# Seeking Advice on Atlas No. 700 Taper Attachment



## Weldo (Apr 6, 2020)

Hey all!  I've had a No. 700 for a long time and just finally want to get it bolted to my machine.  The problem is I'm missing a few parts.  I did a search and found some nice dimensioned drawings in the download section.

I need the clamp, draw bar and the pins.  In the PDF at the bottom of the post I've circled the parts I need to make.

The most complex part is the clamp.  Below is the drawing from the download section and my pencil interpretations are at the bottom of the page.  I'm making a composite part of welded pieces.





So far I have this.





It goes on the ways snugly and it clamps very well.





Now what I'm unsure about is the fitment of the taper attachment body to the clamp.  I plan to make the slot in another piece of plate and weld it to the clamp, like so...





If I hold the rear plate in the center vertically of the clamp, I get about a 7/16" gap between the taper attachment body and the clamp.  As far as I can tell this is normal, I think.  I don't see a dimension for this on the drawing.  If I hold the rear plate flush with the top weld I get a 3/8" gap to the taper attachment.

Below are a few more shots for clarity.














It looks like the rear plate could be made a little longer as well.  But mainly I'm concerned with the gap between the clamp and the attachment.  Will the gap there cause any kind of binding or play issues?

Also is the slot strictly necessary?  Could I not simply drill a hole to connect these two parts?  I'm assuming the fact that the clamp was slotted was so that the taper attachment could be made universal, and a slot would account for any small variations in manufacture of these machines and models.

Any insights would be greatly appreciated!


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## Moderatemixed (Apr 6, 2020)

I have a complete 700. Let me look into what you need and I’ll do my best to help you out. 

Derek. 


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## Weldo (Apr 6, 2020)

Hey that's great!  Thanks for taking the time!


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## Weldo (Apr 7, 2020)

Any word?


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## wa5cab (Apr 8, 2020)

FWIW, Atlas over the years made three different or slightly different taper attachments, the 700, 760 and 6822.  The 760 and 6822 share no parts with the 700, which was also referred to as the Tool Room Taper Attachment.  The main difference between the 760 and 6822 is that the 760 fit the 3/8" bed machines and the 6822 fit the 1/2" bed 12".

To answer your earlier question about the clamp slot, it doesn't necessarily have to be slotted all of the way out the rear end of the clamp leg but I would strongly recommend at least a partial slot to take care of the probability that the dovetail in the bottom of the 10-701A Bracket may not be or probably isn't exactly parallel to the carriage travel.

Also, the 10-705A Clamp leg should not touch nor support the tailstock end of the 10-702 Guide Bar.  The Guide Bar runs in and should be supported by only the dovetail in the bottom of the 10-701A Bracket.  The drawing is a little misleading in this case as it seems to show the cross section of the dovetail and of the Guide Bar as being 60 degrees (or 30 depending upon how you look at it) on the back side (away from the bed) and 90 degrees on the front side.  Which is it?

So it would appear that the vertical placement of the leg on the 10-705A clamp is not critical.  Just be sure that the sides of the slot are perpendicular to the surface of the bed when installed.


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## Moderatemixed (Apr 8, 2020)

Back to you tonight with pics. Sorry. Got tied up. 


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## Weldo (Apr 8, 2020)

@wa5cab Thanks for the advice!  I'll look into that.



Moderatemixed said:


> Back to you tonight with pics. Sorry. Got tied up.



That's not a problem at all!  Again I appreciate you taking the time to help me out.  Sorry for being impatient!


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## Moderatemixed (Apr 8, 2020)

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## Moderatemixed (Apr 8, 2020)

I’m pretty sure this is the 700. Let me reread what you need and I’ll get the details to you shortly. 

Derek


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## Weldo (Apr 8, 2020)

wa5cab said:


> The Guide Bar runs in and should be supported by only the dovetail in the bottom of the 10-701A Bracket. The drawing is a little misleading in this case as it seems to show the cross section of the dovetail and of the Guide Bar as being 60 degrees (or 30 depending upon how you look at it) on the back side (away from the bed) and 90 degrees on the front side. Which is it?



I get that the guide bar should only be supported by the dovetail in 10-701A but the later part of your observation eludes me.  We're looking at the second page of the PDF, right?  I not sure I understand completely to what you are referring.

Thanks for your patience.


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## Moderatemixed (Apr 8, 2020)

Here’s the pin. 
	

	
	
		
		

		
			






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## Weldo (Apr 8, 2020)

That is indeed a 700!  Thanks for the pics!  

Ultimately what I need is dimension A in the pic below.  It's the distance from the top of the lathe bed to the top of the clamp.


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## Weldo (Apr 8, 2020)

And the pin is a slop free fit into the slot in the clamp I assume.


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## Moderatemixed (Apr 8, 2020)

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## Moderatemixed (Apr 8, 2020)

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## Moderatemixed (Apr 8, 2020)

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## Moderatemixed (Apr 8, 2020)

A = .2765 according to my surface plate and Starrett digital height gage...... sorry if all the pics are frustrating you. 


