Did a little more work on the lathe to try and tighten up some wobble on the sheave on the drive motor. Sometimes when I am turning a part it seems like the cut gets a visible line in the work. I'm not sure if it's another issue but wondered if the wobble from the lower sheave assembly may have caused a minor brief difference in speed and caused the line to show up(also, it makes a little noise and I wanted to try and cure that too) This machine came out with a hydraulic variable speed adjustment which had been removed before I got it, now it uses a VFD. I also plan on removing the bolt nut and spacer in the first pic, bottom sheave, and make a larger shaft to use for the sheave width adjustment. I am also going to try to put a bearing on on that same shaft and build a support arm that goes up to just below the bearing in the upper sheave and hold the outside of the shaft on the bottom sheave so it cant move up and down. That is verified one place I am getting noise from.
Old pic, but its the only one I have assembled.
The support arm I want to do will be notched to fit in the tab right below the bearing, and then go down the hold the outer end of the shaft on the bottom sheaves to keep it from "Flexing upward" during use. Not the motor shaft, but the shaft you see in the first pic(homeade) I need to beef it up anyway as it has broke a roll pin on it twice since I got the machine.
This key is in between the two sheaves(no pic) It does not go on the motor shaft(its a straight regular key) Its torn up pretty bad obviously.
Here is my idea of a new key. Made it wider so when I screw the first 2 up I still have more to work with!!!! I just roughed it close and will cut and file to fit later. They are still available for about 880.00 bucks. Nice thing about that price is it comes with 2 new sheaves too!!!! The key I want to make will be wider than what came out of it. The key way in the other sheave is wider than the key that came out of it anyway, so I think it was homeade as well which allowed it to rock back and forth during operation.
From the tooling that came with the mill I bought I used this "woodruff key cutter??" since the diameter was the same size as the rounded part of the key. The cutter is wider though, but since my sheaves don't move in and out to regulate the RPM anymore and they are basically stationary now, I didnt think it would hurt.
And the fun part. When I got it mostly cut I found a nice long crack in the sheave. It has been there a while I can tell, just didn't know about it. So now what to do??? My thoughts are to weld it, turn it down and re-cut the key way. Problem I see with that, there is a black plastic like coating on the sheave shaft. Assuming its for easy movement for the variable speed(which I don't need since it was converted to the VFD) but if it all burns off during welding, now my clearances and sheaves are going to be loose. Any other ideas rather than buying an 800.00 sheave and key set? It does have some plastic style 1/2 bushings in between the 2 sheaves. Since the sheaves don't move in and out anymore, I could probably measure and make a bushing(spacer more like since it doesn't move) to take up the slack. Any advise or ideas is welcome. I'll buy the sheaves and key if I have to, but really don't want to if I can help it. Thank you.
