As I said in the last post of the original thread, all was good until I tried to use my insert tooling, primarily the 5 flute 50mm shell mill (from Arc Euro and is a decent enough cutter).

The max depth of cut I could get away with cleanly in mild steel was just shy of 0.2mm and this had to be run at max rpm (aprox 1600). Anything slower or any deeper resulted in the most horrific noises from the gear head, incredibly poor surface finish – more like the Preseli mountains than milled steel and obviously very poor insert life and the cutter speed was obviously varying, it was clearly visible – gear train chatter I presume (unless the motor was ‘slipping’!).

Running regular end mills was no problem and I’d done a fair bit of chewing metal with them, all sorts of sizes from 4mm to 12mm, roughing, corner radius, ball end etc all ran beautifully and the machine was ruining lovely.

The problem with column mills being the rigidity of the column and the very large gear head weight hanging off the front of them.

The way the gear head fixes to the column also creates problems as depending on how tight you nib the gib on the column, it will give a different (all be it very small) angle in the Y axis of the cutter face. I marked the gib locks to so as to always nip them to the same point as a very slight change in gib pressure will result in a line you can feel (either cutting more at the back edge of the cutter of less) when using an end mill to cover a flat face on the work piece. Not much I can do about that other than keep locking the gib to the same reference marks.

Column rigidity – how bad? Well, with an indicator mounted in the spindle and zeroed on the table, all gibs locked, it didn’t take much pressure at all on the top of the column pushing backwards to move the indicator 0.1mm. Tool push off from the shell mill was obviously bouncing the whole thing significantly.

Was it my fault in the way I used the SKC Resin Machine bonding Epoxy to mount and tram the column?

Was there something else, something loose?

Time to get measuring.

Thanks Michael, I have seen a few things round the internet regarding Epoxy Granite filling, there is a few bits on YouTube too – it did cross my mind but I really don’t have the lifting gear to do it.

I’ve not seen that article before so thanks for that, some good info there however I went a slightly different route (I’ve already done it, and using my self imposed exile from the workshop etc to put it all together and write it up here) but that’s not to say it wont happen! 😁🍻

Cheers Michael, appreciate that!

Anyway.. first things first was to address the wobbly tin box that was the base.

I wanted to make it so the original base panels would fit round it and keep it looking half tidy.

I picked up some 80mm x 6mm box from a local firm from their ‘bone yard’ for the grand cost of putting a few pints behind the bar at the local for the boss. It was proper rusty but as time is the one commodity I have while waiting to get myself fixed so once cut roughly to length it had 24 hours of so in some triple strength vinegar (Patio and path cleaner I believe it’s sold as) which removed all the rust and then I gave it a wash with some phosphoric acid to prevent further rusting over the time it would take me to finish it –

Then began tacking it together.

Back in the summer I picked up a 1200 x 600 hobby fixture table to replace my roughly knocked up welding table from Mac Industries (what a proper helpful bunch, cant recommend them enough!) and what a difference that makes putting stuff together, it stays where you put it even after welding! Absolutely brilliant!

Here is the beginnings of it

It eventually turned into this, here with the template on for drilling the holes to mount the mill.

That phosphoric acid wash seems to create some lovely soot marks, if I wire wheeled the metal clean it didn’t happen but as it was going to be cleaned up tidy prior to painting I gave up bothering with it. The curved corners of the metal meant each weld was essentially a root with 2 further passes over the top so I think it mught be strong enough 😁

And the finished stand (which weighed far more than I could move so dam good job I have that overhead hoist!)

I welded plates with holes and captive nuts over the bottom of the legs to add decent adjustable feet (you can just see the standoff bolts in there to raises it up for painting.

Next job was to get the top of the stand the same as the bottom of the mill base, it would be a bit rubbish to bolt the thing down and twist it so it was the biggest load test of my gantry hoist yet.

Ratchet straps spread through the base and attached to the hoist so I could take the weight with the hoist then lift using the ratchet straps as I simply didn’t have the physical ability to pull the hoist rope. It worked a treat!

Then first off using a feeler gauge to measure the gaps and an air file to bring things into line.

