New build with recycled parts on a ridiculous budget 120cm*60cm work area

[Desertboy]

Going to need 2 plates to mount to bearings and ballscrew mount for each side of the gantry.
I had to use some M6 standard bolts for now just to get an idea of how it will work, will be missing one bolt from the mount. The bolts go through the extrusion T slot corners with a washer to space everything out properly.

The angle bracket is only there so I can mark the centre point of the coupling to have nema mounts made properly.


I'm thinking of buying some cheap ass T6600 stepper drivers so I can deliver the full 3 amps to my motors (Only at 24v) but I will still use Gbrl and Arduino for now with some creative wiring to the cnc shield.

[Desertboy]

been taking measurements with some scrap ali I will use the thicker of these piece to make the 2 ballscrew (It's wide enough to cut in 2 and still cover the ballscrew mount) to supported rail mounts like pictured for the bottom axis.


If the triangular bit had been twice as thick and I had 2 of them then that would have been my gantry mount but I guess I need to spend £90 on ecocast instead ;)

The scrap plate, bolts and ballscrew mount lined up perfectly (Pure fluke) which makes taking measurements a lot easier.

[Desertboy]

Finally worked out how to print to 1:1 scale ;)

When I pumped out to printer it's the correct dimensions, a friend is going to make these parts for me from recovered 6082 aluminium (We like free in case you didn't notice) so I will only need to have the gantry mounts and Z axis mounts CNC'd.



From Left to right
BF12 mounting bracket (4 bigger holes bolt into the t slot extrusion)
Nema 23 mounts to line up with the BF12 mounting brackets for the 2 lower axis (This bolts into 2 rows of extrusion with T nuts)
The last 2 connect the DSG16 ballnut mounts to the gantry mounting plate for drive of the lower axis.

I ordered the Spindle today, so next thing is the Ecocast ;) Toying with going with 25mm thick for the gantry and embedding the extrusion 7mm into the frame.

http://www.ebay.co.uk/itm/181806514041?

Think I will get 4 TB6600, use the cnc shield/arduino and a 480w 24v power supply so I can get the full 3 amps out the stepper motors.

[Desertboy]

I suppose I should start to think about power for the machine, I realise a 13 amp socket is not going to cut it lol.

2.2kw for the spindle
350w for the 24v power supply
100w's for misc
20% leeway

I thought sound this will be ok from a 13amp socket until I realised I need to power a vacuum cleaner at the same time. Also of course I need 1kw to boil the kettle for Tea ;)

So I have 2 choices
1. Run a 2nd 13 amp socket to the machine from the board.
2. Run a dedicated 32amp 5 wire 3 phase socket from the board (This is what I will do) and then tap 1 of the phases with a junction box to power the machine.

[Neale]

A dedicated supply is obviously the gold-plated solution but I'll think you'll find that pretty much everyone with a similar machine runs the machine off a single 13A socket. I use a 4-way adaptor for control box, inverter, and PC all going back to a single wall socket. No problem at all. Don't be misled by the inverter rating. That's max output power and it's unlikely that you will be pushing it that hard, if ever. Run the vacuum cleaner off a second 13A socket but loading is fine even if it is the same ring. In other words, you could swap a single 13A for a double and still be ok. Even if not a ring and single socket is on a spur, I believe that that should be good for 20A/5KW total load (but would need double socket).

No allowance for kettle in that, of course! Sure it's only 1KW?

[Zeeflyboy]

In reality your spindle will never pull 2.2kw on a machine with this level of rigidity... most of the time it will be much lower.

Your stepper motors etc also are incredibly unlikely to all pull peak power at the same instant.

I do exactly as neale said... I have everything running off a dual socket (computer, monitor, compressor on one, CNC on second) and i run my vac from another socket (which just so happens to be on a different ring, but would be fine on same ring).

Obviously if you want to give it a beefier supply then go for it, but it's not necessary imo and doesn't really fit with your cheap as chips goals!

[Desertboy]

Obviously if you want to give it a beefier supply then go for it, but it's not necessary imo and doesn't really fit with your cheap as chips goals!

I have the 3 phase plug, socket (With Isolator) & SY cable (Free of course) so would only need to buy a short length (2m) of 5 wire armoured cabling to the fuse box, luckily where I have the machine the fuse box is the other side of the wall.

My spindle came this morning and when I put it in the spindle mount and weighed them both 6.5kg's add in my z axis and we getting close to 10kg's (Maybe more) on the gantry. So to combat flex I'm toying with pouring 2K epoxy resin into the cavities in the extrusion which I think will increase rigidity considerably whilst being impossible to tell from the outside lol.


I may encase the frame and gantry in angle steel but my worry is finding angle steel that's straight! I would avoid using it on the side where the rails or ballscrews are mounted.

[Desertboy]

A dedicated supply is obviously the gold-plated solution but I'll think you'll find that pretty much everyone with a similar machine runs the machine off a single 13A socket. I use a 4-way adaptor for control box, inverter, and PC all going back to a single wall socket. No problem at all. Don't be misled by the inverter rating. That's max output power and it's unlikely that you will be pushing it that hard, if ever. Run the vacuum cleaner off a second 13A socket but loading is fine even if it is the same ring. In other words, you could swap a single 13A for a double and still be ok. Even if not a ring and single socket is on a spur, I believe that that should be good for 20A/5KW total load (but would need double socket).

No allowance for kettle in that, of course! Sure it's only 1KW?

Thanks for the advice, this is not in a home so unsure how many sockets are on the ring but if I ever move this to my house this will be a consideration.

I have a caravan kettle, It's single phase but only 750w I just rounded up. It's very annoying lol as it takes ages to boil but it was of course free ;)

[Clive S]

2. Run a dedicated 32amp 5 wire 3 phase socket from the board (This is what I will do) and then tap 1 of the phases with a junction box to power the machine.

Is this then in a commercial environment if so.
You have to be careful with running a second 13A socket from the board and make sure it is on the same phase as the other.
I think there are rules to avoid have rings on different phases close together. Reason being is that although each socket would provide 230V there would be around 415V between the two lives from each socket.

[Desertboy]

Is this then in a commercial environment if so.
You have to be careful with running a second 13A socket from the board and make sure it is on the same phase as the other.
I think there are rules to avoid have rings on different phases close together. Reason being is that although each socket would provide 230V there would be around 415V between the two lives from each socket.

It's a commercial environment I have plenty of free space on the fuse board to run a new line in I was going to fit a 3 phase 5 wire 32amp socket then tap one of the phases to a junction box and from there to the machine and to 2 plug sockets. I have an electrician on site so he will do it lol although I have actually done it before and he checked it out and said I did it correct ;) Since everything else on site is 3 phase it makes sense to fit a 3 phase socket and of course future proofing as I see 3 phase in my CNC future lol.

I was told if you tap 1 phase of 3 to get 230v mains you mustn't have a load on the other 2 phases and the load should be balanced over all 3 phases.

The fuse box for the unit is unusually large (Hence loads of empty space) because before my dad bought the place it was Kraft foods and they filled it with industrial refrigerators. He had so much fun ripping out the stainless and weighing it in good old days of cash ;)

I have 10+ 3 phase sockets and at least 4 single phase 16 amp sockets if anyone wants one for free, I always cut them off the machines we scrap if they're still mint and 99% of the machines we scrap were plugged into the wall once when installed and unplugged once when removed for scrapping lol.

I have more issues with recovering the SY cable as my Brother is always stealing that for his fridges but I managed to squirrel away 20m's when no one was looking.