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Refurbishing a 1948 DoAll LHF 16" Bandsaw

DocsMachine

Titanium
Joined
Jan 8, 2005
Location
Southcentral, AK
A couple weekends ago, I took a fair road trip and picked up a DoAll bandsaw- a good metal cutting bandsaw being one of the few remaining machines I felt I needed in the shop. (There's plenty I still want, of course, but that's different. :) )

saw01.jpg


The saw was in pretty good condition- good enough, in fact, that I'd initially taken it as being some thirty years newer than it was. (I'd assumed it was 70s-80s, turned out to have been made in 1948!)

saw02.jpg


There were virtually no dings or dents, the almost certainly original paint was in great shape (nothing peeling or badly stained) the drive was in good condition, the guides were all there, etc.

Superficially, the worst part was the... I guess graffiti would be a sufficient term. :) Having been in an Air Force maintenance shop, and quite likely for a good many years, some wag had hit it with a walrus stamp...

saw04.jpg


... Another had marked it as an "Anything Cutter"...

saw05.jpg


... And yet another had slapped a sticker, over where something else had once been stuck with a glue-stick, and at some point when the later sticker had been pulled off, Airman Walrus stopped by with his stamp again.

saw06.jpg


Fortunately all of that, plus the leftovers of other long-gone strips of tape, boot-scuffs and other marks were easily removed with a bit of elbow grease and some lacquer thinner.

Now, as good a shape as it was in overall, there were a few things that needed attention, and as I've been tinkering on it, more bits have become apparent, so I decided to post this "build blog" of it.

First and foremost was the table. Poor, but apparently relatively brief, storage had allowed the table to rust, though not deeply.

saw08.jpg


The bulk of it pushed right of with a razor blade- or rather, several razor blades, as they of course go dull quickly.

saw09.jpg


After that, most of the rest came off with some Scotchbrite and WD-40...

saw10.jpg


And a small stone took care of some of the nicks and dings.

saw11.jpg


After that, I brought back a bit of the luster with some 600 grit wet-or-dry sandpaper and a sanding block, lubricated with more WD-40.

saw13.jpg


Next up was the classic DoAll "Job Selector" dial. Thankfully both discs were still with the machine, but the center hardware had been lost at some point, and they were just held on with a 1/4"-20 bolt. The knob, too, had been lost and changed at some point, and its' replacement was held on by a roughly ground-down and sawed-off brass bolt.

saw14.jpg


I replaced the bolt by shaving down a 5/16" capscrew until it had only a very thin flange for a head, to match the slight stamped recess in the DoAll dial.

saw15.jpg


That I hit with a Dremel and a cut-off wheel, to give it a rudimentary screwdriver slot.

saw16.jpg


And here it is assembled:

saw17.jpg


The two dials have a small stepped bushing in between, so that the outer dial is fixed, while the inner dial can rotate around it. The manual- still available at DoAll, surprisingly enough- shows the bushing, but gives no dimensions.

However, it's a simple item and was easy enough to gin up out of a bit of scrap white Delrin, with a little cut-and-try.

saw18.jpg


That holds the center of the inner dial, with a step that's just a smidge wider than the thickness of the dial. Therefore it can be bolted tight, but the dial will still be able to turn.

saw19.jpg


The outer dial just sits on top of that bushing- the extra thickness of the bushing necessary because at least on this older model, the outer disc is "domed" slightly.

saw20.jpg


A new 1/4"-20 bolt, a wide washer, and a Nylock nut completes the installation. Felt pads on the backing plate (the part bolted to the case of the saw) add just enough friction the disc can turn easily but doesn't flop around.

saw21.jpg


And that was as far as I could go at the time, as it came with no blade and the one I'd ordered hadn't arrived yet.

Doc.
 

