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View Full Version : Apron removal on 9X20 Jet lathe



Bob Fisher
10-08-2016, 04:51 PM
Looks like you must remove the lead screw pin at the gearbox,remove the lead screw bearing and slide the lead screw out. You should at this point be able to drop the apron. If I have this wrong, jump in and set me straight. Thanks, Bob.

RB211
10-08-2016, 05:07 PM
Looks like you must remove the lead screw pin at the gearbox,remove the lead screw bearing and slide the lead screw out. You should at this point be able to drop the apron. If I have this wrong, jump in and set me straight. Thanks, Bob.

You are mechanically inclined, right? Most people in this hobby are. You'll be fine.

J Tiers
10-08-2016, 05:56 PM
On many, you need only remove the T/S end bearing, and you can slide the entire carriage, or presumably just the apron, off, with no need to remove the leadscrew. You just need to be careful. I'd start with the carriage as far as possible down the ways.

looks like that is possible on the BD920 also. Your choice of methods.

bob_s
10-08-2016, 06:22 PM
As I recall you have to remove the rack.

Bob Fisher
10-08-2016, 07:24 PM
The lead screw has a groove that ends about 2 in from the bearing. That would preclude removing the saddle from the end. I can see no reason to have to remove the rack, as once the lead screw is removed the apron should drop straight down. Am I missing something? If so, feel free to chip in. Bob.

lugnut
10-08-2016, 07:50 PM
I would email Jet's support team and ask them how it's done. Some time back when I was looking into changing the Half-nuts on my Grizzly 9 x20 lathe, I emailed them and they wrote right back with a pretty good procedure on the job. I decided not to tackle the job then and I never saved the email. I do remember there was mention of having to drive out a couple pins that I would have known about otherwise., It won't cost any thing to ask them,

Barrington
10-08-2016, 07:55 PM
This page may be of some help:-

http://www.micro-machine-shop.com/cross_slide_compound_carriage_gears.htm#Half-nut
(http://www.micro-machine-shop.com/cross_slide_compound_carriage_gears.htm#Half-nut)
Cheers

.

lugnut
10-08-2016, 08:01 PM
Bob, I found one of the letters that Grizzly had sent me and I hope it helps you:

Dear Melvin,

Thank you for your email dated November 17, 2014.

You would need to remove the apron from the machine. This is not extremely difficult, but it can be rather time consuming. This would require removing 4 cap screws, and for easier access, possibly the leadscrew, which is pinned in place. Once the apron has been removed from the machine, it is a fairly easy replacement of the half nut.

If we may be of any further assistance, please do not hesitate to contact us. You are a valued customer, and we look forward to serving your future woodworking and metalworking needs.

J Tiers
10-08-2016, 10:26 PM
The lead screw has a groove that ends about 2 in from the bearing. That would preclude removing the saddle from the end. ....

THAT would get fixed while I had it apart...... a little time on the mill and it would go clear to the end!

Does the keyway go clear to the OTHER end? If not, then there must be another way to get the leadscrew out of there.

JCHannum
10-09-2016, 09:00 AM
Barrington's link details the carriage and shows the linkage that prevents engaging both threading and long. feed simultaneously. You would unpin, or disengage the leadscrew from the drive (headstock) end, unbolt and remove the bearing from the tailstock end. Unbolt the apron from the from the carriage and drop the unit, leadscrew and all. The leadscrew can be slid out at this point if needed.

h12721
10-09-2016, 09:21 PM
To pull the Leads screw you knack the pin out and mark the position then losing the right bearing (two screws ) and pull the lead screw out to the right side.
To get it back in is another story. Most likely you will not. since you have to get the key in the worm gear in to the grove of the LS. Besides you could not work on the apron. You better off at this point to drop the front of the apron. To reverse , put the LS back in first and then mount the apron back
And line things back up.
HM