Resetting of Y zero in middle of job???? (HELP)

[walnutman]

I once again have a problem that occurs in the middle of a job. Last time, the machine lost the Y control in the middle of a job. Now, in the middle routing a 3-d image in a very expensive piece of wood, the Y zero just rest it self. Take a look at the photo. This is driving me crazy. Can anyone help me with this? Its frustrating to loose all the time, money and effort in a split second like this. Is this a common problem with the new PRS machines? Im trying to eventually make a business of this,but Im starting to feel like these machines are not reliable. Any help would be greatly appreciated


530-651-4190
JEff
3757

[paco]

Jeff,

I'm not at all sure I can help you about what's going on on loosing position. It shouldn't be but it does... I believe SB is working on it...

To resume your cut, you need two basic things; -good accurate and reliable proximity switches to calibrate you X and Y, -the TBC offsets for the X & Y.

I used a dial to make sure my proximity system is reliable and accurate. I can get back within 0.005" from whatever happen... almost...

Whenever I start a job I set the X & Y working zero (Z2 command) AND I wrote down the X & Y TBC offset so I can revert to the exact same location if SB3 crash, hang, if a power failure happen or the tool bit snap and so on... You can get the TBC offset from the UV command...


3758

this is very important (to me at least). In fact, I have made a small routine to wrote it down with a custom cut command; I hit C5 and that's it! C6 tell me what's wrote down in the message box.

I have suggested that SB3 wrote the TBC offset in the file LOG and that LOG file to be create from the beginning of a file then updated at the end with the elapsed time and other "end" related infos...

Let me know if something doesn't make sense.

In today's case, you would need a reference point from the toolpath and the machined material to revert to your original working zero. From the above picture, it won't be easy... sorry... maybe someone will have a better idea on this particular case.

Do get familiar with the TBC coordinate system and use it as a safety.

Bot on!

[walnutman]

Thanks for the reply and info Paco. I understand the info here you have provided regarding zeroing, resuming cut etc. This is good info and another issue I have been wanting to learn about. However in my case here it does not apply. My material is ruined and I will have to fabricate a new piece to run this job. Start over from square 1. In this job, I zeroed fromt the center of the material. This (or was) going to be a panel attacehd to the front of my refrigerator. The image is a Vetric 3-D file. It was about 14" by 19". Tool path created in Vertor Art 3D Machinist. Not sure any of this info matters.

[paco]

Hey since you know you zeroed (X & Y) from the middle of the panel, wouldn't it be "easy" to find you original working zeros? I understand you may be off by some thousands by eyeballing it but I would give it a try at least...

Make sure you wrote down the TBC offsets next time.

Bot on!

[paco]

One more thought; maybe you could try to restart the file over but a few thousands (0.01-0.03") under the originally used Z zero...

Not so long ago, I helped a friend (who didn't know about TBC offset could be wrote down and used with the proximity system) resume the cut in a such case as yours from the first line of (machining) code and by carefully eyeballing the entry point in his panel... he was withing a hair... pretty "lucky" I'd say but it was well worth the try since it was a $450.00ca HDU panel.

[paco]

Don't remove the panel from the machine until your 100% sure you cannot resume the work.

Bot on!

[walnutman]

Paco, but in my case the resetting of the Y axis zero in the middle of running the file moved the cuting outside of the original area. (see photo). So the piece is ruined. If I restart the project, I still have that area at the top that was not supposed to be cut.

[paco]

Jeff,

when you first start the file, did you center the tool bit at the very center of the panel; i.e.: where the two diagonals meets? If so, just recalibrate your tool (i.e: home the X & Y; since the TBC might be lost too), re-zero the Z where you first did then from the center of the panel, zero the X & Y (Z2). Is that what you did when you first run the file today? Again, before restarting the file, wrote down the TBC X & Y offsets (UV command). If your unsure the tool TBC is well zeroed, it just not worth to write anything down as you cannot precisely relocate from unknown location.

Once you have the tool re-calibrate, if you know where you zeroed the X & Y then you can resume the cut or start over cutting some air. If you wrote the TBC offsets (X & Y) then you should be within pretty close, if not you'll need to eyeball it.

