I'm enjoying the ongoing account ... and especially seeing how you have worked around problems like the change in ceramic nozzle!

Awake, yeah that really ticked me off and it's not a small part of the reason why I have a machine shop. No parts available? Fine! I'll make 'em. I got tired of buying "new", cheaper things just because the older things I owned needed a repair part that could no longer be sourced.

This installment should have covered painting the machine. However, the weather this weekend wasn't conducive to spraying urethane. The temps hovered in the high 50's and low 60's all weekend. I could compensate for that with a faster solvent, but the wind was up as well. Even a slight breeze will make your day when painting with a urethane that requires 80 minutes to dust-free.

So, rather than fight the weather, I started on the wheels.

Assessing their condition

The wheels are Aluminum investment castings, 1.25" wide between the wheel flanges and 16" in diameter to the outside of the flanges. After 62 years of use, they have a few problems that will require my attention.

First, the tires are completely rotten. Heck, it may have the original tires on it!

Second, the drive wheel crown is severely damaged.

Third, the right idler wheel "back" side flange is almost completely gone.

Here's a photo after cutting off the drive wheel tire:



Notice the rough, grooved surface on the crown of the wheel? Here's a close-up:



Chips were getting between the tire and the wheel during normal operation. Under heavy cutting, the tire was creeping or downright slipping on the wheel, resulting in the grooves. The deepest are around .010" deep, with the damaged surface extending the entire width of the tooth side of the crown and some damage on the back side of the crown. This damage can't remain, as narrow blades will track the groove instead of riding the crown ridge as they should.

Here's a photo of the left idler, which is completely undamaged:



The right idler crown is in similar condition, except for the flange on one side. It appears some doofus maladjusted the idler enough for it to run into the trunnion frame, almost completely wiping out the flange on the back side of the wheel.

You can see the damage in the very bottom of this photo:



Figuring out how to fix them

I mulled this over most of Saturday afternoon figuring out what my options were. I came up with three:

1) Call Do-All and hope I can get new wheels, or wheels I can machine to fit. Most expensive, and probably not direct replacements.

2) Build a pattern, cast some wheel blanks, machine. Middle of the run cost, lots of work.

3) Re-machine the existing wheels. Least expensive, just more work.

Initially, I didn't think #3 was an option, as the tires must be a good fit to the wheels if they are to transmit the machine's power to the band instead of slipping. However, it turns out that Sulphur Grove Tool's urethane tires will fit wheels +- 1/2" nominal diameter according to the guys at Peachtree Woodworking. The crown diameter of the wheels is about 15.990" as they stand right now, and I need to remove about .015 from the most damaged surface. Problem solved, tires ordered!

Now onto doing the work...

Measuring the band wheels

To begin, I spent a few minutes thinking about the ramifications of machining the band wheels. Removing .015" of material from the band wheels is going to change the relative position of the band towards the throat by the same amount. I'm not entirely sure if an adjustment guide positioning will be required or not. I'm hoping the answer is "no", but if necessary I'll re-fit the guides when the time comes.

The next minor issue was figuring out just how I was going to machine the wheels. They have to run perfectly true to the hub, otherwise the band will not track square and true. At first, I considered chucking up the lightening holes and dialing in on the machined surface of the wheel flanges. That didn't appeal to me, as it wasn't necessarily a reference to the bore after 62 years. The bore and flange surfaces of the drive wheel was fairly nasty, making an indicator sweep exceedingly difficult.

Rather than mess around all afternoon with an indicator, I decided to build a two-piece mandrel, as shown in my quick doodle below. Drawing conventions? What drawing conventions? :spit:



I removed the bearings from the idler wheels, masked off the bearing bores and sandblasted all the wheels to remove the paint and built-up gunk. Then, I cleaned the bearing bores and flanges with Scotch Brite and carburetor cleaner and stoned off any burrs on the flanges.



With everything clean, I measured the bores.





For those interested, here are the dimensions:

DRIVE WHEEL BORE: 1.1302" - 1.1280" tapered toward transmission side.
DRIVE WHEEL DEPTH: 1.625"

RIGHT IDLER BORE: 1.8495"
RIGHT IDLER DEPTH: 1.345"

LEFT IDLER BORE: 1.8498"
LEFT IDLER DEPTH: 1.360"

As you can see, the drive wheel bore is tapered slightly, probably due to running with the drive nut loose, as that's how I found it. There is some light galling inside the bore, which makes a precise reading difficult. I briefly considered sleeving this bore, but a thousandth or so TIR isn't as important as ensuring that the wheel crown runs square to the bore shoulder which locates the wheel "in-plane". However, due to the damage I'll have to make the final fit to the mandrel by test.

Machining the drive wheel arbor

With my sketch and dimensions in hand, I pulled a piece of 4130 bar stock from the rack and began work on the arbor for the drive wheel.

Roughing in the arbor, .1DOC, S=65, F=.012



After a quick honing of the tool, I took a pass for 1.1270".

