Shopsmith Forums

The stuttering/ chattering/ pounding PowerPro problem has, for me, escalated into a very serious matter. And asking for help and not getting it is now more than a coffee break joke.

Using the bandsaw t'other day, in a familiar configuration--i.e. table saw blade still on, well protected-- part way thru a cut, with the PowerPro chattering and growling merrily away, as it always has, there was a sudden sharp and unusual noise, one time. I stopped feeding the workpiece and looked around/ listened around, saw and heard nothing more out of ordinary except maybe the growling lessened somewhat (but now not feeding, so...), so continued the simple easy cut (on the bandsaw).

Finished cut, pushed the STOP button, waited for B-S to stop, removed workpiece, reached to turn off Shop-Mate, then noticed an odd noise. This now 10-15 seconds after STOP. Noise coming from table saw. Peeked under blade guard and (almost didn't see it at first) noticed Saw Blade was STILL turning, by now practically silently!

The vibrations (effectively Start-Stops) from the PowerPro Pound-o-Rama had finally 'popped' the saw arbor lock screw and the saw blade was merrily, and quietly, spinning away! (And since it is a clean blade the motion was nearly invisible.) The good news: if I had reached over there for some reason and hit the spinning blade, since it was 'free-wheeling' my guess is that I would have lost only a few ounces of meat and blood.
It took another 10 seconds or so to stop.
And another minute or so for me to stop shaking.

I'm going to try again to get this Pulsating Power-Pro Problem fixed. This time I'm not going to wait 3 or 6 months for a reply.

CAUTION! This stuttering start-stop growling (or whatever else one wishes to call it) is DANGEROUS, not a joke.

keakap wrote:The stuttering/ chattering/ pounding PowerPro problem has, for me, escalated into a very serious matter. And asking for help and not getting it is now more than a coffee break joke.

Using the bandsaw t'other day, in a familiar configuration--i.e. table saw blade still on, well protected-- part way thru a cut, with the PowerPro chattering and growling merrily away, as it always has, there was a sudden sharp and unusual noise, one time. I stopped feeding the workpiece and looked around/ listened around, saw and heard nothing more out of ordinary except maybe the growling lessened somewhat (but now not feeding, so...), so continued the simple easy cut (on the bandsaw).

Finished cut, pushed the STOP button, waited for B-S to stop, removed workpiece, reached to turn off Shop-Mate, then noticed an odd noise. This now 10-15 seconds after STOP. Noise coming from table saw. Peeked under blade guard and (almost didn't see it at first) noticed Saw Blade was STILL turning, by now practically silently!

The vibrations (effectively Start-Stops) from the PowerPro Pound-o-Rama had finally 'popped' the saw arbor lock screw and the saw blade was merrily, and quietly, spinning away! (And since it is a clean blade the motion was nearly invisible.) The good news: if I had reached over there for some reason and hit the spinning blade, since it was 'free-wheeling' my guess is that I would have lost only a few ounces of meat and blood.
It took another 10 seconds or so to stop.
And another minute or so for me to stop shaking.

I'm going to try again to get this Pulsating Power-Pro Problem fixed. This time I'm not going to wait 3 or 6 months for a reply.

CAUTION! This stuttering start-stop growling (or whatever else one wishes to call it) is DANGEROUS, not a joke.

Yikes. I agree that is a serious issue and I hope Shopsmith addresses it promptly.

Coincidentally, on another thread yesterday there was a discussion about what would happen if a set screw on a saw arbor failed. Sounds like we now know the answer: the blade can spin freely. Is there any visible damage or marring of the quill where the set screw failed? How about the arbor itself? Did the set screw pop out and strip its threads or the arbor threads or did the set screw just work itself loose?

Al

keakap wrote:The stuttering/ chattering/ pounding PowerPro problem has, for me, escalated into a very serious matter. And asking for help and not getting it is now more than a coffee break joke.

Using the bandsaw t'other day, in a familiar configuration--i.e. table saw blade still on, well protected-- part way thru a cut, with the PowerPro chattering and growling merrily away, as it always has, there was a sudden sharp and unusual noise, one time. I stopped feeding the workpiece and looked around/ listened around, saw and heard nothing more out of ordinary except maybe the growling lessened somewhat (but now not feeding, so...), so continued the simple easy cut (on the bandsaw).

