Newbie new build

[Heliox]

Can you weld? Or do you know someone who can and will for free. This will save you a lot of money.

You will need slides
https://www.ebay.co.uk/itm/15-1500mm...oAAOSwyi9aJP-x
This is the cheapest I've found them and I have this exact set very happy with them, you will not find them cheaper than this new.

You will need a drive as well, ballscrew is your best choice here Ebay is your friend but expect £250 and maybe some import tax.

3. Variable frequency drive it's a inverter that drives the spindle. Spindles are not running 240v single phase they are 3 phase and need the VFD to drive them you cannot connect a spindle directly to either single phase of 3 phase otherwise you get the magic smoke. Water cooled spindle are much quieter if you need a water pump pay postage I'll send you one for free I have a box of them. £200 for spindle with VFD.

4. Everyone seems to go for 3nm Nema 23's ~£30 a motor, I have 2nm on my machine £20 a motor. You definitely don't want less than 2nm.

5. Breakout board to connect to parallel port on a PC, this means you need a desktop PC to drive the machine but it's the cheapest possible way (Yes even cheaper than arduino)
https://www.ebay.co.uk/itm/Mach3-CNC...AAAOSwhqhaRkJb

Buy 2

Think about how your going to control the machine you can buy Mach 3 £200 or use linuxcnc free I chose linuxcnc ;) You need to generate Gcode for the machine most of us are using fusion 360 for this but there's many ways of doing it depending on the job.

The best thing you can do first is learn! Read people diaries ask questions. If the job you have for it is profitable you can probably find someone on here to make them for you and still make money giving you a cnc fund ;)

But once you've done it you're in a special club for sadists that only members can ever understand lol.

It's also highly addictive ;) Most of us on this site would rather get 2 3m lengths of 25mm Hiwin's with carriages for Xmas than a new Iphone, which is the way it should be to ;

Now I built one I can say you build must start in cad! I thought I could build one without cad I was so wrong lol I was being idle. I could have worked it out on paper but damn it would have be sadistic and expensive with mistakes.

1.That's a good size. Big enough to be useful, but not so big that you start to give significant construction issues.

3. As said, water cooling means that the spindle is quieter, and can run for hours without problem. So can air-cooling, but you need to be a bit more careful about dust management so that it doesn't clog.

4. to be pragmatic about it, NEMA23, 3Nm or 4Nm. Might as well go for the more powerful.

6. You will be astonished at how fast and how violently a decent machine can shake itself around. That table will hold the machine while static but it's going to need quite a bit of bracing to handle dynamic loads.

Keep asking. Don't get upset if you get your leg pulled from time to time. Goes with the turf! But you'll get plenty of useful info as well.

What Neale has said.
Plus:-

You could go with supported rails but if you do you will wish you had gone of proper profile rails, although 15mm rails will do and are plenty strong enough the 20mm are much easier to mount and are not much different in price.

For a machine that size I would go with ally profile 90x45 The holes in the ends of them can be tapped M12 use two pieces for the gantry arranged in an L config and three for the main frame with ally end plates 20mm thick. Check out Joe Harris on here and see his vids all built with simple hand tools.

Start a build log to keep all the questions in one place

Guys what can I say, thanks I'm off to a flying start already with all those suggestions, many thanks.

re: preferring Hiwins to a new Iphone,,,lol,,,I totally get that angle ;-)

You've thrown me with the "can you weld" question? I can as it happens (I used to be a coded welding inspector offshore, among other things) but can't think what you'd be welding on a CNC machine, unless your talking about welding some of the Ali (or Steel) sheets/brackets/side plates? And to be honest I'd probably get someone else to do it as I haven't in a long time, other than a bit of mig and stick on various bit's in the workshop. (oh and I don't have roof on my workshop at the moment).

Software: I have been using Sketchup for a number of years, so no issues with a bit of CAD, I was about to download Fusion 360 a few days ago, haven't got round to it yet, but I did see you can use it free as a small business or hobbyist/student so that's good.
I also downloaded a few weeks ago a plugin for sketchup that produces G code 'SketchuCam'
I got that here http://phlatforum.com/xenforo/

I do have a question on designing the CNC machine in Cad though, I can't see the benefit in designing in CAD, what I mean is am I missing something? because to design a CNC m/c in a CAD program you have to know the accurate Dimensions of each part, or box profile and then Draw each into the program. Which means unless your provided accurate drawings of each individual part before buying it, then you have to have the part in your hand and take a vernier to it, which means you have probably already bought the part? I can see how while your building it it might be helpful to make a drawing of it so you can add parts or modifications, but I can't see how your accurately going to draw it before building it? That's not me being awkward, I just don't get it? can you elaborate how you found it helpful?

Re: The controller/PC,,,,,,it just so happens I scrounged a windows XP (or vista) desktop tower off my father in law about 3 yrs ago, and funny enough I wanted it for the parallel port as I have an old laptop with a parallel port that I use to send files to a large A0 A1 printer plotter I bought off eBay a few years ago, the laptop screen is dodgy sometimes so I got the tower for that as backup,,,it's sat in the box just in case but I took it out a few days ago and powered it all up,,with the intention of possibly using it as a dedicated CNC computer, but I also bought a 3d Printer last week that I thought I might use it dedicated for that too. (Tronxy x5s, not arrived yet).

BOB's,,,,,,,,,,familiar with the concept of them, and why opto isolation etc.

Re: the table and how violent the machines can be, I get that Neale and agree with you, many moons ago I worked installing multitool CNC machines in Cosworth in Northampton and I also worked for Sony in Bridgend and Festo pnuematics, so I totally get where your coming from re: the forces, In fact anyone who has had a run-off with a decent hand held plunge router knows when you bolt something like that down and start cutting things there's alot to go wrong and fly about and all round alot of harnessed energy. (I'd thought about bolting the table down, adding a decent slab of something on top to give it a bit more mass and some form of diagonal bracing and beefing up the legs).

Dust management,,,,,mmmm yes that has been in the back of my mind as an issue, not for clogging a spindle but just the sheer pain in the rear factor of capturing it all, I have an axminster dust extractor for a Jet table saw, but extracting carbon fibre dust is going to be a different ball game, I'm contemplating a glass fibre wet tray into the design so the parts are submerged in water during the cutting, something similar to a wet tile cutting machine, has anyone seen anything like that on a CNC on this forum?

I see you all recommend the linear profile rails opposed to the round supported rails, why is this? are the profile rails less susceptible to play? or wear? less vibration? what's the negative issue with the round supported rails?

Thanks again guys,,,off to do a load of reading on here.