Stuck spindle gear pin on 618

[Pat of TN]

Stuck spindle gear pin on 618 (Fixed!)

Hey guys. I am in need of assistance once more.I went to engage the back gears on my Atlas 618 today, and for some reason, I can't remove the pin in the large spindle gear. This of course must be removed for the lathe to function with the backgears engaged.Not sure what to do. Usually it takes just a touch of pressure from a screwdriver to push it out, but I can't get it out this time, even with a long screwdriver. I've even flaked off a bit of metal, which is the scary part. The last time I engaged or disengaged the pin was within the last two weekends, so it can't be rusted in or anything like that, and I don't recall putting it in with any unnecessary force the last time.My lathe sits idle yet again. Anyone out there who can assist me?

Update: Problem fixed, thanks HM!

 

[MedfordChris]

I would try grabbing the step pulley with one hand, the bull gear with the other, and rock them back and forth (like wringing out a wet towel). Then give the pin another shot. If it somehow got cockeyed, that might help loosen it up.

 

[Pat of TN]

Well, I fixed it somehow or another. In addition to what has been suggested, I also found a small set screw in the spindle gear. I took it out, and that freed the pin... I did put the set screw back in a little, but I am curious as to what purpose it serves?

Thanks for your suggestions, MedfordChris.

 

[MedfordChris]

Glad you got it working again!

There should be 2 set screws on the outer edge of the bull gear. The one next to the pin is for oiling the bull gear bearing/bushing. It looks like if it is tightened down it would pinch the pin. The set screw on the OTHER side is to keep the bull gear positioned on the shaft, so it SHOULD be tightened down (gently).

Dean has some awesome pictures of this on his Spindle Removal page (5th & 6th pics):

http://www.deansphotographica.com/machining/atlas/spindle/spindle.html

 

[Pat of TN]

Hmm... I see... welp, I got that taken care of too. Thanks for your assistance, Chris. You prevented yet another crisis!

I must say - single-pointing a 1" - 8 thread is pretty rough on a little Atlas. Whew!

 

[wa5cab]

The bull gear doesn't have a bushing. The bushings are in the spindle cone pulley and the small gear, which with the back gear pin pulled out should rotate freely on the spindle. The pulley has one set screw which is actually an oil plug. You remove it to oil the bushings. And then replace it snugly. The bull gear has one #8-32x3/8 cup point socket head set screw over the woodruff key, which should be tight. Before tightening it, you should insert a 0.002-0.004" shim or feeler gauge between the pulley and the large gear and press the gear against it. With the shim removed, the pulley should turn freely if the pin is pulled out. The bull gear has a second #8-32x3/16 headless set screw that slightly compresses the spring which bears against a 1/8" dia. ball which normally sits in one or the other detent grooves in the pin. It should be run in until it touches the spring and then another 2 or 3 turns.

Robert D.