Sweet dreams CNC - more than one step beyond...

[sweetdream]

Design spec;

Seems like a long time ago I asked the question "what do I want to cut with it?" "Don't know yet" was the unhelpful conclusion! But after much thought about what I needed, opposed to what I wanted. I came up with a basic spec; a very strong, fast CNC that could work anything I threw at it including metals and portable enough to fit through a standard door.

This CNC was not going to be an exercise in what was theoretically possible, just a no frills, very strong, quick and easy to build structure that a tank could drive over! It had to be built without recourse to another CNC or exotic measuring equipment, just the equipment I had, could borrow or was prepared to buy. I did have some milling done on the frame, (making the 26x 22mm holes for the conduits, we had a jig on the mill and just knocked them out but that could as easily have been done with a pillar drill but would have taken a lot longer. Apart from that milling job, it was built with power tools and a pillar drill.

A few additional criteria added during the build, the spec stayed the same and was met. It fits through a fairly standard door frame too!

For the frame, I went for a PVC thick wall tubing with copper plumbing fittings. Skate bearings and ACME thread and I found a couple of old plastic pallets to use as the bed too.. LOL, only joking, just checking you're still awake. I realised fairly early on that for the performance I was wanting, a hybrid of bolted and welded steel construction and profiled rail were the right option. So large quantities of 80mm thick wall box section steel were calculated. The Hiwin catalog and price lists took a beating too.

Other staples were the standard 2.4kw water cooled spindle, NEMA 34, 8amp drivers, Omcron switches, nothing unusual except the later addition of a 250 rpm single phase spindle to deal with any low speed spindle requirements, mounted parallel but alongside the main spindle.

Although I had a good idea of what I wanted to achieve and some ideas I'd not seen used before, when I started I did not know all the questions that I'd need to answer before the build was finished. For the benefit of anyone reading this before building their own CNC thats a small but important point. You may not know all the questions you'll need to answer. :-)

But of course, the devil is in the detail and how you put it together.


So first build a workshop! lol..




or convert an old shed. After repairing the roof [picture coming] putting in a concrete floor, [find pics] some storage arrives courtesy of hearing about them being thrown out!

The wooden carcasses are solid but the plastic trays look a little fragile. Might swap them out for wooden ones as and when they break.

I've ended up with the back wall of the shop, floor to ceiling with these bins and a bench cantilevered out between them at a suitable height for standing at the bench. I had enough left to put them on one wall from head high to the ceiling giving a total of about 200 bays, 17inches deep, with either 3 inch or 6 inch high trays. Some I put shelves in as seen in the Hammer store below.



The storage starts filing up...



All workshops should have a good selection of tools!



In case of working late, some refreshments may be required! :-) [update] the beer has long gone! There's half a bottle of gin, 5 litres of cider and some fruit based cordials in case of visitors.. :-)