Spindle turning off during cut [Archive]

bking1836

01-18-2018, 02:59 PM

Hi everyone,

Today, as I was cutting acrylic for the first time, the spindle started acting up.

First, after I pushed spacebar to temporarily stop the job and then resumed the job, the spindle did not turn back on and broke the tip off my 30 degree engraving bit. :mad: I was having some issues with the acrylic melting/gumming up, which is why I stopped. But it wasn't anything major.

Then, for the next job, I ran a simple .05" pocket with a 1/4 O flute to mark my pilot hole locations. When the job started the spindle wouldn't turn on. I stopped the job before the bit plunged, repeated and got the same results many times. The sbp file definitely has the C6 command where it should be. And then for comparison, I switched to a different file and the spindle started.

I redid and resaved my toolpaths, and the next time the pilot hole toolpath worked fine. Then I ran the job toolpath, and I first noticed that every so often the machine would seem to stutter while cutting. And then the machine simply stopped moving, and then the spindle turned off. It was hard to get out of the SB3 software too, as the software believed it was still cutting and pressing the spacebar did nothing.

I continued restarting the jobs where I left off, and it continued to work for a while, then full stop again.

Finally I switched to wood. Running a pocket in plywood, all was well until I noticed a few stutters again, and then this time the spindle shut off but the XY movement continued until I did an emergency stop. Fortunately my bit didn't break.

Also worth noting...if I manually enter the C6 command, the spindle starts up for literally a second and then stops. I also tried pulling up the keyboard and pressing 1 to start the spindle. That worked at first. Then it wouldn't. After a full reboot (which I've done many times today), it worked for 15 minutes and then the spindle shut off. The housing was a little warm, but certainly nothing was hot. The fan works.

Ahhhh!!!

I am running a 48x96 PRS Standard with the HSD 2.2 spindle.

Any ideas what is going on? Shopbot is closed today due to snowmaggedon in Durham.

Thanks!

Brady Watson

01-18-2018, 03:54 PM

bking1836

01-18-2018, 04:04 PM

You may have overheated the spindle & it shut down to protect itself.

When the control box is on, and the key (if equipped) is in the on position, does the spindle fan run? Does the cooling fan stop or run when the condition happens?

If the cooling fan isn't running, I'd put my money on a bad 24v power supply.

-B

Best I can tell the fan runs continuously. When I first ran the spindle today, I wasn’t using the dust collector because I wanted to see how the acrylic would cut. It did create a decent amount of acrylic dust, and I wonder if it got sucked into the spindle?

But why would the xyz action stop too (every time except for the last time)?

bking1836

01-18-2018, 05:30 PM

And it’s incredibly dry. Static electrical interference? The acrylic dust cling to the machine like crazy. How should my machine be grounded?

tlempicke

01-19-2018, 07:07 AM

Also I have found that shutting the Shopbot program down and re-starting can fix a lot of problems like this. For some reason my machine does not like the C5 spindle warmup program and will, at time, do strange little things like this.

Brady Watson

01-19-2018, 08:49 AM

And it’s incredibly dry. Static electrical interference? The acrylic dust cling to the machine like crazy. How should my machine be grounded?

Good point. It is possible that static is triggering output 1.

Make sure you are properly grounded. Do a search on here for static and grounding. It's been answered a gajillion times over the years...Bare copper wire inside/through the dust hose. Yes, INSIDE it...

-B

bking1836

01-19-2018, 08:58 AM

Good point. It is possible that static is triggering output 1.

Make sure you are properly grounded. Do a search on here for static and grounding. It's been answered a gajillion times over the years...Bare copper wire inside/through the dust hose. Yes, INSIDE it...

-B

Thanks Brady. I wonder why the shopbot assembly manual doesn’t include machine grounding, or maybe I missed something.

Brady Watson

01-19-2018, 09:25 AM

...and rob you of your "CNC career come up 'ins" ??!!

What fun would that be? :p

FYI - those 24v power supplies for the fans notoriously go bad. I've replaced a lot of them over the years. (on the road) - Keep an eye on it, check voltage, re-seat the connections going into it for the fan - and keep an eye/ear out for that fan quitting in the middle of the job. The fans also don't last forever...

