Lathes with Auto Change-Gears?

[Ray C]

Hey Folks,

Wasn't on the list much yesterday -had a job that required 4 different thread pitches... And speaking of that, words can't describe how little I care for changing thread gears. Which manual lathes out there have "automatic" gearboxes" where you don't have to remove/replace gears? -Just curious...


Ray

 

[Grumpy Gator]

My pre 1930 sidney has a lever to change TPI.
******Just Saying**********Gator***********uch:

 

[4GSR]

There used to be a lathe manufacture that had a QCG box that allowed you to change feeds/thread pitchs on the fly without stopping the spindle. You just rotated a dial to the pitch you wanted and off you go. My L & S Model X will almost allow you to do that.

 

[OlCatBob]

I have a 1920's Rockford 14x36 that has a gearbox; at least I think it's a 20's model...
Bob

 

[tripletap3]

I have never seen a medium to small size engine lathe that will do a full range of standard and METRIC threads without some gear changinging. I have seen some threading lathes and some of the newer Grizzly South Bend named lathes that will, but you better make some more room and it's gonna cost you. $15,000 might get you started.

 

[OrangeAlpine]

I'm far from being an expert on the subject and its been ages since I stayed at a Holiday Inn, but the commonality of feed gear boxes seems to be related to lathe size. They are rare on really small lathes, becoming more popular as you go up in size. By the time you get to 10"-12", they are practically standard equipment on almost any lathe made in the past 75 years.

Bill

 

[Ray C]

All,

I'm not familiar with the QC gearboxes common to many of the older lathes but I was under the impression they were just for changing the speed of the leadscrew or feed-rod and are used in-conjunction with the triplet set hanging off the motor assembly that sets the ratios. Please straighten me out here.

Anyhow, my Dad's old 16x54 LeBlond didn't require changing of gears. Just flip some levers as I recall -but it's been a long time...

Not thinking about a new lathe but curious how such an important aspect of a lathe still requires a cumbersome manual switch-over.

-And no matter how you slice it, metric is a pain unless you have a metric leadscrew. I'm wondering if I can get a metric leadscrew to avoid doing the "kill & pull-out" method. I had a shaft the other day with threads up against a shoulder. Pulled it off without incident but had to go really slow.

Ray

 

[tripletap3]

) Bill,You missed my capitalized text. Metric threading in "most" lathes will require you to change gears, if you can do it at all. Same with real fine and coarse pitches. Most older American machines were not originally equipped to thread metric. There are however aftermarket transposing change gears that you can use but they don't always make perfect metric threads, and with the case of my Atlas they were a big pain to use. Much more of a pain than my PM1236 is. I am not sure how the older South Bends do with the metric transposing gear sets but you still have to change several gears. It seems to be that the wider range of standard threads and the addition of metric threads in newer lathes you are going to be changing something unless you have a servo motor driven tool room or threading lathe.
Ray, I have always wondered the same thing. You have to be on one side of the fence or the other. Little Machine Shop sells a small hobby lathe that has some sort of changeable lead screw that converts it to metric? I have also seen a accessory thread dial from the UK that reads a metric lead screw and will work on imperial threads but not the other way around. Well at least you have a foot break on the PM1236.

 

[8ntsane]

Hello Ray

Im not sure if your talking about a machine that does both American and Metric threads without swapping gears. I believe a German make called Meusuer, I am certain the spelling is not correct. They apparently have the ability to do both with only setting the control levers in proper position.

Though I am aware that many lathes of older variety required changing gears to achieve the proper ratios, but even many of the older machines had a full quick change gear box. These machines would do the full spread of US threads without gear swapping. With the US leadscrew, your back to swapping out gears to go metric. The Metric conversion gears, with one other gear in the mix to get the metric threads your looking for.

These type of machines also need the conversion chart shown in the paper back written manual to choose the proper tooth count to use with the conversion gears, and to get the proper lever selection as well. For the machines that have the US gear box, and leadscrew, and need the metric conversion, the ELS, electronic lead screw, is one way to go. This setup can also be installed on machines with no QCGB , and cut both metric and US threads.

The company Automation Artisans sell the ELS, and also on Yahoo groups.
Might want to check into that method if swapping out gears is getting old for you.

 

[Ray C]

)

... stuff snipped...

Well at least you have a foot break on the PM1236.

Yes, and I used it a heck of a lot doing that metric thread butted-up to a shoulder. Nerve racking! I'll say it again, Nerve Racking...


Ray