# Challenging Job On A 109



## ericc (Aug 27, 2016)

Finishing a faceplate on a craftsman 109 lathe was a challenging job. This required trimming the outer rim of a 4 1/4" round. Even with the compound and cross slide all the way out (handles foul) it is hard to reach the rim with a tool. The rim was ragged and it was an interrupted cut. Furthermore, the edge was torch cut. No matter what expert machinists say about it being impossible to add carbon to a torch cut, it really was hard. The first few thou threw sparks with HSS. I had to hold the compound down since the cross slide was only partially engaged. Anyway, it barely worked. This is really a 3" lathe, especially for steel.


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## ericc (Aug 27, 2016)

Picture


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## Charles Spencer (Aug 27, 2016)

I'd have ground off the edge until the torch cut was no longer visible and it was roughly round.


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## ericc (Aug 28, 2016)

Hi Charles. I did use an angle grinder to remove most of the nasty ridges from the torch cut but there was a little left. My comment was partially a remark on a post on another site about myths of machining. But it is not a myth. Torch cuts can have hard spots. So can welds, especially forge welds. Anyway, that little lathe was working hard!


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## wa5cab (Aug 28, 2016)

On a 3996, the way to work up near 12" OD is to turn the compound around so that it points at the operator instead of away.  And mount a backwards boring bar as short as possible.  That keeps the cross slide fully engaged.


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## pollardd (Aug 28, 2016)

Hi Ericc,
It isn't so much the flame cut that makes it hard it depends on what is in the steel to start with and if they quenched it or let it cool down slowly.   I used to use the same trick to grind off the skin before cutting but you have already figured that out.  The blokes I used to work with said that plate steel was made from used ball bearings and old car bodies so it was always a bit of a mixed bag.

The Swing of a lathe refers to the maximum diameter that can spin around and clear the bed.  My Atlas is a 10" and it is no coincidence that the center height is exactly 5".  So actually turning 10" outside diameter would be virtually impossible.  However I could probably mount a 10" job and work on diameters closer to the center.

I have been thinking about making a face plate for my lathe.  I'll start with a 6" piece that I have lying around and call it a drive plate.  I don't know if I'll be ambitious enough to try and make a 10". (although I'd like one)
Yours looks good in the pic
David.


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## aametalmaster (Aug 28, 2016)

Plus that little lathe needs a mirror image pulley set to run back gear properly. I had a dream of making them then got sidetracked. But I have 4" aluminum already cut if you need a piece to make a pulley....Bob                           imum


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## pollardd (Aug 28, 2016)

I just spotted what is described as being an original face plate for a 10-12" Atlas lathe on ebay.
The OD is 8 1/2 inches.  Hmmm I wonder if I should buy it


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## ericc (Aug 29, 2016)

Depends on the price.  Folks told me I was crazy to make my own if you can buy one on Ebay for $25.  But that is for the 1/2-20 spindle thread.  Mine has the (rarer) 1/2-24 thread.


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## ericc (Aug 29, 2016)

wa5cab said:


> On a 3996, the way to work up near 12" OD is to turn the compound around so that it points at the operator instead of away.  And mount a backwards boring bar as short as possible.  That keeps the cross slide fully engaged.



That's a great idea.  I think it would work.  As for the boring bar, that would hold a conventionally ground lathe tool so one could kind of get around the side of the piece that is being turned?


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## wa5cab (Aug 29, 2016)

Good point about the spindle threads.  There aren't too many of the 700 Series around.

Yes, that's the idea with the boring bar.  However, the bar must be the type with a square hole broached through it at right angles to the bar.  And you mount the cutter "backwards" (sticking in instead of out).  For normal boring (working on the ID of the part) I often use boring bars made for a boring head on a mill as they are ready to use out of the box.  However, I've never seen any of these made "backwards" for working on the OD.  So you need the bar with the hole through it in order to do what I was suggesting.


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## ericc (Aug 29, 2016)

Got it!  Thanks.  That's a great idea, and I have that kind of boring bar.  I don't think that I will turn something like this very soon, though, since it was really touchy.  The belt tension was loosened so that the belt would slip instead of bending the spindle.  Too long of a moment arm.


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## pollardd (Aug 29, 2016)

I wasn't suggesting that you bought a face plate.  I was pointing out my lack of courage to make my own.
I reckon 10 points for figuring out how to make it your self with the equipment you have.

I'm in the middle of constructing a wagon wheel hub for a restoration job on a old horse cart.  The OD of the hub is about 8" and as I said my lathe has a 10" swing.
The hub is about 10" wide and the cross side won't go under it.  Luckily it is made out of wood and not steel 
I came up with a hand made reverse boring bar with a hand ground HSS cutting bit.  The bar stuck out from the tool post about 11" and looked ridiculous.
But light cuts on wood and my hubs came out looking like a million bucks.



Here it is mounted on the axle with two steel rings pressed on and the new leather thrust washers.
There are two internal tapers one of which is about three time the length of the travel on my compound slide.
Again,  I'm glad it is wood 
David


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