Slowly getting there ...

Paul Hubbman

Member
Messages
582
Location
St. Louis, MO
In September of 2010, i came across a 1959 Powermatic 65 that a fellow had gotten from the Springfield Missouri public schools. It still had the inventory stickers on it. (I am amazed at how much old school shop machinery there is floating around out there). I brought it home, knowing i didn't really have the time to get to it right then and there. Normally i don't bring things home unless it fits a real need and i have time to get to it right away - small shop - tight storage space. But this arn disease has apparently progressed to a more severe stage.

This saw had an overarm guard, newer (metalic green not the pea green) factory fence, 1.5 hp 3 phase motor, missing dust door, missing miter gage, a break in the table casting where the fence rail mounts, and worn arbor bearings. Not a basket case, but needing some attention. I did have time to start looking into things and cobbling together some bits and parts i'd need.

Fast forward to the post Christmas lull in the shop. Perfect time to dive into a project for me AND clear up some storage space. I found that, not only were the arbor bearings toast, the arbor pulley had been loose on the shaft, wallowing off about 5 thousandths both from the shaft and the pulley. It's pretty handy that my Dad is a retired journeyman machinist. I ordered a new arbor assembly - he bored and sleeved the tripple pulley for me. He's also repairing the broken riser stop on the arbor casting that keeps it from raising too high.

So far, i've gotten a new 3hp single phase motor, a mag starter, dust door, and a mobile base. The new arbor assembly is on the way, along with a new set of belts. I've disassembled, painted, and tuned up the factory fence, am making the little dust chute that keeps the blade from throwing pitch and dust directly onto the trunnion assembly, stripped and painted the cabinet, turn wheels, and other pieces, and disassembled and cleaned up the internals.

I still have to fix the fence mounting point and repaint the top, come up with a motor cover (the shop made one that came with the saw isn't deep enough for the replacement motor), assemble and install the internals, repaint the overarm guard, wire it up, and put it to use.

This will be a step up from the General International contractor saw i've been using (It's a fine saw, but not quite in the same league as this). I'm pretty excited about how it's coming along. It should be done in a couple of weeks. I will post more pics, but here's the "before" shot in the shop of the previous owner.

in the wild.jpg

paulh
 
Looking forward to your re-build Paul. I have been watching Craigslist, because right now there is a lot of old iron for sale. Where did you get the missing parts?
 
that will be daylight and dark from the contractor saw paul...looking good so far how did yu handle the cracked table you mentioned?

Larry,
The threaded mounting hole that you screw the fence mounting bolt into broke. The edge of the top is thicker and taller there, but it still broke. The "top half" of the threaded hole is still there. The piece that would make up the bottom half broke clean away. The previous owner welded a piece of steel bar stock to the front edge of the table at that location, drilled, and threaded it for the fence bolt. It's serviceable, but if i ever decide to go with a different fence (i've got a Biesemeyer style fence i'm considering using because the stock fence only goes 26" away from the blade) i'll need to fix it properly so that there isn't an extra thickness of steel scabbed onto the front of the table. To fix it, i'm going to grind off the steel bar stock that was welded on, remove the piece of the table top edge where the broken mounting hole is, and braze in a 1/2" thick piece of steel to replace it. I'll drill and tap the 1/2" steel for the fence mounting bolt. This way, the front edge of the table will be flush across its entire width, and i can bolt the Bies fence (or any other) right onto it if i decide to later on.

If the stock fence rails were a bit longer, i might not bother, since it seems to work fine as is. But, since i've got the saw apart anyway, i might as well take a little extra time to fix it the "right" way.

I'll post some pics of the process as i move through it.

paulh
 
Looking forward to your re-build Paul. I have been watching Craigslist, because right now there is a lot of old iron for sale. Where did you get the missing parts?

Bill,

I got the dust door, arbor assembly (with bearings, spacers, washers, and blade nut), and new set of belts from Woodworking Machinery Services in Belleville, Wisconsin (608 424-0067). My saw went out of production in 1965, but it shares these and many other parts with the model 66, which was made from 1966 through 2010 - quite a long run and lots of parts available. Other parts, like the worn tripple arbor pulley and broken blade raising stop are being repaired. I'm also fabricating a couple of pieces (dust chute and motor cover).

Other sources for parts include the "Bring out your dead" forum over at www.owwm.org, Ebay, and Powermatic. The motor came from an electrical surplus supply house. It was a new surplus motor, still in its packaging - really cheap. I got the magnetic starter used through one of the woodworking forums (don't remember which one) and the start/stop switch from my local Habitat Restore.

