CNC machine build log

[asbo]

Had the drivers come in the mail. I'm now working on the electronics.


Two old ATX PSU's in series = 24v with lots of yummy amps One of the PSU's makes a nasty hissing noise though which is why I stopped using it in the first place. Guess I need to replace some caps.

I also got this spindle, not massively powerful but I hope it will do for the time being. They do some awesome water cooled ones as well but they are three phase so you have to mess around with inverters and whatnot.

[professor_jonny]

Hook it all up already

I have a metabo variable speed 600w hand held die grinder for cleaning welds up etc and a rotary but on there cutting wood or plastic zaps through it like butter, actually i have to dial down the speed doing slim xboxes as it can melt rather than cut at full speed.
what you have brought shuld work well did you get a spare set of brushes with it because of the low voltage and dc the constant arking will wear them in due time?

if you do get a 3 phase one drop us a pm and ill send you over a inverter i have a few second hand ones from trade ins's etc will save you some cash the cheap ones from ebay from the same supplier might get turned around at the boarder into uk as they dont carry emc compliance:

http://www.danfoss.com/BusinessAreas/Dr ... Series.htm
we export stuff to richard capper dairy services in Faringdon and are well aware of the laws over there:
http://www.rcapperdairy.co.uk/

[asbo]

haha all in due time

I think its brush-less, but looking at the listing it doesn't say anything about that, so I don't know where I got that idea. It sort of feels brush-less though, has that lumpy bumby feeling if you turn it with your hand, if you get what I mean.

Yep I'll certainly do that, I have no idea about 3 phase stuff. Thanks
I'm surprised the stuff I've gotten through customs, and you never have to pay any tax since since the Chinese chaps always mark it as a 'gift' with a real low value. I'm surprised they don't clamp down on it since loads of people must be buying stuff from abroad all the time, but I suppose they have bigger 'fish' to catch.

[professor_jonny]

its only 1 in every 10 packages that get opened to check for customs charges in new zealand, lots of people are starting more often to buy abroad as 9 out of 10 times you dont get charged tax.

that is the cogging from the polling of the magnets the stronger the better the torque of the motor it could be a 3phase motor with a small circuit board inside to make the 3 phase but i guess it would have brushes

i have a novak gtb 3 phase speed controller in my radio controlled car and it is the size of a match box with a 60 amp continuious currrent draw so you never know tecnology is getting smaller!!!

[asbo]

maybe I've been lucky then

hmm well when it blows up I'll take it apart and we can see

The squealing power supply has just died on me whilst I was trying to get the motors to interface with the computer. No explosions luckily but a bit annoying. Need to decide whether to try and repair it, hack apart another old ATX one or buy a 'proper' PSU.

[professor_jonny]

hack apart another old ATX one or buy a 'proper' PSU.

we buy these meanwell supplies direct from the importer in nz (wellforces) at very cheap prices might be worth a look ?
they kick the pants off any thing else for price and reliability.

the open frame ones are even cheaper if you have something to house it in ?

http://www.meanwell.co.uk/enclosed-powe ... ies-2.html

http://www.meanwelldirect.co.uk/ranges/ ... efault.htm

[asbo]

Yeah I'll be building a little box for the power supply(s) and drivers.

I've been eyeing up some PSU's on aliexpress like those, cheaper from china though. Like this. They can't seem to make up they're minds what voltage it is though
And this one also.

[professor_jonny]

Yeah I'll be building a little box for the power supply(s) and drivers.

I've been eyeing up some PSU's on aliexpress like those, cheaper from china though.

you do know they are all made in the same meanwell factory in china just rebranded
the meanwell one come with a decelaration of conformity tho being the only difference.

[asbo]

ah nice I had wondered if that might be the case. I'll buy one of them then at some point.

The squealing ATX one is actually working again It lasts a couple of minutes then shuts down. It'll do for testing for the time being.

