensor when this interface is tightened.