This was back and fore lots of times until I was unable to get a 1 thou feeler in anywhere so then as I’m being silly with the whole thing I rolled some blue on the stand and used that to finish off which turnedb out to only take a couple of really light ‘dressings with the air file on slow and there was full contact so that’ll do!

Next was remove some of the reinforcing from under the original stand’s top plate and that was ready (after a coat of paint obviously!) –

And then try the mill again.

I still cant believe my hoist lifted that no problems at all, it must be over 200kg as I’ve only removed the gear head and according to Chester the Super Lux is 300kg but it did 😁

Remarkably the rest of the panels were easy to fix on with the original fixing holes so my measuring must have been OK!!

I knew the front wouldn’t as I made the stand deeper.

Who’d ever know!!

I had to make up some spacer blocks to fit hinges for the front door panel but that was no drama at all.

Then the bottom shelf had to be cut up and altered to fit tidy in the bottom but that went OK.

I did the shelf and door at the end of the job hence everything looks a little different up top.

Next job is on to the important bit..🙄

Cheers Vic 👍

I’m glad someone is paying attention Michael! Please keep marking, lord knows I need it 😁🍻

Cheers Clive,

One thing I have gleaned from hours of looking at these things round the internet is the wildly varying levels of build and castings, some really good and some that are .. well questionable at best – like the one I picked up. I think mine was quite an early one although no idea if that was anything to do with how it was built.

🍻

I was ordering some steel soon after anyway so tagged a couple of bits on to go with what I already had and ended up with this lot –

The issue of mixing steel with cast iron and the differing thermal expansion rates etc but for what I am doing it really isn’t going to worry me.

It was to become a cradle around the base including over the top where the rear hold down bolts are, consisting of a 15mm steel plate across the rear face, 8mm plate’s down either side and over the top of of the hold down bolts, 2 10mm plates braced together and going up the fill height of the column attached in a couple of places.

Easy when you say it like that!

First to clean off all my new paint etc from all the contact areas –

Then set up the lower plates to get things from in my head to how I’m expecting it to be and start marking up the drilling points for attaching –

My plan was to bolt the lower cradle to the base casting with a bucket full of M12 bolts set out as near to the webs inside the casting as possible then use some M6 bolts as jack off’s to hold the whole cradle just off the base casting.

Once the cradle is fully welded, bolt the whole thing to the base and use Solco Pure Epoxy Anchor Fixing to bond the cradle to the base. The stuff is designed for use in fractured concrete and is therefore totally non shrinking, compressive strength of 88N/mm2 and has an unbelievable bond strength to steel – an m14 stud set in the stuff will shear before pulling out when tightening.. good enough for me.

A few pics..

Then tack the plates together properly and refit –

So that’s the cradle all tacked together and fitting well, resin injection holes and lower vent holes drilled.

I just wish doing it was as quick as writing this up, drilling that many holes and tapping them took more time than I care to say, it was several weeks .. I can do most stuff left handed but that was proper difficult and only managing an hour or 2 over a day (although now the back is fixed that should improve dramatically!) 😁

Anyway, on to the column brace..

Time for a test fit..

It sat really well on the back plate, I used a small piece of 4mm ally plate as a ‘near enough’ spacer at the top and to be honest the clamps are only there as I couldn’t move out of the way quick enough if id did fall off, it sat here quite happily without when I hoisted it into place!

You can see one of the corner braces I will be using to help join the cradle to the upright in this pic.

Time to get welding then.

Good morning all.. !

Welding .. heat .. movement.. 🤔 I’ve tried to keep this thing as ‘true’ as possible, and after the 1st round of welds and using some clamps etc it wasn’t too bad at all. I was quite please with my self!

However, thanks to not using enough clamping force (i.e. just 1 clamp rod instead of 4 when 4 were available!) running the rest of the welds between the rear 15mm thick plate and the column brace caused a reasonable warp. I should have known better but there we are.

So I got the Tig out and ran some fairly high power un-filled mirror welds down the inside of the rear plate and thanks to (I believe!) far more luck than judgement she pulled back into square!

Clear to see here –

Finished welding .. and it’s still the right shape!

I did end up laying a couple more beads down around the side webs when I realises there was just 1 rather dodgy looking run along each edge to get a better fill into the uprights with them being so thick but other than that, time for a test fit.