Drive Belt for Flexispeed

I have started using my Flexispeed and, so far, it seems good, with one exception: the belt from the countershaft to the lathe pulley slips badly as soon as I try taking a cut of more than the lightest whisker.

I have used 6mm green polyurethane belting, but this seems to seem on the top of the pulley grooves, rather than in them. Before I go and order some 4mm belt instead, I was wondering what other people have used on their Flexispeeds.

Regards,

JAmes.

James,

Going by the picture in your Album, I think that your lathe pulleys are designed for a vee belt.

Have a look at the picture about 1/3 of the way down this page, to see what a groove properly shaped for round belt looks like.

As it is; your 6mm belt is probably riding on the top of the vee, and a 4mm belt may be better ... BUT it might jam, because the vee is too narrow angle.

Now is probably a good time to take some measurements of the groove.

MichaelG.

Michael,

Thank you for the information. In my naievity, I had thought that the round polyurethane belt was a modern substitute that could be used to replace v belts. I shall have to have a bit of a mull.

Regards,

JAmes.

James,

People do often seem to get away with it; but I think it's one of those "more by luck than by judgement" things.

I can't remember the number he came-up with, but GHT [Geo. H. Thomas] did some analysis, years back, to determine his optimum vee angle for round belts. ... I'm sure someone here will have the details.

MichaelG.

Edited By Michael Gilligan on 20/07/2015 07:38:43

I have V belts on mine, I found them in a washing machine service shop. One does slip under provocation but that's better than something jamming or shearing.

You can get heat joinable V section belt in some sizes, but if you can, normal V belt may be best.

Ian S C

Measure the V and look on simplybearings web site. The do a wide range of widths of V belts including narrow starting at 4mm and going to 8 if I remember correctly. There are also some industrial sewing machine belts on ebay with sizes given. My feeling is that the narrow cogged ones from s'b' are better.

If round belting actually fits into the V it needs rather a lot of tension to get it to grip well and it wont be as good as a v belt anyway.

John

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8mm cogged v belt seems optimum on mine. However, there does appear to be quite a bit of variation in the size of the spindle pulleys, model for model.

Rod

Thank you for the advice. I did try a 4mm round belt as well, but that was as bad.

Ian: Unfortunately, I have not been able to find any v belting that I can join with heat. Do you happen to know any suppliers?

John and Roderick: It looks like a 5mm belt will be optimum for my machine and Simply Bearings have one of that size. I just need tomeasure the length that I need and place an order.

Next steps: fabricate some sort of belt tensioner.

Regards,

James.

Thank you for the advice. I did try a 4mm round belt as well, but that was as bad.

Ian: Unfortunately, I have not been able to find any v belting that I can join with heat. Do you happen to know any suppliers?

John and Roderick: It looks like a 5mm belt will be optimum for my machine and Simply Bearings have one of that size. I just need tomeasure the length that I need and place an order.

Next steps: fabricate some sort of belt tensioner.

Regards,

James.

When I measured belts up and picked a particular width I found I actually needed the next size up. Fortunately they aren't that expensive.

John

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Thank you for the advice. I have just fitted a 5mm V belt from Simply Bearings, although I need to rig up a tensioner as it is a bit too long and does not grip unaided. However, when I tensioned the belt with a screwdriver handle, it worked a treat.

Regards,

James.

Glad it worked James. I found that they were a little more generous with the dimensions than the actual size of the belt.

John

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