The life of an old mill(K&T 2HL)

MrCrankyface

H-M Supporter - Silver Member
H-M Supporter - Silver Member
Joined
Nov 7, 2019
Messages
428
Hello everyone!

Been posting some of this machine on another machinist forum but figured I should post here as well.
Always fun and education to have more input considering that I'm very much an amateur at these things.
I consider this entire machine an ongoing project hence why it's here as a members project.

WARNING, I LIKE TO POST A LOT OF PICTURES :)

Long story short, I've wanted machines that could work metal ever since I was in the early teens, I like making things simply put.
16 or so years later I finally had the funds and space to turn my dream into a reality.

I had been looking at various ad sites for a while and eventually this 1947 K&T 2HL showed up for aprox $600 so I went and picked it up as fast as possible.
Weighing in at around 2600 pounds it's a bit of a handful for someone with no real equipment. The seller helped us load it up on the trailer I had borrowed.
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Had a friendly contractor working in the area help me lift it off the trailer with his digger but getting it the rest of the way into the garage was a bit of an adventure..
Drove our little golf in and attached a chainblock to try and pull it in, which often resulted in the car sliding rather than the mill...


Eventually managed by very carefully hoisting the rear up and letting the jack act as a dolly of sorts ontop of some scrap plate.
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Here it sits with my entire 'arsenal' of tooling in the background. :rolleyes::grin:
What followed was what felt like an eternity of cleaning to get rid of old grime, loosening seized components and just generally trying to understand my first ever milling machine.


And here's my first "real" project with it.
I had done some tiny milling before but here I milled out all the "teeth" on the bottom thing and milling a bunch of other stuff to square and size.
The whole thing is a manual splitter for firewood
Sure, you could do this with an angle grinder but where's the fun in that?
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After using it for a while I decided to do a small teardown since I was constantly worrying how the ways and oiling systems looked underneath.
It is after all 72 years old.


On top of the knee ways you have a saddle for Y movement and also Z axis rotation(ie the entire X table can rotate).


This is one of the nicer looking parts... Lots of sludge to remove and the oilwicks were .. Let's say they had passed their "best before" date.
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Here's the little X screw, mid-cleanup.


I also started going through the vertical head that would every now and then let out black goo through the spindle bottom..
It was filled to the absolute brim with grease, most of it looking to be from the early 1800's(Ok, maybe not that old)
I took a whole lot of fistfulls of grease out of it...
 
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Here's almost all the parts that go into the vertical head attachment, cleaned up and nice. Most things still in good shape.


Greased up and re-assembled, ready for install.


Whole machine is starting to look a lot better, besides the worn paint.
I have also started installing a DRO here.


With a decent working matt it was a pleasure to play around here!
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Sometime after this I made a bad mistake as I was testing out the overtravel stops...
One didn't work.
When it was supposed to trip and turn the powerfeed off, it instead jammed and caused the entire powerfeed gearbox to bind up and shatter the weakest link...
This is the input gear to the entire knee gearbox, controlling all feeds except rapid traverse.
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Here's the powerfeed gearbox taken out, quite the procedure.
The above gear sits on the backside of this.


I did my best to repair my mistake but without the proper tools and knowledge, it never became 100% good.
I welded on material where the teeth were missing and cleaned it up on my mini-lathe.


Cut the teeth back out with a home made tool, basically a horizontal flycutter I guess. Ground the HSS bit as close as possible to the orginal tooth shape and used a 3D printed indexing plate.
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The gear didn't come out 100% good but it worked pretty well for quite a few weeks, probably closing in on 80h of actual work.
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During those 80h I managed to finish my DRO install, just a "cheap" asian import DRO but works well enough for an hobbyist amateur.


All the brackets cleaned up and painted.
I'm big into re-using materials. Most of what I've used here is scrap that was going to be thrown away or had already been discarded.
Feels good to not let more stuff go to landfill and also tends to be cheaper.
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Enter ... Stepper motors and CNC controllers.
I'm going to use the Mach3 software which needs a dedicated PC for it.
The power supplies and stepper drivers were bought but the rest have just been lying around for years.
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About halfway wiring everything together, took me quite a while with lots of pauses, trying to figure out what goes where and why.


Finished all the wiring and it should pretty much be a CNC controller by now.
3 fans in the front suck in air through the filters and 2 fans in the back throws it back out.
This hopefully keeps the box slightly pressurized so it doesn't suck in dust through small leaks in the box.



Prototyping up some motor mounts I started with paper templates, later moving on to 3D printed templates of my designs.
Rather find flaws on a easily reprintable piece than a piece of metal I've spent all day on.
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Lots of hours later .. Bugs ironed out and remade everything in mild steel.
Left is Z and has a torquier(is that even a word?) motor, right is the Y axis.
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Simpler holder for the X axis. Z and Y became overcomplicated due to my lack of experience designing things like these.
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Still mostly using old scrap to make these things. Got a few of these old pipe lids that I managed to use up making motor plates.


