# Lovejoy face mill modification



## 682bear (Dec 5, 2017)

When I bought my lathe, there was 4 face mill heads in the box of tooling that came with it. One of them is a 3 inch diameter Lovejoy that takes 6 SPG423 inserts. There was also a box with (I'm guessing) around a thousand inserts... but I didn't get an arbor to mount the head on.

I decided, since I had so many inserts, I should machine an arbor for the face mill so I can get some use out of it.

I used a piece of 1 1/4 inch mystery steel and turned down the nose to be a tight slip fit in the head, and fit the other end to my 1 inch R8 holder, then cut a groove in each side and TIG welded 2 lugs to keep the head from spinning on the arbor. I drilled and tapped the nose for a 1/2-13 socket head bolt to hold the head on the arbor.




I then discovered that, for some unexplained reason, the head wasn't manufactured correctly. One of the inserts was .030 farther out than the other 5, so it was basically cutting with only that insert, sort of like a flycutter. Also, 2 of the inserts were slightly tipped where the outside corner was lower than the inside corner, which is the way they should be, one insert seated pretty much flat, and the other 3 were lower on the inside corner...

So I disassembled it and set it up on the mill in my 5c spin indexer angled up about 1/2 degree, and re-machined all 6 insert 'seats'... that gives me about 1/2 degree of rake on the inserts, allowing the outer corners to be lower than the inner corners.

After reassembly...




I set the adjustable upper seats to within .0005 of each other... the outer diameter of the inserts all turned out to be within .0005 of each other, also.

It cuts very good, now and leaves a nice finish.




-Bear


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## 4GSR (Dec 5, 2017)

Those Lovejoy mill heads were supposed to be gold in their days.  They were purposely designed to cut with one tooth sticking out and down for an wiper.  The rest of the insert pockets were at staggered heights.  The theory behind this was, if the proper feeds and RPM's were used, each tooth would cut.  I don't think it ever worked, even on the newer NC, CNC machines of the time in the mid to late 1970's.  

You did the right thing, make it into something that works to your expectation.  BTW- I had the same 3" face mill years back and even with one tooth cutting most of the time, it would leave a nice finish every time!  Boy! it would cut the iron!

Ken


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