A test fit got the wheel about halfway onto the arbor from the "large" side of the bore. I went over the diameter again and took off .0005" per side and just barely got the wheel on. A quick polish of the mandrel with 220-grit sandpaper yielded a very light interference fit for about 40% of the bore with a final diameter of 1.1257" I squared up the shoulder and changed tools for the relief groove.





Machining the relief groove with a flat-ground 1/8" cutoff blade.



Here's the first pass on the threads, 3/4-10 UNC



The finished arbor:



The drive wheel mounted! Note that it is double-nutted for safety.



That concludes the weekend's work. In the next post, I'll document machining the clamshell bushings to mount the idler wheels and maybe a little wheel machining. Then, it's back to painting.

Till then... :beer:

The old sandblast nozzle looks like the ones the TIP currently sells.

Reggie, that wouldn't surprise me one bit! Seems like when one outfit says they can't get it, somebody else has them in-stock. The problem is finding who has them in-stock!

I'm sure in about a year, like clockwork, my local supplier will change nozzles again. Till then, I have a stockpile. I bought them out.

Good thread. Glad to see a Do-all restored. Me and one of my workers is currently trying to get a Do-all ML up and running again. The bronze sleeve that the variable speed drive sheaves run on was broken and unavailable. So we're making a new one. No time for a restoration, I just want to get the thing running again. I got it from surplus for $50. When I say "I" I mean the department, not me personally. We'll probably put in a few hundred dollars in labor and materials getting it up and running again, worth every penny, if you ask me.

It is a damn shame that the older Do-alls are better than the newer ones. You can slide the upper guide with no tools on the old ones, the new ones require a hex wrench and some effort (no rack and gear). Maybe that is the newer "cheap" Do-alls, but I like 'em old, provided they are working. Definitely worth fixing them up. Restoration is even better.

One of the other shops got rid of an old Do-all that was complete with power feed and everything. They got a new Do-all. I liked the old one better, I'm not sure what prompted them to get rid of it. Probably something fixable, but I don't know.

Keith,

Interesting on the ML... The bronze bushing on mine is in GREAT shape, as are the vari-drive pulleys themselves. I was surprised to say the least. Hopefully, the transmission is in similar shape. I don't believe it is the original sheave set, they're just too clean and undamaged, compared with a lot of the Bakelite vari-drive pulleys I've seen.

Can't beat $50!

Hope you can get it back into service. It's sad but true, you have a better saw now than any you could buy new.

There isn't much to a band saw, but if they're not in tune they're miserable to use. I'd try to convince the boss to put some new tires on while you're in there.

Here are a couple videos to go along with the photos:

The machine as received

Machining the wheel arbor

I think the urethane tires for bandsaw wheels are a very significant improvement over the old black rubber tires. I got a pair of urethane tires for my 20-inch two-wheel bandsaw (older Delta/Crescent brand), and I think they are great.

With you lathing the wheel castings true, I imagine that your saw will run very smoothly.

For the old 20-inch wheels of my saw, I found that balancing the wheels makes a difference. I don't know if that will be necessary for the smaller wheels of your machine.

Thanks for sharing the details of your project. If I had space, I would be on the lookout for a saw like yours.

(As it turns out, there is one for sale now in my area. See below.)

http://sfbay.craigslist.org/eby/tls/1171810396.html


Band Saw - DoALL 36 Inch - $4495 (dublin / pleasanton / livermore)
Reply to: see below
Date: 2009-05-15, 1:07AM PDT

DoALL 36" BAND SAW
Model V36

FEATURES:

*
Variable Speed 50-1500 FPM
*
2 HP 220v Single Phase Motor - Run it at home!
*
Tachometer
*
Blade Welder/Grinder
*
Long blades on three wheels - 36" x 13"
*
Will also run short blades on two wheels - 16" x 13"

PRICE: $4,495

CONTACT: Don (925) 371- . . . .

* it's NOT ok to contact this poster with services or other commercial interests

image 1171810396-0

PostingID: 1171810396

Very nice videos. I am watching this thread as I will be starting the restoration of my Grob NS-18.

Jon,

I hope so! I've heard urethane tires are much better than rubber, thus the choice. Plus, I doubt the rubber tires would hold onto the machined wheels.

Good idea on balancing the wheels. I may give it a try with my motorcycle wheel balancer.

That's a nice looking V-36 you found! Looks like somebody has spent quite a bit of time on that one.

Tim,

Glad to hear it! Keep us updated on your project.


Speaking of urethane tires, I ordered the wrong ones! I was excited to get a small package from Peachtree Woodworking Supply on Thursday. However, after looking at the tires, made by Sulphur Grove Tool, I was rather disappointed. They were .090" thick instead of .125" as the original rubber tires. I was specifically told by Peachtree that these tires were .125" thick.

A quick call to Dee at Peachtree confirmed that they only sell .090" thick tires. However, she was happy to allow me to return them for a refund.

In the meantime, I called Sulphur Grove Tool and spoke with Bill. He offered to take back the .090" thick tires as credit towards .125" thick tires. Unfortunately, I had already boxed them back up and shipped them out. We worked out a deal and he said he would make and ship them on Tuesday. Bill also does custom sizes, which I wasn't aware of.

