Table saw motor

[Mojo-Jojo]

Hoping someone with more knowledge that me can help with this.
My table saw has started to burn through the motor brushes. I've opened it up and can see a little damage to the commutator, I've gone over the whole commutator with 1200 grit, cleaned the out the grooves and cleanup up with isopropyl alcohol.
My question is, will I have resolved the problem or do I need to take it in to have the damaged area repaired?
Thanks in advance.

[nigel s]

I am NOT a sparky...........So.........?

On our smaller mobile table saws ( our main ones are 3/4 hp and never give problems ) , according to our firm that repairs them  ?, commutator problems are due to overheating ( feeding in too quick ) and the resultant current ramping up.
Only way is to try. If it still sparks a lot it is probably time for a new armature. Sometimes replacing the motor is cheaper  than repair.

NOT a sparky,  I just use them , and have to listen to the boss bitch about costs / down time...

Sorry all I have... 

[Mojo-Jojo]

Thanks, Nigel.
I'm always mindful to not force feed the piece through the saw, let the blade do the work.
It looks like a replacement armature is available, but I won't be able to contact the spares department until they open on Monday morning.
It takes about an hour to dismantle, and another hour to rebuild it.
Does anyone think it will be worth putting in new brushes and running it?
In all honesty, I'm leaning towards waiting until Monday, but I'm also desperate to get this project finished. 

[nigel s]

If you NEED to get the job done , using  the saw lightly it will go a while ...if that will do it , I don't know how much you have left to do ?
 As you said..let it spin .. as you have a source for a replacement armature , you will lose nothing you were not going to replace anyway ..but if it starts to overheat/ spark a lot stop .
The best way to cool down the motor ( as long as it is not on fire  ) is to let it spin with no load , the internal fan will help remove excess heat better than just shutting it off .

But I am a wood butcher that doesn't have to pay for his tools....

[Mojo-Jojo]

Decision made, first beer of the day poured.
The job I'm doing is huge, I'm installing extra noggins in a double garage that I've been building to house my car & bike.
The noggins are made from 8x3, trimmed down to 7x3 and then the rsj profile rebated, and I have a dozen or so left to cut, so it's fairly heavy work on the saw.
I've been at it for a couple of years, with very little help, so an extra day or two isn't going to make a difference.

[Joe Rocket]

Can you tell me why you're 'nogging' between steel rsj's?

 

[Mojo-Jojo]

Hi Joe,
Because the roof isn't pitched, it's being landscaped over, and without the noggins the OSB boards would sink slightly with the weight, especially if it was loaded with heavy rain or snow. It has been over engineered to accomodate this, but better safe than sorry.
This will be the finished article.

[nigel s]

Nice work Mojo-jojo,
We did the same re noggins when we put a 16 foot wide mezzanine up going down the length (150 foot ish) of our workshop at work.
We used 3/4 marine ply ( we buy it by the pallet load anyway , so get it cheap....er , the ridiculous price of sustainably sourced wood is a topic for another day  ) over steel rsj's , which would have been self-supporting over its 4 foot width ..technically.. but with the noggins has stayed level and unbowed for twenty odd years of boatbuilders rolling around and jamming all over it , so glad we did .  We also didn't have snow or whatever to worry about

[Asmith61]

Mojo-jojo   That’s looks one hell of a project. Good luck with it all 

[Joe Rocket]

I see; thanks for the explanation. 

[The Doctor 46]

Hi Mojo-Jojo. I read this thread and strait away thought, bin it and buy a new one, then I looked at the price of a new one and now understand. Hope you get sorted soon, you and the chaps on here seem to know exactly what your doing. Good luck. 

[Mojo-Jojo]

Mojo-jojo   That’s looks one hell of a project. Good luck with it all 

Thank you. Luckily, I work from home so whenever I have no work in, I can get out there and do a bit more.
These images, show the garage in place behind the trees in April 2023, and how it looks today.
I'm hiring a 5 or 6 ton excavator in the next month to move the remainder of the old driveway from the right hand side onto the top of the garage, ready for landscaping, and will be laying the new steps and concrete as a mirror image to the left hand side.

[nigel s]

I can't quite read that sign on the gate...I presume it says  " WARNING..V STROM ON THE LOOSE "