Other than that, it's been a fair amount of time cleaning up bolts, nuts, and cast pieces at the wire wheel, rattle cans of primer and paint, and some rust removal with a braided wire wheel on the angle grinder.

paulh
 
Time to showcase my Dad's handiwork. First the pulley sleeve - nothing earthshattering here, but a very neat and clean job of it. He centered the pulley based on the V-groove machining, bored it out and turned a recess on the face to receive the flange on the bushing/spacer, turned down a piece of rod with an integral flange and bored it out to make the bushing/spacer, polished the borings in the pulley and the bushing to ensure an exact fit on the arbor shaft and bushing, cut the key slot in the bushing, deepened the key way in the pulley, made a deeper woodruf key to fit, drilled and tapped the pulley for two set screws at 90 degrees apart, marked and machined a dimple in the arbor shaft to positively engage the 2nd set screw, put it all together, and rebalanced the assembly. He also indicated the runout at both ends of the shaft and the blade flange - somewhere around 2 ten-thousandths.
pulley sheeve reduced.jpg


Next up - fixing the broken height stop on the arbor casting. The piece is supposed to look like this:
internal castings - marked.JPG
The stop (circled in black) was broken off where it extends from the main casting. The part cirlced in red was missing on my saw.

So, Dad milled the rough broken surface flat and square, then machined a piece of bar stock to fit. He drilled it to accept a couple of allen screws so that their shoulders would be recessed. Then he drilled and tapped the casting for the screws. The one thing that still needs to be done - locate, drill, tap, and install the adjustment screw. It will go through the middle of the new steel piece and stop against the trunnion casting. There is an arc milled smooth on the trunnion casting that the end of the adjustment screw will glide along if the blade is all the way up when adjusting the blade angle. Here are the pics so far. I'll take another when i get the adjustment screw installed.
ht stop 1.jpght stop 4.jpght stop 2.jpght stop 3.jpg

Now I can see the finish line.
paulh
 
Interesting - and ingenious - fixes. Both were pretty innovative, and will probably make the saw stronger and more accurate that it ever was before.

I really love seeing the 'practical' thinking of some of the "old masters" of machines. Gotta wonder if those talents will get passed along to future generations, too.
 
Today's update -
The height stop is completed, and the arbor casting is installed:

stop 2.jpgstop 1.jpg

One other thing to figure out - the three belts are different tensions when installed. The belt closest to the motor is tighest, the middle one is quite a bit looser, and the one furthest from the motor is pretty much in the middle. Even if i shuffle the belts, the results are the same. Looks like i need to "true up" the pulleys on the lathe.

The last bit of repair to be done is on the top. One of the front rail mounting bolt holes blew out at some point. A previous owner welded a a piece of steel to the face, drilled and tapped it. Since i'm thinking of going with a Biese type fence, i'll fix it now while the saw is apart. Whatever i do, i'll be grinding off the steel that's welded onto the front edge of the top. Options include brazing in a new, 1/4" thick piece of steel flush with the front edge, drill and tap it, OR mechanically fasten a similar piece with recessed screws. I like the brazing option, but probably don't have a torch hot enough to deal with this top. If brazing, should i be concerned about warping the top near the repair? I'd appreciate some seasoned guidance on this one.

top 2 before.jpg

Thanks in advance.
paulh
 
1. What Don said... and

2. Those appear to be brand new belts. I'd run them for a while to see it there's gonna be a bit of stretch involved. After a few hours running, they may be better fitting.
 
1. What Don said... and

2. Those appear to be brand new belts. I'd run them for a while to see it there's gonna be a bit of stretch involved. After a few hours running, they may be better fitting.

I see what you're saying, but even if i shuffle the belts around, the one closest to the motor is always tight, the one in the middle is loose, and the third one is so-so. I'll try running it as is for a while to see if things shake out. More later.
paulh
 
I see what you're saying, but even if i shuffle the belts around, the one closest to the motor is always tight, the one in the middle is loose, and the third one is so-so. I'll try running it as is for a while to see if things shake out. More later.
paulh
Paul if the motor is cocked with the end of the shaft closer to the saw then the end by the motor that would give you the exact result you are seeing.
 
Paul if the motor is cocked with the end of the shaft closer to the saw then the end by the motor that would give you the exact result you are seeing.

I'll dive into it over the weekend. There's also a good chance that, since the arbor pulley ran loose long enough to wallow out ten thousandths of the shaft and pulley, the belts may have worn differently in the three grooves, giving each groove a different effective radius. At any rate, my three plans of attack include measuring the belt wear in each of the three grooves to see if it's consistent, checking the motor / arbor spindle alignment (thanks for that suggestion), and checking again that three belts are matched.

I also think i'm settled on silver soldering a piece of steel in where the table top broke off. Then i'll drill and tap it for the fence rail. Welding would probably be the "best" fix, but i'd have to find someone good with cast iron and take it there and back. Brazing gets hot enough that it might compromise the strength of the iron. Silver soldering should certainly be strong enough and only gets up to about 700 degrees. With a little care, that should not cause cracking, brittleness, or warpage. The casting is grey iron - from what i've read, 800 degrees is about the point where you really need to know what you're doing.

I thought about just drilling a new mounting hole an inch or so from the existing broken one, but that won't work. The front edge of the table drops lower at the mounting points. If i drilled and tapped a new hole where the edge of the table doesn't drop down lower, the bolt hole would be right at the bottom of the edge of the table. I can't imagine that that would hold up over time. I think it's best to actually repair the broken mounting hole.

paulh
 
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