Danny VanVoorn

Titanium
Joined
Nov 3, 2002
Location
St.Louis, Missouri, USA
Nice project and should turn out to be a great saw! I have a DoAll ML 16" saw that is real handy and about the biggest I could get into my basement shop. Mine was made during the war, believe they said 1943 and a replacement variable speed drive replacement has it still running strong. A couple of things about the DoAlls that make them a great value is the availability of wear parts, tires, guides and rollers, etc. and they seem to last forever if not abused. Another plus is the guides for a much bigger saw will fit the little 16" model. I found a bunch with a saw that was being scrapped, kept me from having to make some or buy from DoAll. I had a Powermatic and sold it to get my DoAll and never looked back.
Have fun doing the restoration, i llook forward to seeing the progress.
Dan

On edit; I have a blade welder and a bunch of blade stock to make my own, 120" long seems to do the trick on my 16" model.
 

DocsMachine

Titanium
Joined
Jan 8, 2005
Location
Southcentral, AK
Well, DoAll has some replacement parts, and many of what they do still stock are priced rather steeply. :D

For example, I've been tinkering with the blade guides, specifically the backing rollers. DoAll doesn't carry individual parts, I have to buy the whole guide assembly, to the tune of anywhere from $385 to $585.

So, of course, what I'll be doing is finding an off-the-shelf bearing, and making my own guide plates. More on that shortly- the bearings won't be in 'til the end of the week.

On the blade, yeah, I had a blade welder. :) Except that I had, at the time, plenty of blades for my Wellsaw, and my blind-stab trials with the welder produced useless non-welds. So I eventually sold it- I made a profit off of it, but looking around at current prices, I sold it for way too little.

Mine takes 122" blades- the factory ID tag says so, and somebody at some point in the past 67 years, scratched that on the inner blade door. There's enough travel in the upper wheel, though, that I suspect I could use anything from a 120" to at least a 123", if not a 124". I may try that at some point, as it seems a 122" is... well, not rare, per se`, but not what you'd call terribly common either.

Once I have a couple more blades for the DoAll, and especially after at least one of them has worn out, I'll probably try silver-soldering a couple together, to see how that works.

Doc.
 

DocsMachine

Titanium
Joined
Jan 8, 2005
Location
Southcentral, AK
After cleaning the table off, I was stuck 'til my new blade arrived. Once it came in, I installed it, gave it a quickie alignment, and naturally had to give it a try. :D

saw24.jpg


It ran fairly smoothly, and cut some scrap wood easily and accurately. After that, naturally I wanted to try some metal, at which point I found out the speed control has likely been modified and is somewhat uncooperative, and the speed range indicator was disconnected and nonfunctional.

However, with the use of a non-contact phototachometer and a measuring tape, I was able to determine the blade speed was about 1,450 SFPM or so, which, according to the Job Selector dial, was about right to try some aluminum.

It cut that, too, easily and accurately.

saw25.jpg


However, as you can see, the insert for the clearance hole is thinner than the recess it sits in, and given the wear and chipping around the trailing edge, has been like that for many years.

saw26.jpg


That's not a huge issue, but annoyed my OCD a bit. So while I'm waiting on more blades and guide parts to arrive, I decided I'd try to clean it up some. I remove the table and mounted it to the bed of my mill...

saw27.jpg


And using some machinists' jacks, got it into a reasonable approximation of level. However, there's some dings and dents in the table, so I used a "tram ring" (a big bearing race) to give me a sort of "overall level" as opposed to an estimate of a local level.

After that, it was a simple matter of indicating to the original recess, and using a carbide boring bar to recut the step. I wanted to open up the recess as little as possible (from 2" to 2-1/8") so I biased the cut toward the more heavily damaged rear edge.

saw28.jpg


I got a little chatter as the tool touched bottom, but that won't hurt anything.

After the step, it was a simple matter to then open up the rest of the hole to make the two parts concentric.

saw29.jpg


Now, one thing some bandsaws have but this one didn't, was a 'key' that helps keep the round insert from rotating. It's probably not 100% necessary, but I've run some cheap wood bandsaws whose flimsy little inserts have spun and tried to jam the blade, so I thought having a little extra insurance couldn't hurt.

