Detent for feed reverse lever

Here's something that might be of interest to owners of the smaller SB lathes that use the old style feed reverse lever -- the one that uses the square-head bolt to lock in position.

Since I had the headstock for my 9A all taken apart, I decided it would be a good opportunity to make a couple of small improvements to the feed reverse lever. One thing I don't like about this style is that you have to kind of guess where the neutral position is. There are adjustable stops in the forward and reverse positions, but when you want to take the feed out of gear, you have to just kind of feel around for a position between the two extremes. It's not a big deal, but I decided it would be nice to have a detent that would center the gear tumbler in the neutral position without my having to guess or look down at it.

So, what I did was to drill and tap a 5/16-18 hole thru the back of the headstock, just behind the reverse lever bearing housing. Note: the feed lever should be removed before drilling the hole! Also, I had to counterbore the hole deep enough to clear the shank of the tap:



I purchased a 5/16 spring-loaded ball plunger from McMaster-Carr. This one has a 6 to 17 lb. end force:



Before installing the ball plunger, I temporarily installed the reverse lever and the spindle to spot the location of the detent on the reverse lever bearing housing using a 17/64 transfer punch. Here's what the ball plunger looks like installed:



I used a center drill to make a small indent on the feed lever bearing housing at the previously located point:



The feed reverse lever was then reinstalled in the headstock, and the ball plunger adjusted for a good "feel", then locked in place by jamming a 5/16-18 set screw in behind it.

The detent works very well! It gives a positive indication by feel when the lever is perfectly centered between the forward and reverse positions. An additional improvement I made was to replace the square head bolt with a large wing bolt, so that the lever could be tightened without having to grab and fumble around with a wrench:



A simple little improvement that doesn't take long or cost very much.

Paula

Uh oh, the wingnut isn't stock there....



Jim

Aha! Caught you not reading my post...



It clearly says:

An additional improvement I made was to replace the square head bolt with a large wing bolt, so that the lever could be tightened without having to grab and fumble around with a wrench.

Click to expand...

Paula

"A simple little improvement that doesn't take long or cost very much"

Paula, you're "too cool for school"!

My next project: adding Gits Bros ball oilers to the carriage of my Logan 10 x 20.

Jim, at least Paula's wing nut is a casting, in keeping with most of the rest of the machine.

I read the post!

I guess I'm just heavily conflicted on this.

I really like the style of the square SB
nuts - but I do think the need to use a
wrench to swap the tumbler gears around is
a huge pain.

I think they did that (instead of the brass
handled plunger detent setup on the 10L) to
save costs, but maybe also to prevent novices
from trying to change the tumbler gears while
the machine was under power!

I suspect the wingnut would likewise be a
deterrent to doing that....

Jim

Paula,
Are you kidding me? That looks like a brand-new lathe! I've already read your other posts, but I just can't get over how good it looks. I find myself not reading the text of your posts because the pictures look so good! You should put all of your pictures into a gallery somewhere, unless you already have and I didn't read it because I was distracted by the pictures

Hi Justin,

Thanks for the kind words. Yes, I was very fortunate that this lathe has seen very little use in its 58 years. Fixing it up has been easy so far, requiring little more than elbow grease (and a lot of patience!).

The gallery idea is a good one. I'm reluctant to post too many hi-res pictures on the forum here because it slows some computers way down. But maybe when the lathe is done I will look into your idea, or maybe just post the individual links to the pictures, like you did.

Thanks again.

Paula

Jim,

Don't worry, I'm going to hang onto the original square-head clamp bolt. Note that the wing nut I'm using is actually a wing bolt. The screw and wing part are a single iron casting. I think you're right -- the design of this lever was a cost-saving move by SB.

Peter,

Good luck with your carriage oilers. I just finished installing the ones for my 9A. Will post a picture when I get a chance. They turned out nice.

Paula

Paula,

I noticed in pictures from your rebuild thread, it appears that you changed to the later headstock casting that has the forward/neutral/reverse detents, leaving me a bit confused. Were you not pleased with the mod outlined in this thread? I am just curious as I was thinking about trying this modification to my headstock.

Additonally, when you drilled the hole for the ball detent, did you use a hand drill or go to the effort of setting it up on your drill press?

Thanks for your help.

Brad

Thanks for your help.

Brad,

The detent idea worked fine, but its need was superceded when I decided to add a detented feed-reverse lever. I still used the tapped hole to install a dog-point setscrew for positive retention of the lever assembly.

The details are a bit fuzzy now, but I believe that the headstock was setup on the drill press for drilling the ball detent hole.

(Incidentally... it is unfortunate, but the thread linked to above has been eviscerated of the original poster's pictures, though the ones I added are still in place. Bruce, if you're reading this, I will be glad to host your pictures for that thread -- or any other -- if you want to forward them to me.)

Paula

Wow! Nice work.

Paula,

I'll put those pics back up as soon as my host comes back. I think they're experiencing technical difficulties.

"eviscerated" Not too often you hear that word. Very nice.

My ISP is working properly and my pics are back in this 10K Reverse Lever Adaptation Thread.

Paula, I'm currently OK, but if I run out of room again, I'll take you up on your offer to host for me, OK?

Thanks, Bruce! That's a very useful thread.

Yes, just let me know. I'm nowhere close to using up my available picture-hosting capacity.

Paula