New spindle idea for my machine - DC 1HP

[HiltonSteve]

Got the Z axis back on the machine tonight and spun it up, I'd like to say it worked perfect first time but afraid not, lifes never that easy but thats what makes it interesting!

Noticed some vibration around 500rpm on the motor which after some investigation I found that after running the spindle for 5 mins the bottom half of the spindle head was getting a bit too warm. Disconnected the drive belt and turned everything by hand to find that my smooth as silk running spindle head was now feeling a bit tight and lumpy, BASTARD!

Stripped it down and looks like the bottom 2 bearings are either knackered or the inner race has been slipping on the spindle shaft or a combination of the 2. Flushed out the bearings, re-greased them and fitted them back on to the spindle with some bearing fit loctite.

Now all feels smooth again but not 100% convinced that it has solved the problem, will leave it over night and give it a run again in the morning. Got a feeling I will be off to the bearing shop next week!

Other problem is the weight, when the steppers are powered off the z axis now slowly falls down. Thought this may happen and will be ordering a couple of 150mm stroke variable pressure gas springs tomorrow. The stepper drives it up and down fine but not comfortable with it having to shift that much weight.

But.... it does look nice...!