Rebuilding a Vintage Delta Unisaw - Things You Should Know But are Hard to Research

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Forum topic by David Schwarz posted 11-05-2017 03:16 PM 35696 views 6 times favorited 94 replies Add to Favorites Watch
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David Schwarz

101 posts in 995 days

11-05-2017 03:16 PM

Hello Fellow Lumberjocks,

I’m still a newbie here – I only have a couple of threads under my belt. But I’ve come across a rather unexpected hurdle in rebuilding my recently acquired 1967 Delta Unisaw (Model 34-450). I had been documenting my progress in one of my (two) previous threads titled “Buy a Cheap Saw, Get a Cheap Saw”, but with this new hurdle I thought it might be a good idea to create a new thread for the evolving rebuild so that others can (hopefully) easily find this information and use it during their rebuilding efforts.

Before diving in, please let me make this statement: I am not by any means a qualified machinist, nor have I ever had any proper training. But I have done a substantial amount of building and fabrication work in my earlier days, so I’m not afraid to dive into something. My parents and their parents were skilled (card carrying) Engineers and Mechanics, so it’s in my genes, so to speak. But again, the reality is that I’m a Biologist by profession, so user beware!

Also, I know that there’s plenty of folks here that are really smart and know a thing or two about woodworking machinery. Please contribute – this is intended to not only help educate me, but others that follow down this path.

So, let’s first set the stage for this concert. As already stated above, the performer is a vintage 1967 Delta Unisaw. Here are relevant details that I feel are important at this time – I may add to these specs below as it becomes necessary:

Manufacturer: The Delta Division of Rockwell International (defunct)

Model: 10” Unisaw (Catalog Number 34-450)

Year Built: 1967

Motor: Rockwell Manufacturing Company Model 87-353 (3 Peak HP at 208V and 7.8 amps)

If you want some other relevant history behind this saw, please follow the link I’ve provided above to the first thread on the subject. I’m now going to perform the first song.

1. The mysterious Bearing Closure Nut

This is what we’re talking about:

See that thing with two notches? That’s your “Bearing Closure Nut”. Now, if you watch some of the excellent videos available on refurbishing a Unisaw, you’ll be hard pressed to find any information regarding this beast. Too often, you simply get something much like “consider replacing your bearings – remove them and install new ones”. The reality is that this Bearing Closure Nut stands between you and the freedom of the outer bearing of your arbor.

As referenced above, I’ve done some fabrication work in the past, and after trying to pound my bearing out of the arbor assembly (in both directions), I took a closer look and realized that this “Nut” is in fact threaded. That’s why those two notches are there – they are designed for a spanning wrench that likely looked something like this back in the Rockwell plant:

So that’s where I am right now. I know what I need, but I have to find the right tool. To be fair, you can likely try to place a drift in one of the notches and unscrew it with a good whack or two. But trust me on this, if it’s happy being where it is after fifty years, it might not want to budge. Damage that notch (or God forbid, both of them) and you’ve just created a world of hurt.

So I’m working on this presently, but will gladly accept information from all comers. What I know so far (via digital caliper) is that the outer diameter of the retaining nut is 1.55” and the notches are each 3/32”. Please stand by for the solution to this challenge.

2. Removing the worm screw collar from the elevator/raising shaft

This one is another interesting challenge. This shaft rides on two (bronze?) bushings, one in the front trunnion and one in the rear trunnion. While still in the cabinet, it looks like this:

Technically, to remove this shaft you need to do the following:

1. Remove the retaining nut on the far left of the shaft.

2. Loosen the set screw in the collar that is just inside the rear trunnion.

3. Pound out the retaining pin located on the rear trunnion side of the worm screw collar

4. Remove the rising wheel located outside of the cabinet.

5. (Carefully) remove the pointer bracket (you’ll need a standard screwdriver with a narrow blade)

6. Remove and set aside the two (brass?) plugs from the shaft.

With all of this done, you’ve technically liberated your shaft from it’s Unisaw bounds. But not so fast! Both the retaining collar (#2) and the worm screw collar (#3) are most likely very tightly associated with the shaft. In my case it’s been 50 years – and accumulated dust, dirt, and who knows what else is a very effective glue. In my case I tried to vigorously tug the shaft from the outside of the cabinet. But after a couple yanks, I was very concerned about the durability of the bronze bushing on the front trunnion. So ultimately I unbolted both trunnions and lifted everything out of the cabinet. Once done, it was easy to remove the shaft:

and once removed, relatively simple to pound off the two collars using a piece of 2×4 as my drift:

If you’ve done this and have a better way, please do share :-)

So, this new thread has taken quite some time. I’m going to close this first contribution and begin my day. More to come!

-- I make trees cry.

94 replies so far

View Ripper70's profile


1377 posts in 1686 days

#1 posted 11-05-2017 04:12 PM

Maybe this would work?

