Bigger table for a small mill

My little Micro Mill is a surprisingly sturdy little thing, and has coped with everything I've imposed on it. But on a few occasions the table has been too small for certain jobs, so I ordered a larger table and screw from Arc Euro Trade on Tuesday, it came today (Thursday) and I fitted it today. Great service, and fitting it went smoothly.

I must say that although my Micro Mill mill was bought from Warco years ago, the larger table is for Arc Euro's SX1, they are both the same, so if anyone is thinking of doing the same as me, don't worry, it will fit.

The table is substantially larger (160mm) than the standard table.

All edges and surfaces were de-burred and stoned with a fine oil stone.

Fitted and looking good. I also took the opportunity to give the mill a polish and clean up.

One small issue was that my every day 'go to' vice has a locating bar which fits the old tee slots nicely. The new table tee slots were slightly too tight by a couple of thou, and had to be filed down to enlarge them.

I haven't checked for accuracy or tramming yet, that will be done soon, but all looks okay and feels smooth. And I might take it all apart sometime to scrape in the ways, although there was no scraping at all on the mill, so I'll no doubt leave it alone.

Ian

I did the same to my Clarke CMD10 at the beginning of July.

You filed the Tee Slots?! Or the tenon? By the way, I would make or buy some proper tee nuts to fit and spread the load better than off the shelf coach bolts.

My SX2P mill has M6 tee nuts which work but seem a bit feeble on heavier jobs, I found that M8 coach bolts are a close fit in the table slots. The round head just needs a couple of flats machining to allow them to slide in, I use them most of the time and they are much stronger than the small M6 tee nuts and studding, cant see a problem with them.

Edited By Ron Laden on 01/11/2019 08:37:43

On small machines like this I'm a great believer in aluminium alloy Tee nuts with steel studs loctited in place. I feel the alloy will deform slightly should the slots be imperfectly machined thus spreading the loads. I also figure that any swarf will embed in the alloy reducing the chance of damage to the slots. Digging the swarf out of the alloy nut is also slightly less painful than digging it out of the underside of the slot.

Easy enough to make a strip and cut down to use as and when. You don't actually need a proper thread in thes tem of the Tee so you cna trim the sides right down. Thread in the bottom will be ample.

Clive

Ian, that certainly looks to be a good mod and gives more options with the longer table. The new table at 400mm is still reasonably compact and good that it was a straight change over.

Ron

What's wrong with filing the tee slots? It's what we fitters call 'fitting' that's what fitters do! And now it fits very nicely.

And there is nothing wrong with coach bolts I've used them for years with no problems, they are actually M8 bolts and give the same cross section of contact as the small 8mm tee nuts with a M6 stud, and they cost pennies. The table is strong enough to take any abuse I give it. Very pleased with how it all turned out.

Ian

Ahh! The difference between a fitter and an engineer. The engineer would alter the ‘temporary’ part so that any other temporary parts, fitted in the future, should fit the machine.

The assumption here is that the large fixed item was faulty (needed fettling) whereas it was far more likely that the T-nuts were the offending part (cheap to replace). The slots may well now be too large for any future parts that may come along - and that removed metal cannot be replaced.

Just seemed a lot of work, and awkward, to file the tee slots rather than just the tenon, not to mention filing away at that nicely machined table.

The real problem with using Coach Bolts rather than proper T nuts is that the underside of the slots can so easily damaged owing to the reduced area of contact of the coach bolt head conpared to that of a properly sized T nut.

The phrase 'Can of worms' comes to mind! Yes the table is very nicely machined, but the tee slots were odd sizes, two were machined slightly tight and the other fitted the tenon okay. And now all three slots are not tight, and fit the tenon very nicely. It glides along the slots like an ice skater on a cushion of feathers.

And I can also use the vice with the tenon on the old table if needed because I'm thinking of making it into a mini pallet for my KX1 CNC mill No doubt with a lot of hack-sawing, filing, chiselling and hitting with big hammers to make it fit.

And don't worry about using coach bolts they work just fine.

Ian

I do hope the op was taking the mickey when he said he was filing the tee slots. Or at least only filing the front side of them, otherwise he has wrecked a brand new table. Those slots are dead straight and exactly parallel to the X axis for a reason.

 Making tee slot nuts which fit the slots better than the bought ones is a good idea, they spread the loading better, Mike is making some out of key steel for the Tom Senior, they are also 20% longer than the bought ones.

I worked as a fitter in aircraft engineering but certainly not as a butcher as described.

Edited By old mart on 02/11/2019 20:52:47

Edited By old mart on 02/11/2019 20:56:44

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Respect ^^^

MichaelG.

Respect for fitting skills! Nothing has been ruined and it all fits and works very well. Tested the tram today and the Y is spot on, and the X is out by 0.0015 over 6 inches, that's without any adjustments to the column.

The tee slots are within less than half a thou of each other. Probably better than when they were machined. I also compared the surface area of the tee nuts that came with the machine and my home made coach bolts, the coach bolts have a larger surface contact area!

And don't tell anyone but I filed the underneath of my mini lathe bed soon after I got it to improve the saddle travel, because the underside was machined uneven, and guess what? it's better than ever now!

We should all learn how to use a file, and not to be too precious over a lump of metal. If it was a 5 axis Matsuura I wouldn't need to file anything.

Ian