Another 101.07403 with some broken parts, hoping for replacement suggestions.

Orangetruckman

Orangetruckman

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Good day folks! First posting here I do see this is an older thread, but am contributing some relevant material, so I think it’s okay to bring it back
On what wa5cab said-I recently purchased my first real lathe, a 12x36 atlas craftsman and the cross feed gears have been just beat up! In the process of repairing that. No clear evidence as to how the damage occurred ‍♂️ I can post pics of the carnage if so desired. The previous owner got it from his grandfather and it seemed like he didn’t know much about it.
 
Welcome aboard. Is the gear damage that you refer to on the spur gear on the cross feed screw or the sliding gear that drives it?
 
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@Tailormade If someone mentioned already then I missed it, which is surprising because Robert / @wa5cab is usually a stickler for this disclaimer, but I wanted to give you the obligatory "reverse" disclaimer. As these lathes have threaded spindles, running the lathe in reverse risks rapidly unthreading and dropping the chuck. Best case: damage your ways. Worst case: well, they are machine tools; there's really no upper limit on worst cases.

A lot of newer and/or larger lathes have mechanisms such as spindle posts or captive nuts + keys to retain the chuck no matter the spindle direction, but not Atlas/Craftsman lathes.

Also worth noting this phenomenon only applies to work holding devices (chucks, drive plates, etc.) that rely solely on a threaded connection to the spindle nose. Other devices, namely collet chucks that affix to the spindle by way of mating male taper + a drawbar through the spindle which tightens on the far end of the spindle bore, are okay to run in reverse. At least I believe they are.

For these reasons it's not uncommon to find Atlas/Craftsman lathes equipped with drum switches to either have reverse disabled or have both F/R sides of the switch wired to rotate the spindle forward (as mine does).
 
wa5cab said:
Welcome aboard. Is the gear damage that you refer to on the spur gear on the cross feed screw and the sliding gear that drives it?
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Let me see if I can explain this clearly...The cross feed engagement knob gear, that’s engaged with a combination gear of straight/beveled gear, that is driven off of the lead screw gear. The cross feed knob gear is missing teeth and the straight/beveled combination gear is crunchy (I haven’t taken off the apron yet, but felt the gear and it’s not okay. Here’s the cross feed knob and gear-it was already out.
1606808884426.jpeg
 
wa5cab said:
Welcome aboard. Is the gear damage that you refer to on the spur gear on the cross feed screw and the sliding gear that drives it?
Click to expand...
Oh, and thank you for the welcome
 
I decided that it might work better by splitting the old thread into two. Which I did mainly to hold down the confusion.
 
To get back to your gear problem, I see from your photo that the damaged gear you were actually referring to is the one on the shaft that you pull out to engage power cross-feed. You need to pull the apron and the cross-feed screw and examine the other gears that may be damaged. The reason for not delaying finding out is that some of the other gears turn whenever the lead screw turns. And therefore may possibly cause further damage. If you want to put off repairs until a future date, you can temporarily reassemble the lead screw and cross-feed screw so that the lathe is usable for everything except power cross feed. You would have to re-install the gear on the cross-feed screw that you haven't yet examined and the one on the lead screw but not install the combination bevel/spur gear nor the gear shown in your photo.
 
While researching this issue, I uncovered a mystery. There are two Woodruff keys in the cross feed screw, Every Atlas or Atlas-Craftsman parts manual printed from 1945 until 1965 identifies the key for the cross-feed crank as a #3 Woodruff and the one for the cross-feed gear as Atlas part number 9-196A. The late 12" manuals up through 1965 ID both keys as #3 Woodruff. All later 12" manuals ID both as #404 Woodruff. The early 9" parts manual from 1933 ID's part # 9-196 as a #3 Woodruff. I never was able to determine the difference between 9-196 and 9-196A. Next time that I call Clausing, I will see whether they can answer the question or not. But I'm expecting "not".

However, I then went to the 21st edition of Machinery's Handbook (2nd Printing, 1980) to determine the difference between a #3 and a #404 Woodruff key and found that it doesn't list any single-digit Woodruff keys. All have a minimum of three digests. The last place that I looked was in the 12th Edition from 1943. Where I found that a #404 Woodruff was the same as a #3 Whitney. I think that people were so used to calling the half-moon keys Woodruff keys that the error slipped into print. Most if not all of the earlier Atlas parts lists used the single digit number but call them Woodruff keys.

But anyway, the two keys, regardless of what you call them, are the same.
 
wa5cab said:
To get back to your gear problem, I see from your photo that the damaged gear you were actually referring to is the one on the shaft that you pull out to engage power cross-feed. You need to pull the apron and the cross-feed screw and examine the other gears that may be damaged. The reason for not delaying finding out is that some of the other gears turn whenever the lead screw turns. And therefore may possibly cause further damage. If you want to put off repairs until a future date, you can temporarily reassemble the lead screw and cross-feed screw so that the lathe is usable for everything except power cross feed. You would have to re-install the gear on the cross-feed screw that you haven't yet examined and the one on the lead screw but not install the combination bevel/spur gear nor the gear shown in your photo.
Click to expand...
It looks like the PO played with the machine before I took ownership, after I went to look at it. As everything worked properly when I inspected it, but didn’t reinspect before when picking it up-lesson learned. It looked like the safety pin to prevent both cross-feed and carriage gears from being used at the same time broke several teeth on that gear (the cross-feed gear) and carried over to the bevel gear some as well, but it was still saved. Lack of oil shows up in many ways.
 
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