-- "You know, I'm such a great driver, it's incomprehensible that they took my license away." --Vince Ricardo

View Kazooman's profile


1492 posts in 2729 days

#2 posted 11-05-2017 04:28 PM

Make your own wrench out of a scrap piece of steel (bar stock, angle, whatever). Just drill holes and stick in some pins. If you want to get fancy the pins could be a larger diameter than the width of the slots. File flat faces on the pins to give a larger bearing surface and make a snug fit.

View Reinan's profile


89 posts in 997 days

#3 posted 11-05-2017 04:30 PM

Try searching for ‘adjustable pin spanner’ On your favorite tool ordering site, you should be able to find one reasonably that will work. I would consider soaking the threads with PB Blaster or a similar product before attempting removal, probably for a day or more should get things sufficiently loosened. Heat would also be a good way, use a torch to warm the cast iron and an alignment punch or drift from the freezer slid into the nut to create a small temperature differential.

-- -Russ

View Redoak49's profile


4748 posts in 2766 days

#4 posted 11-05-2017 05:27 PM

Amazon has a number of different ones …

View MrUnix's profile


8097 posts in 2976 days

#5 posted 11-05-2017 06:38 PM

A suitable sized pin punch (or large screwdriver) and a small hammer works just fine. The retaining nut is (should) not be on very tight and will spin right off. A little penetrating oil wouldn’t hurt anything either. It is a standard thread, so just put the punch in one of the notches and tap with the hammer. If it is for some reason really on there, you can fabricate a remover out of some scrap metal. Here is one I made out of some old bed frame angle iron for the retaining nut on the spindle of my 1937 Craftsman drill press I’m restoring:

That particular one was really stuck – and I thought I was going to break my bench vice before the thing finally came loose!

For all the info you could ever possibly want regarding the Unisaw, head on over to OWWM where they live for them (and other vintage machines). Home of the earliest Unisaws on the planet. Anything you could ever ask has most likely already been addressed over there… multiple times :)


PS: The reason the information over at OWWM doesn’t show up in a google search is that they have a very restrictive robots file that prevents google (and other search engines) from traversing the site. Don’t know why they do that, but you can search the site from within once you get there.

-- Brad in FL - In Dog I trust... everything else is questionable

View David Schwarz's profile

David Schwarz

101 posts in 995 days

#6 posted 11-06-2017 05:58 AM

Brad – what you suggested was exactly what I ended up doing. However, I cannot take the credit – someone over at the West Seattle Tool Library had nearly the same idea. While I was somewhat embarrassed that I hadn’t come up with a similar idea – it worked like a charm:

Relative to the “other” project today, the nut wasn’t in all that tight – but having the PseudoSpanner I think made the difference. Of course, once the capture nut was removed, the bearing popped out easily.

If only the “other” project was so easy…

After getting through the full arbor, I turned my attention to retrieving the bearings from the motor. Piece of cake – right? Apparently not so much :-( The journey began with an attempt to remove the set screw holding on the fan blade/front collar (no Rockwell schematic available, so I have to resort to my own nomenclature):

I experienced a misplaced moment of exhilaration when I heard a tiny pop and felt the 1/8” hex wrench nudge – finally, I thought to myself, I got it loose. Well, not exactly. All I had done was managed to crack the head of the screw. More on that later, but I was able to finally remove it using a propane torch and a T20 torx bit.

So after that ordeal, everything should be a breeze, me thoughts. Again, that creeping misguided confidence.

Turns out removing that fan/collar was it’s own special challenge. First, notice in the photo above how little clearance there is between the collar and the front motor housing. Next, take a look at the front of the fan:

My puller arms were unable to clear the center section of the blade – that rather girthy part obscuring the collar. So I did the unthinkable and grabbed hold of that sheet metal center and pulled on that. I know, not that bright right? But I’m a biologist – so how could I know any better? Regardless, that maneuver allowed me to pull the collar just far enough to allow me to barely grab onto the back of the collar with the puller. To keep the grip tight though I had to resort to a quick grip clamp to hold the jaws tight on the beveled lip of the collar. This provided just enough force to finally enjoy the sweet smell of success:

After removing the four rather long screws holding the housing ends to the center section, I suddenly realized I had no idea how to get the thing open. I pondered this for a good ten minutes until I noticed the slight rise of the casting at regular intervals around the front casting. A few whacks on each of these with my wooden drift and it pleasingly popped open!

This then brings me to my final question for today. I had no problem pulling the bearing for the tail shaft, but I’m less confident with how to proceed with the bearing on the front shaft that is currently pressed into the front housing. If I tap the front shaft through the front housing, will the bearing be retained on the shaft so I can then pull it off? Normally I would think so, but after today’s events, I have less confidence, with nightmares of a bearing retained in the front housing and no obvious way to extract it.

Oh, and that pesky set screw? Well, it was on so tight that it actually left an indentation on the front shaft:

No wonder that set screw was traumatized:

With nearly everything disassembled now, I figure the loss of one set screw isn’t too big a loss. I’m actually quite amazed at how good the condition of this saw is. Now to order bearings and then spend some quality evenings scrubbing and painting prior to reassembly.

-- I make trees cry.

