Really Need Help!

[kubotaman]

Okay I really need help trying to solve my problem. I have a 5'x10' Prs Alpha that I have had approximately 1.5 months. I am trying to cut some stair stringers and can't manage to do it. I have tried for over four days with absolutely no sucess! The problem I have is the Y axis will wander off track big time! Today is a following list of what I did.

1. I switched motors from the x axis to the y axis, along with necessary drivers, thinking the y motor was weak. No help!

2. I totally uncoiled all wiring thinking maybe some feed back was being created. No help!

3. I made sure all wires in the Igus chain were seperated as much as possibe. I also made sure the cable for my spindle was to one side as per instructions. No help!

4. I checked to see if machine chassis was grounded and it is. All grounds go back to the electrical panel in my shop which has a common ground. No help!

5. My dust collector is totally grounded.

6. I switched keyboards and mice from wireless to wired with no effect. No help!

7. I totally switched computers thinking maybe software had a play in my problem. No help!

8. RPM of spindle has absolutely no effect on my problem. I know this since I have had the problem no matter what RPM I have set the spindle to.

The problem will arise, when I hit the spacebar, giving a pause command during the file being cut, and give the command for the x-axis to travel at a rate of 3 or even at 1 or anything in between. Forty percent of the time the y-axis will wander off track as much as a 1/4" when z-axis lowers itself and the x-axis proceeds to move forward. I have even had the file being cut,had the Alpha control box open and have shaken all the wires possible without sucess.

I have spoken to Shopbot numerous times and they now are on speed dial on my phone! The only thing I can think of is my wire from the control box to my y-axis is acting up. I have even changed my USB cable to different plugs on the back of my computer. I have had a screen twice come up and say Port4 has lost its signal and there my be a wire loose. Well I sure would like to know which wire!!! I have tried my best and I may use my new ShopBot as an anchor soon!!!! Any help for a loser out there??

[thewoodcrafter]

How about a little more info.

How fast are you cutting?
How deep per pass?
What size and type of bit?
What is the material?
What software/postp are you using?
What spindle size?

[kubotaman]

Okay no problem!
1. Cutting speed is between .7 IPS and 3 IPS.

2. My pass is at .125" and that is all.

3. I have cut with multiple bits but my latest is a HerSaf 3/4" bit. All bits used have been brand new. I thought it may be the bit also but changing bits made no difference.

4. The material I have been cutting has been Red Cedar and since I have had problems I switched to Douglas Fir since I can replace it. My Cedar is not available to me since it is clear.

5. Software being used is Aspire for the tool path and obviously ShopBot 3.15.18.

Spindle size is 1/2" and I have ordered a 5/8" replacement.

[thewoodcrafter]

Don't see any problems with that info.

What HP spindle?

What RPM?

Are you using the arcs/inch postp?

Are the stair stringers cutting at 45deg to the X and Y?

Are you sure you are not overloading the machine?
You are only cutting 1/8" deep???

Does this happen cutting anything else?

Of course you checked all mechanical things like pinon, rack, stepper? Everything is tight?

Your unit values correct?

Your resolution values correct?

[kubotaman]

1. Okay HP is HSD 4HP

2.RPM is between 12,000 and 18,000. No difference.

3. I have used both 3.15.18 and the previous version. No difference. I have saved to ShopBot/inch alpha postprosessor.

4.I am not cutting at 45 degrees. The rise is 7.5" to 11.125" run. What ever angle that is?

5.No overloading on these cuts. Cuts like butter so no stress put on the spindle!

6. Can't say it cuts wrong on other files. I haven't tried any.

7.I have checked all drives and mechanics. They all seem to be very tight and smooth.


8. I haven't changed any values so that should be okay.

9. Not sure what the resolution values are. Can you explain what you are refering to?

[thewoodcrafter]

I would test another file.

Maybe cut a circle. See if it comes out round.

That would not be 45deg but it is angled to both axis.

The resolution value is at the bottom of the unit value page.

I would always use a postp with "arcs" in it. Should give better results on curves and angles.

[myxpykalix]

a couple things i might try is replacing the usb cable, sometimes those little pins may come loose and cause a problem.

