Well, it originated as a blog, and has grown into a DIYDrones attempt at creating a CNC machine.
This group is set up so that we can organize the activity.
For background, the original blog is located here:
Progress on the Harp Fabricator
After a coupla years of thought and compromises and decisions on how to make a rigid small CNC machine this is what I've come up with.It will be cast solid aluminum which is the only real solution for the rigidity issue. If you could do it in cast iron it would be perfect. However this seems to me to be the best compromise after a lot of thought and trials. This is a moving table design not a moving gantry design.We plan to make the casting sometime after the 6th of January when I have help…
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Does anyone own or read about Shapeoko 2 CNC machine? I've done some reading on it and looks promising. Capable of cutting aluminium as well. Hardware price is $299 w/o Electronics and some related hardware and $649 for the kit w/Electronics.
https://www.inventables.com/technologies/desktop-cnc-mill-kit-shape...
Hi Monroe,
Look here: http://www.planet-cnc.com/files/CNCUSBController.pdf
page 17 - really step - direction like the others, just stuck on one connector.
And their SDK makes it fairly easy to get the assorted outputs and inputs to do what you want too.
Hi Monroe,
http://forum.planet-cnc.com/
and their main site: http://www.planet-cnc.com/index.php?page=home
You can take a look at their Windows interface there too.
And they do have an inexpensive 8 axis controller now too.
Love the CNC4Free site that CNC tool kit links to which is probably where you saw the Planet CNC reference, nice to get a qualitative review of the Planet CNC installation too.
It seems like it's quite possible that the Planet CNC solution could work for you.
I have BOB-CAD for my front end and except for a few annoying G-code incompatibilities it works pretty well.
Cutting those tiny little spiral wheels is about the most challenging thing I can imagine, I don't think a wood frame is going to work for you.
Hi guys,
I am currently researching the assorted interface options that are feasible for our DIY community, trying to stick close to open source where possible and still end up with satisfactory value and utility.
The primary open source CNC program is Linux CNC.
But, I would like to run what I have found to be some of the more significant options past you and see what you thought of them and whether you had any other "solutions" to offer.
1. Windows PC running Mach 3 connected to parallel breakout board
2. Linux PC running LINUX CNC connected to parallel breakout board
3. Windows PC running Planet CNC program connected to USB Planet CNC board
4. Windows PC running Mach 3 connected to Dynomotion KFlop USB and Optional Kstep board.
The first one a Windows (desktop PC running Mach 3 and connected to a parallel breakout board) is certainly the most popular and widest spread.
I do own Mach 3 and although it works OK I don't like it because it relies on tricking Windows into running DOS, is completely incompatible with 64 bit mode and Windows really, really doesn't like to run real time software. I have had problems running steppers near their top speeds and using fine resolution microstepping. And Win 8 is worse. Mach 3 software is $150.00 but Art Fenerty does support it very well.
I also have a Probotix (Planet CNC USB) board that internally interprets GCodes and provides the primary runtime environment for the machining operation. You use the Windows machine to load, monitor and control the machining operation. It's Windows CNC program is not as feature laden as the current Mach3, but operationally it is adequate and less trouble prone, with plenty of speed to "keep up". The hardware is $100.00 to $200.00 and the software is $100.00.
The Linux CNC program has the advantage of being open source and although it runs through a parallel breakout box at least Linux is a lot happier with being a realtime operating system. Like the Planet CNC solution, the interface is not quite as fancy as Mach3, but the software is free and you only need a parallel breakout box. As near as I can tell there is no ability to run USB so most current laptops would be out of luck and a USB to parallel converter tends to slow things down and periodically compromise communication which generally does not work well for real time machining.
The last one is a more expensive option for running Mach 3 with a full fledged DSP based USB driven controller board which interprets the G codes directly. The only drawbacks to this one would be it would cost from $550.00 to $800.00 for the software and hardware.
Personally, I am planning on setting up my old stepper gantry system so that I can use it with either my Planet CNC setup or as a LInux - Parallel setup.
But I really would appreciate it if anybody with any other experience, feelings or solutions would respond here.
Possibly there is an actual product here, with the existence of the open source Linux CNC making a complete USB to Stepper drive CNC controller board that interpolates G Codes directly could get us the best of both worlds.
Every project/machine has limitations. Engineering is our attempt to manage the limitations.
