Power twist belt on Shop Fox W1741
EricAnderson
| Posted in Power Tools and Machinery on
I have a Shop Fox W1741 jointer (very similar to the Grizzly G0490). Very nice machine with the exception that the startup belt snap and power down shudder are annoying. I tried a range of tensions with no real effect. I know others have had a similar experience. The noise apparently are not a problem operationally, but I feel that I should not hear this in a machine that is otherwise a very nice design.
I have tried one of the Power Twist belts in this application. Although it damps out the vibrations, I see that it does this because it is quite flexible (it stretches quite a bit). This characteristic causes problems in this jointer design, because the belt path is narrow and the large amount of stretch allows the slack side to impact the edge of the slot for the belt. In addition, the power twist belt (a 1/2 inch belt) stands proud of the pully and tends to rub on nearby structures. The old belt was 1/2 inch also (or rather about 0.48 inch wide), but it did not stand out on the pully as much. I ground out the belt slot in the cabinet and it has pretty well solved the problem, but I would like to have seen more improvement (for the $30 the belt cost) with less rework on my part. I am fairly well satisfied with the end result after my rework.
Here is what I would like to learn about belt designs from this effort. I know that the newer tablesaws (SawStop, for example) have the flat ribbed belts, but I also know that the components are quite expensive. My questions are:
1. Are these flat ribbed belt designs better suited to an application such as this (a pretty powerful 3 HP motor that obviously stretches the belts on startup)?
2, Is there a newer belt technology that still fits the standard V-belt pullies, but possibly addresses the stretch and control problems in this design?
3. Has anyone used the 3/8 inch Power Twist design on this jointer? I don’t feel moved to make another $30 purchase to find out.
Replies
Power Twist belts are thicker and if your old belt was 1/2" wide you have the correct belt. I have a Grizzly G0543 jointer that takes two 3/8" belts and I use Power Twist belts. I have them tensioned just enough to have minimum rubbing during starting and stopping. After the initial stretch Power Twist belts and do not have to be re-tensioned. I find they work best when not too tight.
Flat ribbed belt are excellent for minimum vibration high power transmission. I know Felder uses them on their 7.5 hp saws. I think RickL said they are used on up to 9 or 10 hp machines, he services various machines. They are used on European equipment extensively.
Life is what happens to you when you're making other plans .
Edited 3/13/2008 1:56 pm ET by JerryPacMan
E.A. the shop fox could probably stand two new better machined pulleys. A normal solution for import tools. Just find better parts in the MSC, Granger,Datyon etc, catalogs-not big bucks but better running. The Fenner red link belts have solved many power transfer problems--I love them.
Questions
1- the fox is a run of the mill (read cheaper) import but it should run well with the v belt as most of the other imports do, particulary with improved -machined pulleys. A flat belt is not worth the campaign you would endure to source all the correct parts.
2-NO, not cheaply
3-don't waste your money, get the machined pulleys. Ya can't make a silk purse out of a sow's ear.
paddy.
BTW, the blue ink is cute and the smaller type is neat but it's a bitch to read--please just type and go with the standard , thanks P
Thanks for the ideas. I did a quick check on the TIR of the pullys and they seem to be within a few thousanths of true. Maybe I will check it again.
The blue ink and type had to do with a cut and paste that I did (I sent some of the info to a couple of belt manufacturers). I will try to restore the defaults next time.
Try a cogged belt. Link belts are better on gravity weighted motor and regular belts have a memory and tend to bounce resulting in a power loss on the bounce. I see no improvement on a fixed motor set up and fenner belt. I find the cogged belts are better and a cheaper option for a gravity wieghted motor. Also cogged belts are better on smaller diameter pulleys.
I'll second the idea to try a cog belt. Go to a good radiator shop or auto parts store and get their best quality cog belt that'll fit. Shouldn't be too expensive to try.
Eric, I have the same jointer (and the same problems). I wouldn't waste money on the new pulleys/sheeves as I think the real issue is the belt slap at start up shut down more and the cheap belt (stock). I ran mine with the link belt and it was quite smooth, but it rubbed the shroud and a washer so I stopped fiddling with it and put the stock belt back on.
The 3/8" belt is a novel idea. Too bad I, like you, already have several feet of the 1/2". Maybe the cogged belt is a good compromise. Let us know what you do. Other than this issue I think you'll like the machine.
Jake
I read what I think was a message you wrote before I purchased the Power Twist and I should have listened to you then. Cost me about $30 not to.
I am going to see this through, however, and I am going to look at a belt from gates that has Kevlar cord (the Predator) and if that does not solve the problem, I will look at the toothed belt you suggest. I used one of those on my compressor and it breathed new life into it. The older belt sapped a lot of horsepower and it would not start in cold weather, but the toothed belt allowed me to increase the motor pully and I have never had a problem with it starting in the winter. Of course, that is not the issue here, but if it has less stretch and a higher resonant frequency, it might do the trick.
Reference the Shop Fox W1741 and Grizzly G0490 startup slap and shutdown shudder.....
Well, I tried an A-45 (heavy duty 46 inch Gates belt, an AP-45 (Gates Predator) and a coged v-belt from Gates. No soap! They all gave acceptable performance, but did not solve the problem. Cutting the slot away in the base and stretching the cover gets rid of the startup slap, but nothing seems to stop the shudder. I would sure like to know what that is. Some kind of back EMF characteristic from the motor that creates a varying torque during wind-down? Wish I knew. Not a real problem, however, so I am going to forget it and get on with my life unless someone indicates there is a long term problem from the shock load from this.
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