Finished cut, pushed the STOP button, waited for B-S to stop, removed workpiece, reached to turn off Shop-Mate, then noticed an odd noise. This now 10-15 seconds after STOP. Noise coming from table saw. Peeked under blade guard and (almost didn't see it at first) noticed Saw Blade was STILL turning, by now practically silently!

The vibrations (effectively Start-Stops) from the PowerPro Pound-o-Rama had finally 'popped' the saw arbor lock screw and the saw blade was merrily, and quietly, spinning away! (And since it is a clean blade the motion was nearly invisible.) The good news: if I had reached over there for some reason and hit the spinning blade, since it was 'free-wheeling' my guess is that I would have lost only a few ounces of meat and blood.
It took another 10 seconds or so to stop.
And another minute or so for me to stop shaking.

I'm going to try again to get this Pulsating Power-Pro Problem fixed. This time I'm not going to wait 3 or 6 months for a reply.

CAUTION! This stuttering start-stop growling (or whatever else one wishes to call it) is DANGEROUS, not a joke.

Please explain 'popped the saw arbor lock screw'. Did it break or did it come loose and get chucked away somewhere. This starting and stopping (or what ever it is) that is causing the unwanted noise seems to be something more than just a noise maker. I would jump to a conclusion that there are some unusuall vibrations being set uo on the drive line. However, it is hard to say whether it is caused by the load brought be the band saw or is it a byproduct of the speed control algorithm.

Has Shopsmith made any declarations of cause or intent to resolve? Is this issue covered by warranty? If so, how long is the warranty good for and does continued use tend to invalidate the warranty.

I would not wait months or even weeks to get official feed back.

algale wrote:Yikes. I agree that is a serious issue and I hope Shopsmith addresses it promptly.

Coincidentally, on another thread yesterday there was a discussion about what would happen if a set screw on a saw arbor failed. Sounds like we now know the answer: the blade can spin freely. Is there any visible damage or marring of the quill where the set screw failed? How about the arbor itself? Did the set screw pop out and strip its threads or the arbor threads or did the set screw just work itself loose?

Al

If you are going to leave the blade on for awhile, say your sawing all day in the table saw mode, put a very small amount of finger nail polish on the threads and in a couple of minuets it will set up. When you get ready to remove the blade, it will break loose easily. I repeat, a very small amount. Having said that, the set screw shouldn't be coming loose if the hex wrench is being twisted till you hear that set snap noise. Be safe out there guys, Rick

I have had my PP jheadstock since 10/22/10 and recently I noticed that it seemed to be making more noise (rattling) than before. The noise seemed to be coming from low in the headstock so I suspected something near the motor.
I did have some rattling noises when I first got the PP and those were traced to the set screws on the SPT hubs coming loose.
I suspected then and (still do) that the loosening of those screws was caused by the pulsing of the PP motor and the power supply.
The DVR motor as I understand them runs by the power controller pulsing the stator coils which causes the rotor to move. This pulsing and the speed control aspects can cause a vibration under various speed and load conditions.
When I loaded the system with the sanding disc the flywheel effect and the load quieted the noise considerably. I ran the disc up to the 3450 RPM speed.
I know that that is too fast for the sanding disc but it was just a test. The rattle was very loud at the higher RPM with no load and almost gone with a load on the spindle.
This time the rattle was traced to a loose set screw on the motor pully. It was loose by almost one full turn. After the screw was tightened the noise was gone and the headstock sounded like it did when it was new.
I am going to contact CS tomorrow and ask if it is OK to put a drop of blue loctite on that screw.
I will let the group know what they say.
I bought my headstock factory assembled so I don't have the full information that is provided with the DIY conversions. The book with that comes with the assembled headstock is very limited in providing detailed mechanical info.
Bill V

ricknwood wrote:If you are going to leave the blade on for awhile, say your sawing all day in the table saw mode, put a very small amount of finger nail polish on the threads and in a couple of minuets it will set up. When you get ready to remove the blade, it will break loose easily. I repeat, a very small amount. Having said that, the set screw shouldn't be coming loose if the hex wrench is being twisted till you hear that set snap noise. Be safe out there guys, Rick

Rick

It is good to hear that you are still kicking around in the shop. Wish you were still on the Shopsmith Traveling Academy Circuit.

algale wrote:... Is there any visible damage or marring of the quill where the set screw failed? How about the arbor itself? Did the set screw pop out and strip its threads or the arbor threads or did the set screw just work itself loose?
Al

any visible damage? Cant tell, really, since there's always some set-screw-scratcfh from tightening/testing normal use. I can say nothing unusual seen. I'll take a closer look, out of curiosity.

