Hey guys, my father in law gave me what could be a very nice craftsman table saw, it's a big upgrade from what I have now if I can get it running.
It's issue: turn on the power and you can hear the motor kick on but only very minimal power is getting to the blade. The blade will barely start spinning without assistance, and never gets to cutting speeds. Where shold I start?
I could try to repair it, I could try to cannibalize my old table saw motor and use it on this much nicer craftsman table. I also have a bunch of electric motors ranging from 1/4 to 1/2 hp but I'm sure mounting would be a big issue there
Thanks for your help guys.
You could look into having the old motor rebuilt, that would take care of any mounting issues. Probably a little less cost than a new motor as well.
I'd get a direct replacement.
Capacitor?
I'll open it up today and see if there is anything obvious.
Bad capacitors often have bulging areas or leakage.
in the smaller motors i have found the new are the same price and sometimes cheaper than rewinds. but still worth making some enquiries.
but my first thought was the capacitor too- an easy, cheaper place to start.
does the motor( a lot of the older ones do) have grease nipples for greasing the bearings.
grease could either be old and dried up, or possibly been over greased.
i had a 5hp 3 phase motor refuse to spool up simply due to over greasing on the driven end- but bought a new motor first before i fuggered that one out :mad: :o
if you think you might have overgreased- take the bearings out flush with gas- replace- and lightly grease
Are you sure the motor is not producing power?
Could be that the power is getting lost before it gets to the blade.
As fujimo points out, lubrication could be the problem. Not sure about over-greasing.
Try oiling anything that moves.
I can hear the motor engaging and it sounds like it is under a load, but I'm getting very minimal rotation at the blade. I can give the blade a little jump push and it will have just enough juice to maintain a very minor rotation of the blade.
From a stand still when I turn on the power the motor starts humming but I get 0 rotation.
I'll try to post a pic I took earlier. I'll have to look into the grease issue.
This is not a very helpful image but it is the only one I have at this time. I'll look into the grease issue and see if I can tell anything about it tomorrow. I'm not sure what to be looking for on the capacitor, what would that look like on this unit?
(http://i1077.photobucket.com/albums/w466/tyrelljrutledge/Mobile%20Uploads/20160428_183038_zpsvqmt5dld.jpg) (http://s1077.photobucket.com/user/tyrelljrutledge/media/Mobile%20Uploads/20160428_183038_zpsvqmt5dld.jpg.html)
sounds more and more like the capacitor. can you find the capacitor?
get the numbers off it and get a new one- after cleaning all connections etc- especially if it has been sitting for a long time- as this one has.
Personally I'd buy a new motor. There are a few different configurations of mounting holes and plate shape but not many. Any place that sells motors will be able to help you out. I'd also go for a 1/2hp over what it runs now.
With the switch off, does the shaft spin free by hand?
It sounds like the capacitor may be bad. Do you have a volt/ohm meter and are you capable of discharging, troubleshooting and replacing the capacitor?
Is all the voltage getting there? Switch ok?
If you're not comfortable with such electrical repairs, it would probably be better to just replace the motor with a new one. There are some on the big auction site, not sure if they're compatible with yours but it may be worth a look.
Is it possible this little motor does not have a capacitor? They are typically on the side of the outside of the motor correct?
(http://i1077.photobucket.com/albums/w466/tyrelljrutledge/Mobile%20Uploads/20160429_101651_zpstslbfxcz.jpg) (http://s1077.photobucket.com/user/tyrelljrutledge/media/Mobile%20Uploads/20160429_101651_zpstslbfxcz.jpg.html)
The shafts does spin freely without power.
Also, I have all of these functioning electric motors I picked up at an auction for 2$ each. Guess there is nothing I can do with these.
(http://i1077.photobucket.com/albums/w466/tyrelljrutledge/Mobile%20Uploads/20160429_101516_zpsapvbjnau.jpg) (http://s1077.photobucket.com/user/tyrelljrutledge/media/Mobile%20Uploads/20160429_101516_zpsapvbjnau.jpg.html)
Thanks for the help guys, I'm gonna price around for a replacement.
Try cleaning with compressed air..blow the saw dust out of motor..
All single phase 120 volt motors have a capacitor. Without a capacitor to 'give it a direction', it would just sit there and hum. It may be internal.
I don't believe your saw has a capacitor. The thing next to the switch is a relay that has to be in the proper upright position or it will shut the saw down. I don't think that's it, but something to be aware of when testing. I'm thinking the start windings may be burned. I'd take the motor out, open it up and clean everything good then reassemble and test before buying a new one......if you can even find a replacement. If you take it out, look for carbon brushes and make sure they are making good contact. There is a possibility that you don't have carbon brushes on that saw either though. Also, take a good whiff of the motor and see if there is a burnt smell. Sorry I can't be more help. What is the model number of the saw?
