Powermatic Model 1150 Drill Press Rebuild/Modification

[platypus20]

I was given a Powermatic model 1150 variable speed drill press, it was being thrown away by a school district maintenance shop. When I got it it was a total basket case, no motor, the column, table and numerous boxes of a hodge podge of parts, most didn't have anything to do with the DP. I originally uncertain if I needed or wanted another DP, as I have 5 others, but I couldn't see it going to the scrappers. The first step was to clean it up, remove the original wiring and start to make a list of necessary parts to get it functioning. I had a motor off of a Jet JDP20MF, that I had put a slower/reversible motor on, so now it was just a motor support, a belt and labor. After the initial assembly, I found the DP had a minimum speed of about 615 rpm and a max of 4800 rpm, way too fast for my needs, so after digging thru boxes of machine parts, I found some 4 step pulleys, wrong bore, but workable, and I decided to put a layshaft with the cone pulleys between the motor and the variable speed pulleys, to slow the chuck down to hopefully the 150-175 rpm range, which was more usable for me. After making the motor support, the installation of (3) Browning brand, 3/4" flange bearings, I got the speed down to 235 rpm, usable but still somewhat faster than I had hoped for. I still can change the layshaft pulley and slow it down some more, and may before its over. The original variable speed control system was missing many parts, and what was left were worn and unusable, so I make up a new control system, again using parts from the supply on hand. It works great, easy to use and stays where you put it, what more could I ask for.

1 - the DP as I got it, without motor
2 - making slugs for pulleys, so they could be rebore to correct size
3 - first slug pressed into place with hydraulic press


jack

[platypus20]

4 - the preliminary configuration, set up to get initial measurements
5 - runable version
6 - motor/layshaft assembly

[platypus20]

7 - variable speed setup
8 - cover installed, and speed control handle

Right now the unit is usable, I may redo some of the motor brackets in aluminum plate, and spruce the unit up a little more. I have to get a DP vise and a new chuck key. The more I think about the minimum speed at 235 rpm isn't too bad, as it only has a 1/2" screw on chuck, I guessing that I be using it with drill bits 3/8" or smaller.


jack

[Rex]

Nice job.
I've been looking for one of those DPs to match my Powermatic MVN mill.

[Marty_Escarcega]

Thanks for sharing your mods and for saving a good old drill press from the scrap yard. I have the same machine with a morse taper 2 spindle. I found out why the price was so good. The spindle is slightly bend. Naturally, stick that much shaft away from the bearing in the quill. I was hoping to find a JT33 spindle like yours or I will try and gingerly straighten out the spindle.

Mine too is the variable speed version. It runs pretty well. I still think an old buffalo drill press with step pulleys, a 1hp 3 phase motor and a VFD is the way to go......

Marty

[platypus20]

Marty,

The joy was short lived. Saturday night while running the drill press at about 380-400 rpm. there was an loud BANG, and the spring loaded pulley shattered, the resulting mayhem, also broke the front pulley, severely bent up the belt cover and bent the top of the spindle. As I got the DP in pieces, I can only guess that the pulley, being cast iron, had been dropped or beaten on, leading to the failure. The immediate results is a large pile of scrap. I disassembled the unit, stripped out all of the newly put in parts, all of the new nuts and bolts, bearings, layshaft and layshaft pulleys, etc. The rest of it went to the scrapper, I tried to save it, but only delayed their meeting. The spindle casting cracked right where the column went thru, very little was salvageable. Many dollars, hours and effort was for naught, but luckily for me the belt guard kept most of the carnage inside and keep the escaping shrapnel to a minimum. The quest for a new shop project starts today.

1 - what left of the bottom pulley, the top half of the pulley was picked up with a magnet and a dust pan, front pulley wasn't much better
2 - another view
3 - just as the scrapper arrived


jack

[Harold_V]

Damn! Sort of reaffirms the idea that no good deed goes unpunished.

Harold