|James Montgomery 1||14/07/2020 17:01:44|
|1 forum posts|
This is my first post on the forum, so apologies if I've picked the wrong section. I've recently acquired a 3 phase RJH Linisher which works well, save for a slightly (well, actually very) worn drive belt. In the belt's current state I am struggling to measure it up to order a replacement. I wonder if anyone has one of these machines who knows the correct drive belt size / profile, or if not, could offer some guidance on how to measure from the pulleys the correct size to order? I am assuming from the pulley I could estimate the drive belt width and depth and then run string between the two pulleys to give me the correct length. Does that sound right? I am also aware that the belt will have stretched over time. My current belt:
|Brian H||14/07/2020 17:46:39|
1678 forum posts
That sounds about right James. As I discovered the other day, the piece of string idea results in a belt that is a bit short.
I wanted a belt for the coolant pump on a Senior Major Mk2 milling machine. Using the piece of string measurement, a 33 inch belt was required but when I obtained one it was clear that a 35 would be more suitable.
You definitely need a new belt!
Edited By Brian H on 14/07/2020 17:48:07
|219 forum posts|
You may find this calculator useful
The string method can be used if you measure the OD of the pulleys minus 8 mm for "A" section belt.
Calculate both driver and driven diameters. Add together and divide by 2.
Measure the shaft centres and multiply by 2.
Add the Totals of Half Diameters and the 2 shaft centres will give a close approximate belt length
Edited By oldvelo on 15/07/2020 03:42:11
|Howard Lewis||15/07/2020 11:21:58|
|3394 forum posts|
If it a Vee belt, dimensions for the belts and pulleys are quoted in various places, such as Machinery's handbook.
That belt is so far gone that it could be a round cord type belt!
If it is/was a V belt, measuring the pulley groove width / depth is the way to go. This will tell you if the belt should be Z, A or B section.
Please login to post a reply.
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.