# Repair or replace table saw



## DerfIV (Sep 12, 2019)

I'd buy a new or lightly used saw. Especially with the holidays coming up there are bound to be deals to be had on new ones. I had to make a similar decision about 20 years ago with a saw that was older than I am (I'm 69 now) when the bearings were shot and it just wasn't safe to use so I pitched it.

But, if you'd rather consider a replacement motor, check with a motor repair shop, they probably have one for sale cheap. Any reasonably sized city will have a motor shop.


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## chandler48 (Jun 5, 2017)

If you mean "direct drive" as in Ryobi, RUN. Those motors are prone to burning up too quickly to suit me. I have had a couple of them. If you can find a matching motor for your saw at a reasonable price, replacing it would be the cheapest way out. The saw you have will outlast 5 Ryobi or similar saws.

Unless you are doing it for a living, upgrading to a high end Ridgid or similar just would not make $ sense.


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## Nealtw (Jun 22, 2017)

I would just find another junk yard motor for it.


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## moosehaed (Jul 30, 2018)

chandler48 said:


> If you mean "direct drive" as in Ryobi, RUN. Those motors are prone to burning up too quickly to suit me. I have had a couple of them. If you can find a matching motor for your saw at a reasonable price, replacing it would be the cheapest way out. The saw you have will outlast 5 Ryobi or similar saws.
> 
> Unless you are doing it for a living, upgrading to a high end Ridgid or similar just would not make $ sense.


Not sure if direct drive is the correct term. I was referring to non belt drive saws.
I was looking at something like this or similar.

A basic low price table saw with a stand. https://www.lowes.com/pd/DELTA-Shop...ed-Blade-15-Amp-Portable-Table-Saw/1000795558

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## moosehaed (Jul 30, 2018)

Nealtw said:


> I would just find another junk yard motor for it.


Would I have to stick with 1/3 hp or can o move up to 1/2 hp?

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## Nealtw (Jun 22, 2017)

moosehaed said:


> Would I have to stick with 1/3 hp or can o move up to 1/2 hp?
> 
> Sent from my Pixel 2 XL using Tapatalk


 You can go up up to 1 hp if you find one the only concern is speed, you would like to keep the speed of the blade between 3400 and 4000 rpm if the saw is 10" and you just play with the pulley size to regulate that.
Your old motor was way under powered and should have burned up years ago. :wink2:
An older friend had an old saw like that with washing machine motor and when it didn't have enough power he just put a belt on a second motor the same size.


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## SPS-1 (Oct 21, 2008)

Thats a nice cast iron table top. 

On the other hand, I don't see a fence or even mounting struts for a fence. Gotta have a fence. I would have to replace that saw just for that reason.

New saw would also have the proper safety guards.


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## moosehaed (Jul 30, 2018)

SPS-1 said:


> Thats a nice cast iron table top.
> 
> On the other hand, I don't see a fence or even mounting struts for a fence. Gotta have a fence. I would have to replace that saw just for that reason.
> 
> New saw would also have the proper safety guards.


It has a cast iron fence.

Safety features, like guards that just get in the way? Lol. My dad would always take them off his tools.









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## moosehaed (Jul 30, 2018)

Nealtw said:


> You can go up up to 1 hp if you find one the only concern is speed, you would like to keep the speed of the blade between 3400 and 4000 rpm if the saw is 10" and you just play with the pulley size to regulate that.
> Your old motor was way under powered and should have burned up years ago. :wink2:
> An older friend had an old saw like that with washing machine motor and when it didn't have enough power he just put a belt on a second motor the same size.


I'm sure my uncle replaced the motor some time ago. Probably that was what he had on hand.

It's a 7 1/4" saw.

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## Nealtw (Jun 22, 2017)

moosehaed said:


> I'm sure my uncle replaced the motor some time ago. Probably that was what he had on hand.
> 
> It's a 7 1/4" saw.
> 
> Sent from my Pixel 2 XL using Tapatalk


The concern with the speed is the speed of sound and the speed the teeth are travelling so a smaller blade could go the same speed. That would explain the smaller motor.


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## Nealtw (Jun 22, 2017)

https://vermontamerican.com/circular-saw-blade-speed-chart/


I was a little off, but on the safe side.


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## moosehaed (Jul 30, 2018)

Nealtw said:


> https://vermontamerican.com/circular-saw-blade-speed-chart/
> 
> 
> I was a little off, but on the safe side.


What's the best/easiest way to measure the rpm?

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## SeniorSitizen (Sep 10, 2012)

moosehaed said:


> What's the best/easiest way to measure the rpm?
> 
> Sent from my Pixel 2 XL using Tapatalk


 The formula is: drive sheave diameter X motor RPM divided by driven sheave diameter.