Bill is an avid motorcyclist, like myself. He was just walking out the door to leave for the Springfield Mile in Springfield, IL to watch a weekend of racing when I called. He was ready to go inside, make the tires, and ship them out in an hour, but I told him I was in no rush and to have a good weekend. Props to Bill for offering, that's service!

This weekend, I finished the arbor and machined the wheels.

The Idler Wheel Bushings

Before I could machine the drive wheel, I had to take a good measurement of the wheel crown angle. The drive wheel was too damaged to allow a good measurement, so I was left with the two idler wheels. Of the two, only the left idler had a clean enough crown to allow a measurement to be taken. Since the idlers have a larger bore than the drive wheels, arbor bushings were required to mount the idlers for measurement and machining.

VIDEO: Machining the bushings.

Here's the finished product, ready for the idler wheels. The left bushing is a press-fit to the drive wheel arbor. The right bushing is a slight running fit, to allow the two idlers to be interchanged and swapped end-for-end.



Machining the Wheels

With the left idler mounted on the arbor, I installed my dial indicator on the carriage and zeroed it out just past the peak of the crown. Then, I zeroed out the DRO and swept the the face of the wheel. The result was an indicator dip of .026" in .475", or a single taper of .657" per foot, or roughly 3.14 degrees.

I set the taper attachment accordingly, then double-checked the taper attachment with the DRO.

I planned to take off the same amount from all three wheels, and I expected .020" would be required to clean up the drive wheel. With that in mind, I began cutting the right idler.





I started the first pass at .0025" DOC and 70RPM at .003" per rev. Once I was confident I wasn't going to have a resonator, I upped the speed to 110RPM and the DOC to .005" per pass.

At .020" deep, I flipped the wheel end-for-end and took .020" off the other side of the crown. The arbor repeated to .002" TIR, which I was able to reduce to .001 TIR or less with a mallet, suggesting a burr in the wheel bore. However, the wheel ran out of plane about .007 once flipped, even though the arbor shoulders and bore were dead on. It ran for 62 years with .003" TIR on concentricity and .012" TIR out of plane, so I think I did well. Frankly, I doubt the bearings and transmission shaft will locate the wheel as accurately as I did when machining.

After cutting the crown, I trued up and trimmed the shoulders down to .035" over the crown bottom.

Here's the finished product:



A few photos of the drive wheel, over several passes:

First pass



Second pass



Fourth pass, .020" deep



After machining all surfaces. Notice the crown is centered.



A stack of re-machined wheels, ready for painting!



I should have a video of machining the wheels up shortly.

VIDEO: Machining the Band Wheels

Realy good stuff you are doing I also have 2 doalls v26 and mp20 which needs wheel work I looking forward to see the suff you will be putting on the drive wheels.What size is your American .

It looks like you are making the crown as an angle rather than as a curve. Is that how the originals were made? I had always thought it would be a curve ... but I may have just revealed my ignorance!

Collector,

Same here. I've been told the 1/8" urethane tires "are a bitch to mount". I'm fairly sure the process will involve moderate swearing.

The American is a 1972 14x30 "Zip Shift" B-pattern. AKA "Pint-Sized Pacemaker". She's big-boned though, scaling around 8,500lbs!


Awake,

Yep, that's how they came from the factory! According to Bill at Sulphur Grove Tool, 3 degrees taper per side is a fairly standard crown angle.

The crown operates on the same general principles as a motorcycle tire. I suspect a sharp crown angle tracks better than a "blunt", rounded crown, just like a pointy sport bike tire has a better cornering feel than a rounded sport-touring tire. Except, in the case of a bandsaw, the road tracks the wheel instead of the other way around.

Due to the force vectors at work, the band likes to track as high on the wheel as it can get. Similarly, a motorcycle always rights itself after spitting off it's rider, assuming both wheels still have ground contact.

Not at all!! I used Sulphur Grove urethane wheels, and they weren't difficult to mount.

The trick is to put them in hot water (almost boiling, but not quite) for a few minutes, then work quickly to get it on the wheel.

Took me a few tries, but I wouldn't call it hard. "Tricky" is a better word. I balked at the prospect of rubber tires - they seemed MUCH harder to mount.

Ryan

Ryan,

Cool! Bill at Sulphur Grove said I'd have fun with them and was talking about using tire irons and such. I guess maybe that's because he's getting up there in years and has more trouble doing it than I might.

Did you use any tools to mount your tires, or just stretch the hot tire on using a pair of gloves for hand protection?

I don't recall using any gloves, but maybe I did. I think I used a long 1/4" flat blade screwdriver to help ease the last bit on there, but really I think it can all be done by hand. You have to work quick because the aluminum pulls the heat right out of the urethane.

I actually picked mine up at Sulphur Grove. Bill is a great guy.

Also, rather than repainting those beautiful aluminum wheels, why not polish them?

Ryan