Thread: High temperatures on drive belt and pulleys of combo Planer/Thicknesser - PT-310 HH

50°C is running hot, 80°C is excessive. Even in a car motor which is expected to run hot.

V-belts are generally rated up to about 60°C, which is where they start to degrade. (A very rough rule of thumb is for every 10° above expect roughly 1/2 the life-span.)

My suspicion would be that the pulleys are not aligned, not coplanar or both. That generates a lot of heat.

Air flow is also a factor, as it's what keeps them cool. With limited airflow and high ambient temps (in the cabinet) you can expect belt temps to increase.

But 80°? I can see why you're concerned.

Thanks very much for the reply! Glad to hear I am not being toooo much of a perfectionist and perhaps rightly concerned.

It's a good point re the airflow - these tests were performed with the cabinet fully open - hence much more airflow than during normal operations. I will try testing again after having the cabinet shut for a bit.

I will try tinkering with the pulley alignment/coplanarity some more but the mechanism for adjustment is very rudimentary :/

UPDATE - Timbecon technical support came back with the following advice:
"If there’s clearance & the motor & spindle pulleys have no imperfections and there are no obvious noises then it's not easy to say why there’s a build-up of heat.Is the motor hot?
Just make sure when the motor is tensioned it only needs gravity (no overloading tension).

Install the belt & let us know if there are any wear issues in the future."

The motor is not hot, at least compared to the belts which reach 50C in the first minutes..

Tensioning the belt using gravity alone does not seem to align with the instructions in the manual and definitely results in a low tension belt. The rear of the motor also hangs lower under gravity than the front end (which has the belt tension acting on it) - this seems to make the pulleys non coplanar.

My search for knowledge continues..

Is there any chance the belt touches the bottom of the V on the pulley?
My understanding is there should be slight clearance. Only surfaces touching are the sides?
You'd checked pulley but is there a very minute deformity in either?

That first photo looks like misalignment or something a pulley issue.
I know you said you'd checked alignment.

Just read your comment re motor mount.
Any flexing would not help.
I'd be looking at making that solid

Hard to properly comment with complete ignorance of the machine

Thanks @Avondale - I’ve checked the belt for clearance at the bottom of the pulley and there is still a couple of mm, so should be all good there.

I have checked the pulleys simply by hand, no obvious surface imperfections etc. They visually appear to spinning true on their shafts.

re the first belt and pulley misalignment - I think you are right, pulley misalignment likely contributed to the issue - particularly as the wear is worst on one side. Upon buying a replacement belt I was much more careful try to align the pulleys. Despite these best efforts the new belt is still getting very hot..

it turns out to be very difficult to align the pulleys as there is no fine adjustment of the angle of the motor which simply can be moved vertically in loose fitting slots riding on the treads of some bolts.

If any other owners of a similar machine have figured out any better methods I would love to hear them!

It sounds like it's still misaligned to me, but given the nature of the cabinet I'm pretty much at a loss for any suggestions to get them correctly aligned.

Is there any way you can hold a good, known straight edge across both pulleys faces? Perhaps, if they're coplanar, you may be able to remove a pulley and use washers/shims to move it to a more suitable position? (If they're not coplanar, then that opens up whole slew of other problems.)

Whatever, if the new belt isn't already showing obvious signs of wear you could probably get away with just using it as is for a while, but personally I'd want to keep another spare belt or two conveniently to hand just in case.

Thanks again- yep I have tested with a made up straight edge - basically a piece of straight hardwood with four screw heads protruding, all on the same plane (confirmed with reference surfaces). When holding this up against the face of the pulleys it shows clear angular misalignment of the faces. Even putting a basic digital level on the two faces of the pulleys shows a clear 1.5 degree misalignment.

i have found it surprising that the retailer Timbecon has basically not offered any insights into the issue - aside from suggesting to position the motor under gravity alone. I guess this suggests that it’s not the biggest issue in the world.

I now have a few spare belts on hand so should be able to keep running if another burns out.

Of perhaps greater concern I’ve now noticed that it seems like the motor is also getting quite hot after a period of use, presumably influenced by heat transferring from the drive pulley into the shaft. This concerns me for motor longevity but I admit I don’t know how hot these motors typically get during use..

If the machine wasn’t under warranty I would probably consider fabricating a new method of mounting and adjusting the motor position. A similar Hammer combo machine uses a vertical adjustment screw to help with this for example.

in any case I’ll update the thread if I learn anything new.

once again if any other owners of these machines have overcome similar problems please let me know …or tell me that it’s nothing to worry about…

I believe they're telling you to just let the motor hang by gravity is so that you're not putting tons of tension on the belt. a heap of extra tension is just resistance and heat that everything has to over come.

to me it sounds like they're saying hang it by gravity to get the tension and then tighten everything down.

A photo of how your motor is mounted may help to visualise all of what you are saying. Many machines run with the belt tension applied by gravity so I don't see that being your main issue. At my wood club they have a 380mm Thicknesser and the motor is free floating and doesn't have any overheating issues even used continuously for some time.