I'm no electric guy but that switch looks suspect. I had a saw like that one and don't think that is original.
OK electric guys: Can the switch be wired wrong and make it do that? Or low voltage from something under that tape?
Ken, I didn't notice the switch. From what I can see in that wiring, it looks like, possibly, the original switch shorted (always on, whether in the on or off position), then the hot wire was cut that supplied power to either it or the motor, and a toggle switch was inserted to function as the off/on switch... not the way I would have done it, as you'd be relying on a failed switch to carry the current needed to run the saw. When the contacts in it fail, they can melt/stick together, but with burns, cinders, or other less conductive material between them, and yes, this can keep the motor from getting enough voltage to run properly. It could even eventually burn the motor up.
If they bypassed the old switch entirely, as far as the hot(black) wire goes, it's possible the toggle switch they added wasn't rated for the current and it failed.
Either way, it's possible replacing the switch(s) with an OEM/replacement version may solve the whole problem.
One with some electrical experience could bypass the hot wires of both switches and if the balance of the wiring and the motor and capacitor was ok, it would run normally, thus pinpointing the switch as the problem, and be replaced.
It's too bad he's so far away cuz I like messing with that kind of stuff. It's what I do at work, sometimes. I recently helped a friend figure out an electrical issue on his Delta drum sander. He bought it used, and apparently the switch had failed on it, and the previous owner bypassed it and just plugged it in to run it, and unplug it to shut it off. It just needed a new switch and part of the wiring harness.
I have some buddies that are a little more electric savvy than I am, I'll show them this post and bounce your ideas off of them and see what comes of it. Thank you for your thoughts guys
Being the redneck I am , I would direct wire it and plug it in, then if it works, find a proper switch. LOL
Me too Kenny. I keep half an extension cord with alligator clips on it for such redneck engineering :thumbsup:
redneck engineering- thats too funny :biglaugh:
think at school we called that an oxymoron!!! :thumbsup: :goldtooth:
I was gonna say the same thing Kenny. Make sure the motor works (or doesn't) first, then go from there. Hot wire the thing direct to a cord and see if she turns good. If not, scrap the motor and put on one of your yard sale motors with the same RPM and HP. You could have some bad brushes in that motor too. Have to checked to see if the brushes were worn down or gone?
I did direct wire the motor this morning and is still did not run.
I haven't opened the motor up yet it looks like it's gonna be a bear to get out.
Dang! Be sure to check the rpm like Joe said if you change motors , a lot of motors like you pictured are 1740 rpm, and I think the saw says 3400 rpm in the pic....
i'll bet the brushes are stuck--I just was scratching my head on the same basic motor on my craftsman jointer--its from sitting too long--they are under two plastic caps--unscrew the caps-the spring and cable will pop out-the brush is on the other end-gently tug if it won't pull out freely its stuck--I freed mine by poking the brush in w/ a skinny screw driver[gently!]
good luck!!
I Hope you get this thing fixed it`s an awesome tool to have. I bought years ago vertical and horizontal band saw eurasia brand name it is a vertical and horizontal saw.
I slapped on a better work space(table) a few months ago it start giving problems you can start cutting but after awhile it will start "losing" power.
It will cut but will freeze up :mad: , this thing made my head spin thinking of what will be the problem, I removed the "fan belt" and the motor will run like a nascar motor so that was not the problem. Eventually I checked if it got oil in but also not the problem,I then found it has a tensioner pulley at the top and that it does not have a bearing but only a sleeve that was worn out completely :knothead: .
I send it to a engineering shop and they installed a bronze sleeve that will last a lifetime. Now this saw cuts with worn blades better than previously with new blades.
Hopefully you can figure out this fault on your saw!!
(http://i1077.photobucket.com/albums/w466/tyrelljrutledge/Mobile%20Uploads/IMG_20160505_202545_zpse7002bjl.jpg) (http://s1077.photobucket.com/user/tyrelljrutledge/media/Mobile%20Uploads/IMG_20160505_202545_zpse7002bjl.jpg.html)
Problem found
Motor windings look like they got a little warm. It could be a symptom of a different root cause though. I would replace the motor, check the supply wiring really well and replace the switch too.
I decided to stick with my smaller saw that I know works, it just needs it's motor mount adjusted to straighten up the blades cut. I am retiring this nicer big saw for the time being, I appreciate everyone's help.
Windings get too hot when the motor is starved for voltage...bad connection ..too small supply wire...ect. A motor will do everything it can to reach its designed rpm, voltage drops...current goes up in direct proportion...to much creates heat...and melt down.
I don't like direct drive anything!! If it's not pulley driven I wouldn't own it. My advice is if the replacement motor is over $100 look around, maybe Craigs list or yard sales and get a good tablesaw.