Help, please. Motor failure - Craftsman 2X42 Belt/Disc Grinder. Appreciate any/all ideas.

[tjb]

I have tools for fixing my tools so I can make tools for making tools....

And I suppose the tools you make are capable of maintaining the tools for fixing your tools that you use to make tools for making tools.

 

[bill70j]

Cool Idea MatthewSX, use it as a pillow block, and just cut a slot in the frame to run the belt through.

Or, gut the motor and figure out a way to attach a pulley to the shaft.

Then drive it with a variable speed motor mounted behind the tool.

John

 

[Ulma Doctor]

maybe something like this to modify and build from?

Vintage Craftsman Dual Shaft 1/2 Hp Motor, 3450 RPM Power Tool # 397.19821 | eBay

The Property is sold and conveyed "AS IS, WHERE IS," and without representation or warranty.

www.ebay.com

or like this

Vintage Craftsman 3/4 HP, 3450 RPM Dual Shaft Motor | eBay

Check all photos closely. Motor starts and runs. Cord needs to be replaced. Motor has 5/8" shafts. Last pics are of the saw motor was removed from. You are buying the Motor only. Local pickup available.

www.ebay.com

or this...

Vintage 1/2 HP, 3450 RPM, Dual Shaft Table Saw Motor | eBay

1/2 HP, 3450 RPM, 1/2" D shaped Dual Shafts, Ball Bearing Motor from a early Craftsman King Seeley table saw. Check your sources. Last pics are of the saw before item was removed. You are buying theMotor only.

www.ebay.com

 

[Pops]

If you were close to the Houston area I could get you going real quick. I worked for 20 years in a motor rewinding shop as their machinist. I also did some of the winding.

First off, that motor can be rewound. You would have to wind the whole stator. You can’t replace a few coils. When it was wound new it was dipped in varnish as an insulator. There are shops around that can rewind it but it would probably be cheaper to get a new one. If the shaft is the wrong size on the new one just take the motor apart and machine it to size or if it’s to small make a sleeve that will take up the slack.

I’ve got a shelf full of motors in my shop. If I have trouble with the motor on one of my machines that I can’t repair I just adapt another one to fit


Sent from my iPhone using Tapatalk

 

[darkzero]

Sorry Bill, I can't help with your motor issue. Were you sanding something when it failed or did it just happen one day when you turned it on? I'm just curious since I have the Jet variant.

I've only had mine for a a couple of yrs or so but I really hope mine doesn't fail like that. Hopefully you can get it fixed. BTW I put a glass platen on mine too, such a really big improvement over the crappy stock platen.

 

[bill70j]

Thanks to everyone for thinking through this. What a wealth of information and great ideas! Based on what you have told me so far, here is what I plan to do, in order of preference:

1. Keep searches open on CL and Ebay for a direct replacement motor assembly
2. Try to find a shop that will rewind the stator. There's nothing local, so I'll have to consider pretty high shipping costs
3. Find a used two-shaft drop-in replacement motor. Looks like there are a number of motors listed for sale. Will most likely require re-machining the shaft to fit, along with a frame to accommodate the disc and belt assemblies
4. While working #1 - #3, start design of modified unit that will turn the existing motor assembly into a pillow block that utilizes the existing bearings and assembly end plates. Mount a drive motor on the stand underneath the tool and run a v-belt up to the new pillow block assembly.

My cheapest and best alternative may be #4. I have a spare 220v 2-speed single phase spa motor suitable to serve as the driver. With its 1725/3450 capability, it should make the tool useful both as a sander and as a metal grinder.

As I think through the design, I will plan to post updates, hoping to get additional input.

Also, regardless of which way I go, I will incorporate Will's belt platen upgrade, as well as Mikey's Belt Table Fix into the design.

Thanks again for everyone's help, Bill

 

[bill70j]

Sorry Bill, I can't help with your motor issue. Were you sanding something when it failed or did it just happen one day when you turned it on? I'm just curious since I have the Jet variant.

I've only had mine for a a couple of yrs or so but I really hope mine doesn't fail like that. Hopefully you can get it fixed. BTW I put a glass platen on mine too, such a really big improvement over the crappy stock platen.

Will:
After the motor started popping and sparking during use, I took the assembly apart and found a build-up of sawdust and metal chips inside the motor housing, which bridged from the bottom of the housing to the stator winding. That may have been the root of the problem.

Anyway, I then blew out all of the debris and tried running the motor. There was a delay in getting up to speed, so I figured it was a start-capacitor problem. I bought a replacement capacitor and tried again. Same delay, but this time accompanied with smoke, VERY hot temps, and burned windings.

I had never used dust collection on the tool, so suppose the motor fan sucked all that dust into the housing after many years. (I can't imagine that kind of thing happening in your shop)
Bill

 

[bill70j]

Thanks again to everyone for your input on this. I have decided to proceed with installing a "new" driver for the Craftsman grinder and to gut the existing Craftsman motor assembly to serve as a pillow block.

No issues so far. I got the squirrel cage off the armature shaft and removed the stator windings from the motor housing.

My next steps are to design and model a new driver mount on the existing stand underneath the base of the tool.

Here is a model of the Craftsman motor assembly as it currently sits. Plenty of room for a 2.75" v-pulley inside the existing motor housing.

Fully Assembled Motor Assembly


Assembly Showing Bell Ends, With the Rest of the Motor Housing Hidden

 

[C-Bag]

I’m in awe of your CAD-fu. Just a suggestion. When I did the double reduction on my vert bandsaw I used a motor mount from a dead table saw where it hinges and the motor weight does all the tensioning. Works wonderful, no slipping and total piece of cake change the belt. And never have to adjust the belt!

 

[mickri]

I know that we all like to reinvent the wheel. But getting an electrical motor rewound is no big deal. There are lots of places that can do this in the LA area. I did a quick search for SLO and a shop in Santa Maria Perry's Electric Motors popped up. You might try giving them a call. (805) 925-8761 I have no connection or experience with this company. There are probably others in your area. The central valley will also have places that can rewind your motor.

Have the motor rewound and use your sander for another 30 years.