Shopsmith Forums

So I finally had a project that I could try the speed increaser on my Goldie. I needed to make some 1/4" dados. I got it all setup and aligned and ran some tests. Everything appeared to be working well, so I proceeded to make the dados in the 3/4" beech plywood I am using.

I got about 1/3 of the way through the first one and everything started to slow down. I backed speed back to slow and shut it off.
Turns out the 6 month old drive belt had pretty much disintegrated.

I had the 1/4" bit set to 1/4" depth, I am assuming that I should have done it in 1/8" increments. I also had the speed dial set to "V" per instructions.

The other odd thing I noticed, is that the speed dial was turned all the way up when I went to turn it down.

First question, did the dial turn all the way up because the belt started to disintegrate, or did the speed dial work it's way up on it's own and cause the belt to disintegrate? I that is the case, how do I prevent that in the future?

Second question, I ordered a new belt from Shopsmith on Sunday, but it still hasn't shipped. Is there a belt I can get from NAPA that would work? I can always move it over to my other working Mark V, but I kind of want to get it working on the Goldie.

Some users have reported that SS recently started supplying a commercial belt for the Conventional Headstock lower drive belt. The belt is a BESTORQ X3 size A24 or 4L260. (Ref: viewtopic.php?t=35364) Personally, I think this is a bad idea. In any case, there is some uncertainty as to how well a commercial belt size will perform in terms of commanded Vs. actual speed. That said, the same belt appears to be available on Amazon and other brands listed as 4L260 are available from numerous sources.

Speed control drift sometimes happens, especially in the face of higher vibration that may occur at higher speeds. Some users have clamped something to the speed control to prevent it from turning once set.

You should ensure that your high speed stop is appropriately set. If it allows too high of a speed to be reached, the V-belt may enter the non-V portion of the Idler sheaves. This will destroy a belt, I've done it this way myself. I don't know of any other belt failure mechanism related to high speed.

- David

David may have given the better answers than I am about to.

As to your first question, I don't believe either possibility you described should have caused the belt to disintegrate. Either way the speed shouldn't have changed so that is another problem. My first thought is the belt was bad.

I haven't needed a replacement belt that fast, so I haven't looked for a local alternative. Shopsmith going to the BESTORQ X3 size A24 or 4L260 as the belt it now supplies may have to do with the recent discontinuation of the Conventional Headstock before bringing it back for a limited time. Having a "standard" V Belt for use in the Conventional Headstock would be preferable from a company standpoint than having a "special" Belt made for their tool.

I have used a Speed Increaser with my Mark V 520 before with okay results. First, due to the slower 10,000 RPM over a router, the feed rate should be very slow. Something to consider in your case is the Goldie you list as serial number 369690 would have come with the Gilmer Drive and a 3/4 HP Motor unless upgraded. Just for my own curiosity does the serial number have a C hand engraved after it like the example below?

With this in mind back to the Belt disintegrating, if your Goldie still has the Gilmer Drive the slip point could have shifted to the V Belt if the Clutch is not allowing slippage any longer.

_

chapmanruss wrote: Tue Aug 05, 2025 1:44 pm
With this in mind back to the Belt disintegrating, if your Goldie still has the Gilmer Drive the slip point could have shifted to the V Belt if the Clutch is not allowing slippage any longer.

_
369904C Mark 5 Goldie Mar 61 John Dalton.jpg

I upgraded it to the 1 1/8hp motor and the dual bearing quill with the poly belt.

Another option for a belt is BAND SAW TIRE WAREHOUSE on e-bay.

He is a Great guy to do business with.

It is still hard to tell what happened to the belt. We may never actually know.

As for the speed increasing it shouldn't have been that much of a problem. The Speed Increaser is supposed to go up to 10,000 RPMs by doubling the Headstock speed. V on the speed dial is supposed to be 4700 RPM and W 5100 to FAST at 5200. Not a big difference in the speed going into the Speed Increaser.

Since the speed did change, I wonder if the Speed Dial Ring, Back-Up Spring (reference number 73 in the online parts diagram) is properly in place. It is shown in place on a Greenie "B" Headstock indicated by the arrow in the picture below.

_ .
Is the Speed Control Speed Dial Back-up Spring (reference number 83 in the online parts diagram) In place as seen in the picture below. That one is a little rusty and from a Headstock that needs work.

_ .
Both of those Springs provide some friction for the Speed Control Assembly.