CNC Mill Proposal Autumn'17

I agree on the 440 but didn’t want to jump the gun. And while I’m pro just buying something that works, what’s the y-axis travel on the conversion project?

Joe’s x1 is 250x150mm of travel.
Max depth of cut i can get is 0.5mm, not enough to get decent tool life
Side milling is pretty much impossible, slotting is not much better
The ball screws don’t fit so we need to mill into the cast iron tables
The z is going to be even trickier to convert, i think one person resorted to bolting the ball screw to the outside of the head on the side.
It’s still a £500-600 budget at the very least, not really cheap

Not worth the effort if we have the budget to buy something in my opinion

Really sorry as I feel I should know this, but what’s the purpose of the above machines?

You can sort of do what the 3d printer or laser cutter does, ie make solid forms from a computer model, except unlike the 3d printer you put a block or sheet of material in and it cuts away the excess.

The process is way faster than 3D printing and has a much, much better surface finish than our other tools. It allows you to do plastics, aluminium, and even very tough metals if you want to make something very durable, like mechanical parts. You can also get a good enough surface finish to make casting or vacuum forming molds.

Machines like this are used to build other machines, it would basically allow us to make anything!!

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They’re for “subtractive” modelling. ie you put a block/sheet of material in, and remove the bits you don’t want.

This includes things like engraving a copper circuit board blank and drilling holes for components, or sculpting a 3D form from wood, or making metal mechanical parts.

The ones we’re looking at are proper heavy-duty machines that can cut steel. Very versatile and very accurate.

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You can’t really make this kind of thing at Makerspace, at the moment. Even if it’s basically assembling Meccano, you end up needing custom parts. With a steel-capable CNC mill, you can.

@Barnaby_Coote @tomnewsom thanks for the explanations. Could’ve googled it but there’s so many machines labelled ‘CNC’ that I was lost as to what these specific ones did.

Sounds cool. Can instantly think of some uses I’d have for it…if only I was any good at CAD!

Many things can be cnc, it means it’s computer controlled. The 3d printer and laser cutter fall into the same category, and even a printer in some respects

This particular machine is a CNC vertical milling machine, or mill (also called a vertical machining centre or vmc)

I think the current trend of referring to “a CNC” has confused the issue. There is no such thing as “a CNC”, as these three letters act as an adjective, not a noun, and many different types of machine are CNC–mills, lathes, routers, laser cutters, 3D printers, etc, etc.

Just stands for ‘computer numerically controlled’? IIRC…I suppose I could have asked the mighty Goog up in the cloud…

Yes it does. It seems to have latterly become a synonym for a router with a bed for cutting sheet materials (and not typically including metals).

But the letters imply an important distinction between types of metal mill, because manual mills (without CNC) exist.

How legit were the bridgeport ebay ads?
They seem fairly common. £2-3k. Absolutely bulletproof. The older software and control systems could be swapped for mach3. We’d just need to look into the space issue. Any thoughts?

Table travel on an interact 1 mk2 is 457x 305x 125 mm /365mm with knee

Bags of travel but the knee is not ideal

The one I posted is someone we know

The hackspace one?

A quick check on youtube shows some successful mach 3 conversions. Main drawback is the slow spindle speed, only 3,750rpm. Not ideal for carbide tools through aluminium, or milling plastic

It appears to get through big lumps of metal no problem

That’s Ande of FabLab London, and now GreenLab

Definitely a router, not a mill. This is the one I had when I was head of DT.

also not a bridgeport. I was talking about these
https://m.ebay.co.uk/itm/Bridgeport-Interact-1-mk-2-cnc-milling-machine-/332408202459?hash=item4d6512a4db%3Ag%3AKBUAAOSw9fRZ2mn~&_trkparms=pageci%3A5bf84ad5-aff0-11e7-a2ba-74dbd18059f3%7Cparentrq%3A14d87c1f15f0a9c572f8970ffffbf054%7Ciid%3A1

There’s also this thing listed. Full enclosure.

https://m.ebay.co.uk/itm/Bridgeport-Interact-720-Cnc-Vmc-/222662917321?hash=item33d7be7cc9%3Ag%3AgycAAOSwHqRZ0NB1&_trkparms=pageci%3A5bf84ad5-aff0-11e7-a2ba-74dbd18059f3%7Cparentrq%3A14d87c1f15f0a9c572f8970ffffbf054%7Ciid%3A4