Will heavy 10 gearbox fit on a 9" junior?

I have a 9" Junior change gear lathe. The bed seems to be the same size as my heavy 10. A friend has offered me a basket case heavy ten with a bad bed but many good parts. I would love to fit the QC gearbox to my 9" junior. Have any of you done something like this?

Ooooh..... I have a 9 Jr and I've never entertained the idea of fitting a QC gearbox to it. While the 9Jr and the Heavy 10 have a similar bed configuration, there's a lot more.....a whole lot more stuff to consider.

First you say yours is a change gear lathe. That means that there is no provision for power cross-feed or longitudinal feed in the apron of your carriage. Given that, I'd ask what advantage you think you'll have by going to the QC gearbox if you can't use power cross-feed nor the power carriage longitudinal feed. And, you don't have a lead screw with the slot milled in it to drive the "works" inside the apron used for the power feeds. You'd have to mill the slot in yours but it would still be the wrong length for a QC gearbox. Or perhaps you could find another lead screw with the slot in it and get it to fit your lathe with the QC gearbox on it.

As if that were not enough, I seriously doubt....but don't know for sure.....that there are drilled holes in your bed that you can use to attach the QC gearbox to the bed.

If you want a power feed lathe, then that's what you should go buy. Changing yours over is going to be a nasty project with not very good chances for success.

There is nothing you can't do with your change gear lathe that you could do with the QC gearbox addition. It may take you longer but you can do it.

I find the 9 Jr. has its own charm the way it is. I'd hate to tear it up with a project like you're suggesting.

The 9" is in nice shape so I am not rushing to wreck a nice lathe. My nomenclature is likely not correct as It happens that there Is already a lead screw on the lathe and it is set up for longitudinal feeds, though it does not seem to have power cross feed.

Given that, a quick look suggests that the conversion might almost be a bolt-on conversion...so i am curious if anyone here had seen or done something like this.

Thanks,
Joe

A 9 Jr does not have long feeds, it uses the halfnuts to cut a very fine thread. The fancier models used a worm driven by a slot in the leadscrew to turn the carriage handwheel instead. This saves wear on the halfnuts, and gives a much finer feed due to the gear reduction in the apron.

In the end, I think you will need a single tumbler gearbox that is similar age to your lathe. On most of the 9 Jrs and Series O lathes, the leadscrew is closer to the bed side than it is for the later 10L and Series R/S/T type lathes. What year is your lathe?

allan

Hello Allen,
Thanks for the insight. It seems to confirm Dobermann's point so I'll just leave it alone. It is a nice and pretty well tooled up lathe that will be great for my boys to learn on someday. I have an excellent heavy 10 for my own work. This one is serial numbered 51921.