| Apron Key (Jul 22, 2004) |
Why doesn't my key fit?
(Nov 7, 2004) |
| |
| Apron Key |
| The 9" lathe I recently acquired had no key in the worm to fit into
the keyway of the lead screw. I purchased one through LeBlond with
some other stuff I needed. I have never installed one before and
don't know how to make it stay in the slot of the worm. When I move
the apron to the left it falls out. Henry
(20142) |
| It has to be pinned. Looking at the
back of the apron , (right hand side) There is a round nut with a
hole in it. this should line up with a hole in the screw. Then there
should be a hole in the key . The pin should be tight in the key and
is slipped through the other two holes. (20143) |
| Dunno what model Henry has. If it's
an older one (JR, 82, etc) this key is "U"-shaped, looking like a
piece of a Chinese puzzle, and to install it, the apron has to be
run off the lead-screw. The horns of the U keep it from leaving the
worm gear. If he's getting his parts from LeB, he must have a later
lathe, though. I thought I'd put this post here "for the archives"
if anyone comes browsing through later. Dave (20161) |
| Why doesn't my key fit? |
| I have several Jacobs chucks in my shop. I also
have an assortment of keys. #'s 1 to 3. The chuck for my lathe
tailstock is marked 2A (3/8"chuck), and came with a #2 key, but it
doesn't fit. The pin fits the hole, but the gears don't mesh right.
No visible damage to the chuck gearing, and I tried several of my
serviceable keys. I think I have the wrong key, not a damaged chuck.
The # 2 key fits the 2B chuck and a Rohm chuck just fine, and the #
3 key fits the headstock chuck and the 6A chuck on my dill press.
What is up with the weird key for the 2A chuck? What do I need? What
do I tell my BIL to get. (He's in tool sales.) I'm tempted to swap
the Jacobs for a Rohm I have in the drawer. I'd trade it for the 2B,
but the 2B has a tapped end, and I need a JT. So, the follow up may
be: How do I get the Jacobs chuck off the JT/MT shaft if necessary.
Mike (21826) |
| Check out McMaster-Carr for a listing
of chucks keys... http://www.mcmaster.com , catalog page 2269 (I
can't give you a direct link it seems). That said, it shows the same
key for the 2A and 2B Jacobs chucks. ? To remove the chuck from
the shaft, you want a set of Jacobs wedges. Page 2271 in that same
catalog, but Enco had them cheaper when I needed to get a set a
while back.
Mark (21832) |
| Jacob's shows that
you need a K2 key for your chuck, and for removal...you need to get
some Drill Chuck Removal Wedges. They come in pairs and you use them
with the open ends facing each other. These items can be gotten
through MSC. Jacob Wedges and Keys (21837) |
| One possibility may be that the chuck
sleeve that has the gear teeth on it has shifted toward the jaw side
of the chuck. This would cause the teeth of the key to not be able
to engage fully. You can reseat it by fitting a pipe over the nose
of the chuck so it is touching the gear teeth on the sleeve and
drive it with a hammer. If you have an arbor press, you can do the
same thing in a more gentle manner. Gordon (21839) |
| Gordon wins! The
sleeve had slipped down about 50 thou. This prevented the gears from
meshing. I set the chuck up in my vise with a piece of bored brass
stock as a drift. Two smart blows from a 2# hammer, and Robert is my
mother's brother. Mike (21850) |
