Urgent request for help.
 

I need to remove the table feed motor from my Centec 2B miller. I've
tried removing the three socket head screws holding the motor/gearbox
assembly to the table, but although its very loose (it moves about 1/8")
it won't come off. Just to make matters worse, whilst trying to get it
free the leadscrew has become very hard to turn and I can't see why.
Can any knowledgeable person help please?

--

Regards, Gary Wooding
(To reply by email, change feet to foot in my address)

"Gary Wooding" wrote in message
...
I need to remove the table feed motor from my Centec 2B miller. I've
tried removing the three socket head screws holding the motor/gearbox
assembly to the table, but although its very loose (it moves about 1/8")
it won't come off. Just to make matters worse, whilst trying to get it
free the leadscrew has become very hard to turn and I can't see why.
Can any knowledgeable person help please?

I don't have the power feed and I looked at my documentation for any
information. The Centec 2A/2B instruction manual has information on
engaging and operating the power feed, but nothing on taking it apart. If
you don't have that manual, you can get it for a reasonable price from the
lathe archive guy. I read the one page on the power feed and it referred to
the wrong figures on the wrong pages, etc. so it made me more puzzled than
before I read it.
On my manual feed Centec 2A (and also on my #4 Burke) the table lead
screws have double nuts that can be adjusted to reduce backlash. It doesn't
happen on my Centec, but on the burke, the cross feed nuts tend to loosen up
in one direction and then tighten up in the other. When that happens, the
screw is effectively locked and is indeed very hard to turn. Check to see
if you have double nuts like that on the power feed .. I would think so.
I vaguely recall having to remove a lead screw nut in order to get
the screw out. Having taken my 2A down to the ultimate, including the
vertical head, I have found that there is always a way to take things apart
without doing violence. Albeit, sometimes the method tends to be a little
indirect or downright obscure. British machinery, y'know.
Once you get that pesky power feed unit off, do yourself a favor and
get rid of the damned thing. It is obviously more trouble than it is
worth. Why don't you just send it along to me and I'll take it off your
hands.... I'll even pay the shipping cost.

Boris

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-------------------------------------
Boris Beizer Ph.D. Seminars and Consulting
1232 Glenbrook Road on Software Testing and
Huntingdon Valley, PA 19006 Quality Assurance

TEL: 215-572-5580
FAX: 215-886-0144
Email bsquare "at" sprintmail.com

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Unfortunately, I'm pretty sure that in order to remove the powerfeed,
you'll need to remove the table leadscrew. On my Excello, I had to
remove the powerfeed, in fact the entire table, and I encountered some
rude surprises. Originally, all I thought I had to do was to unscrew
the manual feed handle on the powerfeed side of the table and then
unscrew the SHCS you referred to. When I removed the handle, I found
that the bronze bevel gear that drives the leadscrew was secured to the
leadscrew with a roll pin, outboard of the powerfeed. The powerfeed
fits inside of the gear. I had to remove all the hardware on the other
end of the leadscrew (the side without the powerfeed) and unscrew the
leadscrew (which is over 5" long) out of the machine. The powerfeed
can then be taken off of the side of the table. BTW, the leadscrew is
probably seizing because the bevel gear on the leadscrew is binding
with its drive gear in the powerfeed gearhead. Hope this is helpful.

Thanks for the suggestions. I eventually managed to remove it.

There were several 'tricks' to the job. After removing the screws
holding the gearbox to the table, it was necessary to, little by little,
unscrew the two locknuts on the end of the leadscrew and slide the
assembly off of the leadscrew. Problem #1 was that you can only loosen
the nuts about 1/2 turn at a time, and #2 was that the leadscrew had to
be rotated to line the woodruff key up so that it passes through the
slot in the leadscrew bearing bush. In my case the slot was at the top,
the key was barely visible, and I didn't know it was there.

Once the assembly was removed, the worm wheel could be removed to give
access to the last of 4 screws that retain the motor to the gearbox, but
then problem #3 turned up 'cos the motor cannot be removed until the
worm on the motor shaft is also removed. It is held by a pin that is all
but inaccessible. When finally that was removed the motor was then free.

--

Regards, Gary Wooding
(To reply by email, change feet to foot in my address)

"Gary Wooding" wrote in message
...
Thanks for the suggestions. I eventually managed to remove it.

There were several 'tricks' to the job. After snip finally that was
removed the motor was then free.

Old saying about British machinery ... "Never use one part when three will
do."

Also: "How do you know when a British machine is out of oil? It stops
leaking."

Anyhow, I love my little Centec 2A..

Now that you've got that pesky drive removed, when can I expect the package.

Boris

--

-------------------------------------
Boris Beizer Ph.D. Seminars and Consulting
1232 Glenbrook Road on Software Testing and
Huntingdon Valley, PA 19006 Quality Assurance

TEL: 215-572-5580
FAX: 215-886-0144
Email bsquare "at" sprintmail.com

------------------------------------------