Flexispeed Drive Belt

[James AParticipant @jamesalford67616]

[James AParticipant @jamesalford67616]

Good morning.

The belt on my Flexispeed slips very readily, despite being tensioned, clean and treated with a belt-grip spray. I have tried a 6mm V belt and different sizes of round poly-belt, both the smooth and rough varieties.

I was wondering what size and type of belt others with a Flexispeed lathe are using and whether theirs slip easily as well.

Regards,

James

[john carruthersParticipant @johncarruthers46255]

On mine the original belt was too short to give a good run and would slip at the slightest provocation.
Once I moved the layshaft away a bit I could use an old fan belt with no problems.

[Neil AParticipant @neila]

The original Vee belt for the Flexispeed lathe was a Z section 3/8" wide x 1/4" deep. I have just measured the length of the belts on mine as best I can, the size markings have long since worn off. The first reduction from the motor is approximately a Z21.5 (measures 23 1/4" outside length).The second reduction( 3 step pulley) is approximately a Z17.75 or could be a Z18.5 (measures 19 1/2" outside length). The belts have probably stretched a bit over the years. It does not get used very much now.

Just a thought, when I got my Flexispeed from the Norfolk Lathe Co. in North Walsham one of the 3 step pulleys had been incorrectly machined with an A section groove. Could be worth checking as a Z section belt does not drive properly in an A section groove.

[Roderick JenkinsParticipant @roderickjenkins93242]

Hi James,

I ended up using 8mm wide cogged Optibelt **LINK**

The cogging seems to help the belt to wrap around the relatively small pulleys. Much better than the 8mm round urethane belt which I also tried. New Z/M section belts seem to be too stiff.

HTH,

Rod

[James AParticipant @jamesalford67616]

Thank you for all of the replies, which will be a great help.

Rod: that is the type of belt that I am using, but mine is only 6mm. I shall buy a wider one to try.

You can see my rather convoluted tensioner and belt routing in the attached pictures. I need to move the lathe, so shall re-position the shafts so that the belt has a more natural route. You can also see that the belt sits quite well down in the pulley groove, so there is definitely room for a larger one: 8mm or perhaps even 10mm, nearing the original size that Neil mentioned.

Ignore the wire running through one of the pulleys: the machine is not in use at the moment as I am working on a different project.

Regards,

James.

[James AParticipant @jamesalford67616]

I finally got around to fitting the 8mm belt that I bought a while ago and used the lathe for the first time in ages the other evening. The difference was quite remarkable, with not a hint of slipping, even when parting off.

It seems to have made the machine much less frustrating to use than before when the belt would slip with the slightest provocation.

Regards,

James.

[Michael GilliganParticipant @michaelgilligan61133]

Excellent news, James

Good to see the conclusion on record for future readers.

MichaelG.

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