Delta 36-725 Repair help and warning

[Darrell D.]

Thank you all for the replies, I will be taking it to a motor shop this evening.  He suspects that sawdust got in there and gummed up the switch.  I guess I will have to always make sure I run the DC.

This thing was a bear to take apart.  Believe it or not the hardest part to remove was that little through screw that controls the riser crank backlash.  I guess they used some thread locker on that screw, but I almost stripped the head getting it out.  Heated it with a heat gun and them a pair of vise grips on the head and it came out.

The other thing I learned (like the pics above), its better to flip the thing over, remove the legs and then take it apart. I started out with is up right but when it came time to remove that riser collar I had to flip it. I was planning to remove the top with the motor attached and flip it. But I could not remove the top with the motor attached with the riser crank still attached. And I would have had to remove the cord strain reliefs as well and that was easier with the unit flipped.

Finally it appears that this was an old radial arm saw motor design.  Certainly not a TEFC motor like on the cabinet saws.  So saw dust is going to get in there.  I guess it needs some frequent blowing out and always use a DC.

I noticed in the pics above that the owner has sealed up the dust port. Likely they have some sort of bottom dust connection (I read the post and looks like he was getting ready to add a dust port, I will ask him if it caused any long term issues, it was several years ago). I put a plate and 4" port in the bottom of mine. It might be that if no DC is running, then dust can get in that motor. That design sucks. I would bet a TEFC (or better sealed) motor would add a few more dollars of cost.

   

   

   

[TDKPE]

Being a vented motor in an incredibly dirty environment, I'd have hoped they'd used a potential relay instead of a centrifugal switch.  But a motor guy will find one or the other in seconds, so hopefully it's not too costly to get it back to running.

[Darrell D.]

Being a vented motor in an incredibly dirty environment, I'd have hoped they'd used a potential relay instead of a centrifugal switch.  But a motor guy will find one or the other in seconds, so hopefully it's not too costly to get it back to running.

I will certainly report back on the findings and what was needed to make the repair.

[EvilTwin]

Looking like you made some progress. Hopefully there wont be any twitchy alignment issues when it goes back together. One thought, you might think about maybe putting some type of loose foam over that opening. It may help prevent it from sucking it all inside. But then again, eventually the foam filter may have to be cleaned out, but it might be a better alternative than the dust getting jammed up inside.

In that one thread I linked, one guy did seal up the saw quite a bit and maybe that is where you need to go with this. Did you saw have the shroud around the blade with a hose going out the back? Capturing that dust at that point is probably the best way to keep it under control. Either using a DC or shop vac would be the way to go.

[mike4244]

I am writing this post for two reasons.
1. I am looking for any last hope that I can repair this motor on this saw.
2. As a warning to others that are searching out reviews and trying to make a decision to purchase this saw.


First. I bought this saw used several months back and it had had worked well for me up till now. I have been away from woodworking for some time, and decided to downsize my tools from a unisaw to this 36-725. I was not doing much woodworking a needed the space in my garage.
It had done all that I needed. Then on Saturday in the middle of a project, it quit running. First the motor slowed, then quit running all together. The rear end of the motor was very hot. I let it cool and reset the breaker and still it would only hum.

The saw has been running on 220v since I have had it. After searching some threads I bought both the start and run capacitors. The saw tries to start (stronger than the hum), but wont turn.

I believe at this point that the bearing or something internal has it jammed. I can turn the arbor, but is maybe a bit tighter than I would expect.
As I see it I have two options, 1. try and make a DIY repair (saw new is $600 and replacement motors are $750-1000, or 2. throw it away and go buy a Ridgid or Grizzly.

As I have made upgrades and other add to the saw, throwing it a way is not the best choice.
So with that said, I am looking for thoughts on how to remove the motor and disassemble. I called Delta and they were absolutely no help. The tech basically said open the parts schematic and have at it. There has been a guy on the local craigslist that say they can repair tools like saws, I may give them a shot before I try myself.

So please share any thoughts if you have tried to repair one of these.

