# Delta 34-740 TS / replacing motor advice please



## duncsuss (Aug 21, 2009)

Hello,

Does anyone have advice on replacing the motor assembly on a Delta 34-740 table saw (a.k.a. Super 10) please?

I got this saw from a friend about a year ago, last week the thermal cutout started to trip (even without a blade mounted) so I took it to the nearest Delta repair facility. They told me the motor had to be replaced, it's not a serviceable unit, and the price would be $499 

I think I got a lucky break and found a new-old-stock part on eBay for a lot less -- now I'm wondering if I should attempt the job myself or see if the repair shop will do the job "labor only".

Any advice?

Thanks ...

Duncan


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## rrich (Jun 24, 2009)

Duncan,
The saw blade is attached directly to the motor shaft, correct?

Four hundred seems to be a rather steep price for just a new motor and repair. So let me try a guess or two to help you.

I'm guessing that the saw really struggles to start up. And once it does, cutting almost anything makes the saw stall and trip the thermal protection device.

Try this as a test to determine where the problem is. Move the saw next to the washing machine. Plug the saw into the outlet used by the washing machine using ONLY THE POWER CORD THAT CAME WITH THE SAW. 

If the saw runs fine using the washing machine outlet, the problem is the wiring to the saw where you're trying to use it.

A table saw usually draws at least 12 amps. For best performance, the saw should be connected to a 20 amp circuit without extension cords. A short 12 gage extension cord using a 20 amp outlet would be acceptable.

From everything that you've said it looks like a power capacity problem to me. Too much current being drawn because of too large of an IR drop in the wiring is a common cause of thermal overloads in electrical motors. (BTW - IR means Resistance times Current and indicates the amount of voltage that is lost.)


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## duncsuss (Aug 21, 2009)

Thanks for your help Rich; you are correct, the blade arbor is the same shaft as the rotor, no belt.

The guy at the Delta repair center was very open about the price being high -- and he even suggested I could probably find the part cheaper than he was able to source it. In his defense, the motor lists at $467 on a couple of replacement part websites, so $499 including labor doesn't sound bad (in that context of course.)

The saw didn't struggle at power on (hasn't in the 9 months I've used it), and began to sound different immediately before the thermal cutout tripped the first time.

After that point, it would start up okay, but there was a dull clicking noise that got faster as it ramped up to speed. About 20 seconds in, it tripped again ... and again ... and again. It did this with or without a blade fitted. (I believe it also did it at the Delta repair shop, but didn't specifically ask if they attempted to power it up when the guy called me back to tell me the bad news.)

Re-reading my first post, I realise I didn't actually say "found and bought" a replacement motor on eBay, sorry if I gave the impression I was asking if I should even buy it. That's a done deal -- now the question is whether I should attempt to fit it to the saw myself or leave that to the professionals ... of course, if it turns out to be a simple matter of voltage drop, I'll see if Delta will buy the part from me at 10x what I paid for it :laughing:

Thanks again --

Duncan


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## Sawmilllawyer (Aug 20, 2009)

If you have the tools and the time to do it, I would try to replace the direct drive motor myself. But then I have always been a fix yourself kinda guy. Yes, I have had somethings turn out not so well but in the long haul most projects turn out pretty good and in the process I learn something and save a few bucks towards another tool or project. That said, there are some things that you should'nt work on because you either are not trained/able too or the economics do not justify it. Then you are better off purchasing the most durable and best value you can find.


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## woodnthings (Jan 24, 2009)

*Heck yes do it yourself*

You've probably got 4 bolts and a cord to wire. Not rocket science. You will need to align the blade to the miter slots. I found this site:
http://www.ereplacementparts.com/delta-34740-type-super-saw-parts-c-3275_3334_14087.html
Since you removed the motor, it shouldn't be too hard to install the new one, but I would do a test run before putting it in. Maybe even have the Delta guy check it? :blink: bill


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## rrbrown (Feb 15, 2009)

*Am I missing something here?*

Are you guys telling him to spend $467 on a direct drive saw motor fixing it himself. Hell for that price he could find another saw contractor style with a bigger motor. I wouldn't spend that much money on that type saw. I would take the motor to a motor shop an have them look at it. Delta might be taking the easy way out and just replacing the motor. just my .02


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## duncsuss (Aug 21, 2009)

*yikes no!*



rrbrown said:


> Are you guys telling him to spend $467 on a direct drive saw motor fixing it himself. Hell for that price he could find another saw contractor style with a bigger motor. I wouldn't spend that much money on that type saw. I would take the motor to a motor shop an have them look at it. Delta might be taking the easy way out and just replacing the motor. just my .02


LOL -- I don't think anyone was telling me to do that!

I got a motor off eBay for 75 bucks including shipping -- there's no question I would never sink $400+ into the old thing! My question is "how easy would it be to change out the motor myself?"

Thanks all --

Duncan

(edit -- bought it last night, it could be a week before I actually receive the motor)


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## woodnthings (Jan 24, 2009)

*Yes, afraid so richard*

He's already got the replacement motor. :yes: bill
He didn't say what it cost however?:blink:
OOOOPs he just posted above me!

