Extreme stepper motor noise

[Coogara]

Hi folks,

I've been happily running my Desktop unit since the start of the year. I'm very comfortable with the sounds it makes, the difference in noise type and level from stepper motors when making small, slow movements and when making fast movements. However...

I had an incident yesterday that is causing me considerable angst and I currently have no solution. I had loaded a file in preparation for a cut and realized I needed to stop immediately - can't remember why now - so I hit the space bar (after the movement alarm had sounded and the spindle had powered up but only just as it was starting to move, I think). The Quit/Resume dialog appeared and the stepper motors started making an awful chattering sound as though they were making many tiny movements, but without the gantry visibly moving. This noise continued unceasingly - the only way to stop it appeared to be to shut down the ShopBot.

Ever since this event I am having problems with the machine making small movements. I'm cutting 3mm MDF at 2 ips XY and .5 IPS Z. The machine seems to behave okay when making straightforward movements, but as soon as it needs to cut a tab or fillets, where small adjustments in position are required, the stepper motors start making the same horrible noise and the machine position is changing extremely slowly - so slowly that to cut a tab is taking at least a couple of seconds. I'm cutting files that I have cut before - no change in the instructions.

I'm running Sb 3.8.6 - checked that I have the latest firmware installed. ShopBot and computer have been "rested" overnight. No improvement today. Aside from the fact that cutting fillets and tabs is now tediously slow, the noise from the steppers is awful - I've never heard them like this before.

It's hard to tell if it is all of the steppers. Is it safe to disconnect one stepper at a time from the control box to test them individually?

Anyway, where do I go from here? Is it the control box? The stepper motors? Nothing else has changed on the system. As I said, this started when I had to do a stop immediately after starting a cut file.

Thanks for your time

Graeme

[Coogara]

http://youtu.be/dj0fGfmO85g

[scottp55]

Graeme, That sounds awful. Just posting this so I'll be subscribed as I did my first cut on the new desktop yesterday and paused the cut several times just to check accuracy of resume(great). Hope someone can help you soon. Thanks again for all your help in us picking Desktop. scott

[Simops]

Graeme,

Have you contacted SHOPBOT tech support on this one??

Hope you sort this out.....

Cheers

[bill.young]

Hey Graeme,

As Michael said a call to Support is the quickest way to get you fixed up because they know all the right questions to ask, but you might want to check your ramping values. Use the VR command to open the ramp values fillin sheet, and when you hover over any setting you'll get a tooltip with the default values. See if your values are close to the default...if they are too low they can cause the sort of symptoms you're describing.

Bill

[paul_z]

I have had a similar issue with my PRT Alpha. The file containing the speed and acceleration values got corrupted and had to be reset to the default values. I don't remember how I did that. It turned the growling, shaking machine back into a purring kitten.

Do a search in this forum for "default" and you find how to do it.

Paul Z (A fellow Delphi user)

[jerry_stanek]

Do a UR command and reset to the default settings.

[Coogara]

Jerry, thanks, and thanks to everyone for their concern. I did contact ShopBot support but have no response yet so decided that I should at least take Jerry's advice. Issued the UR command - not quite 100% - switched everything off and on and now all is smooth as silk again. Wow! And yet all the values appeared to have been in range prior to the UR and yet this made all the difference. Good call Paul amd Jerry. Many thanks indeed. It's good to have my machine back to normal.

Hey Scott, I'm glad you're still happy with your Desktop. I wondered whether I'd outgrow it in 6 months but so far it still fits my needs and my available space (more to the point).

Graeme

[scottp55]

Graeme, glad it got straightened out and you're back in business. Off the subject but you said you wrote a spindle warm-up timer program with a sound for spindle speed change? If you still have it do you mind sharing? Also shopbot no longer ships Desktop with the starter projects, but Dianne located a set in old inventory and shipped it. But I can't seem to locate the .sbp cut files (corner jig/dowel holes,illusion etc.) if you or anybody else hung on to those files from your newbie days, could you please e-mail them to scottkport@gmail.com Thanks again for your help in the beginning all.

[Coogara]

Hi Scott,

The file is too large to attach so I put it on my web site:
http://www.coogara.com/zips/ShopBot/CNCWarmupAlarm.zip

As timers go this is fairly simple (and there are are free products on the web that will do the trick too). But as a programmer I like to roll my own so I know what's in them.

There are two files in the ZIP. Put them somewhere that your system happily has write permissions. (I was lazy with this - it creates an INI file locally to store settings. The new Windows UAC does not like writing settings to the c:\Program Files folder so I put mine in c:\CNC Warmup.)

You can replace the alarm.wav file with your wave file of choice. I also manually create a shortcut and add the program to Startup so it's always ready when I boot up.

Click "Start" and the timer runs with the default of 180 seconds. The alarm will sound, I crank up the Desktop spindle speed and click Start again. Three times and I'm done.

As for those SBP files, I'll take a look when I next fire up the machine.

Cheers

Graeme

[scottp55]

Thanks Graeme, the .wav file will help, as sometimes I start something else and miss the code line. I don't like to do things twice if I don't have to. Enjoy you day, suppertime here. scott

[Coogara]

That's exactly why I added the wave file. I was missing the three minutes all the time. Glad to help.

[scottp55]

Graeme, just installed your eggtimer for spindles. First time I heard the .wav on speakers, I thought I had a State Trooper in the wheelchair backpack pulling me over. You can't miss that! Thanks it will help.