Shifting Tumblers "On the Fly"

D

DanMc77

Aluminum

Joined

Aug 23, 2017

Location

Holden, MA

• Mar 2, 2018

• #1

Question: How many of you shift your tumblers on the fly, while the machine is running? I had done this for years with my little Grizzly G4000 and had no issues, but with the SB13 I want to be a bit more careful. I would never shift the FWD/REV selector since those gears are moving much faster, but the tumbler gears are just putting along.

You thoughts?

 

P

Pathogen

Hot Rolled

Joined

Oct 18, 2016

• Mar 2, 2018

• #2

Keep right on flipping, the time you save is worth the downtime and parts replacement.

 

S

SeaMoss

Banned

Joined

Mar 17, 2017

• Mar 2, 2018

• #3

DanMc77 said:

You thoughts?

Click to expand...

If gears don't like what you are doing they will tell you.

If you don't get graunch noises, it's fine. Otherwise, don't do that

 

C

Caesars0331

Aluminum

Joined

May 21, 2012

Location

Detroit, Michigan

• Mar 2, 2018

• #4

I shift the clutch lever Left/Center/Right while things are in motion. Never wanted to move the tumbler, in/out, for/rev levers unless things are at a stop.

 

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iwananew10K

Diamond

Joined

Sep 12, 2010

Location

moscow,ohio

• Mar 2, 2018

• #5

Overall, a bad thing to do....just a matter of time before Murphy shows his ugly face.

 

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gadget73

Hot Rolled

Joined

Mar 8, 2016

• Mar 2, 2018

• #6

I stop mine to shift the gearbox or the reversing tumbler. Rotate the spindle by hand as needed to get the lever to drop in. The feed lever on the apron is no problem, nothing there is moving if the clutch is not engaged. Its a hobby thing for me, a little extra time to turn off and shift is not a problem.

 

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promacjoe

Stainless

Joined

Jan 10, 2009

Location

Tn USA

• Mar 2, 2018

• #7

This question has been asked several times, and to my knowledge it always comes up with the same answer.

Without a doubt, it's a bad idea. This is not a synchronous transmission. And if you read what it says on your gear plate, it tells you not to shift years while the lathe is running. Or at least most of them that I've seen does. And on some machines such as the 9N You could actually trash the spindle. If that happens you have two choices by a new spindle, or relegated to woodworking. No power feed.

Take care of your lathe, and it will last you a lifetime. Abuse it, and you will have a money pit.

Stay safe and have fun.

Joe.

 

jim rozen

Diamond

Joined

Feb 26, 2004

Location

peekskill, NY

• Mar 2, 2018

• #8

NEVER shift the reverse tumblers under power.

The farther to the right, the more likely you can shift gears under power on the SB
QC gearbox.

I'd say avoid doing that for any of them.

 

M

Mark Rand

Diamond

Joined

Jul 9, 2007

Location

UK Rugby Warwickshire

• Mar 2, 2018

• #9

On the gearbox, you've got a chance, but it's not synchro-mesh and there's no oil to damp things so you will get wear. On the Tumbler reverse gears there is a real chance that you will end up with the gear teeth interfering. You won't break the lever or the gears, but you might make your hand ache.