Am I Adjusting My 5C Lever Collet Closer Lock-Up Correctly? Video Included

[Jaylude]

**Skip to my youtube video link if you don't want to read my description below - it basically shows me going through the same question I typed out below**

Hey everyone,

Thanks to some valuable input from the folks here, I've got my 10L 5C lever closer ready to install and use for the first time.

All parts on my unit are OEM South Bend, and all parts move freely and function correctly as far as I can tell. I fully disassembled, cleaned and lubed everything, and fixed a couple of issues up to this point with the drawtube itself and a stuck clutch stop.

NOTE: I do not have the unobtanium special backgear with the extended sleeve and broached keyway that mate with the lever closer clutch stop, as my lathe didn't come with one. My plan is to eventually machine and press on a sleeve, but I don't believe that it is necessary for basic setup and function testing of the lever closer, which is all that I'm trying to accomplish right now.

I was struggling for a while with getting the expected "lock up" and cam action, which seems to be a theme from some other threads I dug up here. But I think I figured it out. Just want to make sure I'm doing this correctly, as I can't seem to find any good existing videos on youtube showing setup and operation.

What I believe is done to set the lockup/camming action is simply loosening or tightening the drawtube itself into the 5C collet, via the collar that is installed on the end of the drawtube (part #30 in the SB literature). That collar is threaded onto the drawtube and held to the tube via a set screw (#9) and shoe to prevent damaging the OD threads on the drawtube (#8). I find that if the drawtube is too loose in the collet, then the yoke cone (#35) will contact the nesting collars (#30/31) without lockup. If I have the drawtube threaded too far into the collet, then I can't actually get the yoke cone to even contact the nesting collars. If I have it just right, I get the expected camming action and then the lever smacks past the cam point, and into the nesting collars and stays in place.

Is that correct? I uploaded a video to youtube here showing what I am speaking about above:

What's the purpose of adjusting the location of the nesting collars? It seem like they just act as backstops for the yoke cone after it cams past center, vs actually having any influence on the lockup strength.

 

[jim rozen]

1) get rid of the protruding screws on the knurled handhweels. Please

The reason there are two collars can be understood by inspecting the part number 32 on the diagram above, in your setup. As in, it's not there. The pin which was designed to be pressed into the 35 part, and allowed the user to set the lockup point and hold that, when doing repetitive work. You'll find that when doing many of the same size part, when the lathe starts and stops, it will creep that setting a bit and you have to reset it for each part of the same size.

Because most users don't do production runs, and the set screw that's supposed to lock 30 to 31 has to be slacked to change collets, they pull that pin number 32 out. You'll see the hole where it went in 35 if you look close. Basically just put allen head setscrews in both of the knurled handles, lock them together and use as one.

I think maybe you need to move the knurled handles a bit to the left, I seem to recall that 35 is not supposed to bottom on them. I'll check mine when I get home tonight.

 

[Jaylude]

Jim - thanks for the reply. And yes, I'll get that fastener out, ha! I don't know why the previous owner added it. I haven't actually spun the closer up under power yet.

OK, I think I follow what you're saying and this is all starting to make more sense. The pin (#32) sits in the keyway of collar #31, which nests onto collar #30 and can be pinned in place onto collar #30 via setscrew (#11). If you get lockup just how you like it in a production setting and want to prevent the drawtube from loosening or tightening in the collet, then you lock #31 to #30 via setscrew #11 so that the index of the drawtube is essentially pinned in place via the pin #32.

I was thinking that the location of #30/31 along the axis of the tube was what was controlling the camover/lockup. In reality, they're just used as a means to keep lockup consistent in conjunction with pin #32. The camover/lockup is solely a function of how far the drawtube is screwed into the collet.

So in reality, the only function of #30/31 is to work in conjunction with that pin #32, and I guess the knurling helps you thread the drawtube into the collet a little easier. You could actually run the unit without #30, 31 and 32 though and it would still be totally functional!

Let me know if everything I'm saying is accurate...I think it is.

 

[jim rozen]

OK, did some checking. The draw tube by itself is 17-7/8 end to end. The handle on the end adds 3/4 inch.

When my collet locks up, there really is no space between the outside of 35 and the inside of 31. I even loosened the two setscrews and shifted the entire thing left by 1/16 inch or so, still pretty much in contact when locked up. So my initial guess (space in there) was wrong.

 

[Jaylude]

Thanks Jim.

One last question, what's the actual purpose of the extended spindle reverse gear sleeve/keyway? I'm not sure I really follow what it does/accomplishes. When I lock up the closer lever, #22 is tightly pressed up against the back end of the spindle and rotates with it anyways.

 

[jim rozen]

It's a belt and suspender thing. The OD of the drawbar is a bit less then the ID of the spindle bore, so the closer can wobble around in there a bit. The key on the closer does engage a keyway inside the longer gear, but as you say it really does not have a lot off force on it while in action. Probably it was more important when that pin was in place, and one wanted to keep the exact setting for the collet, during production work. If the closer rotated in relation to the spindle, it would alter that setting. Often machines are run with the spindle under power while the parts were changed.

 

[Jaylude]

Makes sense. I guess I'll have to decide whether I want to go through the trouble of machining up the sleeve, or just leave it as is.

 

[Jaylude]

Alright, one last question!

How did South Bend expect you to tighten the two set screws #9 to lock threaded collar #30 to the drawtube, when collar #31 obstructs access to those setscrews? I can't slide #31 far enough towards the clutch mechanism in order to gain any access to those set screws.

 

[jim rozen]

Take out setscrew 11, the two smaller setscrews will be visible in the resulting hole.

 

[Jaylude]

That's using your head. I'm kind of embarrassed at that one, jeez. Maybe I should go back to woodworking.

 

[jim rozen]

It was a whacky design. Sort of a ship-in-a-bottle thing. Took me a few days to figure that out, abut 35 years ago....