Z keeps Dropping

Elite Foreman, braking motor, Fusion 360, setting Z to bed. The Z starts quickly and dramatically moving down when I start a carve. If I feedhold or Estop and then recheck against the bed it’s can be off by over 5/8". Bit hasn’t moved in the collet. The machine is very new, with only a handful of operations. PwnCnc Water Cooled Spindle. I haven’t changed anything from the last carves which went fine. I know there are a few threads where people have experienced similar issues but so far I haven’t been able to find anything useful.

Was going to post the above but thought I’d try rerouting my spindle power cable outside of the drag chain. Ran several tests. It seems to stay put if I run an air carve, MDF seems ok, but solid wood carves still cause the Z to drop, but by much less (so far), about a 1/16th.

Any ideas? Is this just an interference problem? Is the higher power draw on solid wood creating more interference? Would grounding the machine help? It’s a shielded cable but should I add to it? It’s pretty darn infuriating with what is a brand new machine to have to do this kind of troubleshooting.

Thanks!

I know this isn’t very helpful… but just wanted to add myself as another user who has experienced similar behavior. Same machine… PWN 2.2kw ATC spindle and braking Z motor. Yesterday I turned the machine on, and when I went to home it, the Z dropped rapidly and made a loud noise while doing so. Probably dropped at least a couple inches before braking and alarming. I tried to home again and got same result. I rebooted the machine, and it has worked fine since. Granted my machine is only a couple months old and I don’t have a ton of hours on it… but it had never done that before. Strange.

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Thanks!

Yeah, it’s not quite the same as mine essentially appears to be cutting ok except that the zero keeps moving down. I’m not sure that it happens all at once or if it’s in multiple steps.

I appreciate any input as I’ve already started incorporating the machine into my workflow and not being able to rely on it is costing me even more money than the nearly $8K I have in setting it up.

OF Woodworker upgraded to pro. I have a “Makita’ router on my Z20. My problem was it failing to stall properly on setting home and it sitting there “vibrating”. If I push down on the router it stops juddering and completes homing OK. OF suggested the router was too light and it wouldn’t happen with a spindle. They also sent me a replacement Z servo it helped but not 100% of the time. I just live with it now.

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That’s interesting that they suggested that the Z20 would do better with a spindle. I understand that the stall homing is different than the optical but still interesting.

I’m afraid if I’ll end up having to buy a Makita and adapter just to get help. I understand their policy but when I have the braking motor on the Z20, it’s specifically marketed as being for 80mm spindles and trying to troubleshoot with a much lighter router may not give the necessary information.

Hopefully the community has some good ideas. I’m not that smart, so I need all the help I can get.

Thanks!

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@Avbates it wasn’t meant to be a reprimand, rather a clarification that it was two unrelated issues was all. I apologize if my way of trying to clarify the explicit differences came across that way.

tKC. I am familiar with stall currents and voltages and was guided through that by OF before they decided to send me a replacement servo, which didn’t cure the problem 100%.
Yes I do know the subject of the original poster, and was just hoping my experience would help build a bigger picture of challenges. You obviously felt the need to reprimand me, so this will be my last post on this topic. My apologies.

From the OP…

I appreciate the input and I understood the purpose of your comment. If you have any other input on the subject, I would appreciate that too!

New Elite Foreman just powered up today. Ordered with 80mm spindle clamp so obviously it was going to have a spindle installed. first time hitting E-stop spindle hit the table. I like this machine but shipping it with such a known problem leaves a bad taste in my mouth. I ordered the brake servo which should have been there all along.

Hey all,

by the way the motors of the Elite Series are not servo motors but stepper motors. The fact that they have a closed loop controller with an encoder disk does not make them being servo motors.

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