Cnc for pcb and enclosures

[Mgt280y]

Been searching the forum for cnc related topic but nothing recent seems to come up?
Are people using cnc milling for pcb and enclosures, there are things like the 3020cnc and 3040cnc going for reasonable prices and wondered if people have/had used these ones. I know they are cheap and there's probably a reason for that but for the looks of some you tube vids etc they look like it might work.
Guessing with enclosures it would be a case of slow and steady and would probably suit doing lots of small DOC passes and maybe the odd upgrade part

[R.G.]

CNC machines are tools, like screwdrivers and wrenches.  I have a CNC mill, a 3040 frame with additional work done on it and a custom controller. Works very well for engraving enclosures and PCBs.

However, if you've just discovered CNC, you may want to do a lot more reading. The cheap CNC frames are a very crude start. There is a huge amount more effort required to actually use them well. People can and do get lost in the CNC world, just like they get lost in the pedal building world, or the guitar-playing world. Either of these has enough depth to keep a person tied up for a lifetime.

A cheap CNC machine from ebay or similar will set you back several hundred dollars (USA), probably more in other countries with stiff import taxes. That is only the beginning. You need a PC to run it, and the cheap machines need a machine with a native parallel printer port, or as an alternative, an external controller that interprets Gcode to machine movements.

Then you need software. First, you have to create the cad files that will be executed. This needs a drawing/drafting program at least, and a 3-d cad program for the really fun stuff. GIMP and INKSCAPE are free, as is FreeCAD. But there is a learning curve with each of these. Hours and days and weeks if you do it well. Same is true of the commercial packages, but with more money spent to get them.

After the theoretical design is done, you need code to convert the design to machine movements (generally g-code). This layer is called CAM software. There are several, very few free if any; CAMBAM is the entry point for many people, at about US$180.

Then you need to actually make the motors run. This is done by the software layer and hardware I mentioned first, the PC and/or the motion controller. The PC almost needs to be dedicated, as moving motors is a real-time task and the chains of software in a typical windows box prevent real-time accuracy. And you need the motors to be real-time accurate to get proper mechanical motion. The cheap software (often Mach3, about US$170) does this with a native parallel port. If your PC doesn't have a native port, a usb port will not do. The time-accuracy is not sufficient. A motion-controller card can solve this on most PCs for about another US$200.

Then there's the time. I have a friend who is a PC and mechanical prototyping adept. He's good at this. He recently bought a 3020 and set about getting it to run. It's been a bit over two months now, and he's just now getting it to engrave.

We won't even talk about tooling, bits, motor speed controls, broken bits at US$15 a pop from running the spinning tool into the table due to a software error, it goes on.

CNC is a powerful tool. I have one, like it, and someday I'll have enough time to really make it work well, without needing a couple of days to get back into the whole mental "nest" of how to run it and the software chains needed.

So I encourage you to investigate the CNC world. But know what you're getting into before you start tossing away money in units of US$100 at a time and your time at units of weeks and months at a time.

[Ice-9]

I was going to start a CNC thread but have put it off a little due to lack of time recently, I will quickly chime in for now until I get more time to go into detail.

I recently bought a Chinese 3040z CNC engraver/miller which I have been using successfully now for a while to cut out Hammond enclosures, I wanted to go down the CNC route as some of my pedals have LCD screens with a recess for faceplates etc. Cutting out oblong holes is a royal pain by hand and a recess is pretty much a no go by hand, so a little research on cnczone.co.uk and I ended up with a 3040z.

I bought the complete machine knowing I would be junking all the electronics and the little DC spindle motor but as I new zero about CNC I thought it best to get a machine that at least worked so I could set it up and then do upgrades as I went along.

The first upgrade was to bin the 230w DC motor and fit a 1k5 water cooled Spindle and VFD that would be more capable of milling alloy rather than just being able to engrave. OI am still using the junk controller box and stepper motors for now and with this I can easily mill out Hammond enclosures. The spindle upgrade was a huge improvement, apart from the better cutting capability it has cut down the noise made from the toy DC motor to a reasonably quiet running machine (The biggest noise is now from vibration of the enclosure which I am looking, possibly by placing a foam block inside the enclosure while milling).

The first thing I did after checking the machine worked after receiving it was to strip it down and rebuilt it so that everything ran smooth and true, it needed all the ball races replaced as they were total rubbish and the frame needed truing up. My next upgrading will be to build some controller electronics and possibly replace the Nema17 motors with some suitable Nema23 steppers.

I have to warn you though, I have the CNC bug now and I see that it could turn into an expensive hobby.