-B

bking1836

01-19-2018, 10:23 PM

Quick update. Worked with the always excellent folks at shopbot tech support and ran a series of experiments. The issue is almost certainly static from the dust collection system. Now I need to do the bare copper wire grounding solution.

bking1836

01-20-2018, 04:30 PM

Another update. I ran bare copper wire inside the flex hose, out the top of the flex hose and wrapped it around the metal brackets that attach the ductwork to the ceiling. My jobs still stutter and then eventually come to a full stop.

31099
31100

I know very little about electricity. Is it a problem that I wrapped the copper wire around the hose clamp at the dust shoe? If I leave it dangling in the hose, it will end up making its way into the cutter at some point. Does the copper wire have to travel all the way to the dust collector? BTW, there's already a ground wire running from the motor to the metal grates that surround the cyclone's filter.

If I've properly grounded the dust collector, now what?

Brady Watson

01-20-2018, 07:34 PM

You want an antenna.

Fold the bare wire over the hose @ the foot and put the clamp over it. Let it slap around inside the hose. Poke it out the other end and you can fold it over the same way - but it would be ideal to run a sheet metal screw right into the metal duct as long as you are 100% sure the dust duct is tied into the building's electrical ground.

Static can do weird things...Make sure you disable the proximity switches with the VN command. They are susceptible to static and are like long antennae themselves. This will not affect your C3/homing. Before you change the VN settings - As the machine is running - stare at input 2 & 3 - do they flicker? If so, that's from static.

-B

knight_toolworks

01-21-2018, 07:18 PM

I find iti s easier to use hose with a built in wire. one end goes on the metal pipe. also I find if the hose touches the metal of the machine can cause issues.

Brady Watson

01-21-2018, 10:00 PM

Hose with wire molded into it is there for structural support - not grounding.

The metal wire is essentially insulated (just like electrical wire) in vinyl and therefore not suitable for grounding static. It's a common assumption that people make & unfortunately it causes them to THINK their system is properly grounded, when in fact it is not...so they chase their tails.

Bare copper wire...IN the hose was deemed the proper way to do it years ago by ShopBot.

-B

knight_toolworks

01-22-2018, 09:55 AM

the grounding wire does not matter if it is on the outside or inside of the hose. it still works well. just like my antistatic shopvac hose. the static still gets to the wire. all you have to do is to touch a ungrounded hose on the outside to see the juice goes right through it.

steve_g

01-22-2018, 11:34 AM

“Hose with wire molded into it is there for structural support - not grounding.”

“the grounding wire does not matter if it is on the outside or inside of the hose”

You’re both right… and you’re both wrong!
As we’ve all found out, static is funny and capricious! As to the static draining ability of a wire molded in a plastic hose, it depends on the design intent of the manufacturer… Plastic is an insulator when it’s sheathing electrical wires in your home because the type of plastic used was chosen for its insulating ability! When it’s in a flexible hose, it can either be an insulator or a conductor, depending on it’s design intent… static dissipative hose is much more expensive than “regular” hose and unless you intentionally bought it for its static conduction properties, likely it’s not!

Static electricity wants to travel or gather on the SURFACE of objects, which is why in a non-conductive flexible hose, inside is better than wire molded internal. A ½” copper pipe inside would be even better (more surface area) … but that would defeat the flexible part…

Part of the capricious nature of static is due to some insulators becoming conductors at higher voltages… The voltages involved are astounding! It takes about 3000 static volts for a human to even feel it! The TTL voltage levels to trigger an input on your control board are in the 5V range… It’s amazing it ever works at all!

SG

knight_toolworks

01-22-2018, 12:56 PM

great info. it is a bit crazy. so far it has worked and once I kept the hose from touching the machine my problems I used to have have been defeated. I found a wire inside the hose just caught junk on it. I know I never get shocked on it and it does not crackle like the non wire ones I have to my table saw and such.

Brady Watson

01-22-2018, 01:49 PM

If you know enough to buy SD hose, then you wouldn't ever come here asking for grounding advice...which makes all that a moot point.

There are many examples of the preferred way mirrored online. Having consulted with actual shops having static grounding issues, all of which were resolved, BTW; I stand my my original recommendation of putting a bare copper wire INSIDE the dust hose. This is the most straightforward, reliable method to cure static-related issues on your machine. If you want to 'dare to be different', that's your right. Don't mislead people with caveats when they're looking for answers because their machine is down.

