free but boken saw, whats wrong with it

What do you mean by no power. Does the motor stop? Slow down? Does it burn the wood? How big is the motor Horse Power wise? 110 volt or 220 volt?

-- Max "Desperado", Salt Lake City, UT

It depends on the motor type. AC induction motors don’t have bushes but AC universal motors do. If it’s a capacitive start/capacitive run motor the run capacitor could be bad.

Post the motor nameplate data or a picture of the nameplate if you can. And a picture of the motor and saw and the Delta part number for the saw.

-- -Curt, Milwaukee, WI

I had a capacitor go bad on a Delta saw several years ago and it was doing the same thing as the op said his was doing. I put a new capacitor on it and it was back to normal again. I also had a capacitor go bad on another Delta and it wouldn’t start and needed a new capacitor. I had a 3 hp dust collector wouldn’t start and it was a capacitor also. I ordered the capacitors from MSC in Atlanta for half what Delta wanted from them. BlankMan could be right about your saw.

-- Bruce Free Plans http://plans.sawmillvalley.org

I should have mentioned, if the motor has two humps on it (the housings for the capacitors) then it’s most likely a capacitor start/capacitor run motor and the symptoms you’re describing sound like the run capacitor failed. It could also be the centrifugal switch, depending on the design and if they just cut out the start capacitor (SPST switch) or if they switch from the start capacitor to the run capacitor (SPDT switch). If the motor only has one hump then it’s most likely a capacitor start/induction run motor, if the single capacitor were bad on that motor it most likely would not spin up and/or growl when you turned it on. Had one do that when the centrifugal switch failed to close on spin down.

Delta used to use Baldor capacitor start/capacitor run motors on their UniSaws, that’s what mine has, it has the two humps. They may have used them on other saws too. Don’t know if they still use them though. Capacitor start/capacitor run motors are more expensive but they are more efficient using less power, run smooth and have less vibration and run cooler.

-- -Curt, Milwaukee, WI

If the motor runs, make sure the belts are tight. ( Not while the motor is running—Goes without saying, but I’ve heard of dumber things being done) They could be slipping, which would cause a loss of power to the blade.

-- http://shepherdtoolandsupply.com/

the saw blade slows down then stops, but the motor keeps running. it s 120 volts, 15 amps, 25-60hz.
serial no 8840, cat no 34-670 ?
the number on the motor is 1313314.
sorry cant post pics of saw at this time maybe next week.

yall are great cant believe the number of replys.

Check to make sure it’s wired right. Wiring the motor for 240 will cause it to work on 120 but have no balls (slow/stall when the wood hits it)

Needs a new belt most likely. If the motor still runs but the blade stops.

-- Carpenter assembles with hands, Designer builds with brains, Artist creates with heart!

If the saw was starved. i.e. it was run using a small extension cord and some hard cutting was tried then it could have burned windings on the rotor. When this happens the saw will become weak.

Aren’t the capacitors mainly needed for the motor to get up to speed only when started?

-- The smell of wood, coffee in the cup, the wife let's me do my thing, the lake is peaceful.

34-670 looks to be a universal motor, no capacitors, so I’d check the brushes to start off with. No external belt, one internal belt in under the end bell. Looks to be a timing belt. I’d check that out too, if the teeth on belt stripped off that would explain it. No tension adjustment so if it stretched and it’s lose thus causing slippage it would need to be replaced. I’d take the motor apart and check out the commutator (where the brushes ride on) and clean it. Material build up between the copper bars on the commutator can short the windings causing a loss of power. And use emery cloth to clean the copper bars back to a nice shine.

But if you say the blade slows down and/or stops and the motor keeps spinning I highly suspect that belt. (I’m assuming the blade is tight on the arbor and that’s not the cause.)

-- -Curt, Milwaukee, WI

so i should pull the motor, unbolt it . pull apart the hub/ whatever its called on the end the brushes are located. does it matter which way faces up?,or do it level. dont want stuff falling out on me. then check the belt. if looks good clean the commutator. i will check brushes first, but if look good dont want to have a bunch of parts on my hands.

Here’s a link to an exploded view of the motor, it doesn’t look to bad to disassemble. The belt is item 226 and it looks easy enough to get the cover over it off. If you do take it further apart to clean the commutator remove the brushes first, that’s probably the only thing that might pop out. Looks like it might or might not be easy to take it apart to get at the commutator. If the bearings on the shafts are pressed on the shafts and into the housing that would be the might not. But if they do slide out that would be the might. I’d take the the screws out and if it comes apart without force then ok, but I wouldn’t force it. If you’re not mechanically inclined (no offense) and not comfortable with disassembling it see if there’s somebody that would help you or do it for you.

Looking at the picture again you might have to remove the pulley to split the case and that looks held on by a clip ring. Not a show stopper.

-- -Curt, Milwaukee, WI

Oh, its one of THOSE saws. Those belts shear pretty easily as they age. Sheared cogs would allow the assembly to run fine with no load and slip as soon as load ate up the inertia.

Sounds like a dehydrated Squirrel to me. Give him some gatorade.

- Just kidding -

-- http://www.MyFirstGarage.com

Check things in order before tearing it apart.
1)Confirm what is stopping when you make the cut. Is the motor still running hard but the saw arbor stopped? That would be the belt if the motor is still running.
2) If the motor truley stops, check to see if it has the 2 humps (capacitors on it). Changing the run capacitor would be a cheap solution. They are usually around $8-$15 at a motor shop. Dont buy them from a manufacturer. You might want to replace them both while you’re in there.
My Craftsman wood lathe had the start capaitor go out. It was $30 at Sears and lasted 6 months. I bought the same value one at a motor repair shop(name brand capcitor) and it was $8 and still going.
3) If the motor stops and it does not have the humps on it, you will probably have to remove the motor and take it in for repair or get a replacement. Grainger is a good source for decent priced motors

-- Jim Jakosh.....Practical Wood Products...........Learn something new every day!! Variety is the Spice of Life!!