Speed of motor (rpm)

[Mike Defauw]

I am new here so bear with me ...
I have a 1/2 horse motor that runs at 3500 rpm..
I want it to run at 1750 rpm ....
What sise pulleys will I need to slow it down to 1750 rpm...
Thank you /////
mike.....

[glenn bradley]

Here you go:

http://www.wfmeyers.com/customer/calculatorPulley.html

2" and 4".

[Hoa Dinh]

I am new here so bear with me ...
I have a 1/2 horse motor that runs at 3500 rpm..
I want it to run at 1750 rpm ....
What sise pulleys will I need to slow it down to 1750 rpm...
Thank you /////
mike.....
Mike,

You'll get better replies if you provide more details: What's the application? What are the sizes of the driving pulley (attached to the motor shaft) and of the driven pulley (the other pulley)? What's the distance between the centers of the pulleys?

In general, to replace a 1750rpm motor with a 3500 rpm motor and keep the same rotating speed of the machine, you can either:

1. replace the driving pulley with one half the size, or

2. replace the driven pulley with one double the size, or

3. replace the driving pulley with one 0.7 the size, and replace the driven pulley with one 1.4 the size.

Essentially the ratio of the driven pulley/the driving pulley has to be doubled.

When you change the pulley(s), the size of the belt will need to change, or the distance between the pulley(s) will need to change. These changes may or may not be possible depending on your application.

[Mike Defauw]

Thanks .... I will give it a try ....... mike....

[Mike Defauw]

Thanks for the reply... I am building a v sander and have a 1/2 hp motor in my back shop and wanted to put it to good use.... So I am not replacing any pulleys yet, that is why I was asking if someone knew the size of the pulleys to get the rpm down.... I found a bunch of pulleys in the back shop so I will try the 4 and the 2 in. first ,,,, thank you so much... very helpfull.... mike...

[Cliff Rohrabacher]

Here you go:

http://www.wfmeyers.com/customer/calculatorPulley.html

2" and 4".

I went there and input some pully info and got this error message

*******************************
Method Not Allowed

The requested method POST is not allowed for the URL /customer/calculatorPulley.html.
******************

It popped up on a white page just a nano second after the calculation was coplete so that If one was looking right at the box to get the solution one could see the result.

I did this with a couple of pully sizes. Same result.