# Line Boring on a US-Type Lathe



## SailplaneDriver (May 14, 2020)

I'm looking for some input from all you people with way more experience than I have. I want to line bore my Li'l Demon block. I see all these posts where the block is supported through the tee slots on the cross slide. Unfortunately, most US-style lathes do not have t-slots on the cross slide. How do you support the block on the cross slide in that case? 

Has anyone added t-slots to their cross slide? What do you need to watch out for when adding the t-slots? Does adding t-slots affect the rigidity of the cross slide?


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## dnalot (May 14, 2020)

Not an ideal solution but I removed my tool post and made a fixture to hold part that mounted to tool post mount. It worked OK but took some time to setup.

Mark T


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## retailer (May 14, 2020)

I recall seeing a youtube video where an 90deg angle plate was bolted down to the cross slide and the engine was bolted to the upright portion of the angle plate -  only need to drill and tap 4 holes into the cross slide is that doable in your case ?


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## BIGTREV (May 15, 2020)

Keith Fenner is the man for line boring


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## alcostich (May 15, 2020)

Has anyone added t-slots to their cross slide? What do you need to watch out for when adding the t-slots? Does adding t-slots affect the rigidity of the cross slide?
[/QUOTE]

I machined the S-4382 T-Slotted Cross Slide for the SB 9A from Metal Lathe Accessories many years ago.
It replaces the cross slide and has, as the description states, T slots to which work can be mounted.
And I've never looked back.

Alan


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## SmithDoor (May 15, 2020)

Around later 1800's they put t-slotes on carriage of larger lathes for boring.
On small lathes they just used taped in the cross slide.
You find the on South Bend Lathes under the compound.
If lucky and have a taper you also use the slot too.
The 9N has two 3/8" NC tap holes.

I would not mill the cross slides Just make a cross side just for boring it can be wider and just use aluminum. 
i have had to make new cross side after some else did that trick

Dave




SailplaneDriver said:


> I'm looking for some input from all you people with way more experience than I have. I want to line bore my Li'l Demon block. I see all these posts where the block is supported through the tee slots on the cross slide. Unfortunately, most US-style lathes do not have t-slots on the cross slide. How do you support the block on the cross slide in that case?
> 
> Has anyone added t-slots to their cross slide? What do you need to watch out for when adding the t-slots? Does adding t-slots affect the rigidity of the cross slide?


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## Richard Hed (May 15, 2020)

SailplaneDriver said:


> I'm looking for some input from all you people with way more experience than I have. I want to line bore my Li'l Demon block. I see all these posts where the block is supported through the tee slots on the cross slide. Unfortunately, most US-style lathes do not have t-slots on the cross slide. How do you support the block on the cross slide in that case?
> 
> Has anyone added t-slots to their cross slide? What do you need to watch out for when adding the t-slots? Does adding t-slots affect the rigidity of the cross slide?


Jeez, Woodinville, huh?  That's so amazing finding so many hobbiests from the good old Soviet of Washington.  I live in Moses Lake.  

Anyway, I'm not sure if building a milling attachment would help you.  That's one of MY projects is building an attachnmenht for my crappy little Enco.  As I don't have a mill, an attachment can significantly add to my capabilities.  I'm drawing one up just in order for me to visualize what I have to do.  It's all "slowly, slowly, slowly".  I am looking into a lathe similar to the Grizz G4003(g).  The Chinese have SCORES of companies selling lathes and mills and other stuff.  And they are significantly lower prices than Grizz.  However, Grizz is very reputable, and if something goes wrong, they don't waste any time in sending a fix--I have never heard yet of anyone who had a problem like that.  --Yes, there are probs but Grizz's reputation is to fix it immediately.  (Remember Iomega?  The computer disk manufacturor?  theier reputation was BELOW the worms.)  

Anyway, if you have some $$ you might be able to buy an attachment, as for myself, I am at that balance point where I COULD buy it, but then I would not be able to buy something else, AND it is MORE fun to build one anyway, and challenging.  I always like a challenge anyway.  Also, any attachmeht I bought would be likely to NOT be made directly for my machine and I would necessarily have to modify it anyway.  I notice Ebay has a few attachments, mostly for Craftsman lathes but a few others.


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## Richard Hed (May 15, 2020)

alcostich said:


> Has anyone added t-slots to their cross slide? What do you need to watch out for when adding the t-slots? Does adding t-slots affect the rigidity of the cross slide?



I machined the S-4382 T-Slotted Cross Slide for the SB 9A from Metal Lathe Accessories many years ago.
It replaces the cross slide and has, as the description states, T slots to which work can be mounted.
And I've never looked back.

