Drum sanders

[Reed Gray]

I have an old Performax 22/44 which they don't make any more. First modification I did was convert the 1 1/2 hp motor to 220 volt because it was always tripping the circuit breaker (made sure to keep the conveyor belt at 110...). This totally eliminated any bogging down or tripping. So, over the last 10 or so years, I have become a huge fan of slow speed sanding on my bowls with the angle drill, keeping in the 1/3 to 1/2 trigger pull range. The abrasives cut far better at slower speeds. As near as I can tell, it is about traction because if you are spinning too fast, then you create heat, but the grit doesn't really dig in and cut. The 4 1/2 inch drum on the sander spins at 1720 or some thing like that, which is far too fast. I was chatting with Supermax as they are called now and asked about turning the speed way down. Their suggestion was to slow the conveyor belt. Well, that doesn't effect how the abrasives cut, and I know I am not the only one to get mad when I get the black burn lines down the middle of the panel. So, I am thinking about getting a 2 hp Leeson 3 phase motor with a phase converter like my lathes, and a variable speed knob. Is this crazy, or maybe a good idea??? Oh, they replaced the 22/44 with a 25/50 and it has a 1 3/4 motor on a 'dedicated 20 amp 120 volt circuit'... I don't know electrical, but that is crazy to me...

robo hippy

[Van Huskey]

I think you are barking up the wrong tree. The Performax will be about a 2000 sfpm where a wide belt runs even faster. No problem with proper cut of the abrasive with a wide belt, they are used in production so you can imagine they have been optimized. The other issue is what grits are you using on the drum sander, in general above 180 is a waste of time as it will load and burn which will also happen when trying to take too big of a bit.

In the end there is no issues with going 3ph and VFD if you decide to.

1 3/4hp is about 1300 watts or about 10.8 amps at a nominal 120v, so if the motor can output 1 3/4hp once you plug in the efficiency fact of the motor and add the multiplier from the NEC you are over 15 amps, thus the 20 amp recommendation.

[Reed Gray]

I did figure long ago that going beyond 150 to 180 was a waste of time. I take a card scraper to it after that, and get a better surface. I don't like 80 grit because it leaves very deep scratches that take twice as much work to remove. I have checked out the 50+ inch wide sanders, and they do run at higher fpm speeds. All that being said, with a 3 inch disc on my angle drill for sanding out bowls, the slower speeds take off way more wood, and much faster than the full 1720 speeds. This is what sent me to this. I have the engineer's syndrome, which is 'if it ain't broke, take it apart and fix it anyway."

The bigger motors, on the 120 volt circuits, especially on wider panels really tax the circuit. Add the draw of the conveyor belt, it was always a problem. When I first set up a wood shop, I did a lot of reading, and every single book I read about wood shops said the same thing, 'any motor 1 hp and above runs better on 220 than it does on 120'. With a 3 phase motor and 2 hp, I can run the drum as slow or fast as I want to, and will be testing it out eventually.

Add to the above, I am wanting to get the blue hook and loop abrasives that Vince Welch (VincesWoodNWonders) sells. I have tried just about every abrasive out there, and that stuff gets almost double the mileage that the red aluminum oxide stuff gets, and more than that when compared to the white aluminum sterate types of abrasives. It is on a mylar film, and not available in cloth backed though, so it may be more experimenting.

robo hippy