[LightSoundGeometry]

I would love to have one..I am still saving up for a good tube amp, a second guitar and stuff like a 2-300 working O scope ..even a good DMM ..but I am still only working with pedal style circuits ..still cant a tube amp thing going and probably wont until I get a nice lab put together to work on things

anyone hiring anyplace doing anything ? I would sell my house and move for a chance at a real job ..I also would like to get medical care and be able to go to the dentist one day..Ive been looking for a job for over 7 years now ..living day to day worrying is starting to literally kill me..I will  not give up or give in and think positively that a job will come to me soon. I am very happy and feeel fortunate I have a laptop, and Iphone and a internet connection ..but some new tools and gear would be nice! I cant imagine having a real guitar amp to play through! or a something other than an old MIM like a PRS or a LP !

I have a decent resume put together but i was never in the military ..we have a lot of folks advertising to only hire military people ..not sure if this is normal nation wide or because SAFB is only 15 minutes from me, but out at the college they seem to only work with veterans and gi's  unless you are a young person and I am 43..im so desperate for a real job I threw this out here in public

[G. Hoffman]

For hobbyists, students, and small businesses, Fusion 360 is free and extremely powerful.  I highly recommend it!


Gabriel

[vigilante397]

Umm, there are definitely CNC threads on here, I've started a couple myself

The prices have gone up and the options have changed in the year or so since I got my CNC, but I got it from these guys http://www.zencnc.com/shop/cnc-machines-kits/

I like it because it was small enough to be relatively inexpensive but still large enough to do anything (pcb or enclosure) I could ever need for stompboxes. I also like that it's Arduino based so I don't need to have a computer with a serial port, I can run it straight off my laptop via USB.

[Mgt280y]

Thanks for all the replies, with the zen cnc was that an out the box unit or have you had to replace and upgrade parts, what software are you using with this one?

[Ice-9]

Here is short video of my CNC3040 in action. Its early days and I am sure I will be able to optimise the speed. The setup at the moment takes about 50 minutes to completely mill all the holes and the LCD recess on this1590XX enclosure.

I am using a 2 flute HSS 2mm end mill to do everything, I might be better off with a 3 or 4mm end mill to cut the recess.

[Ice-9]

For hobbyists, students, and small businesses, Fusion 360 is free and extremely powerful.  I highly recommend it!


Gabriel

People keep saying Fusion 360 is free for hobbyists, students and small business but I can only see that it is available for students and academics, otherwise is it just a 30 day trial. If you have any further info Gabriel I would be grateful.

EDIT......I figured it out, it was right there in front of me I just couldn't see it. Download the trial, click on the clock and register it as whatever you prefer.

[canman]

I've had great luck with Fusion 360 making surfboard fins.  I haven't used it for PCBs or enclosures yet, but it would be awesome for enclosures.  Their CAM function is fantastic.

I've made a few PCBs with my Chinese machine.  If I can get a lousy Chinese machine up and running, anyone can.  A couple of things to note:

The Chinese engraving bits aren't the best, but they work.  The trick is to run your feed speed extremely low, otherwise you'll get rough copper traces.  I run my PCB jobs at 150 mm/min and they come out very smooth. 

When you're creating the PCB, you'll want to get the trace widths as wide as possible, because the engraving bit can only engrave so thin.  If you don't go deep enough, you'll just barely break through the copper, which also causes rough copper traces.  I go about 0.2-0.3 mm deep.  That way you cut some of the phenolic board as well which keeps the copper cut smooth.

I'd recommend checking out diptrace for PCB creation.  Once you have the PCB the way you like it, you can export quite a few different ways.  I use Mach3 with my CNC machine, and diptrace will export the PCB drilling g-code for Mach2/3.  To get the g-code for the PCB traces, I export the PCB as a dxf file.  You can use dxf2gcode (free) to convert the dxf file to g-code.  The program lets you choose the feed speeds and all that jazz.  It's limited to 2D applications, but it's perfect for PCB creation.

Feel free to PM me if you have any questions...I spent a lot of time finding these free programs that yield excellent results and are easy to use. 

Oh, one other thing.  You're not limited to parallel port with CNC machines.  You can get controllers that operate through USB...check out the TinyG controller and ChiliPepper (program that runs with TinyG).  I believe TinyG is around $160 or so.  Chances are good it'll be a massive upgrade to any cheap machine.  The machine I got had controller boards that provided 1A of current to the stepper motors that need 3A...the result, lousy speed and tons of stalling/losing steps.  I recently upgraded to controller chips that provide up to 4A.  Needless to say, the results have been amazing.  The machine moves so fast it walks across the table!