I'm saving up for some ballscrews at the moment. I installed the Y axis threaded rod the other day and I really don't think its going to work.

I'm already dreaming up a new machine made from steel Good thing is all electronics, motors, spindle, ballscrews etc can easily be reused.

[asbo]

Been fiddling with the y axis threaded rod and its actually working really well now With an electric drill anyway


Having problems getting the PC to turn the stepper motors. The pins in the manual are all wrong, hell the manual isn't even for the board I have Guess that's what you get for £8.

[xman]

ah nice I installed the Y axis threaded rod the other day and I really don't think its going to work.
I'm already dreaming up a new machine made from steel Good thing is all electronics, motors, spindle, ballscrews etc can easily be reused.

That looks like a piece of "All thread" your using for the Y axis drive shaft. That size does come in "Worm Drive" thread aye. Worm drive shaft is a flat edged thread with thicker teeth and runs a lot smoother than normal thread when used as drive thread as you are doing. I personally think steel would be the way to go but this is giving you ideas and experience. You could just beef this wood up with steel angle attached direct to the wood but who knows, the wood could be quite suitable for what you want.

[asbo]

Its M8 Threaded Bar 1 Metre 8.8 BZP, only cost £2. Its M8 because that's the size bearing I have.
If I can't get it to work properly I think I'll get some ballscrews, which are the 'proper' things to use.

If I find this isn't good enough I'll make a completely different design from steel/aluminium.

[asbo]

Got a new power supply One of these. I made an offer and got it for £35. Made in New Zealand.
The cost worked out the same as buying two lower watt ones from china.

Its meant to be hooked up to a control unit thingy, so its outputting 54v instead of the <= 50v I need.
Here's the pin in/out:


Maybe if I put a few volts into the control pins it'll change the output voltage? What do you chaps think?
If that doesn't work out I'll have to lower the voltage externally, any advice on doing that?

[xman]

Asbo. is it -50 volt DC you need and is that the only voltage you need from the power supply?. No 5vDC etc required as well for the other electronics?.
Also, what diagram did you get with it if any. Actually, any data would be handy.

[asbo]

ah no, the <= thing means lower or equal to 50v. Somewhere between 48 and 50 volts would be ideal.
And that is the only voltage I'll be needing from the power supply, the breakout board needs 5v but it gets that via USB from the PC it is connected to.

That's it, just that image (it is showing up right?)

This is the spec sheet thingy.
And this is the installation guide. Neither of these is of any help, as far as I can see, since its not designed to be hooked up by itself, its meant to slide into a rack mount.

[xman]

Looks like a 48 volt battery charger you bought, a very nice unit at that reading the data. Shit, that could require a load before it will boot. Actually some of my battery charges need a voltage to read before they give any output. I don't think it will be suitable for a supply to drive motors as such but I may be wrong. It all depends on whether it requires a load, like batteries, before it starts to output anything.

[asbo]

I plugged it in and got 54v out according to the multimeter. So I think that means no load required right?
Its got a fan, fairly quiet, turns on as soon as you power it up. There's also status LED's which are nice. The green one lights up

[asbo]

done a bit of poking around. Between pin 20 and pins 16, 18 and 22 there is 0.3 of a volt. Not sure what that means, maybe its a serial interface? Or more likely some sort of propriety interface.

Found these:
http://translate.google.com/translate?h ... ic%2F96031
http://translate.google.com/translate?h ... 96311.html
The Chinese have been having fun with them. Although I don't think its any help.

I'll poke around a bit more trying to get it to output the voltage I want. If that fails I'll order some 50v voltage regulators and lower the voltage outside the unit.

[asbo]

Need some help from you smart chaps. If I were to buy some of these (same here a lot cheaper) could I use them in parallel (one for each driver) to drop the voltage down and supply enough current?

[asbo]

Been in touch with the seller and he has some control modules, so with any luck I'll able to use one of them to get the correct voltage. Fingers crossed.