# Back gears on a small Atlas (Craftsman?) lathe



## terrylorin (May 23, 2013)

Guys,

I have inherited a small Atlas lathe and I can find no model # anywhere on the machine.  It has a lever on the backside of the gear housing that engages the back gears.  However, I can find no way to disengage the bull gear.  I have been over the machine dozens of times and can find no visible method to get the gear disengaged, so if I engage the back gear lever, it locks up the gears.  Anybody out there know how the bull gear disengages?
I have tried, without success to add some photos of the machine.  Anyone that thinks they might be able to help, I will e-mail photos to you.

Thanks,

Terry


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## itsme_Bernie (May 23, 2013)

First see if this photo helps you:






The previous owner went crazy with the paint on this thing!   ..  But helps in our purpose here-  you can see the bull gear pin in yellow there. 

If you have a problem pulling it, just get a little flathead screwdriver behind it and pry it gently.  Oil it if it sticks too much, and wiggle the cone pulley and bull gear if it is really stuck.  It shouldn't be a problem.


Bernie


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## cdhknives (May 23, 2013)

Also check the sticky at the top of this forum.  On both mine and my Dad's Atlas previous owners changed the spindle pulley oiler screw out for a set screw, permanently locking it in direct drive mode.  The symptoms are identical for both...locking up the gear train when back gears are engaged.


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## terrylorin (May 24, 2013)

Bernie,

Thanks for the photo.  The problem with my machine is that the housing covers the bull gear.  I can see the pulley side of the gear but not the spindle side.  Also, there is no access thru the housing to the spindle side of the bull gear.


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## itsme_Bernie (May 24, 2013)

Hey Terry- 

I don't have your square version of the 618, but with some creative googling:

The "square head" 618, you need to open the cover on the left side of the
headstock (over the pulleys) and pull the collar at the center of the spindle
pulley (surrounding the spindle) to the left, then engage the back gear.

You need to slide the collar back and forth. With the headstock to your left, slide the collar to the right to engage them, then moving the lever on the back of the headstock
to engage the backgears.   Then you slide it to the left to disengage.

Look 1/2 way down here:
http://www.lathes.co.uk/craftsman/page6.html

There is a ball-bearing detent (spring loaded) that pops it in place, which may be sticky.


Bernie


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## terrylorin (May 25, 2013)

Thanks Bernie,for taking the time, you have solved the puzzle.

Terry


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## itsme_Bernie (May 26, 2013)

terrylorin said:


> Thanks Bernie,for taking the time, you have solved the puzzle.
> 
> Terry



Great Terry!  Glad to help- what are you working on at such low speed?  I used the backgear all the time when I got my 618 going.  And make sure you have plenty of oil inside the spindle cone pulley AND inside the backgear.


Bernie


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## wa5cab (May 27, 2013)

For the record, the machine model number is not 618.  It's a 10100 (Inch) or 10200 (Metric).  Also known colloqually as the Atlas 6" Mk2.  The Craftsman 101.21200 is the same as the 10100 except for badge and nameplate.  There was also an earlier Model 3950 which had a Zamak headstock casting and some other headstock differences which was sold only very briefly (apparently less than a year).  It doesn't appear that Sears ever sold it.

I've not come across a 10100 manual (only the 10200) but do have the 101.21200 one.  If it isn't in Downloads and you need it, I can put it there.

Robert D.


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## terrylorin (May 27, 2013)

itsme_Bernie said:


> Great Terry!  Glad to help- what are you working on at such low speed?  I used the backgear all the time when I got my 618 going.  And make sure you have plenty of oil inside the spindle cone pulley AND inside the backgear.
> 
> 
> Bernie


Bernie,

The only speed I use on the back gears is the highest one, and on some small parts, it seems I get a better pass cut at that speed.  Mostly, I make small parts, screws and pins etc. that I need in my gunsmithing work.  The diagram that you found for me on the link to the UK web site really helped, though it still took a little time to figure out how to make it work.  The collar will only disengage in one position.  It has to line up correctly to a spline or keyway in the spindle to dis-engage and to re-engage.  After I found the correct position, my machine now has a punch mark in both parts.  
when aligned, it is quite simple to operate.

Thanks Again,

Terry

- - - Updated - - -



wa5cab said:


> For the record, the machine model number is not 618.  It's a 10100 (Inch) or 10200 (Metric).  Also known colloqually as the Atlas 6" Mk2.  The Craftsman 101.21200 is the same as the 10100 except for badge and nameplate.  There was also an earlier Model 3950 which had a Zamak headstock casting and some other headstock differences which was sold only very briefly (apparently less than a year).  It doesn't appear that Sears ever sold it.
> 
> I've not come across a 10100 manual (only the 10200) but do have the 101.21200 one.  If it isn't in Downloads and you need it, I can put it there.
> 
> Robert D.


Robert,

Thanks for the information.  The machine I have has no model # on it, at least that I can find.  It has the Atlas name plate, but I was told by the old guy that had it, that it had been purchased at Sears in the early 70's.  The machine is an inch machine, not metric.  I would like very much to have the manual and I will look in downloads for it, now that I know what model to look for.

Thanks Again,

Terry


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## wa5cab (May 27, 2013)

Terry,

OK.  Look on page 2 of the Atlas... downloads.

Robert D.


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