Mini Mill belt drive conversion

[John HinkleyParticipant @johnhinkley26699]

A follow-up to my previous posts. I made the pulleys for my design of belt drive, having sent off for a couple of v-belts from America. The project went on the back burner for a while and we went to the UK to visit relatives. Just before we went, however, I celebrated my 65th birthday, and as a very generous present to myself, I took the coward's way out and ordered a belt-drive conversion kit for the mill, also from the USA (Little Machine Shop). On my return from the UK, the kit duly arrived and I proceeded to strip the mill in preparation for fitting it. To my surprise, the hole spacing for the mounting plate didn't match that on the mill and upon further inspection the PCD of the motor mounting holes was different, too! So, beware, if you're tempted to get a kit from the 'States – not all clones are the same! I'm currently awaiting the arrival of some aluminium plate from M-Machine, so that I can make new base and motor plates with the correct spacing for my mill.

Also, can I just add, for those who are advocating toothed belt drives, another reason for using the v-belt and pulley system is the fact that I get two speed ranges, whereas a toothed belt drive would limit me to one.

Regards,

John

[Ian S CParticipant @iansc]

I made one new pully from 3" hot rolled steel bar for a drive belt on a ride on lawn mower, the old pully got mangled when a bit of fencing wire got caughtin the belt, the origional one was aluminium, fairly hard alloy. I think the rest of the machine is now warn out now. Ian S C

[John HinkleyParticipant @johnhinkley26699]

A further update. Well, I finished the new mounting and motor plates and stripped the mill to fit the kit. Great excitement. Didn't last long, however. After removing the top nut on the spindle and the spacing sleeve I put the new driven pulley on the spindle. It rattled around like a good'un. It appears that, although the spindle of my mill has, indeed, a diameter of 30mm, like it says in the blurb, the business end where the pulley fits is 28mm in diameter! So, I'm back to square one – or at least square two – and am having to remake the large pulley all over again. Another wait while the raw material arrives from Darlington! Added to that, the motor shaft is 10mm diameter and not the 9mm I was expecting. At least I can ream the hole out to fit on that one. Alright, it's my own fault, I should have stripped it all down and measured it first. I hold my hand up to that one. First rule of engineering – never assume. Second rule – never assume. Lesson learned. (Sound of twit eating humble pie.)

Original kit now up for sale! Quelle surprise!

John

[Ian S CParticipant @iansc]

John, if it was me, I'd make a bush to fit the pully, and at least try that, a lot less hassle that starting from scratch, loctite it int the pully, then bore it to fit the shaft. Ian S C

[John HinkleyParticipant @johnhinkley26699]

Ian,

Yes, thought of that, of course, but it still means I've got to send off for more material! Plus, I get more practice at turning and boring – I'm still a novice, after all – and I can use the pulley in another, as yet, undeveloped project. May give it go. I'll have to see

John

[Alan JacksonParticipant @alanjackson47790]

I thoroughly agree with Ian and John H about polyvee belts, they give all the power you need and can be made as wide as you choose for extra grip. As to suppliers I have found http://www.essexbearings.co.uk to be very helpful. They even dropped the belts in the post to me then invoiced me afterwards. Great service and I have no personal connection for this plug.

Alan

Edited By Alan Jackson on 05/07/2012 09:20:48

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