Link belt drive problems resolved.

I am sure that you will all be pleased to hear that my drive problems are resolved! The pulleys were looked at VERY carefully and I noticed a wear groove that matched the "tail" of the inner most links. Checked the groove section and noted 40 degrees inclusive. Fenner suggest 34 degrees for pulley diameters under 118 mm diameter (which both link belt pulleys are). I put both pulleys up in a friends 15 inch Harrison and re-machined the grooves to 34 degrees. Belt now sits lower in the groove.

The link belt appeared relatively new but was highly contaminated with oil. I stripped off every individual link (50) washed in Swarfega Heavy Duty Degreaser, then in Hot water and washing powder, finally in

1.1.1 Trichloroethane. Reassembled belt. Re-fitted pulleys and belt and noted Keiths comments about tension, it is now B tight. Refitted motor with new std V belt, aligned.


Originally a .75mm cut on 50 mm diameter free cutting Mild Steel would slow the part down to a crawl. Now a 3mm cut (6mm off diameter) hardly changes the speed. Swarf is not blue so still some way to go

Main reason IMHO is the included angle change to 34 degrees, the belt is now sitting deeper in the groove.

Well pleased!

Many thanks to Keith for his comments on Tension. I actually checked a neighbors Boxford. He has the older Canvas and Rubber type belt so did not help a lot. If I had a Boxford I would definately look after the belt, a change to the modern Nu-T-Link could give problems as it is certainly not as flexible. Damn Boxford is definately quieter than the Viceroy though! However bet it would not take a 3mm cut!


Reply to
Richard Edwards
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Pleased to hear that you have got it sorted now Richard and cutting nearly as well as a Boxford [VBG). I must say that I have always felt that the Viceroy deserved to be more popular than it was but of course it means that they can be something of a bargain although, like the Boxford, they vary greatly in the specification. The heavier build, larger ways and separate feed shaft were definite improvements over early Boxfords but it appears that they were busily copying each other as fast as they could anyway. I might risk a beer token on your final statement though!!



Reply to

I echo all of your comments. I was just "checking the lie of the land" with my feed comment. Seeing that you are confident enough to risk a beer token, the bet is totally and irrefutably withdrawn! Now I need to fettle my QCTP to get it to handle the new loads, will I ever get my little engine built?

Best regards


Reply to
Richard Edwards

Hi Richard

I too have a Viceroy TDS and I was wondering how much tension you have used?

I have never been sure of the correct tension and probably run it a little slack as I was worried about damaging the motor bearings.

It would help if you could give me some idea of the free play at some point on the belt.



Reply to
Paul M

WRT the motor to countershaft belt, I have mine so that I can just twist it a quarter of a turn in the centre of the span. My belting supplier suggests that the countershaft to top shaft link belt should be "banjo string tight, whatever that means in the real world. Very difficult to check this as you know, as there is no access to the centre of the span.


Reply to
Richard Edwards

It might be interesting to fit a torque wrench to the motor shaft and adjust the belts so that they would just transmit the rated maximum torque of the motor. Then you could be the only shop on the block with scientifically optimized belt tensions! :>) (Actually I suspect you do about the same thing by adjusting them until they don't slip before the motor stalls).

Don Young (USA)

Reply to
Don Young

It's probably useful to be able to exceed your motor's rated torque briefly. For short periods of time it won't hurt. A thermal circuit breaker is probably a better way to protect a motor against overheating.

Best wishes,


Reply to
Christopher Tidy

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