Powermatic 1150 (I think)

[Jerome Hanby]

I've got a line on what i think is a Powermatic 1150 drill press. I was curious if there were replacement pulleys to get a lower slowest speed? I've seen the weird modifications that mount under the quill, not interested in that. It looks like there might be room to use a slightly larger pulley for the large end of the stack...

[Will Rowland]

Is it single-phase or three-phase? The easiest option is to use a VFD with a 3-phase motor.

If you want single phase, you can also find a 1/2 hp 1150 rpm motor to replace the 3/4 hp 1750 (?) rpm motor, which will slow it down quite a bit.

[Jerome Hanby]

Knew I should have mentioned that 3 phase was not an option. Those fractional HP motors are a lot less expensive than the multi HP versions that I've been looking at for my bandsaw. Be easier than setting up a jack shaft and converting it to a three belt system... I think low speed is 400 and i need to get down to around 250 (for spinning big forstner bits and fly cutters).

[James Baker SD]

any chance that you could raise or lower one of the pulley stacks so that the motor pulley now is level with a different pulley on the quill? A new belt of slightly different length (used in conjunction with the pivot on the motor mount) might be enough for some speed change.

James

[Kent A Bathurst]

Just FYI - the PM1150A step-pulley [and I'm guessing the 1150 also] came with 2 motor options, and therefore 2 speed ranges: 1800 rpm motor with bottom spindle speed @ 400 rpm, and a 1200 rpm motor @ 260.

[Jerome Hanby]

If I've got my head working correctly, then the biggest speed change would be smallest pulley to largest pulley (small to large for slowest, large to small for fastest). That's already the arrangement. Raising or lowering the pulleys to get different combinations should give some new intermediate speeds...

any chance that you could raise or lower one of the pulley stacks so that the motor pulley now is level with a different pulley on the quill? A new belt of slightly different length (used in conjunction with the pivot on the motor mount) might be enough for some speed change.

James

[Jerome Hanby]

I'm thinking that a motor change would be the easiest way to get the speed down. I'm going to check back with the seller next week and if it's still available and looks to be in decent operating condition, I may pick it up.

Just FYI - the PM1150A step-pulley [and I'm guessing the 1150 also] came with 2 motor options, and therefore 2 speed ranges: 1800 rpm motor with bottom spindle speed @ 400 rpm, and a 1200 rpm motor @ 260.

[James Baker SD]

Jerome,
yep, you're correct. Sorry for the useless idea.
James

[Jeff Duncan]

I'll have to look tomorrow but I'm fairly sure my 1150 had 3 motor speed options. Not sure what the lowest speed possible was off the top of my head either. Great drill press though and probably slower than most of the drill presses out there.

good luck,
JeffD

[Kent A Bathurst]

I'll have to look tomorrow but I'm fairly sure my 1150 had 3 motor speed options. Not sure what the lowest speed possible was off the top of my head either..

That certainly could be. I have an 1150A - VS [mid-80's mfg, IIRC] and was just quoting from the manual that covers both the A-VS and the A-step pulley.

[Jeff Duncan]

Ok so mine has 3 speed ranges listed depending on the motor supplied...

900 rpm motor - minimum speed 238rpm's
1100 rpm motor - minimum speed 330 rpm's
1725 rpm motor - minimum speed 475 rpm's

If it's a variable speed machine (I think all 1150's are variable speed right?), I don't think you would be able to swap pulleys unless you had one custom machined....$$$. Sounds like the 1150A's came in both VS and stepped pulleys, in which case it may be even more difficult to find a stepped pulley in the correct size?

It would probably be better to see if you could track down a slower rpm motor depending on what yours is supplied with. In any case you'll need to find out what exactly your looking at to see what your options are.

Now just out of curiosity, what size are these cutters that you need to go down that slow? I've done 4" on the fly cutters at both 380 and 480 without any trouble. Are you sure you need to go that slow?

good luck,
JeffD

[Jerome Hanby]

Was going by the speed recommendation on drilling speed charts, 250 RPM for 2" Forstner or circle cutter in hardwood. Minimum speed on my Shopsmith is about 700 RPM and i definitely have seen some burning with the fly cutter and Forstners...

[Jeff Duncan]

Yeah that may be a little on the fast side for a large cut on a fly cutter. You also have to make sure your cutters are sharp, fly cutters dull fairly quickly. A 2" forstner should be fine even at 700 rpm's, you may have a dull bit there? I think you'll be fine if you can get down between the 300 - 400rpm speeds and keep your cutters sharp. And the 1150 is a great drill press to have, I don't think you would be disappointed.

good luck,
JeffD

[Jerome Hanby]

That was with a brand new (and free, thanks general!) fly cutter with carbide cutters, so I'm sure the burning was caused from excessive speed. Wish one of those new digital head stocks for the Shopsmith would just (gently) fall out of the sky and land by my front door. I just can't justify spending that much coin when I could spend half that price and get that new Delta DP that's getting all the good reviews...

[Jeff Duncan]

Well only you can decide how to spend your money, so you'll have to decide what will work best for you.

For myself, there's nothing new from Delta I'd want to spend my money on. I'll go with an older version that's better made for less money any day


good luck,
JeffD