10k Reverse Tumbler On A 9in South Bend Lathe

The pin will keep from moving out there a friction ring on the lever that hold in place when you moving the lever
This same way the 10K has it.

Dave
 
I get your question now. I don't have an official answer for you and am also curious. One thing I know is that if you take the head off- the bore that the tumbler fits into is accessible from the bottom. So conceivably you could thread the end of the tumbler shaft and put a washer/bolt on there to hold it in. I do have a 10K tumbler, but don't have a picture of the end of the shaft to see if it's threaded or not. I do recall a retention ring on the end though. Perhaps that's enough?
59_zpsj5d3x1qo.jpg

Of course, as I'm sure you well know, originally it was held in by the square bolt itself that you'd loosen to adjust the Fwd/Rev position:
DSC_2339_rdc_zpsggkncevv.jpg
 
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Smithdoor said:
The pin will keep from moving out there a friction ring on the lever that hold in place when you moving the lever
This same way the 10K has it.

Dave
Click to expand...

Dave,

Thank you!

That was what I wanted to know. I see the friction ring on the 10k lever but was not sure. i never worked on a 10k but wondered if it went all the way through and locked or if it locked in with the friction of the ring when moving it and the pin will help hold it while running.
 
wildo said:
Ah..... Mark- here's the answer to your question. This guy used a split ring on the back side of the plate:
http://www.practicalmachinist.com/v...ng-renovation-270736-post2112453/#post2112453

EDIT- here's another option where a grove was machined into the tumbler shaft, and a dogpoint setscrew as used in the head casting.
http://www.practicalmachinist.com/v...installed-9-abc-129098/index2.html#post589472
Click to expand...

I saw that post where he cut a recess in the plate and cut a groove in the shaft for a snap ring. He mentioned also that that was overkill and wasn't sure it was needed. I have a snap ring but did not want to cut the groove in the shift lever unless it is necessary. I don't want to drill extra holes in the head stock either if not needed.

I am going to try relying on the friction ring. If that doesn't do the trick I will probably go with the snap ring.
 
Yes does work it how mind is day back in 2006 and working great
I agree friction ring is ??? but it works

Dave
 
I have a 1974 SB 10K and here's the reverse tumbler:

tumbler_1.jpg

You pull the selector knob pin out of one of the holes and then pull the whole reverse tumbler assembly away and out of the headstock.

It's that simple.
 
image.jpeg I started making the plate for the 10k tumbler. I bored the hole, and have the basic shape. I am now facing it to thickness. I installed the tumbler and measured for the thickness. It came out to .385". I will make it .390". I had a piece of cast iron left from another project so I am making it from that.
 
I finished up the tumbler conversion today. I didn't take a lot of pictures cause it got frustrating and I forgot :(.
image.jpeg I finished machining the cast iron plate thickness to .400". I used a flat head screw to fasten the plate and if I knew how hard that was, I would have used a regular bolt with a thin head. The flat head screw had to be drilled EXACTLY on location because the taper countersink will pull the plate and bind everything if it is off just a few thousandths. I had to do a little work to fix that.

image.jpegI took the plunger out of the tumbler and put a 1/4" ID X3/8 OD steel bushing in it to drill the holes. I have. Long 1/4" center drill I started the holes with. They came out perfect.

image.jpeg This was not a hard job but a tedious one. I am really glad I did this. It is so much better.
 
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