Don’s Unisaw project

[Don Garland]

I am so glad to have the opportunity to tap into the wealth of knowledge in this community. In 2016, we had a lot of flooding in the Baton Rouge area. A friend of mine bought some flooded tools from a shop a few years later. The tools included a 1950’s Unisaw that had the motor go underwater. He was going to rebuild it, but he prefers to be a metal worker and mechanic, so he gave it to me. (He recovered his money and more selling the other stuff). The aluminum motor sheave broke as he was trying to get it off. So I need to find one. I am almost done rebuilding the bullet motor. Rust cleaned out, copper necklace cleaned, and bearings replaced. Tomorrow I will put it all back together

so, do I go back with an aluminum sheave or do people go to cast iron or steel ones? Recommended sources?

do I replace the arbor bearings that didn’t go underwater or base it on condition?

Is it customary to post the progress on this forum or just useful information I discover?

thanks in advance for the help

[Bill Dufour]

70 year old bearing grease I would just replace while it is apart. In general a iron sheave is higher quality. Are unisaws a common sheave spacing? My 12/14 version is a oddball belt spacing no longer made.
Bill D

[Don Garland]

According to a bearing supplier here in town, the 1.75” thick, 3 belt pulley is not common now. Most will be 1.5”. I was leaning toward replacement of the arbor bearings but have a nagging feeling the new ones may not be as good as the old ones. But I won’t be here 70 years from now to find out

[Mike Kees]

Don I would do the arbor bearings . The sheave I would go steel or cast iron. Do you have the diameter of the old one ? I have a bunch of loose Unisaw parts at my shop and may have exactly what you need. Not much changed on these saws through the years. I will be at my shop in the morning and will see what I have. PM me if you want.

[Don Garland]

Sorry I am new here and can’t figure out how to PM. Will try to find some tech help on that

sheave Has 0.75” arbor, 5.5” diameter and 3 belt, 1.75” thickness

[Jerry Bruette]

If Mike can't help with the sheave you'll need to know the belt size, not the length, but A, B etc.. Then just get a three groove sheave with a 3/4" bore. Don't worry about the quality of the bearings, as long as you buy a brand name bearing, they'll be as good if not better than the old ones. SKF, MRC, FAG, NTN, NSK, NACHI are all good name bearings. SKF and MRC might be the easiest to find. I'd buy them from a local bearing supply house, Motion Industries is a good supplier if they're close by.

[Don Garland]

I tried to get them from motion industries but they didn’t have them in stock. Also tried to get a sheave from them but haven’t heard back after they said they needed to research it

[Lee Schierer]

Sorry I am new here and can’t figure out how to PM. Will try to find some tech help on that

sheave Has 0.75” arbor, 5.5” diameter and 3 belt, 1.75” thickness

You have to be a contributor to send PM's. Click on the Donate button at the top of every page. The minimum donation is $6.00 or 1.6 cents per day. Your donation helps keep the lights on at SMC.

[Mike O'Keefe]

Don I just replaced mine [ 1948 model]. If you want a original pulley try over at the owwm site. There's a guy on ebay that sells new billet aluminum ones. I would highly recommend chainging the arbor bearings. Mike O'Keefe

[Ronald Blue]

Definitely replace the bearings on the arbor. No reason to think todays bearings won't be as least as good if not better. Timken, SKF, and NTN are all good. Maybe ball bearings haven't changed much but the roller bearing technology and finishing process has definitely improved a great deal.

[Bruce Wrenn]

On the belts, I think that a single belt would do. Today's belts have come a long way since 1950. Look at your car. Most likely a single serpentine belt drives all the accessories (PS, AC, Fan, alternator,) which total out to around 20 HP.

[Don Garland]

Ah, will contribute. Was planning to but didn’t see the requirements for PM. Thanks

[Mike Kees]

Don I just returned from my shop and it turns out I do not have that sheave size. I do have a 3 1/16" diameter as well as a 3 9/16" diameter one. Both are the 1 3/4" thick with 3/4" bores.

[Ronald Blue]

Welcome to the Creek Don. There's an amazing cross section of knowledge here. Once I even contributed a small morsel of knowledge but mostly just try to be a sponge and absorb what others know. It's a lot that's for certain. Your contributor status also gives you access to the classifieds for buying and selling as well. It's amazing what the cost of a cup of whatever at a well known coffee chain can get you.

[Bill Dufour]

You have to be a contributor to send PM's. Click on the Donate button at the top of every page. The minimum donation is $6.00 or 1.6 cents per day. Your donation helps keep the lights on at SMC.
And once you join you can see the pictures as well as post your own. Fifty cents. a month for a subscription is cheap. less then the cost to mail one letter.
Bill D

[Don Garland]

I assembled the bullet motor today and test ran it on the table top. Good news is it ran. When I killed the power it took a long time to coast down to stopped, so I feel good about the bearings. The one weird thing was the speed wasn’t steady when at full speed. It surged a bit. Not sure if it is due to no load of being relatively in constrained I feel I may need to doin and do more cleaning on the copper necklace but I thought it cleaned up nicely and felt free. I have a video if any experts want to give me an opinion on what to check

[Don Garland]

I joined at much more than minimum contribution. I always figured if you bought a $50 book and learned 4 things you would not know otherwise, it was money well spent. I am sure I will need, and get, more good info than that as I work on this flooded machine

[Don Garland]

I assembled the bullet motor today and test ran it on the table top. Good news is it ran. When I killed the power it took a long time to coast down to stopped, so I feel good about the bearings. The one weird thing was the speed wasn’t steady when at full speed. It surged a bit. Not sure if it is due to no load of being relatively in constrained I feel I may need to doin and do more cleaning on the copper necklace but I thought it cleaned up nicely and felt free. I have a video if any experts want to give me an opinion on what to check
Some clarification, the speed seemed steady but the motor hum seemed to pulse.

[Tom Bender]

Since your motor pulley is 5.5" I am assuming the motor is 1800 rpm (nominal), not 3600. That's good because 3600 rpm motors need tiny pulleys to keep the blade speed below the supersonic speed. A lower tip speed is better for a non-production saw.

[Paul Haus]

I didn't see where anyone suggested going to OWWM.org and put a WTB there on the "BOYD" (Bring out your Dead). There's a great number of members that buy, sell and rebuild Unisaws there and I suspect you'll find what you need fairly quick. That would be what I would do if I needed one.

[Don Garland]

Thanks. I will do that