"Did the set screw pop out and strip its threads or th..."

Apparently the set screw worked itself loose. It's all speculation, of course, but I theorize that the screw became "unlocked" and subsequently backed itself off from the vibrations as I continued the cut, until it went back far enough to clear the arbor flat. The axial displacement of the blade was less than 1/8 (or so-- frankly I didn't make an actual measurement {dang!- but I was a little "preoccupied" at the moment} and that 1/8 is just what I sorta remember. It wasn't enough to hit the insert).

And I also remember where I'd heard that noise before, or one like it- when one "breaks" a well-torqued bolt, like a head bolt on a small car engine, for instance. More of a mini-clank than a 'pop'. If I'd remembered that at the instant it happened I should have yanked the power plug as I ran screaming into the night.
(so to speak)

By the way, if 'axial displacement' is a totally bogus term, I apologize. It sounded good at the time.

dusty wrote:Please explain 'popped the saw arbor lock screw'. Did it break or did it come loose and get chucked away somewhere. This starting and stopping (or what ever it is) that is causing the unwanted noise seems to be something more than just a noise maker. I would jump to a conclusion that there are some unusuall vibrations being set uo on the drive line. However, it is hard to say whether it is caused by the load brought be the band saw or is it a byproduct of the speed control algorithm.

Has Shopsmith made any declarations of cause or intent to resolve? Is this issue covered by warranty? If so, how long is the warranty good for and does continued use tend to invalidate the warranty.

I would not wait months or even weeks to get official feed back.

Good points and good questions.

--As for "popped", I essplaned my theory in another post already. Theory it is, and as afterthoughts no less. I remembered the noise- later- and tried to figure out what musta happened. I think "start/stop" is the most reasonable conclusion. I can't see mere vibration loosening and then backing off an arbor set screw that is under constant 'forward' pressure. I have NEVER had a set screw come loose "by itself" before, in some 26 years of trying.

--I have no idea what SS intends to do with these things. It's only been about 4 months I've been waiting for that 'call back'.

--covered by warranty? Whatever else I may mutter 'under my breath' about this problem, I cannot imagine that it would not be, as IMHO ShopSmith has one of the best warranty records in the USA.

-- Does continued use void a warranty? I've raised this question and have no idea what the answer is. It bothers me. I can conjure up a mental movie- let's call it "Perry the Mason and the Case of the Badly Buttered Brick"- where someone uses a tool or product (mortar) that he knows is defective, gets beaned by a falling brick he just laid in, and tries to sue the mortar maker. Probably get laughed out of court. (Unless, of course, he is a union "worker" and the mortar maker is a "big corporation".)

ricknwood wrote:..., the set screw shouldn't be coming loose if the hex wrench is being twisted till you hear that set snap noise. Be safe out there guys, Rick

My criteria, as a P2 (Properly Paranoid) operator, for set screw tightening is the amount essperience tells me is sufficient, +4ft-lbs (a total of 387 dynes-per-fortnight-squared), to achieve a significant level of pain in my hand when loosening it with the bare-handled allen wrench. It's always worked before.

wa2crk wrote:...
This time the rattle was traced to a loose set screw on the motor pully. It was loose by almost one full turn. After the screw was tightened the noise was gone and the headstock sounded like it did when it was new.
I am going to contact CS tomorrow and ask if it is OK to put a drop of blue loctite on that screw.
I will let the group know what they say.
I bought my headstock factory assembled so I don't have the full information that is provided with the DIY conversions. The book with that comes with the assembled headstock is very limited in providing detailed mechanical info.
Bill V

Now this is very interesting. Mine is also new and came with scant info. I (perhaps foolishly) assumed that paying for the factory unit would get me something I could plug in and use. Safely.
I've heard about loose belts, but this is the first time "motor pully" caught my attention.
I need to open that sucker up and check both belts and pulley screws, methinks.