Spindle will only start once...

[scottbot]

Hi All,

Here's my latest problem. I sure hope someone can help me with this one.
I've got a PRS Alpha with a 4HP HSD Spindle with the Spindle Controller.
When I start it up I can only start the spindle once. So if I do a warm up routine well that's it. The spindle won't start anymore after the first time.
If I've got a cut I really need to make I'll forego the warm up routine and just make the cut. If I have to make another cut or change the bit well now I've got a problem because I have to power off the ShopBot and restart it before I can get the Spindle to start again. Oh yeah. There's no error message or any indication that there is anything wrong except the fact that the spindle will not start. No way. No how.

It used to happen only once in a while but it got worse and worse until that is what happens every time. My machine is fully grounded as per Gary Campbell and I've eliminated any source of electrical interference that I can think of. I won't even keep my cell phone near it now. The weird thing is that this has kind of crept up over time. I was running 3.6.32 and thought that might be the problem so I went back to 3.6.18. That work for a while and I thought I had fixed the problem. Then it slowly started to do it again until it got so bad that I went back to 3.6.32 again. That helped for a while too but again; it started to get worse and worse until I was back to the same old.

I contacted ShopBot support a week or so ago and was told that others who have had this problem fixed it by plugging the USB for the Spindle Control Card directly into the computer instead of a hub. That worked for a little while but then not.

It's a real hair puller because it's so inconsistant. The thing that fixed it last time won't work the next time.

To tell you the truth I'm sick and tired of spending so much more time working on my Bot instead of working with it.

I'll give Support a call tomorrow to see if they have any ideas. If any of you have any ideas on how to fix this problem I'd sure appreciate the help.

Scott

[Gary Campbell]

Scott...
Try unpluging the usb to the spindle controller to see if that is your problem. You will not have rpm control, but you might narrow down the problem. You may have a loose wire or a bad controller card

open control box, turn on with cover open
Run your warmup routine. Start another file to setup fault condition.
is there power to vfd?
Verify that the console indicator for output 1 is on
check contacts on brown spindle logic connection
check contacts to start switch
check all connections inside vfd

[scottbot]

Hi Gary,
Thanks for the reply.
I've tried running it with the spindle card unplugged. There was no difference. I tried that with the little spindle window in the control software tuned off and on with no difference.

I have not tried your other suggestions and will try them tonight when I get home from work.

The really curious thing in this is that it ALWAYS starts the first time without fail.

Thanks again Gary. I'll try your suggestions.

Scott

[frank134]

Hi. May I ask what type of computer you are using and the software on it windows xp of windows 7?

[scottbot]

Frank,
I'm using a Dell laptop. I've been using it to run the bot for almost 3 years now. 6 months to a year ago I switched from XP to 7. I haven't been having any troubles running 7.

Scott

[frank134]

The only reason I ask is I was having a lot of trouble with mine. First I had and old 386 with window xp. So I got a brand new one with window 7 the best hp had. That gave me more problems. Then I found one in our office. It was an hp Pentium four with 4 gb of sdram with xp. It been working great every since. I also got a little better hub then shopbot supply. the one they ship had poor reviews. I run the control thru the hub and the VFD straight to the computer. I have a PRS Alpha with a 4 hp spindle. I did the grounding and all the other stuff. For a year and half this drove me crazy. I spend more time turn it on and off to get thing done then anything. Both me and my son felt it was the computer causing the problem. I personally think it a communication between the computer and the control and the VFD drive. Well these are my thoughts and I hope you get your fix. Shopbot was a lot of help so is Gary so you’re in good hands.

[scottbot]

So this is what I found...
First thing I did was take the cover off the VFD and check the connections. Both grounds were so loose that they disconnected when I gave them a gentle tug. Everything else was nice and tight. I reconnected the grounds and made sure they were nice and tight.
Confident that this was the root of my problems I put the cover back on the VFD and started the Bot up.

The spindle started, as always, on the first try. I shut it off and tried again. Success! I tried a few more times and it continued to start. yipee. Then I moved the gantry and tried to start the spindle again. No joy. It wouldn't start. I had to turn off the power to the control box and restart it to get the spindle to work again. Just like before. So I continued to mess around with it trying all sorts of different scenarios. It was real hit and miss. Sometimes it would start. Sometimes not.

So it shut it down and went into the control box for a look. Everything looked and smelled ok (not burnt) so I just wiggled a bunch of the wires and tightened anything I could get a screwdriver on. Nothing was loose but I thought it was worth the effort to give everything in the control box a little tweak anyway. I had gone over it and tightened everything only about a month ago. Nothing was loose then either.

Oddly enough that seemed to make a big difference. I was able to start and stop the spindle multiple times and it would start up each time. I was even able to run a couple of small pocket jobs successfully.

Given the history of my machine I'm not overly optimistic that my spindle starting problem is cured but I'm hopeful. Those seriously loose ground wires have likely been major contributors to most of the problems I've been having. That was such a major failure point I was really surprised that reconnecting them didn't immediately fix the problem. I'll take what I've got for now and hope it keeps on working.

Thanks for your suggestions Gary. You got me headed in the right direction.

Frank,
Based on the fact that the Bot would work again if I cycled the power on the control box I was pretty confident that it wasn't the computer. Thanks for the input though. You just never know where the problem lies and all help is welcome. When deep frustration sets in it can be hard (for me at least) to see the obvious.

Scott

[frank134]

scott one other thing. I just remember when I first got my shopbot I had that problem. the spindle would start the first time and then after I move the gantry it wouldn't. with frank help we found the problem to be in the connector at the spindle. the large one on the orange cord. one of the pin inside the connector was not install right. it was bent and not making good contact. frank sent me out a new one and we rewired it. all was been good sence. when you said it wouldn't start after the gantry move it make me think of it.

[scottbot]

Thanks Frank. I'll have a look at that.

Scott