[vigilante397]

with the zen cnc was that an out the box unit or have you had to replace and upgrade parts, what software are you using with this one?

Mine is just out of the box, I haven't upgraded anything. I don't do anything ridiculous with it, but it's great for PCBs and enclosures. I'm using DipTrace for PCB design, exporting to gerber file then using CopperCam to convert the gerber into g-code, then GRBL Controller to send the g-code to the Arduino.

[vigilante397]

Oh, one other thing.  You're not limited to parallel port with CNC machines.  You can get controllers that operate through USB...check out the TinyG controller and ChiliPepper (program that runs with TinyG).  I believe TinyG is around $160 or so.  Chances are good it'll be a massive upgrade to any cheap machine.  The machine I got had controller boards that provided 1A of current to the stepper motors that need 3A...the result, lousy speed and tons of stalling/losing steps.  I recently upgraded to controller chips that provide up to 4A.  Needless to say, the results have been amazing.  The machine moves so fast it walks across the table!

I'm going to have to look into this. When I set my feed any higher than 200 my steppers start skipping steps like crazy. I try to keep the speed low anyway when I use my chinese v-bits, but I have some nice LPKF bits that I'm sure could go much faster and keep the same quality. Thanks for the tip

[canman]

I was blown away at the improvement from upgrading the controller chips.  Any idea what controller chips you're using right now?

This is what I went with:  http://massmind.ecomorder.com/techref/ecomprice.asp?p=416074

You have to build them, but if you can build guitar pedals, this is no problem.  The chips will get hot though, so you'll want to order heatsinks as well:  http://www.ecomorder.com/techref/ecomprice.asp?p=416045

The guy that sells this stuff is awesome.  He's actually local to me and spent a couple of hours at my house helping me fine tune the controllers for my machine.

For what it's worth, with these controllers, my machine can make rapids of 4000-5000mm/min.  I set them lower only because I absolutely HATE when the motors skip. 

If you'd rather buy a plug-and-play controller, the Gecko 540 is supposed to be the holy grail.

[vigilante397]

Plug and play is nice, but the Gecko looks like it's about half what I paid for my entire setup I got my CNC as a kit (saved me a few bucks) so I'm absolutely not afraid of putting things together Bookmarked those pages, thanks!

[Ice-9]

Plug and play is nice, but the Gecko looks like it's about half what I paid for my entire setup I got my CNC as a kit (saved me a few bucks) so I'm absolutely not afraid of putting things together Bookmarked those pages, thanks!

I have been looking at the Gecko 540 and it is said to be very good but I may be looking at building my own controller system using Leadshine DM542A drivers and possibly an Ethernet Smoothstepper. A new C400 Ethernet controller is also on the market which I want to look into.

Putting a good controller together is more expensive than a complete CNC3040 but is worth the effort for a much better machine.

[canman]

These controller kits I built ended up costing me about $100, and they're absolutely fantastic...the price alone of the Gecko controller was what killed me, I just couldn't justify the cost.  But for $35 each for a little controller kit that works perfectly, I was willing to take a risk.  And it wasn't a huge risk because they guy selling the kits has a video up of a bunch of machines running his controllers, including a 3D concrete printer:

http://massmind.ecomorder.com/Techref/io/stepper/THB6064/gallery.htm

https://youtu.be/q2T0FbuN8FE

So I figured if a concrete printer could be run with these controllers, my machine could certainly run better with them.  And such is the case!  Turns a Chinese junk machine into something awesome.  Just need to upgrade my 8k RPM spindle.

[Ice-9]

Just need to upgrade my 8k RPM spindle.

I upgraded the spindle from the 52mm 300w piece of crap to a 1k5 water cooled spindle and VFD £146 on ebay. 24k RPM and much quieter that the crappy dc motor.

The only difficulty I had was I needed to modify the spindle mount to take a new 65mm spindle. I can post details of how I modded the Z axis for the larger spindle if it helps.

[canman]

Actually that would be very helpful...I'd rather get a 2.2kw spindle but those are all 80mm and the 65mm bracket is crap anyways.  Might as well mod it to work better.

[Ice-9]

I considered the 2k2 but as you say it is an 80mm bracket, it is also about 4kg more than the 1k5. The 1k5 is in my opinion about as much weight as the gantry can handle. I will dig out some pictures of my upgraded spindle set up.

[canman]

Could you send me a link to the spindle and VFD you ordered?  Seems like a great price, I can't find anything for less than $250 USD (172 GBP) and if you've had good luck with yours, I'd much rather get a spindle I know people aren't having issues with.