My baby quit turning, but runs!

JohnSWA · Post by **JohnSWA** » Mon Aug 04, 2014 8:07 pm

Hi guys! I'm a total noob on this contraption and was so excited to start today! I made a test cut on a 2x4 and it worked great although rather slow on the cut. Now I'm starting my project cutting a 4x4 and the blade slows and then quits but the motor still runs just fine! I took it apart and the belt was so loose that it wouldn't turn the drive for the blade. Sorry, I'm a little weak on the correct nomenclature regarding all of the widgets involved. Anyway, it's a 1982 model 500 that is practically spotless, less this issue. Any ideas?

dusty · Post by **dusty** » Mon Aug 04, 2014 8:31 pm

JohnSWA wrote:Hi guys! I'm a total noob on this contraption and was so excited to start today! I made a test cut on a 2x4 and it worked great although rather slow on the cut. Now I'm starting my project cutting a 4x4 and the blade slows and then quits but the motor still runs just fine! I took it apart and the belt was so loose that it wouldn't turn the drive for the blade. Sorry, I'm a little weak on the correct nomenclature regarding all of the widgets involved. Anyway, it's a 1982 model 500 that is practically spotless, less this issue. Any ideas?

Don't despair. This too will go away. However, let's try to kept this discussion going on only one thread otherwise we will have related comments all over the forum. Right here in "Maintenace and Repair" is now the right place for this discussion.

beeg · Post by **beeg** » Mon Aug 04, 2014 9:07 pm

JohnSWA wrote:I made a test cut on a 2x4 and it worked great although rather slow on the cut. Now I'm starting my project cutting a 4x4 and the blade slows and then quits but the motor still runs just fine!

At what speed were ya cutting the 4X4? what feed rate were ya using. The same as cutting the 2X4? Is the blade SHARP?

JohnSWA · Post by **JohnSWA** » Mon Aug 04, 2014 10:37 pm

I turned the speed higher for the 4x4 and it quit shortly after backing off hoping for the rpms to catch up. After that, the blade just stopped with the motor still running.

reible · Post by **reible** » Mon Aug 04, 2014 10:40 pm

This sure sounds like a case of a loose poly v-belt. Pull the belt cover and check the tension, if you can push it in more then about 1/8" then it is loose.

You should also look at the condition of the belt, they do wear out and need to be replaced from time to time.

If that is the condition, ie loose or needs replacement we can talk you through the process..... It might be time to do your cleaning and lube job as well.

Ed

JohnSWA · Post by **JohnSWA** » Mon Aug 04, 2014 11:04 pm

Thank you for the reply and that should be the answer to this problem. I couldn't figure how to adjust the v belt. Any advice would be recipricatedly appreciated!

JohnSWA · Post by **JohnSWA** » Mon Aug 04, 2014 11:08 pm

Ok, after my response, the belt on the motor side is rediculously loose. I followed through with the directions for the r/r even though I'm not replacing the belt since it's not showing any signs of wear. I'd love to figure out a way to tighten up the belt where the blade turns!

JPG · Post by **JPG** » Mon Aug 04, 2014 11:37 pm

1) There are two belts.

2) A 1/2" v-belt runs between the motor shaft(lowest) and the idler shaft(middle).

3) A wider poly-v belt runs between the idler shaft(middle) and the main shaft(upper).

4) One does NOT adjust the tension on the v-belt.

5) The tension on the poly-v belt is adjustable.

See about the 20 min mark. http://www.shopsmithacademy.com/SS_Archives/SS104/SS104_Replacing_Belts.htm

If the v-belt is slipping, the floating sheave on the motor shaft is sticking(needs lubrication).

So which belt is slipping?

BTW when increasing the load(sawing a board twice as thick) any speed adjustment should be 'down'(slower, not faster).

reible · Post by **reible** » Mon Aug 04, 2014 11:59 pm

Given the new information you supplied I'm inclined to believe you are looking at the motor belt and what has happened is the that belt is now loose because of a problem in the lower sheave, it is stuck.

Time to take it apart and clean and lube the whole machine.... and hope that is all it needs. It is also possible that there is some damage that could mean parts replacements.

Ed

dusty · Post by **dusty** » Tue Aug 05, 2014 8:07 am

JohnSWA wrote:Ok, after my response, the belt on the motor side is rediculously loose. I followed through with the directions for the r/r even though I'm not replacing the belt since it's not showing any signs of wear. I'd love to figure out a way to tighten up the belt where the blade turns!

At what speed is your Mark V speed control currently set?

The v belt will likely be referred to as the drive belt or motor belt. There is nothing you can do to "adjust" the tension of this belt. The belt is tensioned by the combined actions of the two sets of sheaves. The sheaves function together as a variable pulley set.

You change speed by using the speed dial which in turn changes the the upper sheave.

It appears that with your problem the upper sheave might not be turning at all. The belt is apparently so loose that the upper shaft is not turning. Given this condition, I suggest that you DO NOT change the speed dial until that situation is changed. Attempting to change the speed dial without the upper shaft turning can cause damage to the speed control.

If you a need to change the speed dial, you can safely do so by manually turning that upper shaft. This is most easily done (my opinion) by mounting a sanding disk on the upper shaft and then use it to turn the upper shaft. With the upper shaft continuously turning, you can then change the speed dial.

To work on this, I recommend that you put the Mark V in drill press mode and open it up as shown here.

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