Adapting a pillar drill for vertical milling - new chuck

MRA · Apr 11, 2017

...and the result works really well. I can now put a 1mm cut on in mild steel with a 3/8" end mill, and using some soluble oil in a cheapo squeezy pipette I can get a good cut with very little vibration and a reasonable rate of feed. Finish is good.

So...next installments might be adding power x-feed (I have some ancient small DC motors with worm gearboxes on the end), and if I get really ridiculous, adding the much-too-large spare Bridgeport DRO which I could loan from the lab workshop where I work. We'll see!

cheers
Mark

Cogsy · Apr 12, 2017

A quick note on the bearing (BTW with metric bearings 20mm I.D. and above, the last 2 digits of the number are the shaft size divided by 5, so 6205 = 05x5 = 25mm) you can buy a few metric standard sizes with imperial I.D.'s - 6205 is one of them. Almost any bearing shop should have something like a 6205/25.4-2RS sitting on the shelf. Bit late now I know but if you ever get stuck in a similar situation adapting metric to imperial it's worth a little investigation.

Your mill/drill looks like it was worth the effort. Nice job!

MRA · Apr 12, 2017

Thanks, and thanks for the heads-up on metric bearings for English shafts - I didn't know about that.

I wonder if anyone recognises the maker's trademark cast into the side of the column supporting the miller table. I'm curious to find a picture of whatever it once belonged to.

MRA · Feb 5, 2018

Hello again!

Bringing this thread back from the dead - here's what happened when I added the 'incline motor' from a dead treadmill I bought (for the main DC motor which I'm going to play with on my lathe).

I tapped the end of the x-axis lead screw to 2BA, and loctited a bolt in. I'm using a 12pt 2BA socket as a dog clutch to drive it, attached to a 3/8" square drive filed into the output shaft of the worm gearbox on the motor.

The bronze lump is for the motor housing to push onto - you pull it off until the 'clutch' disengages, in order to drive the table by hand. I did it in bronze since my mate and I were experimenting with melting copper and some tin which 'Abby' of this forum very kindly sold me. If you look closely you can see where I failed to provide a feed for the thick bit of the fixture and it shrunk as it cooled. Works OK, though.

I get 25v ac from a 'Memlo' lo-volt lamp transformer, which was a previously unused part of a shed light fitting. I rectify this in the little die-cast box and feed a PWM motor controller which was something daft like 3 quid from China. It has no feedback so it slows a little under load, but this is OK in this application. On top there's a switch to reverse polarity / change direction, and there's a nice green light on it which my late father-in-law harvested during a TV transmitter re-installation in the Irish Republic many years ago (he was one of the original crew of TV engineers on RTE); slowly I find uses for the bits of his stash I inherited!

All this means I can cut longer slots whilst paying more attention with the plastic pipette full of soluble oil. It seems to work ok.

Oh - edit to add - this also provides a speed-controlled PSU for my Dremel-a-like engraving tools, so that's handy!

cheers
Mark

MRA · Jun 9, 2021

Inspired by another recent thread on millers, I thought I would update this a little more. Here are some pictures of things to make it even stiffer. The metric ball race ended up (I thought) being a little too far from the cutter tip, meaning it would wobble / vibrate, so I turned down the outside of my ER25-chuck-holder and made it into a plain bearing running in an oilite bush which is held by that split clamp thing. I then added some shims to the split clamp so I can do it up tight without making the new plain bearing go tight.

Then another lab at work got a water jet cutter, and I found a scrap piece of 1" plate - so I got someone to do some CAD from my sketch and I now have another brace to hold that split clamp back to the column of the drill. It's a good fit (the water jet seems accurate to <20 thou) and I can operate the quill handwheel when the clamp bolts to the column are slack - it slides up and down OK.

I cut the T-slots you can see under a red-painted bit of old plate in one of the pictures, on this thing, and it was OK though I obviously went pretty slow. That bit of red plate is part of a holder for a 'Target' horizontal milling attachment which would normally go on my lathe, but which I think I can do more with on the Franken-miller. This is also in one of the pictures. I will paint it when it is done, honest (the bits of scrap lay in my front garden for quite a while before a use suggested itself - my shed is too small to keep bits of scrap box-section within it!).

I also bought a couple of incomplete Progress No.1 drills, so I have a spare quill and spindle with a drill chuck on the end (it was getting tiring changing drill bits in ER25 collets) - and enough bits over to sell on a complete drill when I get around to it.

If anyone is thinking it would have been easier to buy a Chinese mill-drill, I have no comment

MRA · Jan 13, 2022

I needed to cut a slot in something, so I finally finished off the gizmo (well, I suppose I could also paint it) so that my Franken-miller-drill-thing will also do small horizontal milling jobs. Here it is having just cut a slot in something. This 'Target' milling attachment works well in the lathe (which it was designed for) with a boring table substituted for the top slide, onto which the job is clamped. However height of the job is very limited, and there is no possibility to (for example) squeeze a dividing head in there. Mounting things this way on the 'miller' gives me a lot more range in the up-and-down direction, which I hope will make it more useful.

You might notice that the drill runs in reverse to drive this. The plastic belt slips a bit, and maybe I'll look into doing the drive a different way if this becomes annoying - perhaps driving the mill spindle with its own small motor-gearbox (I have a couple of old Parvalux-type things).