I'm not surprised at all that the tool did not return to the supposed zeros after if the control software failed. It happen (I know that for sure!) and you need to master the 'how to solve this' or it wont be last time you'll get that feeling.

I hope this help.

[jamesgilliam]

Jeff, This won't help on the ruined piece, but something I do when there is room on the material is use a v-bit to cut very shallow lines ( 0.005 )in one corner at 0,0. That way if there is a mishap, power goes out, anything of that nature, I can get back to 0,0 by putting the v-bit back in and a little eyeballing.

James

[bill.young]

Hey Jeff,

Are you running the latest version of the Control software, 3.5.3? There was a problem with a loss of position in complex 3d file in versions 3.5.1 and 3.5.2 , but that particular issue was solved in 3.5.3

Bill

[harryball]

Jeff,

I'm not sure if you're getting help here... let me say first that my PRT Alpha has run for hours on end reliably so it is possible.

Next, in this particular case... did the SW lock up / fail then you restarted and Y was moved OR did you walk in and to your horror find it carving in the wrong place?

Also, as Bill asked, which version are your running.

Robert

[walnutman]

I am running version 3.5.3. ALong with this problem, I have also had another problem in the past were the Y axis just stops moving in the middle of a file. (link to previous post)http://www.talkshopbot.com/forum/messages/26/21431.html?1180977235
Rob, no lock up at all. I started the file, and about 10% into it this happened. I have heard that there may be a probelm with the version 3.5.3 software. Could this be the problem?

[harryball]

The problem is supposed to be fixed in 3.5.3 I don't do a lot of 3D work but I've done several with 3.5.3 without problems.

I would have to wonder if you don't have a driver or even a stepper problem since you're Y has stopped moving in the past. It would make sense in this case if your Y stopped moving then started moving again creating a position loss unknown to your control software.

I think I'd give SB a call first thing Monday and go over some options, figure out what to test etc... This would not be considered normal behavior and there must be a cause.

Robert

[bill.young]

Jeff,

Tech Support is available on the weekends...give them a call and they'll get back with you and help you work through the diagnostics to figure out the problem.

Bill

[mountie1808]

This same thing happened with me today, twice. Thank goodness I was using scrap 3/8" pvc material to make a template. Two sheets later and I've still no template and a problem that I'm not sure how to fix. I'll be calling tech support in the morning.

[harryball]

Keep us posted as you solve the problem, I've been running almost 8 hours a day most of last week, Saturday and today without a problem on 3.5.3. It's not 3D work but the bot is running grooves every 1/2" over almost entire sheets of material.

Robert

[walnutman]

I called Shopbot and they told me that the problem maybe heat generated in the control box. They told me they have had a rise in reported issues during the hot weather. I was asked to place my control box on its side to help disapate the heat away from the controllers and install a fan to help circulation. I will be doing these item in the next few days and will report back what I find. The probelm is intermintant so it may take some days of testing to be sure. This seems like a posibility, but Im not totaly convienced yet as my problems have not all occurred during hot weather. If heat heat is an issuem it would have ben nice to have a fan already installed when I got the machine.

[richards]

Jeff,
There was a discussion concerning the 4g and heat back in February. Brady Watson suggested a clever way of adding heat sinks to the Gecko G202 stepper drivers in his post here:

http://www.talkshopbot.com/forum/show.cgi?tpc=28&post=45995#POST45995

Personally, I would prefer having the Geckos mounted on a thick piece of aluminum, but strapping on a heatsink would be better than nothing.

(Right now, my themometer is pegged at 110 F. in my shop. Outside temperature is 102 F. I keep a fan blowing constantly on controller box of my PRT-Alpha. So far, there have been no problems.)

[mountie1808]

I called shopbot and they decided that it was a bad board. They're sending out a loaner board to get me through the next couple weeks until my Gecko comes. Apparently my bot doesn't like going faster than 2 inches per second even though we've been running it that way since 2003 for everything except aluminum. I'm hoping this fixes the problem. As always, I'll keep you updated.

Mke

[mountie1808]

Got the loaner board in and swapped them out. Everything seems to be cutting just fine now. Now I just have to wait until I get the gecko board.

Mike