Giant 20' x 3' x 2' router build

**charlieuk** · 18-12-2014

I have been doing some more test cuts with the machine, yesterday I was doing a cut and a bolt on the z axis rail came a fraction out and cased a jam however I was pretty quick at stopping it and I don't think there was any damage.

However today I have had a error come up that I think I have had before in that the z axis is getting a Stall Detection error on it ie 5 red flashes on the driver ( it is a leadshine em806 hocked up to a nema23)

This does not happen straight away it has been maybe 40 min into a job and the z axis has totally stopped, luckily it has stoped at a point were it has not ruined anything yet however I cant find any mechanical problem that would have caused a stall and I can re set the driver and all is ok again but odiously that's not a cure.

so first I need to figure why it is triggering the stall detection? any ideas????

then second is there a way to hock up a signal to go to e stop if this happens for any other reason. ( I have yet to look into this)

so a little confused at the moment, could it be more noise?

many thanks charlie

**Clive S** · 18-12-2014

I think this can happen if the acc is set too high you can set the driver to send out an estop so that the complete machine will stop if any driver goes into fault. I think the signal has to be set up in the software of the driver. I am sure Dean will pop up with the correct way to do it. ..Clive

**JAZZCNC** · 18-12-2014

Originally Posted by Clive S

I think this can happen if the acc is set too high you can set the driver to send out an estop so that the complete machine will stop if any driver goes into fault. I think the signal has to be set up in the software of the driver. I am sure Dean will pop up with the correct way to do it. ..Clive

Spoke to Charlie about other issue and why but you never mentioned the E-stop.!! . . . So Charlie it's easy enough to do. Tony will understand what to do.
The drives have fault output that you use to control a relay which is inline with the E-stop.
The fault signal Logic can be programmed in the drive so can be configured to suit your needs.

**charlieuk** · 18-12-2014

cheers many thanks for the advice dean just ordered a few more pulleys to gear it down and will strip it all down this eve and see if I can find what's wrong and were the binding issue is. sorry I forgot to mention the estop thing as I was more focused on fixing the problem. toney is down next weekend fot Christmas so will get him on to it as he has been after things to play with.

many thanks

**charlieuk** · 22-12-2014

I have changed to a 2:1 gear ratio and made sure it is all running smooth however I still seam to be getting the problem. I am just trying the job at 50% feed rate to see if that stops it. We are wondering if it happening when there is a fast change in direction and feed rate because of the heavy z axis. We think it is sways happening during a similar movement but not at the same point in time through out the job. Wondering if possibly we need to put a gas strut on the z or go up further on the gearing at the moment I have a 20t and a 40t

**EddyCurrent** · 22-12-2014

Originally Posted by charlieuk

then second is there a way to hock up a signal to go to e stop if this happens for any other reason. ( I have yet to look into this)

This is how I did it for the similar (I think) AM882; http://www.mycncuk.com/threads/6565-...7622#post57622

Contacts of the K2 relay would go in series with your emergency stop buttons

**charlieuk** · 22-12-2014

just to add to thins the weight of the z axis is aprox 14kg and its on a 1605 screw and a 3nm nema 23. I ran it at 50% and it actually cut out sooner. I have got another set of pulleys coming which will give a 3.8:1 ratio so hoping that may help and in the mean time Im going to try taking of the spindle to reduce the weight and see what that does.

**JAZZCNC** · 22-12-2014

Originally Posted by charlieuk

just to add to thins the weight of the z axis is aprox 14kg and its on a 1605 screw and a 3nm nema 23. I ran it at 50% and it actually cut out sooner. I have got another set of pulleys coming which will give a 3.8:1 ratio so hoping that may help and in the mean time Im going to try taking of the spindle to reduce the weight and see what that does.

Charlie from what you told me regards velocity and Acc settings being so low and with 2:1 ratio then it should handle the weight without stalling or missing steps.
When my machine was vertical the gantry was much heavier than 14Kg and a single 6Nm nema34 which turned twin 5mm pitch screws via belts that where geared 1:2 to give speed so actually lowering torque by aprox half easily moved gantry. This means you actually have more torque than I do.!

If your absolutly sure there's no sticktion on the linear motion side then Things to check First is if the motor is wired correctly and performing properly.? Have you wired it in parallel or series.?

With 3.8:1 ratio you will be quite low on speed and Acc you'll reach which for 3D work you may want.? So I would try to find the cause.
Counter balance/Strut arrangement can't hurt if you have room to fit so I'd do this any way just to help take the the strain.

**charlieuk** · 22-12-2014

I'm prity sure all is sliding ok. The z axis would fall nearly the hole way under its own weight with the belt removed from the stepper and with the spindle removed it was still triggering. I have since got the screw a hair better by shiming it .10. We did adjust the speeds this morning with the gearing but we have backed the acceleration back again and running another test now