Further reading:
Ensuring Proper Grounding of Fittings and Tubing for a Dust Collection System (http://www.leevalley.com/us/shopping/Instructions.aspx?p=44424), Bill Pentz, Section G, Static Electricity (http://billpentz.com/woodworking/cyclone/ducting.cfm#static_electricity), etc, etc. There are plenty more examples...

-B

bking1836

01-22-2018, 07:33 PM

The saga continues...still having problems.

Today was much warmer and actually wet. My first cut went fine. On the second one, several minutes into the cut the machine stuttered and resumed a few times ever so quickly. And a minute or so later all xyz movement stopped and the xyz readouts on SB3 were going haywire. On the third cut, it stuttered several times but never actually stopped, although the 3D portion of the cut was a mess. So I assume I lost some steps or something.

I've gone over all my computer settings, and best I can tell everything is set up fine. And I now have a bare copper wire running through the flex hose, coming out the top of the flex hose and wrapping around the exposed metal wire of the flex hose, continuing on to the metal ductwork, where it is secured in place with a sheet metal screw. I then have a bare copper wire running from the ductwork to the edge of an electrical box on my ceiling. The DC motor itself has an Oneida-provided ground wire running from the motor to the metal grate that covers the HEPA filter. I'm grounded, right?

I will say that sometimes, when there is slack in the DC flex hose, it ends up resting on the black plastic wire car on the gantry (you know, where the spindle cord etc run). Is that a potential cause of trouble?

Everything worked flawlessly until last Thursday.

I've been working with tech support, but I don't feel like we are getting anywhere. Ahhh!!!!

Gary Campbell

01-22-2018, 07:46 PM

bking1836

01-22-2018, 08:58 PM

Look this over: https://youtu.be/zKzjhp-yDkE Your answer is in there

It is the video version of the doc I produced 4-5 years ago when I was working at ShopBot. Maybe the tech support guys should read their provided docs. :o

Best I can tell I’ve done all of this except for the insulated standoff, and the design of the whole machine makes it pretty hard to keep the flex hose from touching some part of the machine — especially the cords that plug into the spindle.

Where do I find a standoff?

jTr

01-23-2018, 04:54 PM

Just moved my shop, setting up DC and found one of these in my assortment:

http://www.rocklerpro.com/4-stablegate-blast-gate

Seems like an ideal, ready - made stand off. Have searched for a standoff in the past with no luck, so thought this was a pleasant surprise to find. Like me, you'll need to drill/tap some holes in the metal Z carriage bracket to make it work. The fact that it is a gate can be disregarded (left open), but I realized with my new set-up, this will actually be useful.

makes it pretty hard to keep the flex hose from touching some part of the machine — especially the cords that plug into the spindle.

True, but it can be done. Is your collection hose feeding to a relatively central location above the table? Some have had success adding a spring pulling hose away from gantry/Z car wiring for areas of travel that cause the line to contact there.

Hope this helps - I too have experienced static issues and USB/comm issues to a similar point of frustration. Listen to the advice being given here, and you'll soon have the issues resolved as I did. These guys are the best, especially with their intensive knowledge/experience with the Shopbot.

Jeff

bking1836

01-23-2018, 06:40 PM

Thanks everyone for the support. Today was a good day. Based on Gary's video, I rigged (hacked really) a plywood standoff-ish thingy for my flex hose so that it would be less likely to rest on the gantry, and I shortened the hose by about 8 inches. Today's jobs cut without a problem! Who knows if it's thanks to the standoff hack or not, but I am pleased. I will look for a more permanent solution.

31109

My flex hose connects to ductwork above the CNC a bit off center. I've monkeyed with all sorts of bungees etc but haven't found the right approach yet.

Brady Watson

01-23-2018, 07:42 PM

Glad you got it - it can be incredibly frustrating if you have jobs to get out.

Consider building a gallows arm of sorts that connects to the wall, is hinged and holds the hose.

-B

Gary Campbell

01-23-2018, 07:56 PM

Glad yer runnin man!

"
Based on Gary's video, I rigged (hacked really) a plywood standoff-ish thingy for my flex hose"

Do you think there is anything in that video that is there because it hasn't been proven to work? That video may seem simple, but it is the combined knowledge of myself, Brady and a few others that have been in hundreds of shops and solved real problems hands on.

You can call someone or look up the social media gurus that think they know stuff, but in the long run it is actually better to know stuff than to look it up.

