Z axis binding/or stalling

Hi Gary. I have a 840/2 just like you and have the same issue. I presume that your problem is a loss of steps, somewhere, somehow and problably you will be told to fix that. I rebuilt my machine over and over again, making it only worse...
I tried already to use a lighter Dremel in stead of my Kress endmill, which i bought along with the Stepcraft. Made a little difference. Now i'm making some experiments with the speed rates... with various success.
And although it's problably a loss of steps, i can't manage to get the thing 100% perfect aligned... So, i'm keeping my hopes to lower the speed so it won't be losing any steps...

I got all my Stepcraft axes mechanically tuned to a high standard but I still had to run at a maximum speed of 2,500 mm/min. At 3,000 mm/min, the Y and Z axes bind but the Z is o.k. when lubricated. I have run it for many hours over many months for up to 4 hours a session successfully at 2,500 mm/min.

You guys probably understand this already, but the slower the motor turns, the higher the torque output. That's why slowing it down helps overcome minor binding issues.

Doug

Hi Doug,

indeed, because mine isn't that well outlined i had to lower the speed to a shameful 1000 mm/min, but at the end of the day, my Stepcraft is finaly working for hours after hours, without loss of steps.

Although, a rebuilt of the machine is at stake, i'm enjoying the working Stepcraft for the time being...

Thanks Doug, followed similar route last time this happened, may have to lower the speed a bit more. Just can't figure out why it was fine at the default speed for about four months from being built. What has changed???

Cheers
Gary

Well most probably a lot of dust has been blown into it.
Unfortunately the Z-Axis is quite open and can get a lost of dust etc. which is than binded by the grease.
I would say a complete dismantling and cleaning of the z-Axis, including all the the rollers, threaded rod etc. could help a while.
And don't forget to regrease afterwards.