Lathe back gear questuon

[Batmanacw]

This is the eccentric on my lathe back gear in the off position. There is no stop to limit travel. It might have been removed during modification to add the gearbox.



The way the lathe came the lever lifted to turn the eccentric counter clockwise to engage the gears. The problem is that the pressure on the gears will push the gear back out once there is a load. This could lead to the gear disengaging while in a cut.

I can set it up to engage clockwise. This pulls the gear into the spindle gears as the load increases. I have to be careful to limit the travel so the gears don't lose clearance and lock up the mechanism. If there was too much force it could cause issues.

Which way does this eccentric normally turn to engage properly?

 

[Ulma Doctor]

Not knowing the book of Hoyle adjustment specifications,
I would loosen the eccentric retention screw and shift the assembly into the engaged position with a slip of paper between the mating gears, then tighten the retention screw and test by hand after removing the slip of paper.

 

[Batmanacw]

I figured someone with an older back gear lathe would look at their's and advise.

 

[Batmanacw]

I figured the back gear situation out.

I spun it around so the gear is being pulled up by the main gear. This way the back gear won't push up and out in a heavy cut.

I made a solid stop for the handle at the spot when the backlash in the gear mesh was just right. I found tapped holes for set screws clamping the eccentric at the right spot. I used nylon set screws so I won't damage the brass bushing. I can set the back gear and lock everything nice and snug.

I can also lock the back gear in the off position. No worries about it moving without permission.

I should see if I have some knobs I can use instead of needing a hex key.

 

[Batmanacw]

I finally received the knobs I ordered to lock the back gear eccentric. There is a chunk of brass under the screw to protect the eccentric. The little knobs worked okay....



The blue washers are the handle stop that sets the gear clearance properly.



The only problem is I couldn't put enough gronk on the little knobs to get the eccentric really snug. I went back to the huge ugly knobs I had. No worries about it loosening with vibration.



Here is the handle in the back gear position.