To that end I located and milled half a 3/16" recess in the outboard edge of the new recess, and then drilled and tapped it for a 6/32 screw.

saw30.jpg


I then turned down a 6-32 capscrew to 0.186".

saw31.jpg


Which fits in place like so. I could have used a pin tapped into place, but I like the removable/replaceable aspect.

saw32.jpg


After that, it was a fairly simple matter to mill a rough insert out of some scrap-bin leftover on the rotary table...

saw34.jpg


And fine-tune the dimensions with an oversize soft-jaw collet.

saw35.jpg


The thickness I opted to go by "cut and try" instead of working to a set dimension, since the table is both notably worn and slightly warped. A bit of marker and an single-edge razor blade gave me a mark to shoot for.

saw38.jpg


And after three or four cut-and-try cycles, I got a fit I was happy with. No edge is too high or too low, and apart from some of the more severe gouges and grooves, the majority of the worn area is gone.

saw41.jpg


Doc.
 

DocsMachine

Titanium
Joined
Jan 8, 2005
Location
Southcentral, AK
Continued:

Since I still had the rotary table set up, I just used one of the hold-downs top clamp the disc in place, then indicated center and located the edge to mill the other half of that 3/16" "key".

saw42.jpg


et Voila`!

saw43.jpg


Once keyed in place, I just used a straightedge and scribe to mark the saw clearance slot in line with the table.

saw44.jpg


And slit that with a 1/8" saw.

saw45.jpg


Which finally gives us a nice, thick, well fitted table insert.

saw46.jpg


Doc.
 

jkopel

Stainless
Joined
Apr 3, 2010
Location
Seattle, Wa USA
Looks like you are doing your usual fine job!
While you have things set up you might want to make a "zero clearance" version of that as well.

I also have an old ML from the 1940's and find it to be one of the most used tools in my shop.
 

ratbldr427

Stainless
Joined
Mar 21, 2006
Location
jacksonville,fl.
I have a 16 ML also waiting to be restored one day.At work we have a Dake Johnson 16" vertical.
Last week I had been changing blades and left it in neutral when I went home.The second shift electrician calls day shift lead and tells him the saw is broken,he tells him if they need it to fix it.

I come in the next day and find the gear box out and the top removed,WTF's going on it worked fine yesterday.I can't believe the 2ed shift mechanic didn't figure it out before they took it apart.Gotta love them electricians! They both claimed that they tried shifting it into hi or low and it wouldn't go(BS).I embarrassed both of them when they came in.
 

DocsMachine

Titanium
Joined
Jan 8, 2005
Location
Southcentral, AK
I was asking about adjusting the blade guides over in the General section and while investigating various aspects of how the guides mounted and worked, I was starting and stopping the saw several times to check or adjust the tracking, etc.

The most worrying issue on this machine has been a big "clunk" every time it starts up- there seems to be a lot of "lash" or take-up between the motor side pulley and the band drive pulley- meaning something's loose in the gearbox.

This worried me more and more as I was testing the tracking, so out of curiosity I yanked the drain plug on the gearbox to see if there was any metal or gunk in the oil.

Unfortunately, there was no oil. None. The plug was bone dry. Dry like it may never have had any oil. And there's no spotting or puddling or stains on the base housing, basically no indications any oil leaked out.

There's no signs the gearbox has ever been replaced- all the gaskets and the bolt heads, etc. have factory paint on them. But the saw in general has, at one time or another, been reworked. To what degree I don't know, but the motor is not original (the saw dates to 1948, but the existing motor has a printed plastic tag with a bar code on it- plus the wiring is in modern plastic sheathed conduit.)

Plus little hints like all four blade guides that came with the machine- the little trapezoidal wear blocks- were practically new. The tires are also in fine shape, and the sixty-seven-year-old plastic variable-speed pulleys inside are clean and ungrooved. They're not new, but they're by no means worn.

So- and this is a lot of speculation, mind- what might have happened is that at some point the saw was "serviced". The old motor and early wiring removed, maybe the chassis of the saw scrubbed or pressure-washed, then refitted with a new motor, new tires, maybe a few factory parts in the drive, etc.

So perhaps the oil had leaked out over the years (some Airman perhaps forgot to properly retighten the drain plug during a scheduled maintenance) and the staining/traces of such were washed away when the frame was scrubbed.

