Shopsmith Forums

poihths wrote: but you still should check further before you go and lick whatever might be hot.

I will now try to pursue my problem with my PowerPro.

That was priceless! LOL

I am still drying my eyes ....

I have found that the proximity voltage detectors are useless if they are used in close proximity to a live circuit. Using one to check across switch will almost always give a false positive result due the close proximity. The only way to test the continuity of the switch while it is in circuit is with a good voltmeter. IMHO.

Bill V

poihths wrote:Since I've now emailed Shopsmith three times without a response and called them once with the experience of "We'll call you back in ten minutes" now being two days, I think I'm probably on my own. I'll try again on Monday, but in the meantime, I might as well prepare myself for tackling this myself.

As far as I can tell, the next step, as someone has pointed out, is to open up the case and get a look at the electrical connections at the switch and at the power supply.

I have never opened up a PowerPro head and I'm not looking forward to it. I can see that there are several obvious screws holding the sheet metal on, so getting the first two or three pieces of sheet metal off doesn't look too bad.

After that point I will be in "here be dragons" territory as far as my experience and knowledge are concerned. Any tips on how to proceed with the disassembly from those who have traveled these wilds before me would be greatly appreciated!

My guess (and that is only what it is) is your power supply is bad. The PS is (by their admission) a weak link in the system. With that said, disassembly and reassembly is a piece of cake and pretty straight forward. The pan is now just that, a pan, and no longer how the motor mounts. Don't be afraid of taking it apart, it's pretty simple.

Just my .02

poihths wrote:Although I'm sorry that this thread is now about voltage testers rather than the problem I'm trying to solve, it does seem as though some comments would be useful.

I have the impression that the folks who have commented so far haven't used one.

It's really a very handy little device. It will tell you when a wire, a socket, a switch, etc. is hot without you having to open it up and get a contact you can touch as you would need to do with a voltmeter. In response to a previous question about what the pointy end does, well, mostly it makes it clear where you're pointing it. It's just an aid, not a magic wand or an electrician's panacea, as some here seem to expect. You still have to use common sense and allow for the fact that you might be getting a false negative. In my experience, if it tells you something is hot, it is; if it doesn't tell you something is hot, it probably isn't but you still should check further before you go and lick whatever might be hot.

I will now try to pursue my problem with my PowerPro.

It’s pretty obvious that neither JPG nor I have used one of these non-contact voltage testers. For good reason ... although I’m sure that they have legitimate uses. I can’t speak for JPG on this, but I’d lay odds that he has never used a divining rod to find water either! Your description of your non-contact voltage tester device leads me to believe that it is probably a capacitive sensor, but making assumptions on such things mostly just leads to frustration.

It’s a damned shame that SS is dropping the ball on these PowerPro problems. But in fairness to them, It appears that they have over-relied on their motor/drive vendor. I don’t believe that they have significant electronics engineering expertise in-house.

JPG and I both have many decades of experience as electrical/electronics engineers, and we have a deep understanding of the underlying physics. Helping a layman troubleshoot an electronic circuit is always a challenge, even with good instrumentation. Your problem otherwise falls into the “simple” category, as far as identifying a defective component. We’d be happy to help, but this will entail using instruments and tests that deliver unambiguous results.

BuckeyeDennis wrote:

poihths wrote:Although I'm sorry that this thread is now about voltage testers rather than the problem I'm trying to solve, it does seem as though some comments would be useful.

I have the impression that the folks who have commented so far haven't used one.

It's really a very handy little device. It will tell you when a wire, a socket, a switch, etc. is hot without you having to open it up and get a contact you can touch as you would need to do with a voltmeter. In response to a previous question about what the pointy end does, well, mostly it makes it clear where you're pointing it. It's just an aid, not a magic wand or an electrician's panacea, as some here seem to expect. You still have to use common sense and allow for the fact that you might be getting a false negative. In my experience, if it tells you something is hot, it is; if it doesn't tell you something is hot, it probably isn't but you still should check further before you go and lick whatever might be hot.

I will now try to pursue my problem with my PowerPro.

It’s pretty obvious that neither JPG nor I have used one of these non-contact voltage testers. For good reason ... although I’m sure that they have legitimate uses. I can’t speak for JPG on this, but I’d lay odds that he has never used a divining rod to find water either! Your description of your non-contact voltage tester device leads me to believe that it is probably a capacitive sensor, but making assumptions on such things mostly just leads to frustration.

It’s a damned shame that SS is dropping the ball on these PowerPro problems. But in fairness to them, It appears that they have over-relied on their motor/drive vendor. I don’t believe that they have significant electronics engineering expertise in-house.

JPG and I both have many decades of experience as electrical/electronics engineers, and we have a deep understanding of the underlying physics. Helping a layman troubleshoot an electronic circuit is always a challenge, even with good instrumentation. Your problem otherwise falls into the “simple” category, as far as identifying a defective component. We’d be happy to help, but this will entail using instruments and tests that deliver unambiguous results.

AMEN!

However even 'concise' instruments are no guarantee of unambiguous results.

I believe in Murphy's law.

"I have found that the proximity voltage detectors are useless if they are used in close proximity to a live circuit."

Detecting a live circuit is what they're designed to do! If you use them in "close proximity to a live circuit" guess what--they'll signal the presence of a live circuit!

" Using one to check across switch will almost always give a false positive result due the close proximity."

This kind of voltage detector is not designed to do that at all! You're saying the equivalent of "if you try to drive a screw with a hammer it won't work very well."

All they're designed to do is detect the presence of voltage near the sensor so that you don't touch something hot when you thought it was dead. The have nothing to do with checking for continuity or anything else.

poihths wrote:"I have found that the proximity voltage detectors are useless if they are used in close proximity to a live circuit."

Detecting a live circuit is what they're designed to do! If you use them in "close proximity to a live circuit" guess what--they'll signal the presence of a live circuit!

" Using one to check across switch will almost always give a false positive result due the close proximity."

This kind of voltage detector is not designed to do that at all! You're saying the equivalent of "if you try to drive a screw with a hammer it won't work very well."

All they're designed to do is detect the presence of voltage near the sensor so that you don't touch something hot when you thought it was dead. The have nothing to do with checking for continuity or anything else.

Well said!

You larned quick!