Rebuilding a Do-All band saw

[A_Pmech]

The Motor

This afternoon I disassembled the motor and assessed it's condition. The result isn't good.

I began by removing the motor from it's mounting plate. Then, I removed the main drive pulleys, which are just a couple of stock Browning pulleys stacked up on the motor shaft:



You'll notice in these two photos that the motor has a lot of shaft endplay. Over 1/8", actually. I suspected a couple of broken wave washers:





I split the motor, curious to see the carnage:



Years of hammering due to severely worn belts have taken their toll. The thrust washers and shims are in pieces, as is the wave washer:



In places, the bearing is completely worn through. The oiling grooves are full of swarf:



The windings are in OK shape, considering a mouse had made a home in here at one point:



The front bearing thrust face is worn over .020":



Verdict:

This motor is shot. It needs a re-wind and conversion to ball bearings.

Cost to rebuild / rewind:

Magnet wire: $60
Insulation: $25
6005 bearings: $20
Propane to burn out motor: $2.50
Epoxy: $75
Misc materials: $20
Machining time: 6-8hours
Rewinding time: 2 days

$202.50 total
24 man-hours of labor


Versus a $142 new motor:

https://www.surpluscenter.com/item.a...tname=electric

I'll buy a new motor. As much as I'd like to save the old motor just for the fun of it, motors this size are a commodity item. In these sizes, it's orders of magnitude less expensive to buy a new motor than rewind an old one. So, this old Peerless has served her time. A new motor will soon be powering this old V-36.

[A_Pmech]

Aligning the Machine, Part 1

I called Do-All today to update a parts order. While I was on the phone, I asked about how they align a 3-wheel saw. When I explained that I had taken the saw completely apart, including disassembling all the adjustment mechanisms, I got a long pause on the other end of the phone followed by "Oh...."

Apparently, Do-All does not have a field alignment procedure for their machines. All alignment is done in-house at the time of manufacture using "special fixtures" and once in the field one must "just hope that you don't take everything apart".

However, I learned several key pieces of information. The most important fact is that the datum plane for the machine is the trunnion main plate.

I was also able to determine the order of critical adjustments:

1) Establish the guidepost location and perpendicularity to the main plate.
2) Square the guidepost to the Y-axis of the machine.
3) Shim the upper wheel crown distance from the guidepost to establish the blade roller preload.
4) Bring the drive wheel into plane with the upper wheel.
5) Bring the third wheel into the plane occupied by the upper and lower wheels.
6) Install the trunnion and tables. Bring the auxiliary table into a plane parallel with the datum plane and secure.

With these critical adjustments, the machine's wheels are all brought into the same plane relative to the guidepost and upper wheel trunnion slider, who's relationship is fixed to the datum plane.

Do-All does this with jigs, alignment pins, and feeler gauges. They declined to provide me with photos of the alignment jigs, not that I'm going to spend weeks to make them in the first place!

Instead, I have a plan. It involves a master level, a custom plumb bob, and a trip to the music store. Unfortunately, I'll have to remove the main table and trunnion to access the datum plane. However, this method will also be very accurate, at least as accurate than Do-All's jig and likely better.

I'll update as I bring the tools together.

[A_Pmech]

For those watching and reading the thread, my numerous posted updates today bring the thread current, as of this evening.

Some of the machining posts of late are explained at a fairly elementary level, as they're written for a non-machinist audience. I'd appreciate any commentary on how I might have improved those operations if you have any ideas.

Right now, I'm looking for a new motor and collecting the tools necessary to align the machine. I've developed a method that should work fairly well, using a combination of a master precision level .016 music wire, a weight, and a wire mic.

I'll update as soon as I have new info.

[ducatidon2]

thanks for posting the detailed step-by-step pics. learned an awful lot about workholding, fixturing and just general out of the box thinking. nice work

[Dave A]

Very nice thread, my 16" should look so good.

[A_Pmech]

Originally Posted by ducatidon2

thanks for posting the detailed step-by-step pics. learned an awful lot about workholding, fixturing and just general out of the box thinking. nice work

Thank you, Don.

Most of my understanding of workholding and fixturing comes from various old books on machining. The old guys didn't have a lot of machines and they made up for it by getting really inventive, especially on the lathe. Modern machining books barely even cover faceplate work, by comparison.

Originally Posted by Dave A

Very nice thread, my 16" should look so good.

Thanks Dave. Never know when you might get a bug to tear into it!

[Milacron]

Below is a DoAll 2613-3 I fixed up in the early '90's. Didn't need rebuilding really...just fixing some hydraulic leaks and repaint. Back then I wasn't far from a shop with a huge Mattison surface grinder, so I also had the table reground... you could use it as a shaving mirror they did such a good job. Paint was Sherwin Williams Polane with texture finish.



To me this was the ultimate vertical bandsaw... speeds from snail slow to friction cutting, powered everything...from the blade post to the table tilt.

[D Rennie]

Originally Posted by Milacron

Below is a DoAll 2613-3 I fixed up in the early '90's. Didn't need rebuilding really...just fixing some hydraulic leaks and repaint. Back then I wasn't far from a shop with a huge Mattison surface grinder, so I also had the table reground... you could use it as a shaving mirror they did such a good job. Paint was Sherwin Williams Polane with texture finish.
To me this was the ultimate vertical bandsaw... speeds from snail slow to friction cutting, powered everything...from the blade post to the table tilt.

I have one of these. Everything is built so heavy duty and beautifully engineered that it makes the smaller simpler DoALLs look cheap by comparison. Reading this excellent "Rebuilding a DoALL thread I have often wished that it was a Contourmatic that was being rebuilt. Though I bought mine in excellent condition the paint was peeling so I repainted. Though I thought I did a good job at the time it is an embarrassment compared to the work that A_Pmech is doing here.

Simply bueatiful!!!!

[A_Pmech]

Don,

I remember a thread about that saw at one time. They sure did a good job on the table! I'll eventually grind this table, I think. There are not many outfits with a large enough grinder around here, although I may have a bead on an outfit with a 48" Blanchard that could do it.

D Rennie,

Thank you.

I passed up several Contourmatics because they're more complicated than what I need and all were in need of rebuild as well. This saw will mostly be used on aircraft metals. As such, complicated hydraulic power feeds and friction sawing capabilites just get in the way. Should friction sawing ever enter the picture, I'll locate a used 36" Zephyr and rebuild it. However, that will have to wait, as an 10' tall machine will not fit in my current shop!

What interested me in this saw was it's large throat and the fact that it is an old saw. It has a "classic" look about it which I appreciate. While the early Do-Alls aren't necessarily as heavy as some of the later hydraulic machines, this example has managed to last in a production environment for 62 years, proving that it's "enough".

So, I suppose one could say, I bought this saw because of it's simplicity.