New HDZ losing steps!

HI everyone.
I was going to cut some aluminum today (simple 3mm slot at the edge of a plate) but on the first but the Z was off by 2mm (at least), lucky me , 2mm to high so I could redo the cut.
So I redo the zero with the 1/4" probe, start my job, do the tool change (5/16 2 flutes stub from Shars : https://www.shars.com/5-16-se-2-flute-stub-zirconium-nitride-solid-carbide-end-mill-for-aluminum ). Same issue not matter what.
I chage my tool on Fusion 360, re-post, and redo all the zero and what not. This time it seems to be fine and my cut and chamfer are done.
move to the next cut (same cut on 4 plates), redo my zero before re-running the job, that one goes fine.
3rd one … after tool get measure and job starts, first cut is 1mm deep instead of 0.5 (it says 0.5 on Carbide Motion), so once again, the zero was lost after the tool measure.
I recheck all the params for my machine (Shapeoko Pro Standard with HDZ, bi tsetter, bitzero v2 and spindle+VFD from PncCNC), resend all the params, reinit the machine (power cycle VFD and Shapeoko).
Relod the job, do the zero, same issue, started just looking at the HDZ move and then … it was loosing steps, more and more, the more I was just moving down then up the worst it was getting !
Here are 2 small video that shows the issue :
https://sbforum.s3.amazonaws.com/IMG_2182.MOV
https://sbforum.s3.amazonaws.com/IMG_2183.MOV

Has anyone see this before ? The HDZ is new (a few month old).

As others pointed out the HDZ needs to have lubrication. The bearings dry out and have a hard time moving. The HDZ is quite robust but dry bearings will make it lose steps. C3D sells a maintenance kit with a bottle of the Mobil Vactra #2 lube. To properly lube the HDZ you have to remove it to gain access to the bottom screws on the bearings. It takes about an hour start to finish. If you remove it be sure to check tram when done. You could just oil the guide rails and put some oil in the top bearing.

If you do oil the HDZ when you park it be sure to put a paper towel below the HDZ. For about a week excess oil will drip out. Also before running a job wipe off the bottom of the rails to prevent any oil from dripping out on your project.

This HDZ is 2 months hold and I’ve used the CNC a grand total of 5 time since the HDZ update so I doubt it’s a lubrication issue (the ways are plenty oily).

Could still be lubrication. The HDZ is hard to manually move but you can jog it all the way down and then twist the ball screw to see if there is a hard spot. Talk to support and they will get you some help. Occasionally the joint where the stepper motor joins the ball screw at the top can come loose.

1 Like

It’s also worth checking that your retract height isn’t too high.

With longer bits or taller workpieces I’ve had the machine try to retract beyond the top of the Z axis travel and lose Z steps that way, resulting in the zero effectively moving down. You’ll hear it “donk brrrrrr” into the top of the travel.

4 Likes

I doesn’t retract to the top after measuring the tool. What you see in the video I posted is step being lost after the tool measurement (therefore voiding the Z zeroing).
when going aluminum cutting my retract is 5mm above stock, on wood I set it to 15 mm.

Please let us know about this at support@carbide3d.com and we’ll do our best to work it out with you.

Sorry your sweet new HDZ is acting up. That sounds really frustrating. Take the following with a grain of salt bc I have no idea what I’m talking about. I noticed that the Z seemed to descend smoothly in your first video (when it goes to touch off the bitsetter), and that the stuttering or binding is only happening when the Z axis is rising? Are you sure the rails on the HDZ are parallel (people have had issues with this before - HDZ Carriage Binding on Z-; HDZ Install/Use Question; HDZ V Wheel Installation - #3 by ctdodge) - might need to loosen and reallign the rails. Other idea: if you’re cutting aluminum, maybe some errant metal chips/shavings got lodged up in the Z and are gumming up the works. These are total spitballs and hopefully the Carbide folks can straighten you out. Good luck.

1 Like

The first time I used my HDM I destroyed an expensive piece of material. It lost steps running an adaptive 3d toolpath. I was sure everything was perfect but after a thorough investigation *lol, I discovered that my stepper couplers were snug but not exactly tight. I tightened them all until my hex wrench was flexing and have not had a problem since.

4 Likes

I’ll check the coupler, could be it.
Thanks

I second the coupler as @CNCInspiration said. You can see the coupler spinning well, while the ballscrew seems intermittently not.

4 Likes

So the coupler was not quite in the right position and was not firmly grabbing on the ballscrew shaft. I realigned it (centered between the motor shaft and ball screw shaft), tighten it well and now it sound and move a lot better :

I have been in contact with support (let’s give credit where credit is due) and waiting on them confirming that this looks good.
I did a zero test (zero on top with my bitzero v2, remove it, move down to 0… it lands on 0, can’t slide paper under the probe, move up by 0.025mm, can slide paper under, repeated this a few time, results are consistent).

4 Likes

Be sure you get some lube. The HDZ is great but does require maintenance. Maybe add the coupling check to your maintenance interval.

Glad you got that straightened out fast!

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.