(spoken by the poster child for the anti-social media)

bking1836

01-30-2018, 03:46 PM

Do you think there is anything in that video that is there because it hasn't been proven to work? That video may seem simple, but it is the combined knowledge of myself, Brady and a few others that have been in hundreds of shops and solved real problems hands on.

You can call someone or look up the social media gurus that think they know stuff, but in the long run it is actually better to know stuff than to look it up.

(spoken by the poster child for the anti-social media)
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So after things worked, they didn't....and I suspect it is directly related to temperatures and humidity dropping. So today I took two final steps: with an electrician in tow, we ran a ground rod through the concrete floor 6 feet into the ground and attached a massive bare copper wire to the DC frame (and dumped a good gallon of water down the hole). And I reconfigured the flex hose so that it truly doesn't touch the machine using some rigid foam and zip ties as a makeshift standoff. It ain't pretty, but after all that, even though today was quite cold and dry, I got through a job.

Gary - I think your video hits everything except for the ground rod in the floor. I can't believe Shopbot doesn't do a better job educating its customers about this issue -- especially those of us in the upper Midwest where winters can be cold, dry and full of static.

Thanks everyone for the help. Here's to hoping I finally licked this problem.

Brian

Gary Campbell

01-30-2018, 06:41 PM

bking1836

01-30-2018, 07:21 PM

Brian...
The ground into the floor is not in the video because I don't recommend it. If it was that action and not the physical isolation of the hose itself it would surprise me. You changed 2 things at one time? How can you tell which one fixed the problem?

If a ground rod, even tho used in many industrial applications with success to prevent machines from being charged with lightning and injuring an operator, solved your problem alone, then I would say something else is amiss in your electrical system. The reality is, that adding a ground separate from the electrical system ground creates a ground loop, often causing problems with computer controlled machines.

I have never added a driven ground rod to a machine, but I have disconnected the wires from machine frames to them. In most cases an immediate improvement was noted.

You don't give your location, but I might venture a guess that you are in a rural location that hasn't seen a power grid or code upgrade in a couple decades. They seem to be the most susceptible. From my actual experience these locations, especially shops on a subpanel from a residence that have been wired to older codes have shown to be problematic. The ground voltage potential between a CNC machine and the computer that controls it will problematic about as long as USB is the communication method.

Well bummer. The electrician seemed pretty sure that a driven ground rod was a good idea. Note that it's the dust collector frame that connects to the driven ground rod, not the ShopBot.

Tomorrow I will disconnect the DC from the ground rod and see what happens.

My location isn't rural. It's suburban Milwaukee in a light industrial area. The shop, however, is dated and so is my electrical panel.

The fact that all of this goes back to USB is maddening. I am looking forward to upgrading to FabMo wireless once they get that sorted out for my control box. When I was at ShopBot training a few weeks ago, Ted said that FabMo was coming to the Desktop in a month or so and to other machines not too long thereafter.

Gary Campbell

01-30-2018, 08:39 PM

Brian...
I misspoke. I assumed (actually misread) that you were connecting the driven rod to the machine. IF it helps, leave it, but I would guess that if it does help it is masking some grounding issues in the building. Is your building primarily 3 phase power? Is the electrical ground, for the most part, distributed by the conduit or by actual ground wires? In many cases shortcuts are taken with the grounding and especially the neutrals by not running them back to the main panel. The worst I ever saw was in Mexico. Like the worst horror movie I ever saw. 75 volts AC between the SB frame and the electrical panel ground. Torched every computer that was connected to the machine.

Yes, SB has a lot of hopes riding on the Fabmo system. But remember, it was also set to be in production in 2015, 2016 and 2017. Hopefully 2018 will be the charm.

bking1836

01-31-2018, 09:54 PM

Brian...
IF it helps, leave it, but I would guess that if it does help it is masking some grounding issues in the building. Is your building primarily 3 phase power? Is the electrical ground, for the most part, distributed by the conduit or by actual ground wires?

Building is primarily single phase. I'm not sure about the ground...electricity is definitely a deficit of mine.

Everything ran smoothly today. I decided not to make any changes or do any further experimenting. If the foam standoff for the flex hose was the winning move, great! If it was the driven ground rod for the DC system, great! If it was both, even better! All I know is that the ShopBot is operating properly now.

Thanks everyone for your help. It's hard to imagine making my way through the early months of ShopBot ownership without the support.

Brian