3rd controller, think I know where I am going wrong, waiting for some IC's from China to undertake a few repairs, but have been playing with the thin aluminium today, it cuts a lot different then steel, even the blow-back when the torch flame goes over a steel support is enough to burn a hole and the kerf does not break off as it does on steel.
I got very nervous for my plasma cutter today, did a bit on the computer drawing package then Sheetcam then getting the Gcode into the CNC and having a blast.
Was cutting 3 mm so had the current at around 32 Amps seemed to be good, first thing was a sort of house name plate.
This is 300 x 180 mm
Then later did a butterfly "trible style", this is what got me getting concerned. A constant 6 minutes cut at reasonable current was wondering if something would melt and the heat it was putting under the tray onto the bench was a hell of a lot. I have a 2 mm plate on top of a wooden bench to stop all the sparks and it was warping with the heat and causing the whole frame to wobble.
A few hours later and no fires so think all is fine.
This is 270 by 217 mm
Both have been cleaned and cold zinc spayed.
The sign was acid etched in the stuff I got from brewdexta, nasty stuff that is, Ughhh. It removed all the mill scale easily but only an outside task and rubber gloves and glasses as minimum.
But think as a project I can say that the Plasma CNC has got there! Only things now will be minor changes, like I have gone from resistors to short circuit to the tip, will go to around 2.5 Ohms'ish. Will have to get a water tray to stop the heating effects on the bench and will probably keep it down to 2mm thickness in steel I think.
The steel for the frame was peanuts say £50 all in for the 2 x 1 inch and various other bits.
The pulleys and belts around £70
The ball screw from China £30
Silver steel and various bearings, oillite bushes £40
Couplers, have lots left but again around £30
Stepper motors bought two types 3 off 23 frame they were £81 have one left
One off 17 frame for Z axis £16
Straight torch from china £33
Panel meter £8
The control cabinet was free I had that and the 24 Volt 14 amp supply recovered from other things
But bits of wire components plugs, sockets, relay and resisters say £40
the most expensive items have been the CNC controllers at around£58 each and I am on the 3rd, due to bad earthing issues during arc start, so with all three £174.
Although I have some components coming in from Ebay that should allow me to repair and keep as spare the two faulty units.
Sure I would have forgotten something so have tended to up prices a bit here and including 3 controllers
we have a grand total of....................................................£572. I think please check it.
Plasma torch £185, compressor £90, time priceless!!
It has been a project. Need to add on things like software to get to the end product, now as I use Linux a lot of that is free under a GPL! and there is also a lot of Windows stuff that will also do it.
But have bought a licence for Sheetcam and that was £132. So it all soon adds up.
Adrian
p.s.
Will have to shift/sell a lot of plasma cut articles to recoup the cost, but if, and I say if I bought one from Sheffield then anywhere up from £5,000
I would love to build one but i know next to nothing about CNC and i seriously need to finish some other projects first, That is unless you fancy creating MK2
Second post on this as I have been thinking about it! . if i wanted things for production I would go to a lazer cutters and a lot easier/faster for numbers, probably get a lot of one off's within a week or so as well., not sure on price. But it does let me be an artist, just wish my brain worked that way!
Adrian
Just seen your post, not for a while I am afraid, if I make a MK2 then I could always sell the MK1.
Get your projects done, I am willing to show what's what. with it to almost anyone.