lil' old mill

So, I started this project back at uni, 12 years ago.

When I graduated in 2007, this is what it looked like...
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It was a shiny beast back then, surface ground blocks of stress relieved steel and iron.

Too heavy to (sensibly) carry as it should be.

But alas, the responsibility of adulthood left me wanting for time to work on it, and with changes in job, I lost access to the much needed machine shop to continue.

I fitted the motors back in 2012 and that was it for 6 years.

And for 6 years, it has sat in my home shop, untouched, unloved. Slowly loosing its shine, its ways hidden by dust...

Until about a month ago, and like the phoenix, it is rising from the depths of the (man) cave to be born anew...

Pics and progress to follow :)

Started on the Z. construction is a 100x100, 10mm wall box section steel with 25mm plates bolted to either side for the rails:

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And for the record, those are steel toecap sandles :)

I like it. I'm really curious on the details, I'm designing an epoxy granite machine around the same size to replace my G0704. Is there a build log of the original?

Are you worried about resonance in the boxed section? What size rails are you using? What kind of spindle?

Do you happen to have the table dims and a source?

Sorry for all the questions lol

Just quickly before I head home....
I think it's a Taig bed. The linears are 20mm THKs I think (This was all back at Uni and details are sketchy :( )

Z will have 15mm Hiwins and 15mm ball screw. Spindle is 1.5kW watercooled with ER11 collets.

If I have any resonance issues with the box, I'll fill with sand. But I'm giving it the old 'hit it with a spanner and see if it rings' test. So far, it goes 'clonk' and that's it :D

Will try and get some specs tonight along with more Z updates.

Well, as of this evening, this is the state of the mill, dummy steel represents Z.
Base is a solid plate of cast iron 50mm thick with 25mm steel plates either side.
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Confirmed 200x200x200mm travel.
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Poor rusty motor mount.
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Underside of X axis (table)
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Current Stand Status with space for le' handy electronics
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So, these are my steppers, reclaimed from a skip. Does anyone know ANYTHING about this brand/make? Greatly appreciated if you do, all I know is that it's a FEA2M55 :)
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So, the X&Y assembly hasn't been touched for about 5 years, hence the surface rust.
As for the Z axis. It's been the most recent work (read, last month of so). And that has gone from nothing but a pile of scrap steel to this.
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The spindle and box section are just mock ups for now. Spacer still to be designed.

Next job is to get the ball screw mounted. Going to be tricky as I'm having to mount a bearing at either end and pre-load together down the whole length of the screw. Second hand screw had had it's locknut thread cut out for some reason.

Got the Z linear components finished over the weekend. Despite some initial worries that some of the components may not be square enough, playing around with the 20 adjustment bolts has left it with almost zero binding, am very happy with it.
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I need to start thinking about how I'm going to finish it. I could leave it bare steel and just accept the surface rust will be an inevitability if I don't keep it oiled. Or I can paint it. What do you guys think?

There is something nice about being able to take scrap blocks of steel and make them into something usable :)

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Can't wait to see what I can do with a CNC.

With the Z mounted, the next thing to do is make a mounting bracket to hold the spindle to the saddle. I'm putting the spindle in the middle of Y movement for the biggest cutting area, which means it need to be about 100mm high.

Decided to use some spare 100x100 section (left over from the body of the Z), 12mm plate for the spindle to bolt to and 20mm thick block inside the tube for the saddle to bolt to.

It'll hopefully be the only welded assembly on the actual mill (except for maybe covers / guards), but I don't want it to look out of place, so it'll get a full re-machine after welding.

Bits machined and assembled.
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Got a friend to weld it together and then faced off when I got it home. I was considering welding it myself, but 1) I don't have the most powerfull MIG, 2) My welds are just a bit pants and 3) He has access to a industrial beast.
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These holes will bolt to the Z saddle plate (4x M12) with the spindle mounted on top like so:
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Probably go for M12 on the spindle - spacer interface. But need to skim the spindle mount, it's a horrible aluminium casting, but does the job with some decency. I may, if I can find a decent source of a steel block, make a steel one. orrrrrr get an ATC if the boss lets me. Maybe once it's up and running :)

looks like it'll be a stout little mill for sure!

Yea, Stout is a good word. Thankfully, I didn't go too big as doing anything this size on a Chester 626 mill requires some horrible setups.

Managed to get the spindle mounted, only to find I've got bolt heads hitting bolt heads, so need to do some re-work. But I'm happy with the rigidity.
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Also machined the plate for mounting the top stepper. This was a REALLY nasty bit of plate that I had used to smash rocks on, so excuse the nasty :)
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As for the top of the column though, it wasn't square, straight or anything, so had to mill the whole thing. Through 4 operations, with terrifying clamping methods, each clocked in individually. But the end result is nice and square.
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Got to drill and tap the column to mount the stepper plate tonight. Will be a mark out and pillar drill job, so fingers crossed for accuracy.

Bit more work getting the last of the Z machined and fitted. But in theory, this thing could start cutting with the electrics. So, machinist hat off, sparky hat on.
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IT LIVES!
VIDEO!
:banana::banana::banana::banana:
https://www.youtube.com/watch?v=dv7KQE0dG1w

Congrats! What an awesome build. I wish I had the equipment to work steel like that.

Just curious, as I've been researching motor/shaft couplers for my CNC project recently, are those helical couplings suitable for a machine as "stiff" as a mill should be? Wouldn't the mass of the table cause the coupler to stretch or compress axially when the motor accelerates?

Cheers :) The shaft couplings will suffer some torsional stretch, but unless it becomes a problem during test, I'm going to ignore it :)

I'm planning on doing some acceleration tests when the mill is next together (currently disassembled on bench while I work on the mounting table).

Did get a quick video of repeatability though:
https://www.youtube.com/watch?v=z4q0w8EKQ9w

So, there has been some more movement. I added an old desktop PC (With a 5.1 surround sound system because, why not). Spindle coolant is in. Made a mister (although that needs testing) and it's had all the swarf guards and limit switches added. Will get some more pictures as and when I can.

https://www.youtube.com/watch?v=DjLdB4Nxtak

I think.... I'm about finished.
Except for
- Coolant
- Mister
- Compressor
- Feeds and speeds
- Cleaning electronics cabinet
- Better cable routing
- Limit for Z homing
- Better desk for keyboard and mouse
- Network connectivity
- 4th Axis
- Laser cutter head
- Lathe spindle attachment.........

https://www.youtube.com/watch?v=SbnLRLIJnsA
Oh, and it makes chips (takes a while for spindle to register full speed.... needs an encoder)