Re: Fw: Lead Screw
You are installing the Pick-O-Matic gearbox on your lathe,right? If so,they are different than the Quick change gearbox that most folks are familiar with. The Pick-O-Matic extends further to the right so the leadscrew needs to be shortened. I think that all of the 5/8" section and maybe part of the 3/4" needs to be cut off. Hold the leadscrew up next to where it goes and measure how far back into the box it needs to go and cut it accordingly. The leadscrew on this set-up is keyed to the gearbox by the keyway on the 3/4" part of the screw. Hope this helps. Andy
--- In email@example.com, "VBrannick" <valestreet@...> wrote:
> Perhaps someone in the group has an answer.
> ----- Original Message -----
> From: VBrannick
> To: Lee Mann
> Sent: Monday, November 30, 2009 7:52 PM
> Subject: Lead Screw
> Hello Lee,
> I'm hoping (against hope), that you can answer a question for me. The lead screw on my 10"X36" Atlas lathe has a 3/4" Acme thread. After removing the lead screw, preparatory to installing the newly acquired Quick Change Gear Box, I layed the lead screw aside, and proceeded to remove the Reverse Feed box, and replace it with the QCGB. Upon reassembling the lead screw, I discover that the unthreaded end of the threaded shaft that engaged the Reverse Feed Box is 5/8" in diameter, and not only doesn't fit the bushing on the QCGB, but seems to stop short of full length insertion. The question is; Does the QCGB require a different lead screw? If it does, would you have one to sell that would fit properly? Or know of a source for such an item? Or could/should an adapter bushing be made? I'm quite frankly at 'wits end' about what to do. I will call on the Atlas Lathe-yahoo group (AGAIN), for their collective wisdom, but I'm beginning to become somewhat of a nuisance, I'm thinking. Will appreciate any help you may be willing to offer.
> Vince B.
> [Non-text portions of this message have been removed]
- As I remember the lead screw on the Atlas has several variations. There
were two diameters supplied as sometime during the production it was found a
larger diameter lead screw was needed. Two lengths depending on the
length of the bed.
The the question of length for the models with quick change gear was
different than the lathes with loose change gears. The models with the loose
change gears had a longer lead screw that went through a bearing on the left
end to accept the last gear of whatever gear set was employed, while the
lead screw for the QC models was a little shorter and fit into the QC box that
was bolted onto the way or head stock. (I think that one also had a slip
clutch which prevented damage to the works if you ran the cross slide into
the head stock or some other kind of overload or crash. On the lathes with
manual change gears the "safety" was the breaking up of the right hand
bearing where the lead screw was held. It is fairly common to find a manual
change gear Atlas with no bearing or a home built bearing on the right hand
end of the lead screw.
Then there is the absence or presence of a groove down the lead screw. The
groove was not there in some models without a power cross feed.
The best way to look for the lead screw that will fit your particular lathe
is to get the parts list from Clausing (contact them by telephone) and get
the parts list for your particular model which will have the proper part
number to search for a replacement lead screw.
I think also you can use the Sear's model number to bring up a parts list
where you can find information on the lead screw along with a break down
drawing of your lathe. Sears (at least the last time I looked) still has some
parts for various Atlas model lathes.
The last resort would be Ebay where the seller may or may not have a
correct part number so if you buy an unknown part be sure to get some kind of
arrangement so the "unknown" part does not fit your particular lathe you can
return the part for refund or credit.
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