need help with 9" Model C assembly

I have almost completed assembly of my lathe. It is a Model 415, I think from 1952. I am assembling the banjo with the change gears. The reversing gears do not align properly with the change gears. I must be doing something wrong, but I cannot figure out what it is.

The upper most gear on the banjo, the compound one - try flipping that around so that the small gear is facing out. Some ratios, i.e. fine feeds/threads, will require you to mesh the screw gear and the smaller gear on the compound; to do so, you would remove the spacer that you have between the nut and gear at the end of the leadscrew, put that spacer on first, then the gear, then the nut. I don't see the end cover for the gears - that's where the chart for applying the change gears is usually affixed.

Paul

paulsomlo said:

The upper most gear on the banjo, the compound one - try flipping that around so that the small gear is facing out. Some ratios, i.e. fine feeds/threads, will require you to mesh the screw gear and the smaller gear on the compound; to do so, you would remove the spacer that you have between the nut and gear at the end of the leadscrew, put that spacer on first, then the gear, then the nut. I don't see the end cover for the gears - that's where the chart for applying the change gears is usually affixed.

Paul

Click to expand...

Paul, I took off the cover while I was working on the gears. I was following figure 3 on the cover regarding the position of the 80-tooth gear at the bottom arm of the banjo and the 72/18?-tooth at the top arm of the banjo. I'll look at moving the spacer and flipping both gears, but I think that will move the 72/18 gear too far towards the headstock.

Here's what you're after:

The 80 tooth gear that you want at the bottom of the banjo is the one that has the hub, and no keyway, might be marked as "33NK1". Hub is facing in.

Maybe you need to adjust the location of the headstock on the bed?

If you can't figure it out, I've been through it a bunch of times, and I'm local.

I had something similar happen to me. Some of the parts looks similar size. Only thing that saved me was when I dissassembled everything I took a lot of closeup digital photos, which came in critical later.

You need to move the headstock towards the tailstock slightly, so that your first gear on the banjo can pass outside the stud gear.

allan

Yea, I should have thought of moving the headstock. I moved it and the gears line up fine, but the end of the headstock is 0.3 inches past the end of the bed. This is not a concern, but it does not seem right. Also, at that point the reversing gear casting interfered with the round guard on the banjo. From what I have read the Model C usually did not have the round guard, but my banjo has tapped holes for it. I took it off for now. If I decide things are assembled correctly I can make a small notch in the guard and it will fit. I suppose it may fit fine with other gear combinations. I end up taking off the 72/18 compound gear because there was too much play. The hole is apparently worn.
I think the previous owner dealt with the problem of what oil to use by not using any!

The headstock should be within maybe 1/16" of the edge of the bed.

Put the 80 tooth idler on the upper arm of the banjo, with the hub facing out as in "figure 2", then adjust the headstock.