My First CNC, own design, buidling in progress

[arie kabaalstra]

Hey!.. easy on the compliments guys, you're makin' me blush

I'm just doing for myself what i also do for a living... being a toolmaker is just that, making tools, precision parts.

through the years my colleagues and me have built some other machines, so building a thing like this isn't entirely new to me
For example:, we built two vertical lathes to machine parts drawn from sheet stainless steel, "cup-like" parts have to be cut, formed and a chamfer is machined to finish the product.
the machines we built basically consist of a turntable with 5 collet chucks to clamp the parts, two gantrys are built over the turntable, with two machining posts each.. first 2 cutting discs are used to trim the top, then 2 posts use rollers to profile the product, and finally a chamfer is cut.

back to the VMC: .. the only thing new to me is designing one.. but since i've built numerous machines in the past 10 years, i know a thing or two about designing..

Rust Combat?.. there are basically 3 options.. first: Oil, but.. since i wil make small chips, the oil will turn into an sticky layer of "Crap"
Second: Paint.. Nice finish, paint is cheap, but paint can wear off, because its surface isn't as hard as: Third: Powder coat.. knowing people saves money, the husband of a colleague of my sister recently started his business

options 2 and 3 are most likely to be applied.. if i go for paint, i can do it myself ... i like doing thing myself.. don't like being dependent on others remember i'm waiting for my guides for a couple of weeks now?...

[Pres]

I'd go for option #4 !
i.e. a nice bright nickel plating thin enough to show the surface grind but thick enough to inhibit rust.
(at least on all the non-critical surfaces)

To me that metal is simply too beautiful to cover up

Actually just keep it oiled - like you must do on the table.

Now, about that bolt-together kit of it you could sell?

[arie kabaalstra]

Bright nickel?... boy.. why not Gold-plate it in some area's and nickel plating in others?... it just would be too shiny..

it's a machine to produce parts, and enormous heaps of chips and swarf, not a work of art!!..

i think i'm going for a spray-paint finish, off-white and grey-ish blue metallic, along with some brushed Stainless steel parts

Bolt together kits?.. boy.. if i only had a "Big" CNC machine, and a tablegrinder.. i think i would seriously consider producing machineframes like this, to bolt together.. though i would change the design in some parts... like the table, i woulb use a Rexroth Aluminium table, instead of making those steel ones i've got.. i would also get rid of the recesses in the X-axis Frame beams.. too much work to get it right..

[arie kabaalstra]

Today i spent working on something i'm not really used to..
Wiring a CNC machine.. but Hey!.. we all have to start learning somewhere..

Because i have the controllers inside de PC casing, i had to find a neat way of connecting the controllers to the parallel port, what i did was fitting a 9-pin connector to the controller dir and Pulse ports, which is fed into the big 25 pin connector by a short cable





Here's how i connected the controllers, i put a piece of Vinyl tubing on each 2 cables for the controllers, the Orange/grey one in the front is for the ( optional ) A-axis

directly beneath that are 4 9-pin connectors for the X, Y, Z and A axes, they will be fitted to the controllers later this week, i have to get some sleeve to fit over the cables



and an overview of the PC, on the bottom right, i will mount a 32V DC powersupply for the Stepper motors..

the other cable out of the 25 pin connector wil be used for things i "bolt onto the machine" things like home/end switches, electronic handwheel, E-Stop, Motor Relay, and Cooling Relay, and maybe some other things.. Like Feed override if possible, and a touchprobe.

[arie kabaalstra]

Today i spent some more time on the collets..



1.5, 1.6, 2, 2.4, 4 and 5mm finished, tomorrow i wil turn the 3, 3.2, 6 and 8 mm ones.. and then i will use a Wire-erosion machine to cut the slits.
I also ordered an 4th controller and a small 1.3 Nm Stepper motor, to make the 4th axis.. i think i'm going to attach a 3 jaw chuck directly to the spindle of the stepper motor

[arie kabaalstra]

More progress.. still no guides

but!!.. i did some more Wiring, i got some "shrink-sleeve" ( Don't know what it is called in english, but you get the picture )



so i bundled the cables for each axis... and connected the X, Y and Z-axis.. A-axis controller is ordered, and so is the motor..

as i wrote before.. AIR-Cooling, i made 4 "Beads" and soldered a piece of Tube in.



the Tubes wil just stick out the motorplate, around the spindle, the beads are spring-loaded, so i can adjust them, just stick a small allen key in, and move to new desired position..

[arie kabaalstra]

And some more progress..

i hooked up an air line on the motorbracket:



to feed those li'l critters:



i've got four of 'em around the spindle



Further work this week: spark-eroding the collets, making some more collets, machining a piece of plastic to store the collets that are not in use...
and!.. Further designing my touch-probe.. i've started out designing yesterday, and this is what i got after one hour or so..



oh, and keep in mind.. it is only 25 mm in diameter ( with housing which is'nt visible here )

[thkoutsidthebox]

.....wow!

[arie kabaalstra]

i want the probe as compact as possible, furthermore, i think i'm a bit masochistic, trying to design a touchprobe with a diameter less than an inch.. why?.. just to prove ( myself ) that it can be done..

still no guides.. it's starting to aggrovate me.. but i'll keep my cool.. lots of other things to do.. ( and hey!. who's got a hobby machine like this?.. whith 4 Airjets blowing at the tool?... )

[arie kabaalstra]

Bought the last items for the CNC machine.



flexible couplers to connect the motors to the spindles



i also did some testing, i hooked up all the hardware i got, and tested and dialed in everything i could sofar..
Steppermotors run in the right direction for the machine, rapid traverse and Feed traverse are set
The 4th axis is also connected and set.. G01B360F100 means "a full rotation"




This is what the PC looks like now.. controllers mounted, power and communications connected.. only the handwheel encoder is giving me a Headache.. it doesn't do what it's supposed to.. the axes rock back and forth instead of running smoothly.. anyone, any clue?..



And a little screenshot.. as you can see i'm running TurboCNC right now, but i'm not sure it will stay that way.. i also like the looks of Desknc, but i'm still trying to get that right... let's first concentrate on Turbo..

[arie kabaalstra]

At last!!.. some progress on the machine again..

i machined the spindle bearing brackets



I took a sort of shortcut on how to keep the bearings in place, they're held by four M4 Bolts




I also Fiddled around with ZEUS CNC, i like the screen layout!!

Less "DOS-editor" than TurboCNC, less graphical than DeskNC, but all the info i want..


I only need to figure out some things, how to set some speeds, and how to set limit switches and so on.. also.. will it work with my handwheel?..

More to Puzzle.. ..

BuT!.. Finally i got some prices from Rexroth.. it's gonna cost me 'bout 1800 Euro's which is some $2250.. Doable... since a Sieg X3 will cost me almost twice that much, and that's still a "dove-tail Hobby mill".. not that it's a bad machine, but it's just something I don't want..

[martinw]

I took a sort of shortcut on how to keep the bearings in place, they're held by four M4 Bolts
.

Dear arie,

I really like that.

Thank-you

Martin