View coxhaus's profile


152 posts in 1671 days

#7 posted 11-08-2017 05:11 AM

I rebuilt an Unisaw JR and a Delta contractor saw. What worked best for me to get stuff lose was to use a mixture of 50% acetone and 50 % automatic transmission fluid.

To remove the bearing after getting the arbor bearing and shaft out I used a hydraulic jack pipe to tap the bearing off by sliding the pipe over the shaft and tapping it off. It was last year so I have slept since then. This is the way I remember it.

View MrUnix's profile


8097 posts in 2976 days

#8 posted 11-08-2017 06:33 AM

The bearing should come out on the shaft, hopefully. Normally they are a press fit on the shaft and a slip fit in the housing to allow for thermal expansion, and frequently will have one or more spring washers between it and the housing for that reason. If it doesn’t come out with the shaft, you should be able to tap it out with a pin punch on the inner race.


-- Brad in FL - In Dog I trust... everything else is questionable

View Nubsnstubs's profile


1723 posts in 2507 days

#9 posted 11-08-2017 01:02 PM

There is a proper method to removing the bearings from the housing. You can find the instructions on OWWM. If you don’t do it right, the apposing bearing will put enough pressure on the housing to break or crack the housing. I know this because I didn’t read all the instructions on mine, and had a crack before I got the bearings out. Fortunately, I have access to a welding shop, and also a high tech machine shop to inspect the housing after getting it welded. ............... Jerry (in Tucson)

-- Jerry (in Tucson)

View jonah's profile


2122 posts in 4076 days

#10 posted 11-08-2017 01:58 PM

My Unisaw doesn’t need any rebuilding, but I’m learning a ton from this thread. Just thought I’d mention it.

View David Schwarz's profile

David Schwarz

101 posts in 995 days

#11 posted 11-08-2017 02:37 PM

I owe apologies on this one. I thought I had posted an update, but must have forgot the final step <sigh>. So let me please update now.

The bearing was easily tapped out of the rear housing. I simply placed the shaft on a block of wood and then placed two more blocks of wood on top of the housing. A couple of taps with a hammer and it came right out:

After that, the bearing easily pulled off the shaft. The only thing left to do was separate the motor bracket from the yoke. That required removal of one pin (you’ll need a long-nosed pin drive for this) and then pounding out the shaft with a hardwood dowel and mallet – it takes some effort but you should see it slowly exit.

With that final task, I was left with one completely disassembled Unisaw:

So last night began the trip back. I started with washing/wet sanding the cabinet. No easy task, which was why I chose it first. It probably took a full two hours to remove all the badges and thoroughly clean it inside and out. Tonight I’ll begin uploading photos of the reverse process.

-- I make trees cry.

View splintergroup's profile


3798 posts in 1999 days

#12 posted 11-08-2017 03:04 PM

A buddy has one of these
Very inexpensive and nicely made, perfect for those nuts.

View Andybb's profile


2762 posts in 1380 days

#13 posted 11-09-2017 04:29 AM

David, seems like we need to swap meeting places. You’ve definitely got the most interesting thing to see. You’re gonna get a lot of satisfaction the first time you fire this up!

-- Andy - Seattle USA

View klassenl's profile


207 posts in 3436 days

#14 posted 11-09-2017 04:30 AM

Is that long arc on that plywood marks…scars of a kickback?

-- When questioned about using glue on a garbage bin I responded, "Wood working is about good technique and lots of glue........I have the glue part down."

View David Schwarz's profile

David Schwarz

101 posts in 995 days

#15 posted 11-09-2017 02:38 PM

I know – I said this would be a resource for things that were hard to research, and now it’s morphing into a running diary of the restoration. I guess part of the reason for this is it’s SO much work that in sharing the restoration, folks are aware of what lies ahead (and maybe take advantage of tome easier approaches).

So two nights ago, I started the cleaning process. First thing I chose to tackle is what I perceived would be the hardest – the cabinet itself. For the next few photos I’ll do my best to find representative before and after photos. So here is the cabinet before:

And here it is after removing badges and cleaning (all cleaning, unless otherwise stated, is with soapy water and a nylon bristle brush or wet sanding with 800 grit):

Having scrubbed, I realized that the spot welds on one of the four sides fusing the top mounting plate to the cabinet had failed:

Any thoughts on whether I should have these repaired? There’s still three sides intact, but with that single piece of metal essentially holding the cabinet to the saw top – I’m concerned. Particularly since the table is the easiest way to initiate any movement of the entire saw. I should also mention I noticed some welding in the corner, I have yet to examine more closely, but from the feel of those welds, I suspect an “amateur” performed a repair. I say this because it feels like there’s blow through of the base where it was welded to the top.

Last night I turned to the base (no before on this one) and the underside of the cast iron top:

I had thought the base would be bad, but turns out scrubbing all that webbing is no walk in the park either. I saw where one restorer had access to a sand blaster. If you have one, or the funds to have someone do it for you, then I’d highly recommend selecting this option.

-- I make trees cry.

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