Recurring false 'Hard limit triggered.' Alarm

Thanks for your response Peter. Since I’ve removed the limit cables from the black box, how can it be thinking their has been a limit hit? Also, without limits working I suppose I can’t really use the homing feature.

 

I had the same problem. What I've ended up doing is put a capacitor between the in pin of the limit switch and the ground and my problem was solved.

See this thread.

 

I’m running black box, Xtension switches, and the Makita trim router others use, as well as the openbuilds high torque nema 23s. I have noticed a few times that I’ve got shocked touching the machine - figure it’s static from cutting the mdf.

 

no dust extraction yet, I’ve seen some people replace the router cable with a grounded cable instead.

I’m confused though because I presume others are able to build and run these kits without all these issues.

 

if the limits are entirely unplugged from the black box (no wires plugged in to the limit pins in the black box), then even if there is a possible emi source, how would that signal be even getting into the black box?

I’ve plugged the router into a different circuit than the motor power (I have the openbuilds 24 v power supply). I’ve moved the router cable away by hanging it from the ceiling so it’s nowhere close to any other wires. I’ve unplugged the motors switch wires from the black box. I’ve made sure the openbuilds interface cable is away from the motor wiring. Still same issue.

 

Update: I plugged all the limits back in and ran the job with the router on but cutting in the air. The job ran fine to completion. I then tried to run the surfacing job again, and noticed while vacuuming that I was getting static shock (vacuum was not touching machine). As I have the surfacing job taking 2 mm off the mdf spoil board, a metric ton of dust gets generated. I am also in snowy Canada where it is very very cold, low moisture in the air of the shop. Is it possible that static due to the low moisture and ton of dust in the air is causing a static shock to the machine and then that’s triggering the false hard limit alarm? I’m in the process right now of trying do run the surfacing job with a 0.5 mm depth of cut to generate less dust and reduce the chance of a shock.

 

Yes, that's definitely possible - best solution is to earth your dust extractor hose - length of bare copper wire along the inside, connected to mains earth at the vac end.
Alex.

 

I don’t have any dust extraction, but I think that the dust that’s spraying everywhere may be causing static on the machine itself. I tried to run with less depth cut but same thing happened. Next Ill try running a wire from the machine to the ground. Any other suggestions?

 

Alright so I tried running a ground from the frame to a ground plug, same issue. What’s next?

 

I’ve got it sorted! I ran a ground from the Makita router to a wall plug ground to test if it would work fine and bingo bango it worked! I plan to change out the power cable for the makita router and add a proper ground to it. I googled how to do it and there’s other forums where people have done this here: Makita Router - adding a three prong plug

Thanks all for your help!

 

I know this is an old post but is there anyway to incorporate a resume cut feature after a lockout? This is the second time it has happened in the middle of a job and starting over a 5 hour cutis a real pain. I can not for the life of me see any reason that the error should be happening. The machine is cleaned and all switches are intact. I am using the BlackBox on my WorkBee.
Thank you.

 

Holy Smokes. Well I am Smart but not smart enough to figure all that out. Oh well I started over again at 200 percent the Current cut Speed and will Slow it down when I get back into the Wood again.
I will check out that page.

Thanks for your time.
Randy

 

My issue turned out to be static discharge caused by cutting mdf (spoilboard surfacing) - the makita router isn’t grounded, just double insulated. I grounded it and now it never happened again.

 

I will over everything when I get this job done. Never thought about static as everything is grounded correctly but now that you mention it my Vacuum may be the culprit. Not sure how to explain it.
I believe having the hose mounted to the machine might be the issue. The plastic hose is building up static and then releases a charge? Unseen to my eye of course.

Thank you.

 

I’d bet more than I should that is your problem. Look up how to ground a dust collector hose and do that!

 

Well worth earthing the vac hose - just some bare copper wire along the inside and connected to mains earth at the vac end.
Alex.

 

Thanks. I never even thought about it. But stupid me used a piece of binder wire to attach the hose direct to the side plate to hold the hose in position. It’s removed now but I would have never thought it would interfer being I have the machine on a wood surface. In any case I am not turning on the vacuum until this done hahah.
The piece I am carving is fantastic. I have to give CNCplanetart.com coodos for this design. Best detailed model I have ever carved.
Thank you.