Again, just a guess. But whatever the cause, the gearbox was completely empty, and there's a significant amount of "lash" or slop as it comes up to speed. Oddly enough it doesn't sound bad- there's no grinding, rumbling, whirring or screeching. The blade rubbing on the guide roller makes more noise.

But between the "no oil" and the nasty "clunk", there may be significant damage in there, so before I do any further work on anything else, I'd best pop it out and open it up. If the gearbox is junk, that's a pretty serious- although not necessarily fatal- problem for the rest of the saw.

Doc.
 

ratbldr427

Stainless
Joined
Mar 21, 2006
Location
jacksonville,fl.
Our Dake Johnson has always had a really long lag when first switched on until the blade wheels start turning.It also makes a clunk,not very loud though.Due to our little episode last week I inspected the gear box while it was open and didn't find any thing worn just a lot of back lash which may be amplified by the vs drive pulleys.It has been this way for the last 15 years.

A while back I was cutting some Delrin WFO and the saw was shaking badly,some thing out of balance(it has always vibrated at high speeds somwhat).The center "v" pulley half was grossly out of balance.It had been into previously and I thought the vs pulley assembly may have been originally balanced as an assembly and some one dissasembled it and reasembled it out of phase.I tried all the positions and still was out,so I took the die grinder to it and statically balanced it.Smooth as silk now.I must say that I like the design much better than the Do-All.We bought it used and have only put on one set of belts in 15 years and there is very little wear on the pulleys,must have a lousy balance job at the Tiwain factory that made it.
 

DocsMachine

Titanium
Joined
Jan 8, 2005
Location
Southcentral, AK
Earlier I speculated that this saw has been refurbished before, and I now have strong evidence thereof.

Closer inspection of the gearbox mounting bolts revealed signs they'd been removed, and at least one of the tin cover gaskets had clearly been hand-cut.

Not that it really mattered. With the worrisome slop and the fact it was empty of oil- and I had no idea how long it had been run in that condition- my only choice was to remove the gearbox and open it up. Fortunately it's fairly easy to remove. The drive side pulley slid right off, and the band pulley came of with a light tug from a gear puller.

saw48.jpg


That left the gearbox by itself, bolted to the chassis "firewall". The upper shaft is the high/low selector lever, and will have to come off too.

saw49.jpg


The eccentric link on the end is held in place with an old-fashioned taper pin, which drove out easily.

saw50.jpg


And then four bolts, and the gearbox pops right out.

saw51.jpg


Note there's no streaking or sprays where oil may have been leaking out of the box- and note the box itself was clean, with no traces of dust or dirt stuck to wet, oily areas.

On the table, I blocked it up. I laid papers down because I had, in fact, tried putting oil in it, to see if that changed/helped anything- it actually didn't seem to make any difference at all- but I eventually decided that no matter what, it was going to have to come apart.

saw52.jpg


The two halves are held together with just four countersunk screws, each with clear signs somebody with an undersized screwdriver had already been there. They were also all only a little more than just finger tight.

saw53.jpg


Inside, note how dry the top half was. Even with the half a pint of oil (the recommended amount) I put in, and being run at high speed for a few moments, the upper bearing and top half of the housing were still bone dry.

saw54.jpg


The rest of the gearbox was reasonably easy to dismantle. And, I was surprised- and considerably relieved- to see the gears were all still in fine shape.

saw55.jpg


Certain parts were, however, rusty.

saw57.jpg


Rusty.

Fortunately, as it turned out, it was a fine, light surface rust, that brushed right off with some solvent and a toothbrush, but still, rusty. The gearbox had, in fact, been dismantled, degreased, reassembled and installed, but never filled with oil.

Even more fortunately, however, it seems it hadn't been run long in that condition. It may, in fact, not been run much at all before being surplused and sold, and I know it's only been run less than five minutes in total since then.

So while I was hoping not to have to do it, I'm glad I did. No, I couldn't have just filled it with oil and called it good- the rust would have come loose into the oil and formed an abrasive, and even multiple flushings wouldn't keep it from doing some damage.

saw61.jpg


Unfortunately, there was some damage- I can feel slight roughness in a couple of the bearings, and at least one had surface rust on the inner cage. I could flush everything and throw it back together, but the bearings would only last a few years before they started making noise- and the debris of *those* wearing could cause damage to the gears too.

