From: "Harry Wade" <hww@xxxxxxxx> To: <modeleng@xxxxxxxxxxxxx> Sent: Thursday, November 22, 2007 2:04 PM Subject: [modeleng] Re: Mystery thread > > My next task will be to fabricate the step pulleys and this brings me to a question for the group, which is, . . . in order to slack the V-belt for speed changes I plan to use an idler pulley and in thinking about that it occurred to me that the idler must be on the "slack" side of the driving pulley as opposed to the "pulling" side. Am I correct in this, or does it matter in the long run? > > Regards, > Harry I think it is better to have the idler on the slack side, primarily to reduce wear and tear. As V belts generally don't like being bent backwards you will need to use a vs. pulley as the idler . I have a very short V belt run on my milling machine vertical head and the idler does reduce the pulley wrap significantly but if you have a decent distance between centres this should not be an issue unless you have a lot of belt slack to take up. Best Regards Dennis Kent UK MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.