Hi, my name is Scott, this is my second build... well if you want to count my first as a build, it's a mdf Frankenstein that performed, just not well.. I built it using linear rail bearings for the x and y and z. Acme rod, nema 23s, a Gecko G540 controller and Mach3. It works, but is cumbersome to say the least. The Beast, dont hate... lol it's all from scratch and completely built from the hip. Well being that I have taken the beast this far, I am hooked... and the beast no longer satisfies my desires to CNC stuff.. So I have decided to open the wallet and get serious. This new build will be an OX, 750 x 1000 x 250mm. I have purchased the RoverOx plates from SNB Solutions to use 40/80 C Beam the x, the feet plates that have the option of using ball screws or lead screws.. I'm still on the fence with this as of now, but the option is there if later I decide to. I also have enough 5 start rod and backlash nuts that I could use (upgrades for the Beast that never really took off) I went ahead and got belts and pulleys also.. Plates (these pics are borrowed ) Mine are not in my possession yet. I've ordered most everything I believe I will need from the Open Builds Store yesterday... Shims, spacers, nuts bolts, belts pulleys, wheels, z plates and lead screws ect. I am eagerly waiting the arrival of them. I'm really on the fence about using the Gecko G540 with this build... Any suggestions on a possible better driver? My steppers now are 287oz, they seem weak with the Beast hopefully this build will be better suited for them. I have been using a 46v power supply, I also have a 24. I have read what seems like good things about the TinyG but IDK Any advice or direction on my build will be really appreciated! I will update as I can.
The G540 is an upgrade over the TinyG and xpro. It's a great start. Ballscrew and rack and pinion seem to be the way to go. Belt isn't too bad, there are just a few more issues to deal with to get things right. Lead screws are inefficient. Still, you shouldn't have too much issue with the 540 and leadscrew especially if your gantry ends up lighter than the beasts. If you do you should probably reconsider your choice of motion translation and/or the steppers you are using. That said, if you switch to say ballscrews later on you may end up changing steppers for something with different torque curve. I like to put motors on these things last. This way I can run through the math in regards to weights, accelerations, as well as the mechanical efficiency of the components. Since you'll have everything, throw it all together and see how she runs. Joe
Thanks Joe, I'm going to start with belts and eventually move on to ballscrews. The Gantry on the Beast is very heavy! I imagine the new build will be much much better. I guess my main hangup with the G540 right now is that it's limited to Mach3, and serial port(I assume).... which means Windows Xp. I'd love to use a single computer in my shop for the whole process design, cad, cam but as far as I'm aware Mach3 will not work with 64bit and newer OS. I guess I can use a partition on my drive and install XP on it, bootload to it when needed.. To me it just seems like it's going obsolete and eventually changing will be necessity. I assume Mach4 will run 64bit..I'm still in the process of reading up on it. Seems like there's a some GRBL based apps or programs that seem to be gaining momentum, the ones that I've looked into seem a bit easier to navigate. I can't WAIT for this new stuff to arrive to me so I can start on this build!
I've run mach3 on my 64bit win7 laptop through the Ethernet port. Since that is what I use for designing and programming toolpaths I have another 32bit winXP Dell that only runs Mach3 and a program editor at the machine. I use the Ethernet smooth stepper board by Warp9. There are a number of other usb and Ethernet options out there like machforwin64, UC100, UC300, and more. Since it's recommended to have a dedicated barebones PC running mach3 it may cost less for you to find a used desktop instead of one of the options previously mentioned. However, with an outboard device like ESS you could potentially achieve your plan of keeping everything central to one PC with the added benefit of increasing your IO's. Boards like the ESS and USBSS take a load off of your processor. That's described hereHow It Works ??? and in a few other places on the net. Or you can jump to Mach4, PlanetCNC, smoothieboard, or another arduino based system. Regardless of what you do, I agree that it's a good time for home CNC and it's constantly getting better. Enjoy Joe
Thanks Justin, I will most def keep that in mind. I have a full blown wood shop 750sq ft. Part of which is partitioned off for office space which is climate controlled and insulated. My plan (for now) is to have the PC and cnc located beside one another but with that partition wall between them (if that makes any sense) So essentially the CNC will be in the shop, the PC in office.. The PC is setup with dual monitors, one for the office, one for the shop a wireless mouse and keyboard for the shop and wired in usb set for the office. All required wiring will simply go through the wall... So the pc will be out of shop elements all together and in my office where all the design work will take place. Regardless of how many pc's I end up with I will likely do a setup like this to keep each pc in the office, I have AC in there and it gets blazing hot here in Tx! I build guitars, so I spend a lot of times designing bodies, templates and shapes ect, I spend much more time with cad stuff than anything else so I like the PC to have a lil pep to keep up!
My Openbuilds order arrived yesterday. Whoever packed it is brilliant, everything is sorted and was wrapped and stacked to Tetris perfection... Hopefully my plates will arrive today or tomorrow.