Can you rerun the same file and find that it happens at the exact same place each time?

I would try reloading a earlier version of the software on the computer and remake the file, then rerun it.

[erik_f]

Have you checked the speed of your USB connection? Also you want to shut off all power saving features, screen savers and any extra poo in windows. There is a thread on how to do it somewhere. There is a utility in the control software to check your USB. You should be running the USB 2 hub that Shopbot provided...ideally the usb port on your computer should be usb 2 also. SB says your connection speed should read around 70% minimum.

[zeykr]

You seem to say it only happens when you hit spacebar to pause. I think we need to examine what's happening there.

How many times in a run are you pausing? I've had similar problems in past when I paused multiple times.

Do you need to pause - i.e. what are you doing when you pause? If just changing speed a little can you use shift < or shift >? or are you doing somthing else during pause?

I usually use S to stop machine and then insert an ms command to change speed. not sure if that's any different than using spacebar or not.

[beacon14]

I've also seen a loss in position after using the space bar, especially if I hit the bar more than once. I try to avoid using it except in emergencies.

[kubotaman]

Okay, thanks for the suggestions!

1. Changing USB cable is a good suggestion but I have shaken it to see if I had a good connection without any failure occuring.

2. I will check circle cutting today. I had thought of it but neglected to do it.

3. I have checked the speed of the USB cable already and it is at 74% which ShopBot said is okay.

4. No screensavers are running nor any windows updates. All are shut off.

5. My USB port is a brand new 2.0.

6. Ken there is no need to pause as often as I am doing, once every ten feet of cutting, I am doing it to find out what my problem is by trying to duplicate it. If my memory is correct, the problem originally happened when I wanted to speed up the feed rate from .7IPS to 2IPS. When pausing all I am doing is changing feed rates, again trying to duplicate problem, not out of necessity.

7. I will try the suggestion and try hitting "s" key to see if the problem persists.

8. Keep any suggestions coming, I need the help.


A little more information that happend yesterday is after pausing and changing feed rates, no matter what speed of feed, twice the spindle completely lost y-axis and cut wildly for about 6" at 1/2" cutting depth. Talk about sucking wind by the wrong end!! It would then give me a screen that I lost communication on 'port #4'. Can all of these problems stem from the fact I hit spacebar insted of the 's' key? Thanks for the help!

[knight_toolworks]

74% is pretty slow. I was only getting 73% till I got a new powered usb hub. shopbot says don't use a belkin. a new hub got me into 83% range.
what kind of computer are you using? you can change the cut speed with shift >< to change the cut speed while the machine is running.
or if you have a need for speed changes all the time you need to change the way you raw your parts out.

[kubotaman]

Steve I don't think the speed of the USB port is my problem. The drawing is nothing more that a stair stringer which let's face it is pretty bacic drawing. I didn't know about the shift <> I will try it. Thanks for the suggestion. Maybe all this time it was a fault of the command given by the 'spacebar'. Time will tell. I will try your suggestion!!!!

[erik_f]

Maybe its the USB input board on the controller? Maybe I missed it earlier, but does this only happen when you pause cutting? If you let the file run all the way through do you have the same problem?

[dana_swift]

You can change the cutting speed while the tool is running without pausing the cutting operation. Use the < and > symbols. Each click increases or lowers the current cutting speed.

Be careful to use the shift key, not escape or option!

I change the cutting speed often now. These days my cutting file will specify a move speed around 1ips then when the file starts cutting I increase it till the router loads up or the corner acceleration becomes jerky. Then each piece of material that I cut will be cut close to its optimum.

Really handy commands to know about-

Daryl- the problem you describe is very unusual. Something is clearly going wrong other than the stopping the cuts. My machine never looses its marbles if I pause and resume, or abort and re-run the file (or another file).

At least you can stop pausing the file. Like Dave Buchsbaum I only use that in an emergency. However I have hit the space bar by accident and had to continue, and it runs just fine.

FYI I am currently running 3.6.1 beta 16.

D

[knight_toolworks]

it may not just be a speed thing. I had all kinds of wacky things happening till I replaced the hub and the serial to usb jack on my setup.
like I would type a jog command and my machine would do a move command. I would zero the machine make a cut or two then it would be off. it's easy to get a powered hub and test it.

