# First time line boring



## springer (May 25, 2020)

Small part of a project ibwas working on. Machines are packed up for a move right now so the project is on hold, but figured I'd share my first attempt/venture into a sort of line boring. 

Had to start by making the tool...
Then made a mount to bolt the part to the the cross slide. 
Then drilled...
The bored...

Went surprisingly well given I had no idea what I was doing. Very uneventful but very pleasing to see it work as planned with a great finish and excellent dimension tolerance.


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## springer (May 25, 2020)

Guess I didn't get as many pictures as I thought. Here are a couple videos I took.


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## Ed ke6bnl (May 25, 2020)

nice job have not tried that yet.

Another job showing the versatility of a lathe.


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## Downunder Bob (May 25, 2020)

Looks good, what is the end product?

Another job showing the versatility of a lathe.


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## SLK001 (May 25, 2020)

In your first photo, you have mounted a rough hunk of steel in your chuck.  The FIRST thing you should have done was to turn the mounting end true (ie, skim cut the skin off).  This will give you a round surface to mount in your chuck.  It will also allow you to unmount your work and remount if needed without much loss of registration.

Secondly, your boring bar is too big and also not true.  You run the risk of chips jamming and deflecting the bore with the little clearance that you have.  You should also use a true bar (like a piece of O1 tool steel) for your boring bar.  It looks like you used a piece of 3/4" round 1018 CRS for your bar.  The concentricity of the head end and the tail end of your bar is not known.  Also, the relationship between the cutter and the head end of the bar is not known.  It can be made to work your way, but it greatly increases the difficulty of getting it right.


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## Downunder Bob (May 25, 2020)

The comment about mounting of the job is really not really relevant the job was done in one setup and finished

Likewise the the truth of the boring bar is of no consequence. the only thing that matters in this operation is the circle described by the tip of the cutting tool. Your comment on the lack of clearance is sort of valid for the first cut only, but after that, again of no consequence.


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## benmychree (May 25, 2020)

Having done a significant amount of line boring up to about 5 ft diameter, and down to approx. that which is discussed here, I concur with the above post.


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## epanzella (May 25, 2020)

I like doing and reading about innovative setups to do more with less. Fine Job!


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## springer (May 25, 2020)

SLK001 said:


> In your first photo, you have mounted a rough hunk of steel in your chuck.  The FIRST thing you should have done was to turn the mounting end true (ie, skim cut the skin off).  This will give you a round surface to mount in your chuck.  It will also allow you to unmount your work and remount if needed without much loss of registration.
> 
> Secondly, your boring bar is too big and also not true.  You run the risk of chips jamming and deflecting the bore with the little clearance that you have.  You should also use a true bar (like a piece of O1 tool steel) for your boring bar.  It looks like you used a piece of 3/4" round 1018 CRS for your bar.  The concentricity of the head end and the tail end of your bar is not known.  Also, the relationship between the cutter and the head end of the bar is not known.  It can be made to work your way, but it greatly increases the difficulty of getting it right.



Thanks for the info, however, as mentioned above, I made it in one setup so no need to get it true again once i parted it off. 

And being my first attempt, I cant say for sure but tend to agree as stated above that the 7/8" bar is of no consequence if not perfectly true. Only the cutter makes contacts and turns as it will no matter the bar it is held in. I did true and center drill one and turned the other end true to indicate in the 4 jaw, but of course it wont be perfect, but I dont see it being an issue. It wasnt actually since the cut bore came out better than I'd ever need it to be. I dont recall exactly, but bore diamter was within a tenth or 2. 

Also, I see no reason to use a tool steel for the bar, def not for the limited use it will see.


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