Example IIR correctly: 1750 RPM X 3" motor sheave divided by arbor sheave diameter of 2" = 2,625 blade RPM.


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## Nealtw (Jun 22, 2017)

moosehaed said:


> What's the best/easiest way to measure the rpm?
> 
> Sent from my Pixel 2 XL using Tapatalk



It is the circumference you figure out 


2x3.14 r=c 

3 inch pulley
2x3.14x1.5 =9.42"
2" pulley 

2x3.14x1=4.71" 



9..42/4.71= 2 

so a 2" blade pulley rpm would be 2x the 3" motor rpm.


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## Nealtw (Jun 22, 2017)

SeniorSitizen said:


> The formula is: drive sheave diameter X motor RPM divided by driven sheave diameter.
> 
> Example IIR correctly: 1750 RPM X 3" motor sheave divided by arbor sheave diameter of 2" = 2,625 blade RPM.



It is the circumference you play with and your speed would be 3500:wink2:


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## SeniorSitizen (Sep 10, 2012)

Nealtw said:


> It is the circumference you play with and your speed would be 3500:wink2:


I'd rather play with diameter.:biggrin2:


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## Nealtw (Jun 22, 2017)

SeniorSitizen said:


> I'd rather play with diameter.:biggrin2:


 but the key is 2" is 1/2 the size of a 3" :wink2:


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## SeniorSitizen (Sep 10, 2012)

Nealtw said:


> but the key is 2" is 1/2 the size of a 3" :wink2:


If the above is correct, I'm certain we attended different arithmetic schools.:biggrin2:


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## Nealtw (Jun 22, 2017)

SeniorSitizen said:


> If the above is correct, I'm certain we attended different arithmetic schools.:biggrin2:



Yes, not sure what I did wrong but yes. I spent 20 years in an industry where we had to show all the long math, for belt speed. Hopefully my math skills were better then.


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## Drachenfire (Jun 6, 2017)

moosehaed said:


> Not sure if direct drive is the correct term. I was referring to non belt drive saws.
> I was looking at something like this or similar.
> 
> A basic low price table saw with a stand. https://www.lowes.com/pd/DELTA-Shop...ed-Blade-15-Amp-Portable-Table-Saw/1000795558
> ...


That is essentially a circular saw mounted to an inexpensive plastic box with an aluminum table top.

You can get a 1/2 hp motor for under $100 on Amazon.


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## SeniorSitizen (Sep 10, 2012)

The formula, I originally posted, was for driven RPM if we have both sheave sizes and a known drive RPM.

I had to re-teach myself how to determine what size sheave to attain a certain RPM of the driven if only RPM is known of the drive sheave and diameter. So I went back to pencil / paper and with difficulty re-taught myself how to solve ratio and proportion problems. 

To soften the pressure on my deteriorating memory I picked an easy problem I could solve in my head.:smile:So in this instance if we want the blade to rotate 3,500 RPM we would need a 1.5" sheave in the saw arbor.


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## Doboy (Dec 5, 2018)

Moosehaed,,, These guys are going overboard!?


#1; Search Craigslist or Ebay for a replacement 1/2hp motor. (make sure rpm, rotation, & shaft sizes are the same)

#2; You just might find another TABLE SAW for 1/2 the price of a 'new' motor.
#3; Since 99.5% of everything that's reasonably priced comes from China, just skip the 'middleman' & buy a 'FARM GRADE' 1/2hp or even a 3/4hp motor from HARBOR FREIGHT! (Check mounting bracket hole spacing)

OR
#4; Just BUY a NEW HF 10" TABLESAW (if you do more ripping?) or a 10" COMPOUND MITER Saw for everything else! (Christmas sale, or 20-30% OFF coupon! ;>)


https://www.harborfreight.com/10-in-15-amp-benchtop-table-saw-63118.html


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## ktownskier (Aug 22, 2018)

@moosehead, 

Go back to the beginning. What do you want to accomplish? What do you do mostly?

Are you trying to replicate what you have? Or do you want something new. 

From your original post, you say that you mostly rip down sheet goods. A track saw would be better for that. Or even a good straight edge cutting guide. Kreg makes a good one. 

I am not sure what you did with the 2x's. If you cut off a 1/4 of them, a Miter saw would be a a better buy. If you ripped a 1/4" off of them, then a table saw is what you need. You could do it with a circ saw, but I wouldn't. 

A 7 1/4" table saw is very small. Most are now 10".

And most portable/work site saws are almost always direct drive.

You can get ones with stands on wheels starting at $249. Or with folding stands and no wheels for $169. At HD Delta has a saw with wheels for $249. It has a better motor, better rip capacity, better fence. 

Stationary saws are typically belt drive. And they are usually much more expensive. But, they have much better components. And make MUCH more accurate cuts. And are used for woodworking. 

