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kendall
06-24-2015, 05:55 PM
Been working on a project that requires a simple power drive system to work around a corner, maybe 1/4 horse at 130 rpm. Been toying with the idea of an automotive serpentine belt with a set up like some of the old camel back drill presses had, quick search showed these images which show what I'm thinking of : http://knifenetwork.com/forum/showthread.php?t=59186

I can't seem to find any information about minimum distances required between the horizontal drive and the guides/idlers, or from the vertical pulley to the idlers. To me, that upper section on the picture looks like it is nearing the shortest length to allow the belt to twist enough to lay on the pulleys smoothly enough for function. Anyone know what that length would be or how to determine it short of build and see?

Normally I'd be happy to experiment and see, but just tore old shop down to rebuild, and all tools,toys etc were moved, stacked and then built a temporary shed over them without providing a way to get them out except when tearing down the temp shed to put them in the new shop.

EddyCurr
06-24-2015, 06:22 PM
Do you have your mind set on a sepentine flat belt
and does it need to conform to close quarters as
shown on the camelback DP example?

If no and no, I will offer that my 60's era Cub Cadet
drives the horizontal mower pulley with a v-belt that
runs past two idlers in the transition to the vertical
PTO pulley mounted to a 12 HP Kohler. On request,
I will take some measurements ...

.

kendall
06-24-2015, 07:05 PM
No, I'm not set on a serpentine/flat belt, it's just what came to mind when discussing the design. About the only thing I have actually ruled out is a gear to gear system because of weight and 'crud' in the operating environment. Sounds like the v belt may give me an idea to work with.
Don't put yourself out, but I'd be happy to see the measurements when you get a chance.

Lee Cordochorea
06-24-2015, 07:33 PM
Have a peek at the second page: http://www.ptaustralia.com.au/sites/default/files/V-Belts%20Drives%20with%20Twist%20and%20Non-Alignmnet.pdf

J Tiers
06-24-2015, 07:42 PM
Notched V belt. Small "section".

Works for this vertical head, driven by 1/4HP, despite being probably a little too sharp a bend for the belt.

http://img.photobucket.com/albums/0803/jstanley/machines/Lewis/LewisnewV-head1_zps24e49cc4.jpg (http://smg.photobucket.com/user/jstanley/media/machines/Lewis/LewisnewV-head1_zps24e49cc4.jpg.html)

platypus2020
06-24-2015, 09:16 PM
That how GM ran the fan belt on a Corvair

Mike Burch
06-25-2015, 12:40 AM
If it's only a quarter horse, would a round-section belt do? It wouldn't have to twist.

thaiguzzi
06-25-2015, 12:45 AM
Our petrol grass cutter / lawn mower has a 5hp Chinese OHV petrol engine, and the design of the drive is a vee belt twisted on itself at 90 degrees, only now started to fray after 2 years of abuse. I reckon i may get this year out of it before it finally breaks. So yeah, vee belts work with a twist in them.

boslab
06-25-2015, 01:39 AM
There are rubber double belts, vee on the inside and the outside, giving it a sort of barrel shape in section, you don't have to twist them to drive round corners, I've seen loads of machines with a 45 degree direction change, the biggest direction change roller I've ever tinkered with took steel strip out of a finishing mill into a continuous anneal shop, amusing to see steel zipping through at 60 miles an hour when it's 5' wide.
http://www.bearingboys.co.uk/BB131_Hexagonal_Mower_Drive_Belt-12364-p?gclid=CjwKEAjwqqmsBRDGy_3h_eS80jYSJACS95Cvvqp7CI P2GVlDj8HMSgrlvgOvlpneeYbfY45I9Id36xoC_MDw_wcB
Mark

Doozer
06-25-2015, 03:59 AM
1/4 hp @ 130 rpm is 10 foot pounds.
You will need some large diameter pulleys
and a wide belt to make that work
without slipping.

--Doozer

velocette
06-25-2015, 05:24 AM
Hi Kendal
Had quick look at Knifenetwork oof the Camelback drill. the two speed option will NOT work with "poly vee belts"
It can be done with ribbed belts BUT the alignment is critical with the idlers positioning angle line up will be tricky to say the least if anything but equal driver and driven pulleys.
Poly vee belts are superior to vee belts at slow speeds.

Eric

Doozer
06-25-2015, 07:24 AM
Eric-
OK, gotta ask,
what pray tell is the difference between
poly vee bents and ribbed belts?

-D

Seastar
06-25-2015, 08:52 AM
Exactly?
Bill
Eric-
OK, gotta ask,
what pray tell is the difference between
poly vee bents and ribbed belts?

-D

A.K. Boomer
06-25-2015, 09:50 AM
Notched V belt. Small "section".

