21 Feb from Hartmut
The inner clutch plate is ready for CNCing. I leave the outer clutch plate as is - its strong enough. Will only check geometrically and lighten it slightly. As there is space enough on the splines I could fit another friction disc and steel plate - let me know if you want this and if so send me a friction plate and a steel plate - better two steel plates as one of those that I have here is slimmed down a bit.
The chain tensioner is shaped enough to go into the case without disturbing anything. Had it closed today and was able to turn the rear crank by hand with the chain turning freely - the only rubbing is happening on the tensioner but now that the chain runs on the rib with its rollers it should be smoother than before as there is less shock from one roller to the next. The links were bumping much more into the old tensioner.
Maybe tomorrow I can take the engines apart and do some welding for the tensioner screws and finish it all on the mill. Then its time to finish the outer cover and the left side is done.
Max's reply
I should make you aware of a little background on the clutch plates. When we blew the HYVO chain, and I changed everything over to the monster chain, I had to increase the thickness of the tail piece of the big cover by 1/8". You can see where I screwed the 1/8" plate onto the tail plate of the big cover. I built the first jackshaft, locating the clutch splines on the shaft to accommodate a three friction plate clutch. I felt when the HYVO chain broke, it would be a good idea to make a four friction plate clutch. The stacked height of four friction plates and five steel plates was about 5/8" too much. The 5/8" included the 1/8" I lost on the inner cover. To get the five steel plates and the four friction plates on the clutch shaft, I had to machine the friction plates, reducing their thickness by .050 each. Taking material from each side of the plate by .025. The inner broached spline was also reduced in it's root thickness to prevent tube locking, as I also reduced the thickness of the five steel plates by .025. They were quite warped, and my buddy ground the plates on a huge grinder with a magnetic table. So that reduction in total clutch pack thickness was reduced by .325.
In lieu of all of this, the spline length that you have should not be reduced in length. The outer plate should be made adjustable. When the outer plate bearing comes within 1/32" of tube locking on the spline end. This would be the length of the standoff tubes without any shims. Next would be to determine the length of the clutch studs. A friction plate should be placed on the shaft, the short side of the friction plate broached spline is outboard. Then add the thickness of a steel plate, plus .050, that would be .025 for the removed .025 on the friction plate, and .025 for the reduced thickness of the steel plate. Then with the outer clutch plate assembled, slide the clutch plate on the outer clutch studs and inner clutch bearing. When the pressure plate float plate comes in contact with the steel plate, back off the predetermined .050. Make up various shims. Those are the ones that go between the outer clutch plate and the stand pipe tubes. Enough shims should be made to provide full stroke adjustment of the outer plate. Studs should be long enough to accept adequate clutch stud nuts. It appears the shaft is plenty long enough to thread, make a nut, and revamp the Torrington bearing design to something more robust.
With the clutch plates I have here, many new friction and many new steels, and with the worn clutch plates and turn down clutch plates, there will be no problem coming up with a four plate clutch pack, and maybe even five, as you suggest. I don't think we'll have any problem doing it that way. The clutch plates that I have here probably weigh 100 lbs. So it's my vote that we don't send any clutch plates your way, and just save the money. It would be easy enough for me to stack and adjust the clutch here with the starting clearance of .040 total between plates.
You mentioned that the seals would be good up to 6500 rpm. The clutch turns about 4000 rpm, so we're in good shape there.
Again Hartmut, you're doing some pretty fine work over there. I can't tell you how much I appreciate the time, effort, and expertise you're putting in to the gear train. Looks super strong and bullet proof to me.