Voilá, one CNC almost ready to run!
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Feeds perfectly now. You can mill "as normal" by just jogging it with a wireless keyboard or you can send it a full program to do more advanced manouvers.
Keep in mind it's still using the original screws with tons of backlash.
The software can compensate for that backlash up to a point but I'm not expecting thous here.
Screen on the wall can show both the hidden raspberry and the CNC computer, just select input depending on what you're doing.
The wireless keyboard on the worktable is to the CNC.


I also dabble in making youtube videos so here's a summarization of the project up to this point:
 
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Excellent!
Cheers
Martin
 
Welcome to the forum. Thanks for the pics
 
Man I wish I could find a decent K&T for 600 bucks.
 
The universal table is a great feature, and nice job on the CNC conversion. Thinking your going to want some sheet metal covers (clear lexan would be cool) on your belt drives to protect them from swarf. Welcome to the forum, and looking forward to watching your project progress. Cheers, Mike
 
Very nice conversion- you have been busy! As to the broken gear earlier, a better repair would be to machine off all the teeth and find/make a new spur gear with the center cut out, then pin the two together and braze or weld
Mark
 
Thanks everyone!

NCjeeper: Not sure if this qualifies as decent. The ways are VERY worn down :(
Want to give scraping and rebuild a shot but currently got too many projects to go that route.
FOMOGO: Guess you're in for a treat! :cool:
markba633csi: I considered going that route but the gear is nonstandard and I had a hard time enough just making those 3-4 teeth with a broken mill so making an entire ring would've been horrid. Sending it to a shop wasn't an option due to the cost of it which was my only other alternative.

Pictured is two driveshafts driven by the one and only motor in the mill, they're responsible for powerfeed and rapid traverse respectively.
I removed the bevel gears here to make it stop driving the knee and feeds entirely since that gearbox doesn't need to turn anymore, reduced both noise and load on the motor.
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I then started looking into making a cover for the Y and Z motor so they'd stop getting chips on the belts. Originally I was just going to put a plate here that'd double as a tool area ...
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But then I kinda let my creativity loose on this thing... I believe this is the point where things start getting out of control. :grin:
My DIY sheet metal bender also didn't quite like this 1/8" plate. :grin:
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Attached a foldable 'desk' area.
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Overkill? Probably. But fun!
Switches from left to right:
On(impulse) for PC box.
On/off for CNC PSU's(if driver sees an error you need to reboot it to reset alarm).
On/off for lights(there is none yet).
Manual-0-auto switch for cutting liquid pump.
Manual-0-auto switch for spindle.
Emergency stop(Yeah I know this isn't correct kind of switch for this purpose).



I've always been a bit annoyed by how far chips can fly and with the machine "automated and unreliable" I'd prefer to have some kind of shield between me and the machine.
I could've gone the 'easy' route and just had something around the spindle but I didn't like that idea since it might hit the work piece/clamps and so on.

I started with a rough concept and ended up around here somewhere.
The main requirement was to shield from any chips aimed "out into the room" and also fold up to minimize space when not in use.


It was going to be manual until I realized I'd be too lazy to use it .. So automation here we go.
Plastic sheet that will get raised up to bea couple of inches above the spindle.
With the plastic sheet down it stays below the top level of the table, incase I have to mill something that extends the table.


Here's a look of one sides mechanism. Another motor closes/opens the doors.


Tore down the control panel and sanded the middle plate while painting everything around it.
Tried to get that "brushed aluminium" look on the panel.
Also added a third switch for the shields/windows in/out.


Everything except the plastic windows is now mounted, still need to start running wires.
 
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I decided that it was an absolutely horrible idea to have the CNC screen so far to the side since I need to look at it more often than I thought ...
Found a cheap replacement monitor(used) and of course over-engineered the heck out of the new mount.


A small geared DC motor runs a winch through a pulley system to raise and lower the screen with the flick of a toggle switch, it stops at either end.
A small string lifts the "shield" when it's down in "use mode".


This allowed me to move the smaller screen to the machine instead.. But I still want to keep the DRO on there due to the backlash in the screws.
Just need to make some kind of bracket so I can mount both.


First time welding steel with TIG, a lot of fun!
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Just need to plug them back in now but might move computer box first to a better location.


PC box has been mounted to the wall to keep it free from chips.
It has a flex hose going to the control panel for all the wiring.


Rewired inside the PC box. All DC 0V are now going to one point in a star configuration. This is to make sure there's no floating ground potential between the different PSU's and simplifies wiring.


Control panel also has a bar for connecting all grounds. Should be plenty of space for potential expansions(feed hold/run for example).
Both this and the other connection bar are sitting on plastic spacers, insulating it from the metal around it.


This brings us almost up-to-date on this project.
I'd say I'm fairly on track of my original idea of "let's spend one week and just throw on some stepper motors and run it".(it's been over 3 months) :rolleyes:
 
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