Works for this vertical head, driven by 1/4HP, despite being probably a little too sharp a bend for the belt.

http://img.photobucket.com/albums/0803/jstanley/machines/Lewis/LewisnewV-head1_zps24e49cc4.jpg (http://smg.photobucket.com/user/jstanley/media/machines/Lewis/LewisnewV-head1_zps24e49cc4.jpg.html)

That is one of the worst examples iv seen --- smelling rubber burning after firing up your mill for only a couple minutes should not be considered a good "drive system"

also - if your starting out with only 1/4 hp you can expect about 1/8 getting to the spindle - the rest is going to heat in the belt and the pulleys...

keep in mind "slurpentine" belts can be used quite efficiently in this configuration - of course given more flex room, they do not suffer the frictional losses as much from the lead vee-blocks scrubbing against the side of the pulley and also when disengaging it... plus - over all rubber distortion is kept to a minimum in comparison...

J Tiers
06-25-2015, 10:11 AM
That is one of the worst examples iv seen --- smelling rubber burning after firing up your mill for only a couple minutes should not be considered a good "drive system"

also - if your starting out with only 1/4 hp you can expect about 1/8 getting to the spindle - the rest is going to heat in the belt and the pulleys...

keep in mind "slurpentine" belts can be used quite efficiently in this configuration - of course given more flex room, they do not suffer the frictional losses as much from the lead vee-blocks scrubbing against the side of the pulley and also when disengaging it... plus - over all rubber distortion is kept to a minimum in comparison...

Well, you can stop worrying, because there is no smell, no heating, and no fraying. it works fine, and has not had any bad effects show up since starting to use it quite some time ago.

I can use it for hours with no significant heating.

So much for the expert opinion, I guess! :D

Edit..... The design was copied from the successful "Marvin" vertical head most often associated with the Atlas Milling machine.

http://www.lathes.co.uk/atlasmiller/page2.html

A.K. Boomer
06-26-2015, 01:37 AM
I can use it for hours with no significant heating.

by significant you mean not having to call the fire department???




So much for the expert opinion, I guess! :D



again got any brake horse power specs of whats left after it leaves the already underpowered motor and actually finds it way to the spindle after negotiating the frictional maze??? :p it's a wonder that belt doesn't get lost...





Edit..... The design was copied from the successful "Marvin" vertical head most often associated with the Atlas Milling machine.

http://www.lathes.co.uk/atlasmiller/page2.html


Sweet --- is that a stegosaurus? how long ago did that one become extinct? any idea as to why? lol

J Tiers
06-26-2015, 02:00 AM
A good time is always fine, but you really didn't need the Jaegermeister after all the previous stuff!

It works fine, as well as the hordes of mowers with similar setups. Nothing wrong with it. Sorry to ruin your fun.

Power measurements? Does the job. If I had known you wanted measurements I am sure I would have set them up, but unfortunately the servants failed to pass along Your Highness' request. They will be flogged.

A.K. Boomer
06-26-2015, 09:16 AM
Just giving you a rough time JT :)

it really is one of the closest transitions iv seen for that kind of set up and the closer you get the more all problems mentioned get amplified --- but if it works it works, I really could see serpentine's doing quite well in this application, given a little more space...

wierdscience
06-26-2015, 10:28 AM
If the OP used a 4 rib J section belt which is less that 3/8" wide he should get away with it just fine.Besides as John showed us J-section sheaves are easy to make with a 11 tpi thread chaser.

http://www.mcmaster.com/#9003k41/=xsirz8

A.K. Boomer
06-26-2015, 10:50 AM
I think Dayco even makes those with relief ribs so they are even more flexible,
would make for a neat project figuring out and cutting serpentine pulleys,

I think about doing it for the step pulley mill but am holding off because I might end up going VFD and will not need all the combinations...

J Tiers
06-26-2015, 10:50 AM
It absolutely would NOT work with a solid belt, I think. It is the notched belt that allows this to work.

Bigger idler pulleys would not hurt it either, I had material for this size so I used it.

There ARE thinner section belts, and at the lower power, they might work perfectly. A 2L for instance, available from McMaster-Carr. If you recall, Sears (King-Seeley) drill presses used a very thin belt that may have been a 2L, which would never notice going around those pulleys.

Willy
06-26-2015, 11:11 AM
If the OP used a 4 rib J section belt which is less that 3/8" wide he should get away with it just fine.Besides as John showed us J-section sheaves are easy to make with a 11 tpi thread chaser.

http://www.mcmaster.com/#9003k41/=xsirz8

Great idea!
Since most dryer belts are either "H" or the more common "J" section belts a large variety of lengths would be available at a local appliance parts supplier as well. Also since most dryers have a motor output of 1/3 hp I believe the torque and rpm levels would be in line with what the OP needs too. These belts are very flexible this will be another bonus.

platypus2020
06-26-2015, 11:21 AM
I have a vertical head on my small Atlas horizontal mill, that uses that belt configuration, I used a Fenner Power-Flex Link belt.

wierdscience
06-26-2015, 11:43 AM
Great idea!
Since most dryer belts are either "H" or the more common "J" section belts a large variety of lengths would be available at a local appliance parts supplier as well. Also since most dryers have a motor output of 1/3 hp I believe the torque and rpm levels would be in line with what the OP needs too. These belts are very flexible this will be another bonus.

I was impressed by the 5hp walk behind line trimmer my brother bought a few years ago.The thing is unstoppable and only has a 4 rib J-section driving the spindle.Tough little belts,not to mention all the millions of 3hp roll around air compressors that have the 6 J installed on them.