Author Topic: Too small V-belt pulley for Classic B-profile  (Read 4670 times)

Offline PekkaNF

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Too small V-belt pulley for Classic B-profile
« on: October 16, 2015, 05:52:24 PM »
Father bought a Pile of various metals and calls it a tractor (Massey Ferguson). Mom calls it his mistress Fergie...

It's missing an DC generator. He bought a chinese ARC18 alternator copy, that has small modern V-belt pulley, that is for modern belt profile, that can'not be fit to tractor without making two new pulleys.

Therefore I'm of to make one. According to table values, pulley of correct size is outside of the working envelope in every aspect. Althoug that table states that it is not valid for agricultular and automotive use.

www.alexandris.bg/images/products/vb.pdf

Minimum pulley diameter 178 mm. All pulleys ae smaller than that on this tractor.

So, the plan is use eneough iron and make it smaller utill alternator rescharges battery eneough on normal use but does not spit belts out at alarming rate.

Roughed out from 85 mm dia rod and now I'm waiting a compact inser tool that will allow me to machine the groove.

The grove will be turned when pulley has been mounted on arbor to make hole and groove concentric.

All pretty basic really.

Pekka

Offline Lew_Merrick_PE

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Re: Too small V-belt pulley for Classic B-profile
« Reply #1 on: October 17, 2015, 12:16:12 AM »
Pekka,

"Fenner" linkbelts (now sold as "PowerTwist") will drive much smaller pulleys than conventional v-belts.  The reason I know that the name has changed from "Fenner" to "PowerTwish" is that the 15 year old "Fenner" that drives a small bandsaw of mine gave up the ghost (after nearly 15 years) a week ago.  The pulley on the bandsaw was so small that it "ate" conventional v-belts on a nigh-weekly basis before I changed to the (then) "Fenner" linkbelt.

This is probably an "easy" solution to your problem.

Offline PekkaNF

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Re: Too small V-belt pulley for Classic B-profile
« Reply #2 on: October 17, 2015, 04:30:36 AM »
Thanks,

Now I even have plan "C". My father has few original belts and bracket/pulley desighn starts from there. If I would tell him the price of tha belt, I'd better order medical assistance as well. But it's a back up plan.

Plan "B" was to use BX-profile or another, which is close to it (XPB I think) toothed belt that would do tighter bends than "classic" one. Has pretty close same V-pulley dimessions and because here load is only an alternator and water pump, load is not even close to nominal for the belt profile.

Pekka

Offline wgw

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Re: Too small V-belt pulley for Classic B-profile
« Reply #3 on: October 17, 2015, 06:11:30 AM »
Pekka- don't worry about it, use pulleys similar to originals, except I expect the alternator will have to go a bit faster than the dynamo. The belt life will be shorter, maybe quite a lot shorter, but how many hours will the old massey be doing?

Offline PekkaNF

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Re: Too small V-belt pulley for Classic B-profile
« Reply #4 on: October 17, 2015, 08:08:52 AM »
You are right.

My starting point is close to original DC generator size. Alternator need abround 2 k rpm to start charging. But I want to make sure I have somewhat leeway on this one. Easier to cut somewhat smaller than remake the whole thing.

I think my father is fixing it just to keep his mind ocupied. Which is a great thing. Also they have few kilometers of private road that needs to be kept clean. Even when it is winter.

Pekka

Offline PekkaNF

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Re: Too small V-belt pulley for Classic B-profile
« Reply #5 on: November 09, 2015, 03:29:50 AM »
Finaly got keyway broaches from ARC eurotrade and friend twisted my arm to accept his small press. Just about enough for 2 and 3 mm broaches.

I had to make "special" bushing for 15 mm ID kole and 3 mm keyway broach. making that bush and broaching my first ever keyway took whopping 40 minutes total. Bit of an anticlimax after finding out all the facts. people and papers were right on this one. Takes surpricing large amount of force, best use plenty of cutting oil, align everything and goes well. What surpriced me is that every tooth cuts quite a bit. All tooth spaces are filled with the swarf.

Used this broach set:
http://www.arceurotrade.co.uk/catalogue/results.aspx?search=060-400-00100

And about 40 kg weight 2-ton or something arbor press, arm is about 400 mm long and it feels rigid at this force, but throat is pretty small. I'm not sure if it can accommodate much bigger broach.

Pekka

Offline velocette

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Re: Too small V-belt pulley for Classic B-profile
« Reply #6 on: November 09, 2015, 12:34:29 PM »
Hi
Yes you have to do what you have to do to keep these old machines running keep up the good work.

Eric

Offline PekkaNF

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Re: Too small V-belt pulley for Classic B-profile
« Reply #7 on: November 10, 2015, 03:25:58 AM »
Best part was that I finished it for my father for fathers day.

Pekka