About a year ago I bought a 1919~1920 JD Wallace 16 inch bandsaw. The man selling it was an retired contractor foreman that been collecting all kinds of tools. He was taking back his garage space, I ended up getting this saw for $145 with a couple car loads of other stuff. He was happy to pass it on to someone that would use it and get enough room to maybe get a car in his garage. I was happy to get a real bandsaw.
After getting help from a friend moving the 350lbs saw ( considered portable in its time) I found out the working saw was going to be a project. The first time I plugged the saw in I heard a shrill squeal. The problem was the motors brush system had been jerry rigged. the motor is cast into a housing specific to the saw so the problem isn't as easy as swapping a motor on a 4x6 bandsaw or something like that. I have given up on finding ( for the time being) an original replacement.
my back up plan has been to use a DC treadmill motor. the tricky part is the mounting of the motor as my current challenge. I would like to brainstorm with the homemade tools group as to a good solution.
I want to mount the DC motor inside of the ac motor as pictured above roughly.this way the housing could in the future be restored to original. (If it comes down to it I will forgo this idea) what kind of mount should I make? would a pair of plywood doughnuts with the motor in the middle work? Any other suggestions criticisms would be great. feel free to chime in even if its just a thought
Last edited by jere; 08-19-2015 at 12:09 PM. Reason: if anyone can get rid of or tell me how to get rid of the compressor attachment please let me know. it was my mistake
Jere, can you post photos and dimensions of both drives on the motors? Also of the mounting surfaces? That will give everyone, including myself a good idea of what your dealing with. If your adapter plate just consists of a OD and a ID and a couple bolt patterns, I could make you something from steel or aluminum if I have a measured drawing with exact dimensions. was the original motor keyed? Jonathan
I'm with John, it's a little hard to see exactly what we're brain storming here. It looks like the field coils are still in the old motor housing. If you are trying to go for a vintage look without doing any damage to the old motor it's going to be a little complicated to leave the coils and try to mount the motor in the coils. While the doughnuts might be ok to hold the motor centered I'd personally be worried about air circulation and there's the sticky wicket of how to hold the motor steady under load. If the coils weren't there it would be fairly simple to make mount and bolt it down to one side of the motor case. That old of a motor isn't going to be very efficient and could be close to impossible to find parts or somebody to fix it. I've had old motors rewound and in my case it wasn't worth the $$$.
I too have fallen down the treadmill motor rabbit hole. So I've been doing a lot of looking on treadmill Dr. Com and eBay and what I've come too is its a lot more to know than I thought. There is a ton of cheapo motors out there on the cheap treadmills that you run into a lot. But on the higher end treadmills like gym models it's another world. #1 being they are keyed shafts(not threaded) have fans, can be taken apart and are not throw always like the cheap motors. They are way heavier duty and seem to be more conservatively rated. Not knowing anything about treadmills I was checking the local Craigslist and there was a StarTrac 4500 for $50! It was an old gym mill and while rough in appearance the electronics/motor worked perfectly. When I took it apart it had a new motor by a tech who wrote the replace date on it. It's almost 30% bigger and heavier than the other motor I got out of a home mill. The home mill was rated at 3hp and the new one is rated at 2.5hp.
Thanks for the replies guys! I will try and answer some more questions when I get home and can get some measurements
here are a few more photos I will take some more when I get home. the fan looks like it will have to come off to fit in the original housing as will the flywheel. the shaft legths are very close in length but the DC motor shaft is narrower in diameter. Maybe the pulley on the shaft could be turned down to fit the bandsaws cog? the cog/ gear on the bandsaw's motor's shaft does have a keyway that looks like it way hand cut, not completely straight and is rounded towards the center of the shaft.
Last edited by jere; 08-19-2015 at 11:55 AM. Reason: Hopefully fixed the photos
Glad you posted this Jere. Be glad to sidewalk suggest if I can.
