What is a reasonable speed for the Z axis

[davida1234]

Of all the places, the ones at Home Depot worked best.





You can find more pics at my thread:

https://www.cnczone.com/forums/diy-c...h-top-cnc.html

[ger21]

What do you have the current on the drives set at?

80ipm is only 160rpm. You should have plenty of torque at that speed.

Are the screw and nut perfectly aligned? Even a small misalignment can cause binding.

[tkms002]

I use air tool oil. If you've been running it dry, oil can make a big difference.

Are you sure there's no binding in the bearings?

I am sure the bearings are not binding

[tkms002]

What do you have the current on the drives set at?

80ipm is only 160rpm. You should have plenty of torque at that speed.

Are the screw and nut perfectly aligned? Even a small misalignment can cause binding.

drives are set to 5 amps

[tkms002]

What do you have the current on the drives set at?

80ipm is only 160rpm. You should have plenty of torque at that speed.

Are the screw and nut perfectly aligned? Even a small misalignment can cause binding.

When I got the screw and nut it was so tight I could hardly turn it by hand. Is that normal for lead screw and anti backlash nut? CNCRouter parts support said it was normal so I just used it.

[ger21]

No, it probably shouldn't be that tight. Oiling it should definitely help.

[tkms002]

OK after adding the pneumatic tool oil I was able to get it up to 360 IPM safely. It stalled at 400.
Increased the acceleration to 1200 an it seems nice and fast now.
Is that good now?

[ger21]

I would think so.
5x faster is quite an improvement.

I have the same motors and screws for the dual Z axis machine I'm building, and was hoping for ~400ipm. I'm using AM882 drives and 60V.

[tkms002]

I would think so.
5x faster is quite an improvement.

I have the same motors and screws for the dual Z axis machine I'm building, and was hoping for ~400ipm. I'm using AM882 drives and 60V.

I would guess that 60V would get you there. I could get 380 but lowered it to be safe.

[ger21]

And my Z axis won't weight more 20-25lbs.

[tkms002]

And my Z axis won't weight more 20-25lbs.

what are you using for spindles?

[ger21]

2.2KW round air cooled.

[wizard]

This is good to hear.

Honestly I must be slipping here because one of the first things I do at work on a failing axis is to try turning the leadscrew shaft. I’m surprised by how much turning resistance you indicated before lubrication. It does seem excessive but your lube has apparently cleared that up. This highlights the importance of maintenance, a good operator makes sure his machine is lubricated before the start of his shift.

By the way I’d make sure that you can easily lube all of your machines axis. Sometimes the best solution is a pipe or lube tube ran to the bearings or nuts.

OK after adding the pneumatic tool oil I was able to get it up to 360 IPM safely. It stalled at 400.
Increased the acceleration to 1200 an it seems nice and fast now.
Is that good now?

[tkms002]

2.2KW round air cooled.

interesting. My 2.2 KW round water cooled spindle weighs 16 lbs.

[ger21]

My Z axis are pretty compact. And half of them are plywood.

[asuratman]

Very nice Ger21

[Ntl]

What program did you draw that in Ger21, nice cad work.

[ger21]

Fusion 360.

[tkms002]

My Z axis are pretty compact. And half of them are plywood.

Ya that really looks nice.

[Ntl]

Fusion 360.

Very nice work, fusion 360 sure is nice for rendering.