Problem shifting power feed on Hendy Tie Bar

I have a 1915 Hendey 12 x 5 in real nice shape. My problem is when single point threading under load it is hard to shift the feed to neutral. What happens is the feed handle will fly thru neutral and slam into the opposite feed direction. WHAM. It makes me shutter.

Right now my approach is to duplicate the Mercruiser interrupter switch technique. This momentarily cuts power and unloads the dog for an easy shift. I just have to figure out the details.

Anybody have a better suggestion?

Pete

Could you make a stop that would stop the lever when it was in the neutral position that you put on when you are going to thread? Do you need some lube on the ways or in the half nuts or leadscrew so things move easier so the load on them is less?

What's the problem with it reversing direction? Just back the tool out a bit, let it reverse and then feed the tool back in and take another pass.
Are you manually moving the lever or are using using the stop block? I find using the stop block works much better, little to no chance of it going through neutral into reverse.
After rebuilding my Hendey it was difficult to operate the feed handle under load but it loosened up over time (and of course... lots of lubrication of everything).

Another thought... you say "WHAM"... what is your spindle speed? Even in a complete change of feed direction I don't get anything that I'd call a "WHAM". Maybe just going a little fast?

"Whamming" - if the actual case - is a sure fire way to ruin that jewelry underneath the head stock. Think slow - always. Seems reasonable for a machine 104 years old

A while ago these Tie Bar Hendey were everywhere so every time I seen one I purchased it. Seems no one wanted them and most of the shops were buying gear driven machines. I didn't have a machine shop but liked to work and run lathes, my father was a tool and Die maker. I guess it was in my blood! I would buy them fix them up for the hobbyist or guy that wanted a lathe in their garage or basement. I would keep the best ones for myself only keeping one of each size and sold the duplicate. Eventually I started a Machine shop and I too graduated to the gear driven lathes. I currently have 4 Gear drive Hendeys. Would have had 5 but sold my 16" Hendey to make room for a 16" P&W.
Back to the topic, I onetime bought a Hendey that did as the OP mentioned. Someone welded then re-cut the dogs on the reversing mechanism, possibly because they were rounded and slipping. Also the clearance between the gear and the hub was almost zero. In doing so the faces of the dogs on the bevel gears and the driven shift hub had a "positive rake" so when engaged the dogs pulled themselves together. That lathe did have a thread dial so the half nut I assume was used not the reversing mechanism. However if disengaging the feed it was difficult and more so when the load was higher like in threading. Simply because of that "positive rake". The force needed would cause overshoot and instead of neutral it was pulled or pushed into the other direction which too had the dogs cut positive and whey would also be hard to disengage. I re-cut the dogs neutral though with a very slight positive angle. Worked fine, I removed the thread dial and mounted it on one of my Keepers. (Lathes I kept for myself)

Here’s one.
Hendey 6X16 metal Lathe - US $250.00 (Hague, VA) | VintageMachinery.org

WdTom

A neutral stop is a possible choice but it might be tricky working out a convenient release.
Pete



RCPDesign

Using the stop blocks is probably the best idea and it requires no modification.
Pete



Johnoder
Slow is indeed good, too slow is not. Remember that when you WHAM a shift your bevel gears are out of sync by times 2.
Pete


Froneck
It must have been a devil identifing the dog positive relief.
Pete

To check if you have positive relief turn the spindle by hand with the reversing mechanism engaged. Be sure the lead screw turns. with pressure on the spindle to prevent it from turning look at the output gear from the reversing mechanism and slowly disengage. If the gear turns slightly then there is a problem. Look close it will not move much. The one I found had quite a bit of positive "rake". I'm thinking it slipped out one time too many and screwed up one too many threading operation so it was "fixed" so it would never happen again. Good if using the half nut and thread dial. I guess you can put an indicator on the carriage, select a very course thread, en gauge the half nut and turn the spindle as I mentioned until the carriage moves. Then disengage the same way preventing the spindle from turning and see if the carriage moves when the dogs disengage.