How to properly engage the backgears?

[HMF]

How do I engage the bull gear without locking up the spindle? This is to run the spindle at slower speeds. Someone mentioned pulling a pin or something to engage the backgears. How is that done?

Thanks,

Nelson

 

[Sparkey]

On my lathe a south bend 10 you open the gear cover on the head. On the gear on the right there is a pin that pulls out, you may have to turn the head to bring the knob around for the pin.

 

[pjf134]

My 9a is in the same place as the 10 shown, in case anyone wants to know. Remember to turn off machine before you engage the back gear, and also you might have to move spindle to engage gears. There is an adjustment below the small gear, I think it is to be full mesh and back off a 1/32", I think.
Paul

 

[oscer]

Also at the front end of the spindle and below the back gear shaft there is an adjustment to apply pressure to the bushing of the back gear shaft in case it wants to run out of back gear. in other words if the back gear lever moves back and the spindle stops when you turn on the lathe you need to tighten this adjustment screw. Mine was all the way in and it still ran out of back gear so I made a small brass pin about 1/4" dia.x 3/8" long and put it ahead of the screw.

 

[gary.h]

JUST WANT TO ADD THAT IF YOU RUN YOUR BACK GEAR (oopps damn caps lock)you want to run your lathe at a lower RPM its way nicer on your machine,pretty positive it states that imprtant fact in the south bend lathe book i have,hope this helps.

 

[gary.h]

hello desmocrat,you are right ive ran my back gear on all spindle speeds,but i recall reading somthing as a word of caution about the back gear,not including do not engage while lathe is running,ill go to the books and recheck what i read,and get back to ya,i should of been more thorough in my post"sorry"..

 

[ScrapMetal]

The SB's "How to run a lathe" also recommends that you not use the highest couple of speeds with the back gear engaged.

-Ron

 

[dcms]

Do you know if a 10k has a bull gear pin?

I recently bought a 10k and am spending some time cleaning / understanding the machine before I fire it up.

In "desmocrat's" post he indicated that the spindile would lock up with the back gears engaged and the "bull gear pin" is locked.

I am experiencing the spindle locking (with lathe turned off) when I engage the back gear. I don't know where the bull gear pin, so I don't think I have locked it.

What I do nown is both the spindle and the back gears rotate freely when the back gear is not engaged. When I engage the back gear the spindle locks up tight!

Any ideas what I am doing wrong?

Thanks

 

[mosedawg56]

In order for your backgears to work as intended, you have to disengage the pin in the bull gear. There should be a pin similar to the one in the photo above that will be pulled out, effectively separating the cone pulley from the bull gear. In other words, they should be able to turn independent of one another. Once this pin is disengaged, you then engage your back gear lever and turn on your machine and your chuck will turn at a much lower speed. My lathe is a 10L like the one in the photos, I am not familiar with the particulars regarding a 10K, but they should be very similar.

Edit: Just looked at a .pdf copy of a 10K exploded diagram and it does have a plunger to engage / disengage the bull gear from the cone pulley. It is located in the same place as the 10L pictured.

Pat

 

[dcms]

This site is amazing!

Thanks for the help. Found the pin just as you described. Once it is out, the back gear and spindle turned as intended. I assumed they moved. Just could not figure out how.

I originally thought the pin was an lube hole???? Dumb me!

I have a copy of South Bend's manual on "How to Run a Lathe" but didn't see anything in it about pulling the pin on the bull gear. They probably assume you know something about a lathe to begin with. Bad assumption.

I am really new to this. I am not afraid of it but am trying to be cautious so I don't get into trouble. . I have been looking but have not found any classes on running a lathe. Are there any good courses you can buy. The best thing I have found so far is this site and youtube.

In the interim my plan is to take it slow and tap into users like yourself for advise when I run into a dead end.

I apologize if I am asking stupid questions.

Thanks again for the help.