So I'll have to order up a set of bearings- they're all fairly conventional items- and do a fairly proper rebuild. And what caused the slop? I can only guess it was the dog clutch- that selects high or low range, and I can only assume that the slop was just the dog teeth engaging.

Learn something new every day, I guess. :)

Doc.
 

Marty Feldman

Titanium
Joined
Feb 21, 2005
Location
Owl's Head, Maine
A couple weekends ago, I took a fair road trip and picked up a DoAll bandsaw-

saw01.jpg


Nice work on the saw, Doc. That's a good machine, and I bet you will have it running sweetly when you're done. Keep this thread going.

I assume your photograph is of the Richardson Highway, near the base. It's in much better shape than most of our interior roads here in Maine. Must be all that military money.

-Marty-
 

DocsMachine

Titanium
Joined
Jan 8, 2005
Location
Southcentral, AK
Actually, it's Oil money. :D Pays for virtually everything major in the State... at least it did when a barrel was worth something. :)

Anyway, getting back on topic: I've ordered some replacement bearings for the gearbox. None of the originals were "bad" per se`, but with wisps of surface rust and the possibility they've run for at least some time with no lube whatsoever, I figure it's cheap insurance. Looks like it's run a little over $50 for the lot, so it'll hardly break the bank.

However, I have a question about the output shaft bearing. In this photo:

saw54.jpg


It's the larger of the two. Sealed on the outside, open on the inside. Now, the next picture...

saw55.jpg


... Note there's a little oil pump down at about 6 o'clock. It's a cam-operated piston pump, much like the carriage pump in some lathes.

After discovering the gearbox was empty, but before removing it, I poured in about half a pint of gear oil and ran the saw at various speed for 20 to 30 seconds or so, before deciding that the box was going to have to come out pretty much no matter what.

However, note the first pic- the upper output shaft bearing is still dry, even after 20-30 seconds of running and pumping oil. It seems the bearing is shielded, to some degree, by the big gear on the shaft in the second pic. The oil tube seems to spray toward the middle of the gearbox, away from the big gear and output bearing.

Now, the only bearing I could find for the output shaft is sealed on both sides, so technically, I could just use it as-is, without worrying about it getting sufficient oil from the pump or via splash.

Or, should I pull the inner seal on the bearing, and maybe redirect the oil spray a bit- or even fabricate a "Y" nozzle to spray both sides of the gear- and hope the oil bath is enough to keep it lubed.

Any suggestions?

Doc.
 

ratbldr427

Stainless
Joined
Mar 21, 2006
Location
jacksonville,fl.
I would definitely pull the inner seal and direct oil to the top of the bearing,won't take much.I would install a magnetic drain plug.
Most modern sealed bearings are sold with the expatiation that the lube lasts the life of the bearing,however I have pulled many gear boxes apart similar to that of a band saw that had splash oil bearings that lasted 10-20 years and had a lot more run hours on them then a band saw would ever have.
A lot of government surplus equipment had the oils/fluids removed before they went to auction to stop any chance of a potential spill during handling.
 

DocsMachine

Titanium
Joined
Jan 8, 2005
Location
Southcentral, AK
I tend to agree with pulling the seal- after all, the original bearing, or at least, whatever replacement was in the box when I got it (and, for that matter, A_PMech's V-36 rebuild) was open to the oil inside. I just tend to wonder how well it gets oiled, considering it's clearly just splash lubed. I mean, apparently it workes, but that's the highest-stressed bearing of the bunch, being on the output shaft and thus under considerable tension from the blade.

I like the idea of trying to redirect some of the pump spray, and it wouldn't take much to replace the existing aluminum tube with a chunk of soft copper, and have a small branch tube soldered off to the side.

But the gear is right up against the housing, and doesn't leave much room. I suppose I could just aim it at the sidewall above the gear, and let it run down into the bearing...

