The Home Machinist!

I'm getting ready to cut the mid gear notches in the reverse lever for my Kozo A3. He says to put the right side of the engine on either BDC or FDC and adjust radius rod to be level and the reverse lever 90 degrees up and down. I'm guessing if the radius rod is where it is supposed to be, moving the link back n forth will show no movement at the valve, correct?

Where I'm confuse is do I do this for each side separately and then average them? My issue is that if one side is perfect, with no valve movement, the otherside's radius rod is a bit too low causing quite a bit of movement to the valve. Kozo alludes to this but not for the Mid gear section only the sections on cutting the full forward and full reverse gear notches.

ken-

i assume this is Walscheart's gear. if so the principal is that at either dead center the eccentric rod should be adjusted so that the valve has no movement when shifted from fwd to rev. this is what he is saying. in order for this to happen the expansion link must be vertical. the ecc. rod is adjusted to make this happen

the radius rod length should be made so that in neutral, at dead center, the valve is open by the amount of lead. since this gear has a constant lead you can shift the Johnson bar with no movement of the valve. you then move to the other dead center and see where the valve is and adjust the valve stem to make both ends equal.

treat each side of the engine as a separate unit. each side operates independent of the other. they are only connected via the drive axle so you will put the other side on dead center and make adjustments to it just as you did to the first side.

i highly recommend that you download Dockstader's program and study the motion given in the default example. you will understand it better then.
good luck,

_________________
Fred V
Pensacola, Fl.
home track:
http://www.waleswest.com

One possible issue is if the reverse arms are not set at the identical angle then the radius rods won't be at the center point. A difference in the weigh shaft lengths could also be the source of the discrepancy. This would be easy to check.

Thanks. It is Walscheart's gear. I have no control over the length of the radius rod as both are per Kozo's dimensions. The hangers for the radius rod are currently both the same dimension. My guess is that the reverse levers are not exactly perfect and one is slightly lower than the other, for whatever reason. I'll make another reverse hanger to get them to the same heights.

Ken

i would also suggest that you actually RUN the loco (on air if necessary), at each 'corner' to ensure that you are getting the notches in the correct place.

Then find 'center' and again, see if the loco will run there, on air (should not).

There is nothing more embarassing than having a loco, quadrant set on center and throttle leaking a little, drift down the track away from you.

I think I was doing it backward. Kozo says to put the lever at 90deg and then adjust reach rod length until the valves don't move. I was trying to cut the notch so the valves don't move; not easy to do but from what I can tell, even if the valves move a little, say .010" back and forth they still don't uncover the ports.

ken

at dead center and neutral the valve is not centered over the ports. at front dead center the valve should be open by the amount of lead on the front port. the valve will only move a little as the driver turns and close the port so it shouldn't run away. get the Dockstader program.

_________________
Fred V
Pensacola, Fl.
home track:
http://www.waleswest.com