Good news, it fits with the screws and seems secure. Bad news, it might not do the job. My chain isn’t sticky so a gently held it to the sprocket and the chain decided to just push the protrusion out of the way… I think it’s the base plate being too thin (catch-22). Other problem is that I realized after I installed it, my frame is still pretty much the original stock frame and the motors are at 45-degrees. Therefore, I’ve got the tape measure slot in the wrong spot and the slack chain doesn’t feed cleanly onto the sprocket (more likely to skip with less chain engaged).
So… I think instead the design needs to interfere with the sides of the chain rather than the leading edge. Sort of like a comb. I wonder where I heard that before. Now I understand @blurfl . Anyway, that’s what weekends are for.
I’m going to hold off work on this until I rebuild my frame (might be a while). I can only test on a tilted motor at the moment and most people that have such a frame don’t experience chain-wrapping (i.e., their chains are probably fairly loose by now)
@madgrizzle I was just reminded in another thread about chain skipping. It would be a nice feature if you could incorporate a wall around the top of the sproket close enough to the chain so that if it tried to skip it would hit the wall and not be allowed to. Would love to get your CAD file for this if you’re willing (.stp). Is your idea in the community garden?
The design, as it is, doesn’t work. If you are are starting calibration and the first chain link sticks, the chain link will push the guard out of the way and continue to wrap. I don’t know if it would prevent wrapping of subsequent links as I stopped testing it. I think the design needs to change to try to pull the link off the sides of the sprocket as well (like a comb). I need to rebuild my frame to use this design (as shown in the picture above, I forgot my motors were at 45 degrees) so I’ve kind of stopped working on it for the time being and wouldn’t recommend using it.
Edit for new wood chippers: We had all the time we needed to move the ladder from the left sprocket to the right while left chain was feeding out. We just didn’t know it unit the right chain started feeding.
A random thought: if we find it hard to build a device that can reliably detach a chain from a sprocket, could we design a device that could at least detect that problem to signal to the controller to stop before damage is done?
