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Heavy 10 gearbox

 

Hi group,
Over the years now in then I need the use of my wide rangedouble tumber gear box for cutting screw threads. The problem is I do not have rotation to my lead screw in?
E,F,G speeds only A -D speeds. Could it be a broken key in the 3large power gears? I read some where only the first 2 large gears are keyed.Need your thoughts Bill
 

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??? ??? You might also ask over? here

Lots of South Bend knowledge over there

animal

On 7/3/23 6:05 PM, bill tober via groups.io wrote:

Hi group,
Over the years now in then I need the use of my wide rangedouble tumber gear box for cutting screw threads. The problem is I do not have rotation to my lead screw in?
E,F,G speeds only A -D speeds. Could it be a broken key in the 3large power gears? I read some where only the first 2 large gears are keyed.Need your thoughts Bill
 

Bill,
Those gears that mesh with the tumbler gears are not keyed to the shaft. They are part of a progressive reduction as they go from the input end of the gearbox to the center. That tumbler selects where you are tapping into that reduction chain and then it transfers that rotation via the tumbler gear shaft over to one of the cone gears in the other half of the gearbox. If I remember right, you have pairs of gears tied together -- a big one and a little one -- to get a reduction and then motion is transferred between these gear pairs back and forth from one shaft to the other. The result is that as you get closer to the center of the gearbox, the reduction causes the gears to be spinning slower at each step. So E, F, G are the slowest (most reduced) positions.

I don't remember how the gear pairs are held together -- maybe they're pinned. So if I got this right, then maybe there's either a stripped gear that's ending the reduction chain, or possibly one of the pairs' coupling (pin?) is broken, which could also end the reduction chain.

You should be able to unplug your lathe, make sure your apron is in neutral, engage the lead screw select lever to either forward or reverse, turn your chuck by hand, and you can peek into the bottom of the gearbox to see where the motion is stopping and whether it's a stripped gear.

If you've never cleaned and re-felted your gearbox to assure that everything is getting lubricated, this might be a good time to do that. But it takes a lot of disassembly, possibly including removal of the headstock. I recommend the Ilion book & felt kit if you do this.

John
 

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About half way through,Steve Wells, shows how to rebuild a Heavy 10 GB.?


Jim B,

_._,_._,_

--
Jim B

_Steve Wells Heavy 10 Restoration-Part 2.pdf
_Steve Wells Heavy 10 Restoration-Part 2.pdf

 

Where can we find the first part of the Steve wells rebuild pdf?
 

Bill,
Are you sure about E,F & G not working or could it be just F & G? ?I think F & G share one compound gear and I can see losing those two ranges if their?compound gear has a problem. ?If you lost E as well, I’d think D wouldn’t be working also.

Thanks,
George H. Meinschein, P.E.
Firearm and Ballistics Engineering LLC
150 Brittany Drive
Freehold, NJ 07728
gmeinschein@...
Cell#: 732-580-1736


Sent from Proton Mail for iOS


On Mon, Jul 3, 2023 at 9:05 PM, bill tober via groups.io <iwirewrt@...> wrote:
Hi group,
Over the years now in then I need the use of my wide rangedouble tumber gear box for cutting screw threads. The problem is I do not have rotation to my lead screw in?
E,F,G speeds only A -D speeds. Could it be a broken key in the 3large power gears? I read some where only the first 2 large gears are keyed.Need your thoughts Bill

--
-George M.
 

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It’s on the Southbendheavy10 group, in the files section. In a subdirectory containing files from the old southbendheavy10files group.?


Jim B,

On Jul 4, 2023, at 10:13 AM, Robert Bradley <rcbradley@...> wrote:

?Where can we find the first part of the Steve wells rebuild pdf?

--
Jim B
 

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I second the ilion book

animal

On 7/3/23 8:29 PM, John Burt wrote:

Bill,
Those gears that mesh with the tumbler gears are not keyed to the shaft. They are part of a progressive reduction as they go from the input end of the gearbox to the center. That tumbler selects where you are tapping into that reduction chain and then it transfers that rotation via the tumbler gear shaft over to one of the cone gears in the other half of the gearbox. If I remember right, you have pairs of gears tied together -- a big one and a little one -- to get a reduction and then motion is transferred between these gear pairs back and forth from one shaft to the other. The result is that as you get closer to the center of the gearbox, the reduction causes the gears to be spinning slower at each step. So E, F, G are the slowest (most reduced) positions.

I don't remember how the gear pairs are held together -- maybe they're pinned. So if I got this right, then maybe there's either a stripped gear that's ending the reduction chain, or possibly one of the pairs' coupling (pin?) is broken, which could also end the reduction chain.

You should be able to unplug your lathe, make sure your apron is in neutral, engage the lead screw select lever to either forward or reverse, turn your chuck by hand, and you can peek into the bottom of the gearbox to see where the motion is stopping and whether it's a stripped gear.

If you've never cleaned and re-felted your gearbox to assure that everything is getting lubricated, this might be a good time to do that. But it takes a lot of disassembly, possibly including removal of the headstock. I recommend the Ilion book & felt kit if you do this.

John
_._,_._,_

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