Budgets and resources constrain most of us - no kidding. That extra decimal place in accuracy or precision could cause a project to double in price putting it out of reach for most of us.
I went with the Momus because the designer is actively involved and there is a very active group at CNC Zone. Just released Version 2.1 added Z axis thrust bearings to overcome a potential issue. The Momus probably won't be my last machine. The accuracy and precision will do for making the parts I intend to make.
The Momus is too big for many of our members. It will also top the scales well over 100 pounds when all assembled.
This subject is just like discussing multirotors. Of late I have advised newcomers to the hobby to go turn-key regarding kits (without RC electronics). If budget is not an object, I tell them what a RTF system will cost. Many do not have the space, tools, or experience to build one from scratch. On the other hand, they are able to follow instructions (well written instructions) and be successful.
CNC machines are the same IMHO. If we can develop a 'macro-kit' folk can assemble, we will have achieved an amazing goal.
The brushless drive idea has merit. There are several brushless drives setups for spindles now.
-=Doug
Hi again Monroe,
The reality is that this isn't rocket science and the people in this community are imminently capable of producing a superior solution if they have a mind to.
There are plenty of inexpensive stepper controller boards out there and even some that support serious microstepping and encoder feedback.
At least some of those could be reasonably interfaced to a decent microcontroller board and their the field runs from Arduino through Linux and Android SBCs and even exotic SBCs with parallel processors.
I am thinking a Android / Java / Eclipse board with similar processor power and memory to the PX4 would have plenty of firepower.
Easy programming with Android and Java on the microcontroller end and Windows on the PC end could make a really interesting product possible and not an insurmountable programming task.
I think I might explore this a bit, G codes can be fun.
I agree,
My little home made one is a Gantry type machine moves the head in all 3 axes and I agree that a better solution is probably to have a single axis table and a 2 axis head.
Don't stack quite as much misalignment that way and easier to keep rigid.
BTW a fairly decent source for those Hiwin Guideways is: http://www.automation4less.com/store/index.asp
This is where I got mine originally and although they have gone a bit more upscale now they are easy to deal with.
I am a retired microcontroller engineer and I did a lot of consulting work that often required me to fab everything from scratch so I have an OK machine shop including a nice Jet Bridgeport clone, and a pretty fair complement of sheet metal tools (shear, brake, punch, etc) as well as a nice MIG with a spool gun for aluminum, in addition to the ordinary stuff.
It's all stuck in an insulated cargo container now but fully operational if a bit crowded.
Hi Monroe,
Wow, you really are a rocket scientist.
I followed here from a comment you made about the Disrupter Blog.
I am a member of the Planet CNC forum although I haven't been to active of late.
http://www.planet-cnc.com/index.php?page=home
But I do think they have the right idea, there board takes (and loads G codes directly to internal memory and then takes responsibility for executing them).
Back at the PC it just shows progress and lets you step in if you need to interfere, completely off loads the PC of the real time tasks.
Which Windows machines are seriously bad at anyway.
I am positive this is the right way to go, and now they have a potential for 6 axis drive, but I still think their a little light on the microcontroller end.
By the way I'd really like to use brushless servos myself, AC or DC, they are just so not a consumer product at any level, and at least the Chinese have made really decent steppers affordable.
And with decent microstepping and encoders for in the loop feedback they can do a decent (if somewhat slow) job.
Unfortunately, the drive part of the equation looks like the most affordable part, balls screws not so much.
I still favor linear ball guideways and I have several projects I built on Hiwin Linear Guideway here: http://www.hiwin.com/html/lg/
But they do have limitations, if you can keep them clean and lubricated and don't apply too much force they can maintain reasonable tolerance and last a really long time.
Basically OK for high speed machining aluminum, wood and plastic, but definitely need to keep your feed rate down with steel.
Work better with a high speed spindle and not too much force on the feed.
The biggest problem whole thing is that half the stuff you need is reasonably priced and at least fairly easy to find, the other half not so much.
Still, I look forward to digging back into this and may pick up one of the Planet CNC boards to retrofit to my old(ish) Aluminum extrusion, ball screw and linear ball bushing machine.
If any of you know of any other CNC boards that work like the Planet CNC USB ones and are affordable by mere human beings, I would like to know about them.
Actually seems like a good candidate for an open source, open hardware project, maybe even Kickstarter.
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