Boffins , Pick your Brains

[speewa158]

Boffins out there l have a 2 HP single phase electric motor that turns at 2040 RPM . l require that produces 16500 RMP to run an 8in Jointer  ( wood working kit )  How big a pulley do l need to put on the motor to increase the speed to a 2in pulley at the power head . l reckon its a 5.8 to1 increase  , but l don't know how to work out the correct size of the belt pulley .
So its over to you     ,       teach me                 

[glenm64]

16500/2040 = 8.08
2in x 8.08=16.16in

A 16 inch pulley on the motor is hard to fit on some setups. You will need either a bit of distance between pulley centres to give contact on the small pulley, or use a tensioner pulley. Maybe 2 step ups of around 2.85 :1 or any combo to give the speed is better

Cheers Glen

[duggie]

 According to this you need a 404.411764mm pulley.  Or a 16" pulley.  Length of belt would be decided by the distance apart of the pulley centers .

http://gadi.agric.za/software/renting/pulley_calc.php


https://www.google.com.au/search?q=15.921723+inches&oq=404.411764mm+to+inches&aqs=chrome.1.69i57j6.13061j0j8&sourceid=chrome&ie=UTF-8

[duggie]

  hi glenm64, bugger you posted while I was typing. But same result.

[speewa158]

Thank you for the feed back Glen & Duggie   . As l am able to create the optimum distance between both power & delivery , a long belt can be used  .
l will keep you informed on progress                        

[speewa158]

Now Then ,, l have consulted with boffins down this way & a 2 stage system has been discussed . Dose it make better sence to run a stepped system 8in pulley to a 2in to an 8in to the final drive of 2in . Or do l louse power with all the belts . Back to the boffins . l have been told a 16in pulley would be a bit unwieldy in action .
                               Your thoughts                         

[IanS]

I'm not a boffin but i suggest that you may have minor losses but having a stepped intermediate shaft is pretty common, have a look at most bench or pedestal drills. It will certainly make it easier for the motor to start up, a 16 inch pulley would take a bit of effort to get it spinning.

[speewa158]

Thanks lans that's sort of what we were thinking around here .         
What part of the Wheat Belt are you in 

[tryagain]

Is the 2in the circumference or diameter of the pulley you already have?

[speewa158]

Haven't measured it as yet , but its in the Vib                 

[IanS]

Thanks lans that's sort of what we were thinking around here .         
What part of the Wheat Belt are you in 

I'm in the dry part  Actually Central Wheatbelt but in the northwest corner of it, nearly Central West.