Tecomec Super Jolly Chain Grinder

Pretty good idea.

 

Here’s one for the group




Started this yesterday after putting on a new disc and immediately had this noise.
Checked everything installed tight and correct. Still had noise
Swapped back to the old disc, still had the noise
Broke it down to this point and it sounds like it’s coming from the outboard bearing.
It has been in an unheated garage and it’s been between -5F and 20F here for the last couple days.
And I used the grinder 2 weeks ago last and there was no noise issue on that chain.
Do I just need it to be warmer or did this motor make a mess of the bed all of a sudden?

 

Mine stays in my unheated basement where it only gets to about 55°. I've had it a couple of years and only had a problem with the hydraulics. That turned out to be nothing more than a loose fitting I overlooked. My guess is the cold bit it.

 

Is it a bearing or a bushing on the outboard end?

 

good question
I haven’t pulled the rotor to see.
I have little experience with small electric motors and not sure I could tell with out pulling the rotor or some OEM documents. There was a sticker on motor.



Turns out that sticker is a UL label, for a Recognized Component, not necessarily providing any oem info, unless that number at the bottom gets me to a file

 

Weird, Mike. Either way, there’s most likely a $4-5 bearing in each end. I’d guess yours was faulty from day 1 and it just exposed itself. If you can rebuild a chainsaw, you won’t have a problem taking the armature out and replacing those bearings. If the brushes aren’t externally replaceable, they can be a little bit touchy getting back in as they’re spring loaded and need to be held in while the shaft slides through

 

i think I’ll bring it in and warm it up, see if that makes a difference. Even if it does, something is still probably not exactly right.
The runout looks ok by eye
I’ll keep us posted.
Thanks for the insight

 

I’ve cut drywall with a laminate trimmer and after 10-20 small jobs it would occasionally chatter like yours. Some penetrating oil would flush it out for a bit, but it would always revert back. Went to the local hardware and found a bearing. Fixed on site in a half hour or so

 

Lean it on its side drop a few gun oil drops in there and fire it back up in the morning and seeing goes away

 

Auto correct gets me a again (seeing) see if it goes away

 

Ours did the same thing the other day. Chartered a bit. I think I sprayed a bit of WD40 on the shaft/bearing. It quit chattering in just a second...

 

pretty cheap step to try

 

I did try a couple squirts of WD40 and it worked for a little while, but wasn’t the solution. Motor came off very easy, (take wire harness pics and mark the four blue conductors at the two mechanical connectors). Don’t forget to unplug it before you start.

Disc mounting hub came off the shaft with a two jaw gear puller and turning the jacking screw by hand, while holding the jaws with the other.

The black cooling fan shroud was a gentle progressive pry job. I left the cooling fan on

The 4 stator bolts came out as you would hope. I used a 8mm wrench because that’s what I had.

Rotor pulled out by hand through the fan end.

I didn’t see anything apparently wrong and the inboard bearing felt great, by pink roll. The shaft at the bearing looked a little scuffed. Not being an interference fit, I’m guessing some small chat got in there.

Noted the bearing types, in case I needed to order some, did a dry paper towel and cotton swab cleaning and reassembled.

I think it still sounds a little off. Better though.

Bearing info below




Outboard Bearing, below



Next two are the inboard bearing

 

Good bearings, too.

Awkward

 

A side from a little run out, I’m stuck with the idea that the cold weather in the garage negates any interference fit there might have been between the shaft and the bearing and that squeal is one moving relative to the other, until it gets warm enough to bite.

 

Sounds great now

 

Thanks Jeff.
I’m not 100% convinced this is licked.
We’ll see what happens when it warms up outside.
I’m surprised how not tight that shaft is on both the old and the brand new bearing
The journal area is scratched and worn, to the eye. Theoretically the shaft OD could have been milled down by chain dust.

 

You could pull it back apart and reinstall the bearings with Loctite on the shafts if there’s no interference fit

 

Now that I see what I think is happening, I considered that.
It’s a pretty quick in and out once you’ve done it a couple times.
The biggest PIA is getting the cooling fan off. It’s a nylon piece and the shaft has a phonographic finish on that end. Pull and unscrew.

inboard journal

 

I bet the arbor is just a scoshe undersized