Z truck trouble

[knotjustsawdust]

Z truck is not moving up and down smoothly. Also carving is looking very rough. Any ideas?

[fwharris]

Dirty or bad Z bearings, Z bearings loose, Z gear box bearings bad or the mounting screws for the gear box to motor loose.

[knotjustsawdust]

If it is the bearings how do I go about replacing them??

[fwharris]

If it is the bearings how do I go about replacing them??
Follow the Y or Z truck replacement procedures.. http://support.carvewright.com/downloadable-documents/#repair-documents

[cestout]

Grab the end of a bit in that is installed. Tug in and out to feel for any play. if any, determine if it is the Y or Z rollers the are not tight. Use your 12mm wench (from CarveWright) to adjust the appropriate rollers tighter to the tracks.
Clint

[knotjustsawdust]

Guess it’s time for me to buy a new z truck

[fwharris]

You probably do not need a new truck, just the bearings.

[knotjustsawdust]

That would be the adjustable bearings not the fixed , correct?

[fwharris]

That would be the adjustable bearings not the fixed , correct?

Without seeing them I really can not say. Do you have the truck off yet to see what bearings are the problem? I would order both sets just to be sure.

[knotjustsawdust]

I will order both, thanks for the help

[Digitalwoodshop]

1 week ago.. I would have mentioned to order the screws too.... Extras... As they snap easy....

Before you change them... Get some light weight spray oil and try to flush the bearings as sawdust gets in the seals and the head makes a thumping sound as you move it up and down. Catch all oil in a rag and later be careful of Spontaneous combustion of the oil rags.

Keep a tooth brush size wire brush to scrub the roller rails. Sawdust sticks to the rails.

Clean the rubber drive belt cogs.

Good Luck,

AL

[DickB]

Before you change them... Get some light weight spray oil and try to flush the bearings as sawdust gets in the seals and the head makes a thumping sound as you move it up and down. Catch all oil in a rag and later be careful of Spontaneous combustion of the oil rags. Al's suggestion is definitely worth a try. I always keep a close eye on my machine while calibrating and loading bits, to make sure that the bit plate pops out etc. A couple weeks ago the bit was not dropping down all the way to the bit plate. I suspected that the bearings were dirty and creating resistance, which was being interpreted as hitting the bit plate. By hitting Stop and retrying I was able to finish my project. It subsequently took 3-4 applications of WD-40 to get things back to normal. BTW this is the same Z truck from my Carvetight conversion, probably has 800 hours on it bearings have never been replaced.

The best way to check proper bearing tightness is to pull the plastic dust covers off. Hold the truck steady and try to rotate a bearing. If you can rotate a bearing while holding the truck still it is not tight enough. Or try to hold the bearing still and move the truck; if the bearing rotates despite your best effort it is tight enough.

[knotjustsawdust]

Changed the bearings , tested y and z and both move smoothly now. Just did a small 12 inch sign and it was going good until I got a clean y rail message.. I cleaned the rails and it went for another 5 minutes and I got the message again.. cleaned it again and when it started to carve, it shifted about a half inch to the left and started carving. Now what??

[fwharris]

Verify that the Y belt tensioner set screw is tight and maybe retension the belt. Loosen the set screw, move the Y truck back and for a couple of times and then retighten the set screw.

Double check that the Y bearing nuts are up "flush" against the truck plate, they are not cantilevered as shown in the instructions.

[Digitalwoodshop]

Could be the two 685ZZ Bearings are shot in the Y Gearbox.

Does the Y make a clucking sound as in 3 clicks when the head goes over to the bit place? That is a sure sign of bad bearings or a worn shaft.

AL

[knotjustsawdust]

No noises when it’s moving. I just replaced the y motor also.

[Mugsowner]

Wondering what roller bearings you changed. from what I been reading I assume the Z axis. I see you also changed the Y axis motor, did you also change the Y axis roller bearings, in which case you may have the bearings a bit tight.

[knotjustsawdust]

Didn’t change the y bearings

[Mugsowner]

I would try wiping down the rails with LPS 1 or WD-40 and some in the Y bearings. I cover the bearings with a rag to catch over spray. Look at the drive belt to make sure there is nothing in the teeth of the belt causing resistances.