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## Moderatemixed (Apr 8, 2020)

The pin is a snug fit. No slop, correct. Do you need dimensions for the draw bar?


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## Weldo (Apr 8, 2020)

Awesome!  Thanks you so much!

I got this from the download section of the forum.




As far as I can tell this is adequate to reproduce the part.

Thanks again!  This was a great help!


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## wa5cab (Apr 9, 2020)

Well, I still don't know for certain whether the gib sits straight up and down like the carriage gib on any Atlas lathe does or laid over at an angle like the cross slide gib.  But the front edge of the 10-702 Guide Bar is straight up and down, cut at 90 degrees to the top and bottom.  So the 10-701A Bracket probably only has half of a dove tail, cut on the back side.


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## Weldo (Apr 9, 2020)

On the one I have there is a normal full dovetail on the guide bar.



Moderatemixed said:


> A = .2765 according to my surface plate and Starrett digital height gage...... sorry if all the pics are frustrating you.



Last point of clarification, the top surface of the rear arm of the clamp (the part with the slot) ends up 0.2765" ABOVE the lathe bed when installed?  Is that right?


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## wa5cab (Apr 9, 2020)

Ok.  I finally saw what the dovetail looks like on the bottom of the guide bar.  It is just barely visible right at the bottom of the first photo in Post # 12.  The guide bar is quite a bit thicker than I thought.  And my comment about the female dovetail on the bottom of the bracket being incorrectly drawn was correct.


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## Moderatemixed (Apr 9, 2020)

Yes


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## Moderatemixed (Apr 9, 2020)

wa5cab said:


> Well, I still don't know for certain whether the gib sits straight up and down like the carriage gib on any Atlas lathe does or laid over at an angle like the cross slide gib. But the front edge of the 10-702 Guide Bar is straight up and down, cut at 90 degrees to the top and bottom. So the 10-701A Bracket probably only has half of a dove tail, cut on the back side.



What are you talking about. I have read this several times and am completely lost. The only gib on the entire setup runs parallel to the bed and is along the outermost edge of the bracket. 


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## Weldo (Apr 9, 2020)

I think what he's referring to is this here:





In the drawing it looks like the rear face of the dovetail is straight vertical while the other one is the standard 30* angle that we've come to expect.

The drawing is not super clear on that but the guide bar does indeed have an angled face on each side, like a normal dovetail.

And thanks again @Moderatemixed for the clarification.  Maybe these dimensions aren't even all that important to the function but I wanna be as close as is reasonably possible to the original.


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## Moderatemixed (Apr 9, 2020)

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## Moderatemixed (Apr 9, 2020)

Hopefully that helps clear it up. 


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## Moderatemixed (Apr 9, 2020)

So once you get it all put together you have to show me how to use the darn thing...... I’ve never had it on my lathe or used it. (But I am going to). I just picked up an Atlas horizontal mill and I need to make a 1” arbour for it. I need to turn an MT2 on one end of said arbour. This thing should be just what the doctor ordered.... or at least I hope it is. 

Let me know if you need anything else.

Derek. 


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## Weldo (Apr 9, 2020)

It might be a while til mine is up and running but the PDF attachment in the first post has the mounting and use instructions.

Doesn't sound too difficult.  It's covered in the first page of the PDF.  Check it over and see what you think.


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## wa5cab (Apr 11, 2020)

OK.  The most recent batch of photos answered my questions.  The drawing in the manual copy of the right end of the guide bar is wrong as your first photo in this series shows that the dovetail on the bottom of the (inverted in the photo) guide bar should be clearly visible as it extends out all of the way through the radiused right end.  And the drawing of the tailstock side of the Bracket is wrong.  As drawn, the near (to the operator) line representing the front edge of the right end of the dovetail is drawn too close to vertical.  It should be laid over more to the right.  But now that I know that the dovetail should be visible on the front of the handle on the right end of the guide bar, I probably wouldn't have questioned the bracket drawing.

Also, there are two other errors in the text part of the instructions for installation and use of the 700 Taper Attachment.  As with the 760 and 6822, Step 1 for installing is to remove the chip guard and attachment screw from the rear of the cross slide.  Step 2 is to remove the cross feed brass nut and its attachment screw.  Then proceed with the rest of the installation instructions.

The 10-24 x 1/2" round head mach. screw shown above the left end of the draw bar goes into the hole formerly occupied by the chip guard.  Tighten it after installing the pin through the draw bar and into the hole formerly occupied by the cross feed nut and adjusting the three 10-32 x 3/8" set screws.  After tightening the screw but with the screw for the 10-704A Slide loose, confirm that the cross slide and draw bar move freely across the carriage.  This is your coarse adjustment of where cutting is going to take place.  After tightening the bolt through the draw bar into the 10-704A Slide, all further adjustment will be done with the compound feed.  The compound slide should be set to 0 deg. and if you are using either a QCTP or a 4-way turret, they should be square with the lathe axis or with the piece of solid round that you usually start with.  

One further tip - before starting the installation, check and if necessary adjust the carriage gib screws.


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