Just my nickles worth.


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## PatentPending (Aug 7, 2018)

Good lord, that thing is a trip to the ER waiting to happen. Blade all the way up, not even a splitter, and a fence that I'm guessing doesn't get used (how does it even attach?)... Also, that's way too small for breaking down sheet goods.

Anyway, it's not my fingers on the line, so to respond to your original post, single phase induction motors like that are limited by the line frequency, so they generally only come in nominal 1800 (i.e. 1750) RPM and nominal 3600 (3450) RPM varieties. You shouldn't have a hard time finding a cheap replacement, just make sure it has the same diameter shaft so that you can re-use the pulleys (thus obviating all of the RPM calculations discussed above).

I would go the "replace" route, though. Check Craigslist for something like an old Delta "Contractor's" saw. There must be millions of them out there so there are deals to be had, it's a better product than any "jobsite" table saw, and will last forever if taken care of.


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## ront02769 (Nov 28, 2008)

Not sure what your financial situation is. I have a delta unisaw (3 hp mother , biesmeyer fence, new for around $2,000 bucks. But what is use way more is my portable delta what you can grab at Nd for like $299.

https://www.homedepot.com/p/DEWALT-...Vxp-zCh1gPQRvEAQYAiABEgIOIvD_BwE&gclsrc=aw.ds


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## moosehaed (Jul 30, 2018)

ktownskier said:


> @moosehead,
> 
> Go back to the beginning. What do you want to accomplish? What do you do mostly?
> 
> ...


The table saw is used to rip down plywood and big stuff mostly. I had to rip off 1/4" off the 2x4 to put in inside steel studs when I finished my basement. I did this because I knew I was going to mount things to the wall and I wanted the extra support.

I have a miter saw and a radial arm saw also.

I know this is just a basic table saw with no bells and whistles. But it is cast iron and will outlive anything made today even though it may be 40 years old. It's mounted to a home made table and the motor mounts will have to be rebuilt. It's has no safety features, not even a brake.
It's only used a handful of times a year. When I do have a need for it it really comes on handy.

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## ktownskier (Aug 22, 2018)

moosehaed said:


> The table saw is used to rip down plywood and big stuff mostly. I had to rip off 1/4" off the 2x4 to put in inside steel studs when I finished my basement. I did this because I knew I was going to mount things to the wall and I wanted the extra support.
> 
> I have a miter saw and a radial arm saw also.
> 
> ...


If you look in your last paragraph, you have your answer. NO SAFETY FEATURES!!

Just because it is cast iron, doesn't mean it is automatically great. It is mounted to a home made table, needs new motor mounts, probably new bearings. Please understand that I am not denigrating your work. At one time I am sure that it was a wonderful saw and did what you needed. But remember what most old shop teachers were called: Lefty, Stumpy, No Thumb, 2 finger....

I agree that a table saw is wonderful to have. And when you need one, nothing else will do. 

Just took a look at Craigslist for table saws. Damn, wish I wouldn't have. Now I am lusting after a bunch of things. Do yourself a favor and take a look there for something that might meet your needs. With modern safety features. 

Ktwon.


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## Doboy (Dec 5, 2018)

Moosehaed,,, Your not all that far away from Y-Town, Oh. A good friend of mine is now handicapped, & is selling almost everything,,,, 'downloading'.
I just went over his house & he showed me a brand new, *still-in-the-box* DELTA table saw (kinda). I'd say that it's a commercial grade,,,, it even has leaf/ table attachments
that are made of GRANITE! I never seen a table saw built like that before.
He said that he would sell it to me for $350.
I didn't have time to look it up, yet, but I'd bet it sold for close to a $grand!?
If you, or anyone is interested, I'll go & take pictures & post 'em?


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## sestivers (Aug 10, 2007)

Just a quick note about y'all's RPM math. The label plate is not the operating speed of the motor. It is the speed below which it will start slipping poles and you're then damaging the motor. With zero load it will be either 1800 or 3600 if your electrical supply is exactly 60 Hz (so if you turned it on and checked it with a tachometer, you'd see it operating around 1795 or 3595 rpm due to friction losses). Once you start feeding wood through it it will slow down due to the extra load. If you try to fit something through that is so difficult that it slows down below the nameplate speed, you will be damaging the motor.


So if you're trying to set the maximum rpm of your blade, just note the real maximum speed of the motor is greater than the nameplate says.


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## surferdude2 (Nov 21, 2019)

Nealtw said:


> It is the circumference you figure out
> 
> 
> 2x3.14 r=c
> ...


You might want to rethink that math answer, especially the 2" pulley circumference. :wink2:

Actually, you'll get the same ratio of speed by comparing either the circumference, diameter or radius. Noxnix.


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