[ron_moorehead]

Steve,

What brand of USB hub did you get?

[knight_toolworks]

dynex. I never has a speed increase with the belkin hub but got a 10% increase with the dynex. it made more of a difference then changing out everything else. my computer is a older dell and that could be part of it too.

[gerald_martin]

Daryl:

I have a 2008 PRS Alpha tool. I had lots of erratic issues most of which we finally isolated to a BELKIN usb cable. I bought a Monster Ultimate cable that is triple shielded, this seems to have corrected my problems. The speed test was no different with the new cable (about 74% I think) but obviously it's better at rejecting electrical noise.

Stick it out, your Shopbot will be an "anchor" for you some day in a whole lot better way than you think right now.

If you work thru the slow process of elimination with tech support and cooperate with ideas that seem certain not to fix the tool, I think eventually you will nail it.

I've been there too. It's better now.

Don't hesitate to email me (see profile) I'll be glad to help if I can.

Gerald

[ron_moorehead]

Here’s a problem I have been having. If my shop gets much over 72 deg I start having problems with my PRT Alpha. When I run a file and it goes from the variable window to the start spindle dialog box and if it pauses about a second or two, once I click on ok on the start spindle dialog box it will pause the required time and once the carriage starts to move to cutting position it will move about 12” and then crash the system. I have to then reset and re-zero and start over. What I have found to fix my problem for now is to open the door on the control cabinet and put a fan on the electronics to cool them down. Then she works great no mater the temperature. I need to call in and see if I need to replace something or not, or install cooling fans on the control box. Hope this helps someone.

[khaos]

As far as getting your PC to strip the un-needed (as Erik says) poo out of the system. look here http://www.talkshopbot.com/forum/messages/26/32297.html?1215604790

rotflmao That post should be titled bot control PC colon cleansing! OMG

[kubotaman]

Well thank you guy's for all the help!!!! Today was a lite day for ShopBot! I only called them 3 times!!!!!!! I have sent them my file because it may be the problem.?? I haven't cured my problem but I stated earlier that I would try to cut some circles today which I did. They seem to cut fine even though I used the spacebar to pause, while cutting the circles. That led me to believe it was my file. So guess what I decided to do? I cut my stringers, which were 3.75 inches thick, 1/8" at a time and as long as I didn't pause for any reason they cut perfect. I had tried to use the 's' key to pause which was suggested earlier, but that even caused problems. I therefore didn't touch anything and attempted to cut my file without any pausing by me. They cut perfect!! Why I had problems I don't know. If anyone would like to look at my file I would be glad to forward it to them. Maybe I fell on to something that throws a glitch into the software??

[thewoodcrafter]

If you are cutting circles correctly then it must be the file.

You should be cutting at way more than 1/8" at a time.

[kubotaman]

No I feel I could do much more than a measly 1/8" cut but since I am doing such a deep cut i really thought I would play it safe. The end results made me happy so I am pleased!

[road_king]

Daryl,

On 4/30/09 item 3 , you stated
"3. I have used both 3.15.18 and the previous version. No difference. I have saved to ShopBot/inch alpha postprosessor."

On my PRT Alpha, I always use Shopbot "arc inches" post proc. I currently have Aspire Version 1 software installed and will be upgrading to Version 2 "Aspire" this week.

Don't know if this will work for you but it may be worth a try while "air cutting".

GB

[kubotaman]

Gerald, I try "air cutting" with all my files that I have made. I do this since I am new to the ShopBot. Yes I have also saved to "arc inches" but doesn't seem to make a difference. Since I have aircut this file it doesn't seem to show any flaws but when I cut and pause that is when the spindle will grab the material since it loses the y-axis. Hope you understand what I am trying to say.

[beacon14]

You can change the cutting speed while the tool is running without pausing the cutting operation. Use the < and > symbols. Each click increases or lowers the current cutting speed...

I change the cutting speed often now. These days my cutting file will specify a move speed around 1ips then when the file starts cutting I increase it till the router loads up or the corner acceleration becomes jerky.