"Re-reading my first post, I realise I didn't actually say "found and bought" a replacement motor on eBay, sorry if I gave the impression I was asking if I should even buy it. That's a done deal -- now the question is whether I should attempt to fit it to the saw myself or leave that to the professionals ... of course, if it turns out to be a simple matter of voltage drop, I'll see if Delta will buy the part from me at 10x what I paid for it :laughing: "


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## knotscott (Nov 8, 2007)

duncsuss said:


> LOL -- I don't think anyone was telling me to do that!
> 
> I got a motor off eBay for 75 bucks including shipping -- there's no question I would never sink $400+ into the old thing! My question is "how easy would it be to change out the motor myself?"
> 
> ...


I'm late to the party Duncan, but I think you made the right choice. :thumbsup: It's worth a $75 repair...no way it's worth $400+.


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## duncsuss (Aug 21, 2009)

*what does "that type saw" mean?*



rrbrown said:


> ... I wouldn't spend that much money on that type saw ...


Being a newbie to table saws, I don't know how to interpret this -- I can guess there are different categories of saw?

What features make one more desirable than another? (If there is a primer on this somewhere, please point me at it.)

Thanks again --

Duncan


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## rrbrown (Feb 15, 2009)

Well a direct drive saw isn't quite as good as a contractor saw (belt drive hanging off the back) then you have the hybrid which the motor is inside like a cabinet saw but not as large a saw. then the cabinet saw which usually has larger trunnions and motor.

However I did miss the I already have the motor part and couldn't have known $75 for it but that is a good deal.


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## duncsuss (Aug 21, 2009)

rrbrown said:


> Well a direct drive saw isn't quite as good as a contractor saw (belt drive hanging off the back) then you have the hybrid which the motor is inside like a cabinet saw but not as large a saw. then the cabinet saw which usually has larger trunnions and motor.


Thanks -- that adds a whole new dimension. Interesting that belt drive is rated higher than direct drive -- I'd've thought it was more prone to slipping (but that could be a good thing if the blade stops, better a belt slip than the motor burn out ... oh, wait, that already happened to me :laughing

Duncan


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## knotscott (Nov 8, 2007)

duncsuss said:


> Thanks -- that adds a whole new dimension. Interesting that belt drive is rated higher than direct drive -- I'd've thought it was more prone to slipping (but that could be a good thing if the blade stops, better a belt slip than the motor burn out ... oh, wait, that already happened to me :laughing
> 
> Duncan


Induction motors in general are quieter, have more torque, and tend to be more reliable than the universal motors typically used in direct drive. Back in the day of turntables (record players), the better tables were all belt driven. A belt reduces vibration, which just makes the whole machine operate more smoothly. Compare overall dimensions, weight, materials of construction, duty rating, fences, etc., combined with the motor advantages, and I think you'll see that full size cast iron contractor saw are basically an overall upgrade. Hybrids and cabinet saws have more advantages yet, as RRBrown pointed out.

Rockler's TS article explains the differences pretty well.


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## rrbrown (Feb 15, 2009)

knotscott this is where you usually have pictures of the saws there inners and such. whats up?:laughing:


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## rrich (Jun 24, 2009)

Duncan,
The clicking is a key symptom. I'm assuming that the motor is a "Universal" type. i.e. The motor has brushes. The clicking is usually caused by a failure of one or more of the armature contacts. OR the brushes have worn out.

You probably could replace the brushes for $15 to $20 plus labor.

I'm not sure why the motor that you purchased on eBay would even be up for sale, unless the saw was "Parted Out". If the motor was brand new, it's possible that the seller experienced what you have and...


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## knotscott (Nov 8, 2007)

rrbrown said:


> knotscott this is where you usually have pictures of the saws there inners and such. whats up?:laughing:


I got nuthin but a schematic, but that doesn't really show much about the beefiness of the parts...:boat:


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## duncsuss (Aug 21, 2009)

rrich said:


> Duncan,
> I'm assuming that the motor is a "Universal" type. i.e. The motor has brushes.


I can't remember where I got the notion, but I believe it's an induction motor.



> I'm not sure why the motor that you purchased on eBay would even be up for sale, unless the saw was "Parted Out".


Pictured alongside a box with its Delta part number and "Motor Kit" on the label. Looks like a replacement part that never got sold/used.



knotscott said:


> I got nuthin but a schematic ...


Not the right schematic though -- that is "34-670_Type_2_WW_2.gif", at a guess the 34-670. Mine is the 34-740 ... there is no exploded view for the motor










Thanks to everyone for the ideas and encouragement; I've decided to get my saw back from the repair center and attempt to do the replacement myself.

Duncan


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## rrich (Jun 24, 2009)

Duncan,
My only advice would be to flip the saw upside down to work on it.

Then as Bill says, a few bolts, a few wires and reailgnment.


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## duncsuss (Aug 21, 2009)

I just talked to the Delta repair shop to let them know I'd be coming down to retrieve my saw. On a whim, I asked if they would fit a replacement motor that I furnish myself, and if so how much they'd charge.

After a few minutes on hold, the rep returned and said with the caveat that they wouldn't warranty it, they would install it for $66 (+tax).

It sounds reasonable to me -- even if they can do it in 10 minutes, I know it would take me at least an hour, and I'd need help lifting it and turning it over, etc.

The motor kit didn't arrive yet so I still have time to think it over ...

Thanks to everyone for the advice -- next time I have a question I hope it will be about how to do something with (rather than to) one of my tools!

Duncan


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