Alan
[/QUOTE]
That sounds very interesting.  Do you have a photo of that?  What about a drawing?


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## karlw144 (May 15, 2020)

Here’s what I did on my lathe. Removed he compound and added the table. Was boring the crosshead on my Mery Engine. Engine base mounted on a plate that was bolted to my angle plate.


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## Richard Hed (May 15, 2020)

alcostich said:


> Has anyone added t-slots to their cross slide? What do you need to watch out for when adding the t-slots? Does adding t-slots affect the rigidity of the cross slide?



I machined the S-4382 T-Slotted Cross Slide for the SB 9A from Metal Lathe Accessories many years ago.
It replaces the cross slide and has, as the description states, T slots to which work can be mounted.
And I've never looked back.

Alan
[/QUOTE]
Alan, I went to see your S-4382 T-Slotted Cross Slide which ended up in a dead end.  Could you fix that?  Thanx


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## Sprocket (May 15, 2020)

mlatoolbox.com/S-4382.html   Try that.


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## SailplaneDriver (May 16, 2020)

karlw144 said:


> Here’s what I did on my lathe. Removed he compound and added the table. Was boring the crosshead on my Mery Engine. Engine base mounted on a plate that was bolted to my angle plate.



That looks like it might work on mine. I have t-bolts that hold down the compound and would extend too high. I may be able to replace them with t-nuts or come up with some other arrangement to hold down the slotted table. Did you purchase or make the table?


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## SmithDoor (May 16, 2020)

I would use Aluminum plate as simple to come by. 
Drill and tap hole instead of tee slots. Tee slots takes thicker plate and takes away some capacity.

Dave



SailplaneDriver said:


> That looks like it might work on mine. I have t-bolts that hold down the compound and would extend too high. I may be able to replace them with t-nuts or come up with some other arrangement to hold down the slotted table. Did you purchase or make the table?


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## karlw144 (May 16, 2020)

SailplaneDriver said:


> That looks like it might work on mine. I have t-bolts that hold down the compound and would extend too high. I may be able to replace them with t-nuts or come up with some other arrangement to hold down the slotted table. Did you purchase or make the table?


Table came as part of a bigger purchase. Had no use for it at the time, but it got thrown in as part of the deal. Only takes a couple of minutes to install it and it’s really solid.


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## kuhncw (May 16, 2020)

Do you have any photos showing how the table attaches to the cross slide?

Regards,

Chuck


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## SailplaneDriver (May 16, 2020)

Here's proof of concept for mounting an angle plate on my Precision Mathews PM-1236 lathe.

The compound is held onto the cross slide with nuts and two t-bolts in a circular t-slot.





I can't bolt a large plate that overhangs the cross slide since the DRO's scale protrudes above the cross slide by about 3/8 inch. A spacer will be needed.





Unfortunately the t-nuts extend a bit over an inch above the surface.





I made a couple of M10 rod couplings and thich washers to bolt the angle plate down onto the two 1-2-3 blocks.





This arrangement gives me about 4 inches from the spindle center to the face of the angle block, more if I use different mounting holes. I have a leftover piece of 1/2 inch steel and I will make a thinner spacer to keep the angle plate lower and provide better support. I may need to make some special nuts since the rod couplings likely won't work - sholder nuts may work.


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## karlw144 (May 16, 2020)

> Chuck, I took the compound off and used the 2 bolts that attached it to secure the table. Those are the bolts that allow you to rotate the compound. I made some special nuts and punched some clearance holes in the table that gave enough room to use a socket to tighten the table. Used an indicator off the bar to square up the table before tightening the bolts. In the first picture I’m just fiddling around with location and best way to set up. I had an 1 1/4” bar in the chuck just holding the casting in approximately the location for line boring. 2nd picture gives an idea of the table cross section. The 2 long t nut strips (not sure what else to call them) I made to provide enough t nuts to secure my angle plate. Table slots were unique, didn’t match any of my other machines. Any other questions, please ask.
> Karl


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## SailplaneDriver (May 16, 2020)

Finished installation.






Made some M10 sholder bolts to hold the plate down. I wish the plate was a bit bigger since it doesn't fully cover the t-slot but I didn't have anything wider available. It will work fine. I'll cover the open portions with something to keep swarf out. I have to be careful I don't squash that socket head cap screw in the lower right corner with the big plate. I'll see if a button head will fix the issue.


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## kuhncw (May 16, 2020)

`

Nice setup.  Thanks, Karl.

Chuck


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