The 'E' Type Forum

Spent the weekend renovating my Grandpa's old workbench. He built it in the mid 1930's out of slotted angle iron and it was held together with Whitworth hardware.

Trued it up, welded in some supports for a toolbox and a few storage crates, a coat of paint and a shiny new galvanised top.

I plan to mount my new mill on it.

Very smart!

With all due respect, lovely though it is , that does not look anything like strong enough for a milling machine, which both for safety and accuracy require a really immobile fixing

It rather depends what type of milling machine. Size and weight etc. If it's a small nodern high frequency machine then the reaction loads are relatively low and therefore you can get away with a less rigid mounting than the more conventional machines.

I would suggest that Andrew's bench would be more than adequate for some of the budget machines that are out there.

Regards

Aha! The 1.5mm galv sheet covers a 40mm thick hardwood top. The frame is 1/8" slotted angle and I have reinforced it with 2" x 3" x 1/8" tube underneath. I have tack welded all of the angle pieces to reinforce the bolts.

I think it will probably do the job but if not I'll build a more robust stand for it. The mill weighs in at 300kg.

I was originally going to replace the top with a solid piece of 10mm steel plate but the top itself would have weighed 120kg and I would have struggled to get it into the back of my shed.

To paraphrase;
You can’t “judge a workbench by its cover”


Ok - I know it’s poor !

Progress.

3 axis DRO kit to install.



X axis installed.



X axis power feed installed.


Next! Y axis DRO. This is the tricky one. Watch this space!

Andrew , I really urge you not to do this, at least unless you run the scheme past a consulting engineer. I am really concerned as to what would happen if a sudden jam on the milling machine created substantial out of balance forces . My fear would be that such an event could cause the whole thing, machine and bench together, to spin round and/or to topple over. What does the bench weigh compared with the nearly 1/3 tonne of the machine ?

The bench can just be moved by 2 strong men. So maybe 100kg?

This is a commercially available mill stand. It's made of 3mm steel and weighs 50kg. The slots in the bottom are for fitting adjustable feet to level it.



What I have is bigger heavier and as rigid. I think it will be OK. I plan to bolt the mill down to it.

I have got a sniff of a 1600 by 800 piece of 25mm plate steel. If I can get my hands on it I'm going to put it on my other bench which is made out of pallet rack frame. It will weigh 250kg and I would weld some lifting eyes onto it to move it. It would make a good combination mill stand and welding table.

You really do need to have adjustable feet on your stand. You could back the rear and sides with welded -on panels to prevent vibrtaional movement which will play havoc with your finished work.

christopher storey wrote: ↑

Fri Sep 13, 2019 12:21 pm

I am really concerned as to what would happen if a sudden jam on the milling machine created substantial out of balance forces . My fear would be that such an event could cause the whole thing, machine and bench together, to spin round and/or to topple over.

..... and I don't understand how that could possibly happen. Any jam (if it happens) can only be one part of the machine acting against another part of itself. How does this cause it to suffer "external force" which would be necessary to spin or topple it? The only thing I can think of would be some momentum action due to the motor's rotor stopping suddenly, but how much energy is there in that compared to the dead weight of the machine?

That frame looks like Dexion. My dad had a ladder made from that, all bolted together.

I agree Jerry. There's nothing wrong with a supporting structure weighing less than the mass it's supporting, that's usually the way of things. An engine hoist usually weighs a lot less than the engine it's lifting.

The question is one of stability, not mass. Andrew's bench has a very large footprint which will bestow great stability on the machine.

As for toppling, if the machine is properly bolted down, then it's unlikely to move as a result of any reaction forces occurring.

I'm sure Andrew is more than capable of getting things right.

Regards