Doc.
 

ratbldr427

Stainless
Joined
Mar 21, 2006
Location
jacksonville,fl.
Why don't you grind a small vertical groove in the face of the casting centered above the bearing to the top of the outer race and direct the oil to it.Capillary action will wet the bearing sufficiently,that bearing really doesn't turn very fast even wfo.
 

Danny VanVoorn

Titanium
Joined
Nov 3, 2002
Location
St.Louis, Missouri, USA
I think I missed something; Has the pump been checked to see if it's operational? Twenty to thirty seconds may have been only long enough to get the pump primed. I haven't had the pleasure to get involved personally with one of these so I don't know how they're supposed to work. If the pump checks to be working as far as the bearing goes, I would pry the inner seal off of it and leave the factory grease in it and call it good to go.
Dan
 

DocsMachine

Titanium
Joined
Jan 8, 2005
Location
Southcentral, AK
I finally got the bearings and a chunk of bearing bronze in, so I was able to reassemble the gearbox.

As above, the rust was easily removed, the bearings were to be replaced, and the gears were in fine shape. The only damage was the central shaft, which had a bronze bushing mating the input and output ends. This had gotten moderately scored, as the gearbox had been run at least some time without any oil at all- the roller bearings took the abuse easily, but the bronze plain bearing took some scoring.

It was a fairly simple repair, starting by chucking up the shaft and indicating on the bearing boss.

saw62.jpg


I couldn't indicate on the outer stub of the shaft, as it turns out the shaft has been repaired before- besides the rough file marks left on the OD for some reason, the bore had been sleeved before having the bronze replaced.

saw63.jpg


But the bearing boss was true enough, and I was able to bore out the old bronze.

saw64.jpg


Turn the new chunk to a .0015" interference...

saw65.jpg


And press 'em together.

saw66.jpg


Bore to size (0.003" over the shaft size) and face to length.

saw67.jpg


And finish off the existing notches with a Woodruff cutter.

saw68.jpg


And done. Note the bright ring of the previous repair sleeve.

saw69.jpg


To be continued...
 

DocsMachine

Titanium
Joined
Jan 8, 2005
Location
Southcentral, AK
Now we can reassemble the gearbox itself. A simple matter of first pressing the new bearings into the cleaned housing...

saw70.jpg


The input shaft gets a new center bearing and dog clutch element...

saw71.jpg


And gets gently pressed into the center.

saw72.jpg


The large plain gear and it's thrust washer go in the lower chamber.

saw73.jpg


As noted earlier, the long spiral gear had some burrs left over from the original machining. Just for a little preventative insurance, I carefully ground those off so there was no chance they'd come loose into the oil at some futire point.

saw74.jpg


And that gear, along with the pump eccentric, goes through the plain gear and into the lower bearing.

saw75.jpg


Next up, the pump itself is installed and bolted down.

saw76.jpg


Then the center dog clutch element and the shifting fork...

saw77.jpg


And after that, our newly-repaired output shaft, which needs these two keys.

saw78.jpg


All together like so.

saw79.jpg


Now the upper gear with the dog-clutch teeth...

saw80.jpg


And it's thrust washer.

saw82.jpg


I used the output side cover as a template to cut out a gasket, and hit it with a coat of gasket tack before assembling.

saw83.jpg


Due to the fit of the output shaft in it's bearing, I had to lightly press the two halves of the case together. Right aboout that time, I was telling myself, hey doofus, you should have pressed it into the case half, then assembled it- it slips right into the dog tooth ring.

saw84.jpg


Anyway, I then added the shifter eccentric assembly.

saw85.jpg


And finally the outer bearing covers.

saw86.jpg


As I didn't have any pieces left over, and the shafts all turned smoothly and quietly, it was a simple job to go ahead and bolt 'er back in place!

saw87.jpg


Hey, did I remember to put oil in there...? :D

Doc.
 

boaterri

Cast Iron
Joined
Dec 10, 2004
Location
Florida
Very nice documentary on the rebuild. I think I would have left one walrus as a tribute to all the airmen that previously used the saw.

I look forward to future installments.


Rick
 








 
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