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Spindle run-out in K and T 3B Plain Horizontal Mill

Tatertots

Plastic
Joined
Feb 11, 2018
I purchased an old Kearney and Trecker 3B Plain Horizontal mill with three different overarm supports and some random basic tooling for about double scrap price last year. I was excited to try to bring something made 80 or more years ago back to routine use (no serial number located - researched with limited success and believe it was made in the late twenties into the thirties). It had been sitting for years in a barn, and after cleaning it and figuring out how to change speeds and feeds was pleased to find everything appears to work including the oiling system and coolant. The table, saddle and knee move without excessive slop or too much backlash. The spindle has about .015" run out at the spindle measured from the variety of arbors and tool holders that came with it. I do not have a dial indicator that will fit far enough into the bore to determine if there is a single high spot or the whole shaft is bent. In case there was a burr or debris in the spindle bore I bought nice used #12 Brown and Sharpe hand reamer. There was very little improvement in run out after several attempts to ream the bore. The mill loads and unloads the cutter so much on each revolution that it sets up a slow vibration or oscillation with a new 2" wide HSS helical shell mill I chose to try on a mild steel block. I can't work around it despite changes in feeds,speeds, or depth of cut.

I thought about taking the compound slide off my big lathe and attaching to the mill table and using a boring bar to attempt to make things true, but the low spindle speed would likely create a very poor finish even if I got the taper right. Does it have to be ground rather than bored to be done properly?

I would appreciate advice on the correct approach to fixing this problem. Do I have to take the shaft out of the machine to repair it properly? If I am going that far should I consider making a new shaft with a more modern taper that has more tooling readily available (BT40 or similar). I don't mind spending a little coin and decent effort to return this machine to work, but at some point it becomes foolish (may be there already depending on your perspective). I know myself well enough that once it comes apart I will be on the slippery slope of a full tear down and rebuild - only to have a machine with no rapid feeds, no vertical head (unless someone has one laying around :)), and more time and money into it than buying a much newer mill - and all the time without a working horizontal mill in house.

Anyone have a line on a book for this machine?

Thanks for the help!
 
Plain bearing spindle. If post 1914 will have FLANGED spindle with face keys - that's a little after they patented that feature

You will see this feature on it own page in the link below

If it is FLANGED, how do OD and FACE of spindle flange run?

Bottom line to really know is have spindle out and checked to see if its bent (I once bought a 20" P&W lathe that turned out to have a bent spindle, which I straightened)

Thanks to Greg Menke for hosting this for me

http://pounceatron.dreamhosters.com/docs/kt/kt-milwaukee-catalogue19-circa1917-port.pdf
 
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It is the flanged face type spindle. Both the face and outer diameter of the flange run true at about a thousandth. I am waiting on the correct mount for one of my indicators to try and reach inside the bore and check for a high spot.

The marking on the front of the knee that the catalog indicates is needed to order accessories is 4/453... anyone know if its the 4, the 453, or the combination that I need for a match? Would a vertical attachment span multiple models of the size three mill (hoping to expand the possibility of finding one...) Thanks again!
 
Its mill number 4 in lot 453, which is way back. They were up to lot 671 in 1920 - which is as far back as the Serial Number Reference Book for Metalworking Machinery goes

I did two of the flanged spindles to NMTB 50 - one started out as B&S 12 and the other was B&S 14, both Cincinnati


It is the flanged face type spindle. Both the face and outer diameter of the flange run true at about a thousandth. I am waiting on the correct mount for one of my indicators to try and reach inside the bore and check for a high spot.

The marking on the front of the knee that the catalog indicates is needed to order accessories is 4/453... anyone know if its the 4, the 453, or the combination that I need for a match? Would a vertical attachment span multiple models of the size three mill (hoping to expand the possibility of finding one...) Thanks again!
 
After checking the bore of the mill spindle it was still pretty rough. It obviously has had tools spin many times. I got the reamer out again with little more success. I finally placed a ball bearing between it and a piece of scrap stock held in the vise to apply some pressure to the ream. After several cut and clean out cycles a lot of debris was removed. I finally got shiny material over the whole taper area (with holes of course). Tooling now running true inside of two thousandths. I made a new arbor from 4340 and attached to the spindle without the overarms attached it is 2 thousandths out 18" from the spindle... I am very pleased with that result. The old girl is back on her feet and cutting true. Now I just need to figure out the cutting speeds and feeds that it likes. Thanks for the help in getting it going again. I am proud to have a machine working in my shop that should be about 100 years old! If only it could talk...
 
That's great. At least it feeds in inches per minute. I had a little older Cincinnati that fed in inches per revolution:rolleyes5:

After checking the bore of the mill spindle it was still pretty rough. It obviously has had tools spin many times. I got the reamer out again with little more success. I finally placed a ball bearing between it and a piece of scrap stock held in the vise to apply some pressure to the ream. After several cut and clean out cycles a lot of debris was removed. I finally got shiny material over the whole taper area (with holes of course). Tooling now running true inside of two thousandths. I made a new arbor from 4340 and attached to the spindle without the overarms attached it is 2 thousandths out 18" from the spindle... I am very pleased with that result. The old girl is back on her feet and cutting true. Now I just need to figure out the cutting speeds and feeds that it likes. Thanks for the help in getting it going again. I am proud to have a machine working in my shop that should be about 100 years old! If only it could talk...
 








 
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