Thread: Hercus Tool and Cutter Grinder - Spindle Drive Belt and Pulleys

Choice would depend really on how you want to make them.
There would be no particular reason why you would run a convex captivated pully.
The duplex on the machine appears to have a much wider flat on the bottom of the vee than the taper lock,although the orientation of the photo does not clearly show it.
If it is worn as you think,it would appear to be a exceptional amount of wear.
To get a flat as wide as your photo indicates you would think that the sides of the vee would be paper thin if not even there at all.
It isnt a B section duplex.

Hi Bob,
Firstly i am surprised at the taper lock being so badly out of balance. I have used taper locks up to 250mm with no problems and mi locks up to 225, with some problems, mainly from not doing up the retaining bolts evenly.

In my opinion i would make the pulley flat with a lip each side. My Conrick still has a 30mm wide flat belt, and it has convex pulleys, and no lips. Whilst i understand how the convex surface should help to keep the belt centered, as soon as you put a VERY high load on the belt it tends to move to one side, and as soon as it does the convex surface causes the belt to come right off (not a pretty thing whilst cutting)

My Felder saw/spindle uses a rather tiny 20mm wide multi V belt to transmit its 3kw. I have never had belt slip on it, even though the high speed router spindle pulley is only about 20mm dia. Thats not much surface area!

Either way, multi V or toothed, the power your transmitting should not be a problem, however these type of belts do tend to need to be tighter than a v belt as they don't wedge themselves into the pulley, and your bearings may suffer due to the extra tension.

Ewan

Edit: you did not mention if you are using an A or B belt, all the taper locks i have used are A section, could the Hercus pulley be B section and thats an A section belt your trying? Mi locks should work with both A and B.

Hi Bob,
Naturally I will say a flat belt. I have the curvatures for flat belt pulleys somewhere. I can find for you if required. If more transmission power is required from slippage you just lay another belt over the top.

Phil

Originally Posted by pipeclay

Choice would depend really on how you want to make them.
There would be no particular reason why you would run a convex captivated pully.
The duplex on the machine appears to have a much wider flat on the bottom of the vee than the taper lock,although the orientation of the photo does not clearly show it.
If it is worn as you think,it would appear to be a exceptional amount of wear.
To get a flat as wide as your photo indicates you would think that the sides of the vee would be paper thin if not even there at all.
It isnt a B section duplex.

The belts are about 3/8" wide Peter. The original belt was a 2300 Fenner. This machine is old, 1949 or older. All the ways are heavily worn. Maybe the original belt profile was different. The sectional spindle drawing showing the duplex vees is for a 3A grinder. Newer than mine.

Bob.

Bob
I agree with Phil, a flat belt would be the go.
In the morning I will photo a small pulley, I machined hundreds off, for an abrasive belt machine, we once sold. It was done with the Turret attach on the Hercus lathe.
Anyway this pulley uses a crown & flanged sides, always worked well & ran smoothly at high speed. No probs with belt run off.
regards
Bruce

Ewan,

The belts I have are Gates TRUFLEX 1265 (3L265) - Gates 3L265 Truflex V-Belt 8400-1265

Neither an A nor B.

Phil,

My little Dumore TPG has curved pulleys. The belt stays put at 38,500rpm.

BT

Originally Posted by Abratool

Bob
I agree with Phil, a flat belt would be the go.
In the morning I will photo a small pulley, I machined hundreds off, for an abrasive belt machine, we once sold. It was done with the Turret attach on the Hercus lathe.
Anyway this pulley uses a crown & flanged sides, always worked well & ran smoothly at high speed. No probs with belt run off.
regards
Bruce

Ah, even more photography to look forward too. It's looking like you have a full day ahead of you Bruce.

Originally Posted by Anorak Bob

Ah, even more photography to look forward too. It's looking like you have a full day ahead of you Bruce.

Blokes your age need to be in bed at this late hour
regards
Bruce

I would have thought it'd use an M section belt (3/8") for the pulleys that small in diameter, like some of the lathe tool post grinders.

I am fading. My excuse is that I was up and down a ladder this arvo trying to refix a plaster cornice. I had to make it look like I hadn't spent the entire day playing in the shed.

Originally Posted by Graziano

I would have thought it'd use an M section belt (3/8") for the pulleys that small in diameter, like some of the lathe tool post grinders.

I'm looking Mark - http://www.gates.com/catalogs/file_d...tes%5Ccatalogs

Bob - why don't you try an A section belt?
The belt you nave there is clearly to narrow. BTW, there is an M section belt which I have used a few times and it's about 3/8" wide. A section is about 1/2" wide.
Joe

Graziano beat me to it while I was still reading posts.....
He is suggesting the other way 'roud: excahnge you taperlock pulley for an M section one.
Joe

Originally Posted by jhovel

Bob - why don't you try an A section belt?
The belt you nave there is clearly to narrow. BTW, there is an M section belt which I have used a few times and it's about 3/8" wide. A section is about 1/2" wide.
Joe

Too late for nocturnal photography. An A is way too big. I'll post a photo after work tomorrow Joe.

Bob.