PM1500 problem

[Robert Hayward]

My PM1500 bandsaw started occasionally dropping the blade tension handle causing the blade to come off the tires. Not realizing the tension handle was dropping first I replaced the tires. Problem continued and then I saw the tension handle drop before the blade came off the wheels. Started happening more frequently until this past weekend I could not get the tension handle to stay up long enough to turn the saw on.

Took the top wheel off and could see wear on the tension cam and locating block it rides against. Powermatic part numbers PM1500-069 and PM1500-010-18. These two little parts are $184.00 with tax and shipping! They will be delivered tomorrow according to UPS.

The flats on the cam have wear rounded corners which appears to be why the weight of the tension handle would allow the cam to rotate off the fully tensioned position.

Has anyone else experienced this? How do I prevent this from happening to the new parts? This is a lightly used hobby bandsaw that I bought new, a one owner/user saw.

To say I am shocked at the cost of these two parts is an understatement. When I first saw the damage I said to myself no big deal I will just go in and order two new ones. I think I will keep the bad ones and see if I can weld new faces on them and file/grind to proper shape. Then keep these for a backup.

[glenn bradley]

To say I am shocked at the cost of these two parts is an understatement.

JMHO, YMMV. My apologies in advance to the mustard lovers.

Welcome to Powermatic . They make some nice stuff but price it as if it were a lot, lot nicer. I keep waiting for the brand-loyalty goggles to wear out but they keep on working.

[mike stenson]

I think I will keep the bad ones and see if I can weld new faces on them and file/grind to proper shape. Then keep these for a backup.

this is exactly what I'd do. Kind of hardfacing.

[Bill Dufour]

Bad heat treat. I would contact the maker and request free replacement. They should want to know bad heat treat slipped through. Make a new one from prehard, round.
Bill D

[andy bessette]

I just leave the blades tensioned on my bandsaws.

[Robert Hayward]

Leaving the blade tensioned is what has been going through my mind. The bandsaw is out of warranty so I doubt Powermatic would replace the parts free, although I did not try.

Bad heat treat was also a thought I had. Thing is only about half of the two mating surfaces are marred or a better term galled. Also both mating pieces being galled in the same place? Not likely both parts missed treatment in the same spot, at least to my thinking.

I am going to take a closeup shot of the galled areas and post the pics here. I am thinking some kind of mechanical damage started the problem. Maybe a blade jumped the tires and got caught back there while it still had momentum. I have looked closely at the assembled saw and that looks possible. A close up photo will show why I believe that is a possibility. $184 for two little parts I can conceal in my palm makes me real cautious before installing the new ones.

[Robert Hayward]

Close ups. Cam and locater block.

A deep gouge on the cam in the area the teeth of a blade jammed between the two parts could be. Just a theory, but I am leaning towards mechanical damage. At least to start the failure.

[andy bessette]

...Maybe a blade jumped the tires and got caught back there...

Very likely.

[Bill Dufour]

That looks ripped not worn down over time.
Bill D

[Robert Hayward]

That looks ripped not worn down over time.
Bill D

After looking at it more I agree. I am convinced it is mechanical damage from a blade. Not sure what else could have gotten into the upper housing behind the wheel. I do not saw old car parts or such.

[Robert Hayward]

The new parts were UPS delivered at 8:40 PM Wednesday. Put the box in the shop with the idea of working on it in the morning. Then could not stand it as it was only 9:00 PM at that point. Installed the parts and put the rest of the bandsaw back together. Put a blade on the saw, lifted the tension lever and reached for the wheel to give it a spin to check tracking. The tension lever falls down. What the....

Checked tension and whatever else I could think of. No luck, better let this go until in the morning when I can call Powermatic tech support. Powermatic was completely stumped. Especially when I told him I could put tension on the saw with no blade on it. Kept asking me how can you tension air? I am doing it right now while I am talking to you. Not possible he says. I know, that is why I called. This saw has a problem that I do not see the fix. Keep in mind I do not remember or maybe never knew what this saw looks like from the factory, I only know what I am looking at as it sits.

Look at the two circled collars in the attached picture. Turns out they had moved down to the point the upper wheel could not go high enough to put proper tension on the blade. The cast iron block below the collars was stopping the proper movement by being up against the collars. I had not loosened either collar in my troubleshooting but had looked closely for any sign of marking on the guide rods indicating movement. The cast iron block was tight up against the collars as it is shown in my picture. With the weight of the wheel on its axle there is a gap. That gap allows the wheel to move up and tension the blade.

Just by chance I loosened one of the collars and looked for marks on the guide rods indicating movement. Shiny smooth like new. Not even a mark from the set screws. Hmmm, if that rod is so hard the the grub screws did not mark it the collars could move and it would not show. I called tech again and left a message asking for the factory location of the collars on the guide rods but they never called back. So I started fiddling with the collars positions. Success! I was able to tension a blade, but not enough. More tinkering and I think I am back at factory location. I can tension a 1/4" through 3/4" blade and the tension handle stays where I put it!

[Robert Harding]

pm1500.jpgI am having similar issues with my pm1500. I am having a challenge aligning the "3 positions" for the blade tension. I am including the cam picture. For the life of me--I can only see 2 flat surface (one has an allen bolt) what am I missing?

[Robert Harding]

I bought the annual subscription and was able to see Robert's photos--It answered my questions--my cam had been turned around 180 degrees.

all set--thank you

[Robert Hayward]

Glad I could help. My problem was not the cam position, but the collars had slipped. That was discovered after I replaced the cam.

If you need to work on the upper tensioning mechanism in the future the upper wheel is very easily removed. One bolt and the wheel slips right off its shaft.