I ALMOST had all my parts..I short myself 3 wheel kits and the standoffs for the Z's stepper..plenty of everything else..
Thank you sir! Yes, I robbed 3 off the z so I could get the others going. The z ones can be added last where as the others are kinda built around.
Yeah. It's probably easier to rip them from the Z. That way it's easier to adjust eccentrics by feel later on. Doing this you should be able to proceed with a bunch of other work while you're waiting on the post.
So this is my first build using these V wheels and eccentric style shims. I adjusted the Y axis last night using what info I could find on the web, the rails are spot on but movement seems a bit tighter than what it should be. Any tips for doing this, my touch my be a bit too heavy.
I had to return my Gecko G540 to them to repair, About a week ago I was giving the Beast one last horrah and it was working fine but all the sudden the machine shut down. The driver showed both power and fault lights and before I could shut it down it emitted a pop and the associated smoke that normally accompanies such pop. I powered it off and found it really hot under the A axis so I assume for some reason it blew some chips there. I'm waiting for the diagnosis.... The question I have now is there a sufficient way to check out the stepper motor that was on the A? I want to make sure the motor wasn't at fault. Seems unlikely they're all fairly new.. Of course I will check over all the wiring and such, as I plan on re-using all of it.
Well I got the news on my Gecko, they said that all drive winding's on the x axis driver were destroyed. "customer induced damage found likely caused by shorting motor winding's". I've not done anything to the cables or wiring so I suspect a bad motor. Since it was still under warranty they replaced the driver and tested it, the charge is $45 total. I am happy with that, Gecko has great support, I'm happy I chose them. So rather than even attempt to try using my used 287oz.in motors again for this build (probably stressed from the weight of the Beast) I have opted to purchase a new set of 4 Nema 23 600 oz.in 3.5 amp motors..The kit includes new wire and connectors...Probably over kill.. I should be good on power
Holy cow, talk about overkill. If you have an issue you could bend something. On my Ox, I have three) NEMA 34 170in/oz motors on X and Y and a NEMA 17 76in/oz motor on Z and don't have any issues. I can drive everything way faster than I can cut. How are you connecting the motors to the X and Y axes? I wouldn't think there aren't any belts around that can handle that much torque. You could drive a full size mill with those.
I have belts, 5 start acme, but eventually the y and x will be ballscrews (the reason I opted for the plates I used) I'm not trying to purchase stuff that will only hold me over for the time being.. Future plans always seem to require bigger and better.. Torque is irrelevant until you have an opposing force working against it. These motors should be plenty strong for anything I want to do, even under micro-stepping conditions Opposing force.. Now if something goes wrong yes it can be a problem, that's true with any sized motor, that's why having limit and stop switching is important as well as being careful. If I were to use belts, one would break or slip before something bent. Most likely not the case with the 5 start or ballscrews! What is it the kids say? yolo? I will wear my safety glasses.
Just be careful that big of a motor hanging off the end of the gantry doesn't tip the machine up on its side. [sarcasm off]
That's why I was asking. Belts will slip or break, ball screws won't. The safe assumption is that a critical part, like a limit switch will fail and what happens if it does. In most cases, the motor isn't strong enough to bend anything. In your case, not sure. I always worry about someone sticking an arm or hand where it shouldn't be. Not being critical, just careful. Nothing wrong with more power.
As an aside, I have limit switches and have run into the ends several times. Once because a stop came loose and once because a wire going to a switch broke from fatigue. Also, several times when I was setting the machine up for the first time due to software issues. I have been really glad that the belts slip. My Z-Axis doesn't have enough power to be a problem. I can't tell you how many times I have run the bit into the bed when the router was turned off.
You're absolutely correct, it's def food for thought. Some type of break away style motor coupling could be used as a safety measure or a key way that will shear. It wouldn't be difficult to design or build something for applications similar to this. I would imagine on the big industry style machines they have something like that.
It's not difficult on the threaded rods with the ball screws. Those aluminum connectors with the spiral cut into them (below) will break if too much torque is applied. I know that for a fact. The belts will slip. You may be okay now and when you add the ball screws in the future. You probably want to have some spare connectors on hand for unforeseen situations.
This will likely be the first real work this machine does. I've started designing some clamps to mount my Hitachi M12vc router. Still not final obviously.
Motors are mounted and boy are they fast! Here's a tip for anyone who's trying to use Mach 3 with an old laptop and having parallel port issues. Go into the device settings, click the little + sign by the computer icon at the top of the devices list. You'll see where it says the computer is ancpi, update that driver, choose from list, install "standard pc" instead of ancpi it'll reboot, after reboot it'll reinstall all of your device drivers (mine did automatically) and whamo.. All my parallel port issues are gone!
Thanks Scottyd. Could you put a copy of this, maybe with any more related ideas, into the "Helpful Tools" section. Stops it getting lost. Many Thanks