I'm with Jonathan and C-Bag and unfortunately can't open the attachments above. As C-Bag pointed out leaving the field coils in may create some issues with heat as well as EMF that might be induced back into them, possibly creating a live terminal somewhere. Also what is the HP rating of the new motor...cooling these is important in order to maintain efficiency, so If you have to remove the fan I would put another on the outer housing to draw air through it. Just thoughts till we get some more info.
‘‘Always do right. This will gratify some people and astonish the rest.’’
Take the fields out , not to hard to do. As far as a fan you can buy small box or round fans that are electric. Just add them to the end of the motor and wire them in. With the fields out there should be room to make a mount inside the old motor housing, then mount it just like the old. Motor was with the original brackets no one will even no it's not original accept you.
Now we can see. Yup, dump the fields(good call PJs on the possible induction into the old coils), dump the flywheel on the dc motor. Looks like the dc motor has a keyway? and the drive pulley is separate from the flywheel? A lot of these treadmill motors aren't.
Like you jere I would use the old dc motor pulley to turn it down to make a bushing/adapter to fit the old gear. So it's gear driven? wow...so it's going be real handy to have the dc motor if you want to do a speed change. Does the drive(motor) gear engage from the bottom to the driven gear or? would be nice to have some kind of adjustment in the motor mount to adjust lash correctly otherwise you're going to get in trouble. I've never seen a gear drive bandsaw but then again I'm no expert. I'd be tempted to just come up with a mount that goes right on the saw that can be adjusted in and out for proper alignment of the drive and driven gears and for lash. Then just put the empty motor can over it after everything is working....just my 2c.
I am a little overwhelmed by all the great advice guys, thanks! Its a good thing I decided to post this project there are few ideas I would have completely overlooked otherwise. The coils potentially making a current being a possible big one!
Since some photos will save a lot of typing here goes.
To illustrate the initial problem and throw some more speculation for others that might come across this in the future. There seems to be no induction system just the repulsion ceramic brush system. the two petrusions on opposite sides of the casting must have held the ceramic brushes with a spring at one point in time. this is what was driving the motor when I first got it.
Something like the brushes on this DC treadmill motor
even though one motor is ac and the other DC neither have capacitors. Both use ceramic brushes the old motor (repulsion induction supposedly) disconnected the brushes when the centrifugal induction switch got up to the right speed. The repulsion motors system was known for having a very high torque start and for being high quality and long lasting.
Hopefully the treadmill motor will match the originals power or come close. it is considerably smaller but is rated for higher hp 1/2hp vs 2.5 hp( or so other motors that still have motor plates suggest.) the old motor on this saw seems much larger that other photos I have seen like this one on ebay vs the one I have note the center sections width compared to the ends
I found a second treadmill motor I forgot I had stashed away. one is a larger "everlast" made in Taiwan rated at 2.5hp it has a keyway for the flywheel it once held. It also has a larger diameter shaft and smaller fan.
here is the label for the tiawanse motor
here is the Chinese made motor that is rated at 1.75hp and was from a popular brand ( like live strong or Nordic track) it has the threaded shaft holding the flywheel on. I will save this one for a belt sander that is in the works. thanks for covering the treadmill motor C-bag I never thought about there being a difference in the treadmill motors.
Chinese treadmill label
original motors keyway handcut?
Back of the motor housing, which doesn't have much in the line of ventilation holes
each DC motor only has 2 holes on each side, this is the Taiwanese bracket.
Chinese original mounting bracket
how are the windings in the center section held in place? is it just pressed in? if the copper wire was removed could it be a stable mounting point?
what should I do about the potential for heat? I have heard of pc computers being filled with mineral oil as part of a cooling system. would mineral oil damage a DC motors internal components? Or could the DC motor be fully submerged I the oil? a cheap harbour freight mini fountain pump could circulated to a heater core or somelething?
what would lash adjustment for the gear look like? would it just move in two directions or more C-bag?
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