Hello Wolffie
To try and eliminate possibilities one by one, you might want to take a look at the z axis bearings by taking them off of the shafts.
They might have build up that could cause the balls to stick and bind. I am not sure if the bearings you have use recirculating balls or if they stay stationary in the housing, but it would be good to know that they are clean and lubricated in their tracks. From what you describe it sounds like some kind of binding. If you replaced a lot of your plastic parts with aluminum, the alignment of the parts gets more critical as the plastic has flex in it to compensate for some misalignment that the aluminum will not be as forgiving with.
you can also try exchanging the motor and cable assembly with a different axis to see if the issue follows the motor and cable pair.
Loss of Z axis
Moderators: ddw, al wolford, sbk, Bob, Kayvon
Re: Loss of Z axis
I tried to swap the cables and it made no difference.
I have changed the original bearings with new open linear bearings (or whatever they are called )
Strange thing is that despite the added weight, there is no problem going up but it stops halfway down when gravity should assist the movement.
I am taking the thing apart again tomorrow and double checking everything.
Today was wasted with me having an injection in my lower spine.
Cheers
Wolffie
I have changed the original bearings with new open linear bearings (or whatever they are called )
Strange thing is that despite the added weight, there is no problem going up but it stops halfway down when gravity should assist the movement.
I am taking the thing apart again tomorrow and double checking everything.
Today was wasted with me having an injection in my lower spine.
Cheers
Wolffie
Re: Loss of Z axis
Any update as to what the problem and fix is?
Re: Loss of Z axis
I took the whole thing apart again.
The plastic bottom of the cradle was starting to move (rock), causing the screw and rods to be slightly askew, so I replaced it with a20mm (3/4") aluminium one.
Haven't had any problems since, fingers crossed.
It was cutting all day yesterday without any problems.
The plastic bottom of the cradle was starting to move (rock), causing the screw and rods to be slightly askew, so I replaced it with a20mm (3/4") aluminium one.
Haven't had any problems since, fingers crossed.
It was cutting all day yesterday without any problems.
Re: Loss of Z axis
I'm a new member, can't seem to post a new post, so will try piggy-backing on this one, with "similar" issue.
I have a Shark 520 with the larger Shark water cooled spindle, doing a 3d project, 16"x 13"x1.8" white oak. Ran roughing pass, no issues. Started a VERY long smoothing pass with Very small tapered bit (1/32" diameter tip, 1/4" shaft), slow feeds (40 IPM, but only cutting .0028" per pass, slow Z axis movement(12 IPM), 8% pass overlap, expected to run 53 hours. After 6 hours (maybe 5 hours into that), I was checking hourly, looks like it dropped the Z axis about .6", and kept carving beautifully, but .6" too low now, ruining the piece, of course. No issues like this before, but haven't run too many projects through this new machine yet. No static, since I didn't have vacuum hooked up and no one was in the shop to touch it while it was running to transfer a static shock.
I need to know what happened to prevent it or I can't really use this quite expensive paperweight to ruin more expensive wood. The cut was perfect in every way for the first 5 hours, then the z-axis drop, then an hour of deep cutting. The kind of thing that really ruins one's day.
TIA,
Merle
I have a Shark 520 with the larger Shark water cooled spindle, doing a 3d project, 16"x 13"x1.8" white oak. Ran roughing pass, no issues. Started a VERY long smoothing pass with Very small tapered bit (1/32" diameter tip, 1/4" shaft), slow feeds (40 IPM, but only cutting .0028" per pass, slow Z axis movement(12 IPM), 8% pass overlap, expected to run 53 hours. After 6 hours (maybe 5 hours into that), I was checking hourly, looks like it dropped the Z axis about .6", and kept carving beautifully, but .6" too low now, ruining the piece, of course. No issues like this before, but haven't run too many projects through this new machine yet. No static, since I didn't have vacuum hooked up and no one was in the shop to touch it while it was running to transfer a static shock.
I need to know what happened to prevent it or I can't really use this quite expensive paperweight to ruin more expensive wood. The cut was perfect in every way for the first 5 hours, then the z-axis drop, then an hour of deep cutting. The kind of thing that really ruins one's day.
TIA,
Merle