Finally, If you are considering this saw, I would highly caution you against it. Unless you buy new and it is under warranty. I think my saw is about 4 or 5 years old (but no receipt sense I bought used). It was in great condition and care.  But from reading, its seems that motor failure is a common failure with the saw.  I dont have data, but I see too many negative comments. So be warned. And consider another saw.

I just went thru a motor problem myself on a metal lathe. The motor ran hot, tripped GFI. Removed motor, real PITA. Had to hoist the motor off the bench to get to the bottom bolts. Took the motor to a repair shop. I was told to buy a new motor as the labor charges on a motor exceeded the cost of a new one. Take motor home and I decide to see if I could repair it. I am not enamored with working on anything electrical but figured I can't screw it up any more than it is now.
Remove the cover on the bell housing where the fan is. Plastic fan is broken and melted. Order new fan from Grizzly. This was as much of a PITA as motor removal. Had part# ,reference# etc. After two techs they find a replacement fan that had a completely different part#.
Fan cost $2.00 , shipping and sales tax and the part $12.98.  Fan came Monday. Opened the box and saw that the bore  was wrong, too small.
Imperial dimensions were .783 , fan bore was .637 if I recall. I wound up boring the hub with a boring bar to .784. I forgot to mention that new fan is aluminum. Installed new fan. Installed the motor. Used the lathe for several hours today. Motor temperature was cool, cooler than the shop temperature. 
Open up the bell housing and take a look. Not familiar with your saw so I do not if the motor needs to come off . 
mike

[TDKPE]

What is that white unit in the middle picture, with the two blue and one black wire to it?

[Darrell D.]

Looking like you made some progress.  Hopefully there wont be any twitchy alignment issues when it goes back together.  One thought, you might think about maybe putting some type of loose foam over that opening.  It may help prevent it from sucking it all inside.  But then again, eventually the foam filter may have to be cleaned out, but it might be a better alternative than the dust getting jammed up inside.

In that one thread I linked,  one guy did seal up the saw quite a bit and maybe that is where you need to go with this.  Did you saw have the shroud around the blade with a hose going out the back?  Capturing that dust at that point is probably the best way to keep it under control.  Either using a DC or shop vac would be the way to go.

Good idea on the filter.  maybe something like a hair net or panty hose.  Something with not too small openings.

I removed the blue dust connection, and closed up the hole in back.  Added a hood with 4" port on the bottom.  I think I need to make sure I always run the dust collector and maybe seal up some more opening to make sure that there is good flow around the motor and down to pull all the dust out.

[Darrell D.]

What is that white unit in the middle picture, with the two blue and one black wire to it?

I was not sure. It looked like a microswitch to me, but I never saw a button.  The repair guy is thinking that it might have a relay or centri switch issue.  I do know that the white box blue wires go to the run capacitor and the black wire goes to the start capacitor.  So it could be some sort of relay.

   

[daddo]

First, it slowed then quit running and was hot. This describes in part, a bad running capacitor or over amping, such as a tight bearing or a restricted movement.

Then it hums and won't start. This describes a bad start circuit or bad start capacitor- or over amping caused by a tight bearing or restricted movement.

The one thing in common is a restricted movement, such as a tight bearing or part.

I would first check to see that all moving parts operate easily and correct that if needed.
I then would test the capacitors and start circuit and correct that if needed.
If neither of these fix the problem, then to the shop it goes.


I will be keeping my old Delta belt drive saw.
It's a shame on manufacturers engineers who probably have never touched a saw in their life, designing them.!

[lkomroff]

That little white unit looks like a microswitch.  It fan also appears not to be a standard type. Could the fan be 2 piece and part of it should move when motor starts?  If that happened, there is a metal bracket (L shape) that looks like it is pressing on the microswitch, that could move along with the fan, open the microswitch and disconnect the cap. So , if the fan is stuck, bracket needs adjustment, microswitch is bad or the fan section won't move, the start cap will never be disconnected from the circuit.

Possibility or am I dreaming?

Larry