Shopsmith Forums

Quick background: I was having speed control issues, system bogging down while using the table saw. I found the retaining ring on the button-bearing had pulled off. I also found the idler sheave to be stuck closed causing the ring to be pulled off. I diassembled practically all inner parts and cleaned and oiled both idler and motor sheave points. No burs found on the key of idler. I ended up having to adjust the the high speed stop. And did find the quadrant teeth worn slightly. After reassembly all parts were freely and smoothly moving. Speeds even seemed correct and the stop was almost exactly tuned to stop at fast and slow marks.
Current Situation: I used the table saw again to rip a 2" thick cherry board at the "Saw" mark. The blade was up about 1/2" above piece. The board would barley cut (new blade) I was moving it so slow but it would bog down and blade stop turning. I'd back off a tiny bit and wait for speed to come back up before continuing to push. It got so hot it started smoking at v-belt. Took cover off again and noticed the belt was hitting the way tube. What else could be the issue? I've looked everywhere on this issue but trying to see what caused this as well as why everything got so hot. Am I just really limited on ripping hardwood? Too fast on speed control (I'm not feeding fast)?? Operator error or issue with idler sheave?
Your help is greatly appreciated

Somebody check my dimensions. I don't see any belt-way tube interference possible if components are properly located.

Welcome to the forum. My input won't be much more than a starting point.

On a sample size of one, I measured about 3/32" clearance between belt and way tube with the speed control at Saw speed ("R") and power off. I used drill bits to gauge the gap. IIWM, I'd check the V belt itself to ensure proper fit in length and width.

When your machine bogs down, it is important if you can differentiate between the motor itself bogging down Vs one of the belts slipping and causing the blade to spin slower or not at all. Is your new blade a rip blade? If not, what is it? A dedicated rip blade would be ideal for what you are cutting. Some combination blades should be able to rip 2" hardwood, but some would not and you'd definitely be pushing the machine's limits. And some would say it should be a thin kerf blade. Anything that contributes to a wider kerf means more work for the saw, so I'd question blade runout and the alignment of the fence to the blade.

I see in your first picture that your machine is a Model 520 and that the fence appears to be off the left (?) end of the rail by a good bit. I would automatically suspect that the fence may not be parallel to the blade if that is where it is located when you are cutting, or may not be holding position throughout the cut. I would not be comfortable with that setup, and I think in this case it can be easily changed by moving the fence to the right side of the blade.

- David

The only thing I can add to the previous excellent suggestions is to lower the speed to "L" or so on the dial. Lower speed will give you more torque.

As to why belt is rubbing on the way tube, perhaps belt has stretched or is slightly larger than it should be? I haven't measured the clearance on mine, but it is relatively close. I found a video of the belts of mine while running, but it doesn't really show how close the belt comes to the way tube. The belt comes to within an 1/8" to the outer edge of the sheaves. If your belt is too wide, it might also ride too high in the sheaves.

I'll guess the belt has stretched. Explains the lack of power from slipping and the belt contact with the way tube.

What is the v-belt length? What is the v-belt width?


???First pix / 520 / fence left??????

The only thing I can think of that David hasn't covered as to the belt rubbing is how is the Eccentric on the Idler Shaft adjusted. It appears that the rubbing, as indicated by your picture, is on the front Way Tube. The Idler Shaft Eccentric is used to adjust the tension on the upper Belt. If not properly adjusted that could be the source of the Belt slipping and a possible cause of the "loss of power" you are experiencing. The Eccentric also moves the lower belt a bit closer and the closest to the front Way Tube in the position shown in the picture below. Rotating the Eccentric counterclockwise around and properly tensioning the upper belt may help stop the lower belt from rubbing or may cause it to rub on the rear Way Tube. In that case one of the other suggestions may be the problem causing the belt to rub.

_

Update: Thank you for the welcome and you all are awesome! So I checked each suggestion and found it was almost a combination of everything. Mine was made in 98' and was left untouched brand new until i bought it. I've used it regularly for the past 2 years, mostly on slow for lathe and bandsaw so I didn't think it was the belt but putting the new one on I could tell a difference in the tightness. It looked ok but feel was different. It was right at 1/2 so likely it was just stretched. I think the main issue with hitting the way tube was the alightment with the eccentric. Pictured below. As soon as I saw that it became obvious! Thank you! The blade I was using was a crosscut as well, so operator error! I had pulled the blade off without check table alignment but it was definitely feeling like pinching, I'll be trying it with the fence on the right next time. I included a couple follow up pictures of the quantrant and worm location at high speed, idler sheave and belt distance (for some reason the explanation confuses me as im a visual learner) as well as upper belt, with your experience does the set up look like the correct positioning on these components?
I'm so grateful for all the responses.Thank you!
Mel

JPG wrote: ↑Mon Dec 30, 2024 1:31 pm What is the v-belt length? Came factory but I replaced with this pictured below, it came with it from previous owner What is the v-belt width? 1/2"


???First pix / 520 / fence left??????

I have a 510 and fence was on left

Poly-v belt location on the main bearing pulley shoiuld(IMHO) have two empty grooves at both the front and rear end.

IIRC the M5 poly-v belt has 9 ribs. The control sheave has 9 grooves. The main shaft pulley has 13 grooves.

Clean up the idler shaft with a flat file to remove high spots/dings.






P.S. Ripping 2" cherry can be a challenge.