Shopsmith Forums

Something sounds off. Can you take pictures with the belt cover off so we can see what this looks like? The only thing that occurs to me right now other than a belt problem is something wrong with the idler shaft and pulley. I can't see how the belt can shift without it being extremely loose, which is also a possibility.

The only reason I can think of offhand for the Motor Pan (cover) not going on would be not repositioning the power cord hole. Unlike the conventional Headstock where the motor is mounted to the Motor Pan the Power Pro Motor is mounted to the Headstock casting itself.

As Ed said, for the belt problem, pictures would help in seeing how the Belts, Motor, Idler Shaft and Drive Shaft align.

SamV wrote: ↑Mon Jan 30, 2023 7:53 pm Hello all: I am new to this forum so hope I am not high jacking a thread. I am on my third Shopsmith. The first being a 1957 model. I lost it in a fire so I found a 1982. I rebuilt the head stock on this one and its a very good unit. Recently I purchased a 1984 model that was ungraded to 520. I bought it mostly for the upgrade. I decided to upgrade the 520 to the Power Pro and have spent the last 2 days on that project. I have it all completed but am having issues with the lower belt tracking properly. The tension bolts are all properly distanced and the straight edge test is right on. As soon as the machine is turned on the drive belt on the motor sprocket moves down and rubs on the motor casing. I am thinking it may be a faulty belt. Also when the belt is properly tensioned the motor cover will not fit. Another reason I am thinking the belt is the issue. I would appreciate any responses. Thanks

Welcome to the forum. Sometime last year Shopsmith made some changes to production PowerPro headstocks as noted in this thread: viewtopic.php?p=298999#p298999 You can look at those pictures and determine if yours is 'original' style or 'new' style. In my experience, which was 'original' style, the straight edge test caused a serious misalignment of the motor. The lower belt was visibly not running true to the motor and idler shafts because the adjustment did not result in the motor shaft being parallel to the idler shaft. IMO the goal is for the three shafts to be parallel and for the pulley pairs to be running in the same planes. The adjustment seems to make some assumptions that in my case were not true. The lower pulleys were not in the same plane, so the adjustment made the motor shaft also not parallel to the other shafts. Two wrongs appearing to the straight edge as correct. In my case the belt stayed put but ran even hotter than normal.

An angle cube is useful for determining if the shafts are parallel. I used a small lathe face plate on the idler and measured directly on the motor pulley. Referenced to level, these should measure the same. Only the motor angle is adjustable ('original' mounts). My approach was to set the angle parallel, then deal with any error in the straight edge test as linear. I adjusted the pulley location on the shaft and modified my motor mounts to get the motor pulley where I wanted it.

- David