Dana,

I also use the "shift >" and "shift <" to adjust the move speed on the fly, but my understanding is that this might not be the best practice to recommend or use on a regular basis. I'm told that there are certain ways the SB controller calculates ramping and look-ahead values which do not get adjusted when you use this method to change speed, making it more suitable for small changes in move speed but less desirable for large changes (1 ips up to 4 or 5 ips would be a large change).

So what I would recommend would be to do what you say on some scrap or sample cuts, determine the optimal speed for that bit and material, and then program that speed or something closer to it into the file before cutting the actual project.

[dana_swift]

Thanks David- that explains why it gets jerky when I run the speed up. I do that pretty often, hadn't thought about the ramping not adjusting automatically. Shouldn't it? Sounds like a good idea for the next beta..

I think my unit works anyway because its an alpha, those corner accelerations get higher than a standard bot might be able to track.

D

[harryball]

Maybe I missed it, but does it loose position when doing aircuts with the spindle off?

/RB

[kubotaman]

R. Ball, the answer to your question is no. It does not lose position when the spindle is on but then again I don't think I would know if it did since I am only cutting air. I have run my spindle while "air cutting" with no faults that I know of. It only will lose position when cutting since that is the only time that the cutter has the ability to grab the material since it is cutting. I also have to say that I have no problems with the shift <> keys. I only will have the problem when I raise the spindle and that is a guesstimate of about 40%.

[harryball]

OK. If it were me I would try the following.

With the unit powered up, can I force the Y to move manually?

With the X moving (and being VERY careful with spindle off) can I force the Y to move manually?

With X and Y moving (and being VERY careful with the spindle off) can I force the Y to move manually?

If such a light cut can cause the Y to wander, but air cuts work perfect then I'd try to isolate lack of holding power vs loss of steps.

I don't know where the diagnostics information will lead, but it's information I would gather.

/RB

[Mike Windsor]

I had a similar problem a few years ago . What I finaly found was that my dust colection hook up was making static when I cut . I could see the sparks shooting to the table , and eventualy back to the control box . The air cuts worked just fine , because there was no moving dust to make the electrickery . ---Try cutting with your dust collecter turned off .

[kubotaman]

R. Ball I have tried to hold back the x-axis along with the y-axis and believe me it is near impossible. I have thought that the y-axis was losing power when entering the cut after being paused and lowering itself. The spindle will move maybe an inch and then off it goes! I did have static electricity give me problems when I was surfacing the table but have completely cured that problem by completely grounding all hoses and dust collector. I don't believe that is the problem. I am firmly convinced that the file is causing the problem now! I again cut the same file along with a stringer 3.75" deep and it again cut perfect! The one thing I did not do it pause to raise the spindle. Again it acts up only when I raise the spindle. ShopBot has my file but to tell you the truth I don't think it will go anywhere, hope not since I really don't want anyone to have the same problems.

[thewoodcrafter]

Daryl,

I would think if it cuts a circle fine then you are right it has to be the file.

[knight_toolworks]

try doing test cuts ( a new file) and do the manual things again and see if you still have the issue. myself I think they will still be there but you never know.

[Gary Campbell]

Daryl...
Usually when I use the [S] key or [Spacebar] to pause a file it is because something is wrong. You havnt said why you are doing this.

I have done this to adjust speed or depth to achieve proper cutting action, usually at file start. In most cases I will restart the file from the beginnng.

By now you should have this dialed in. Just run the file.... start it and step back.
Gary

[kubotaman]

I stated earlier when I first had the problem I had to adjust the feed speed. That is when I had the problem. After that when I would raise the spindle I was trying to discover why I was having the problem by cutting 2x12's that were "samples". If I cut circles , small or at reasonable speed, I have no problems what so ever. What I am trying to say is if I have to change tips, replacable inserts, I want to feel I can do so without the worry of having problems. That is why I am trying to attempt to solve the problem. Is anyone out there want to try the cut on their machine?

[frank134]

I have a 5 x 10 prs Alpha for only a fews month. after getting it set up and starting to used it we found a problem. every once in awhile the spindle would go dead or wander then stop. we found the proble to be in the connector on the orange wire to the spindle. The plastic clip in the conector was broke and the pins insdie were making poor connections. Hope this may help. we have not had a problem since we fix it.