Thread: Linisher overheating

Ive got one of those big boy type linishers. A lot newer than yours by the look of it but made in the same country. Have had the motor re-wound 3 times. Maybe electric motors are not the Taiwanese's forte'.

The first thing I would do is check out if the coils are shorting internally or to earth.
Naturally you do this with the power off and machine unplugged

A 1HP motor should have some 10's of Ohms resistance across the coils so if the meter measures the coils to be a few ohms
Or
There is a short or low resistance between the coil and earth
Then the motor coils have been overheated and cooked the insulation off and will need a rewind

Those sanders based on what is totally enclosed fanless grinder style motors certainly don't like working too hard for too long and will eventually die from overheating.
The 1HP is also too lightweight for that width of belt and size of disc.

I have a similar size (belt and disc) but mine has a 3HP 3Phase motor with a serious external fan on it.

Bob, I wouldn't even know where to look for the coils or what they were if I saw them. And I don't have anything to measure Ohm resistance. Point taken about the size of the motor, it does have a fair bit of work to do.

Evanism(?), yes everything is spinning freely so I don't think bearings are shot.

Looks like comparable machines are $1000 plus new so i guess it's worth getting a repair quote; just hope I don't need three rewinds like yourself ABodger.

I deleted my post because it was stupid. If you had tough bearings that were hard to spin, then of course you would have noticed it.

On reflection, what BobL says makes a lot of sense. If a motor works hard then it melts the goopy on the windings and this causes problems. I've seen this before and there isn't much for it other than a replace or rewind.

We seem lucky here in Canberra. There are a couple of places that still do it. But the way things are going, it's getting a more throw-away society every day I had the starter motor on the HSV die the other week (click click click!) and the biz just sold me a new one, told me to toss the old. What a heinous waste!

There is nothing worse that a misbehaving machine. Especially one as necessary as a linisher! (love mine! Shame it's not one of the big long ones!)

Originally Posted by Evanism

If you had tough bearings that were hard to spin, then of course you would have noticed it.

You're flattering me mate, a lot more than that passes me by without me noticing.

I'd probably prefer to replace the motor with a 2hp rather than rewind, but wouldn't it be hard to find something that swaps and attaches easily...Bob?

If you pull all the crap off and send just the motor Id reckon it would be OK. Send it via courier (e-go.com.au) and it will only be ~$10 there and the same back. Don't be dragging it around, let the courier do the work.

Originally Posted by JB

I'd probably prefer to replace the motor with a 2hp rather than rewind, but wouldn't it be hard to find something that swaps and attaches easily...Bob?

Unfortunately you'll be struggling to find a larger replacement motor - there's too much built into that setup to begin with.

Because you blokes have double the normal voltage we have here, my suggestion may not be relevant.

Open up the motor shell and clean everything. Sitting here on the wrong side of the International date line, my guess is that the centrifugal starting switch is not dropping out after the motor gets up to speed. If these switches are not dropping out, the starting coils are not dropping out. This has a tendency to cause the motor to overheat.