Depends on a bunch of factors, like what you are going to be cutting and design of the machine.

 

No it's not, use 2 c-beams....

 

Mark, love the C-Beam "kit". Ended 3 years of procrastination to build a router.

Running through the build as I watch your build video I got to nearly the last step. Installing the Y beam assembly on the uprights. When I went to install the upper plates is when I realized the C-beam for the y axes was to short. I can not install the plates because the nut plates hit the end plates. I would have to pull the top of the uprights in to make it work. I double checked the entire rig for square and it is.

I measured the y C-Beam and compared to the flat beams that space the sides and the uprights. C-Beam 19-23/32" and the flat beams 19-13/16". So the uprights are 3/32 to wide, the difference between the lengths of the flat beams and the C-Beam. You might want to mention in any build video amendments that it is critical the C-Beam chosen for the Y axes not be shorter than the cross beams chosen. In my kit both C-Beams where the exact same length and all 4 flat beams where exact same length, 3/32" longer than the C-Beam. No matter what beams I choose I it wasn't going to work. A more experienced builder might have realized the impasse I was going to hit before assembly.

My immediate thought to fix my problem is to rotate the plates on the top of the uprights 180 degrees so the screws and nut plates where inboard a bit and then center the y-beam on the rest of the frame as it is. I do not think this will compromise anything except the max travel for the Y axes will be more limited than the max possible. Still I think more than the specified 11" of travel. I will probably not rotate the plates but disassemble the machine and shorten the two flat cross beams.

In closing as your "kit" matures, I'd think you want to make sure the C-Beams are exactly the same length, or a pinch longer wouldn't hurt, than the flat beams to avoid this. Otherwise I've only had to shorten the Z screw 1/8" and in hind site probably didn't have to do that.

Thanks for putting this kit together giving me the push I needed to get started.

Bruce

 

I could be not understanding you 100% but you are saying your t-nuts don't have enough room to line up with your top plates? The length of the C-Beam stays the same, mounted or not so I don't understand how your issue would limit travel. You are saying the frame is too long and too wide to properly mount the C-Beams too? Seems like it shouldn't cause you that much grief.

 

I got my C-Beam completed. Built a rolling cabinet for it as well. The idea came from Shapeoko 3 Table & Cabinet
Here are a couple of pics.
I am using a DeWalt 611. I used rubber gasket material from the big box store plumbing section to make a shim.
Comes in a square aprox 5"x5" 1/8" thick. Made some foot pads with it as well, this is the leftover.
This enclosure is an old drill bit box had laying around.
Just used Velcro to attach to the top of the PS, which is a Meanwell 24v 10a, I believe I got from Amazon.
I have tried reversing the Z gantry attachment, but there is too much play using the existing z-plate, so I ordered another X-gantry plate and will use it to make the Z to X connection along with the existing X plate. This should yield a tighter connection with no play.

I'll let you know.

 

@Shadow39 Nice build! I'm having a hard time picturing where you plan to attach the extra X-gantry plate. Sounds interesting. Could you draw a sketch of what you mean?

 

Rick's got it exactly. I happen to have a metal cutting table saw from the hot metal printing days of my ancestors which should cut the extrusions but many will not have such a saw.

Yes as Rick says this is a QC problem but only if they want to improve the "kit"

BTW, best I can measure now that I've found a tape in metric, is all my 20x60 beams are 503 mm and the C-Beams are 500 mm as they should be. Only makes a difference in this case I can't make up the extra 3 mm as Rick may have described better than me.

I posted here rather than send directly to QC because it seems Mark Carew views this thread and he can take care of QC if they care to but also others building their first machine like I am might see it and measure their beams before they build rather than have to disassemble after.
Bruce

 

Fantastic looking kit, and one I'm looking at investing in before the end of the month, but I do have a few questions as I work my way through this thread...

1) I see most examples seem to have a palm router modified to drive the spindle. I have an Elu MOF 96 router, and I was wondering if I could just mount this onto the C-Beam machine? It's obviously bigger and heavier than a palm router, and maybe produces more vibration with being 0.8hp?

2) Having never used a CNC machine before, I assume that you can set the zero wherever you would like? e.g. in your video you show it in the corner - I could just as easily mark the centre of a piece of work and have a CAD design with a zero datum set centrally to the computer design?

3) What precision will this machine to?

4) Finally, is there a software chain that would take a circuit schematic, generate a PCB, and then convert that PCB to a set of gcode? I'm thinking along the lines of milling copper plate sheet to create PCB's rather than etching them!


Thanks!

 

I'm am not familiar with your Router model but most people are using the Colt or Dewalt DWP611 router. If yours is similar size and weight you should be OK. You just don't want to mount something too heavy. I believe both the routers I mentioned are 1.5 hp.
Yes, you can set the zero anywhere you like.
As far as accuracy goes...there are two terms people use accuracy vs repeatability. Accuracy will depend some on your set up and machining methods and how much stress you put on the machine and partly will have to do with the limitations of your machine. Repeatability is you being able to account for all the variables and adjust your machining to get the accuracy you desire. I would thing with proper set up and tuning this machine could be repeatable down to .005" without too much work.
I know there is software out there that people use to design pcbs but I don't do that so someone else will have to chime in. I there are lots of CAM programs out there that will turn your CAD files to gcode. I just paid $50 to support Estlcam and am going to play around with that for a while.
If you have never used a cnc give yourself lots of time to get up and running. There is a pretty good learning curve to get the results that you desire but nothing like in 2000 when I started. It's a lot of fun. It's awesome when you get to the point you can use your cnc just like going out into your garage and using any other tool. Welcome.

 

Thanks, great reply. Mine is definitely bigger than the Colt, but looking at the Dewalt (http://www.amazon.co.uk/Dewalt-Dwp611pk-Torque-Variable-Compact/dp/B0049ZFUK2) and if I picture it with the dual handles in the left hand picture fitted, that's probably on a par with mine. Whether I can remove the central body is another matter though - is removing it essential or can the base plate of the router be fixed to the gantry?

 

Just looked at your router on Google and it is a plunge router. It is all one piece, and while I'm sure you could find a way to get it to work it wouldn't be ideal. The kit will come with a 71mm router/spindle mount. I would say if you are trying to do it on the cheap, you would be better served finding something used or just look for a good deal on a new router. I went with the Dewalt for a few reason that will make my machine more useful down the road and easier to upgrade. When figuring for your machine...plan on spending another $250-$300 getting it up and running with electronics, power supply and a good router. You can get rolling with free software. Estlcam is actually free to use to get started, but I really liked it so I "bought" the pro version.

 

Looks very similar to some of the other Makita clones.

 

I have used

1. Diptrace (free for upto 300 pins)
2. CopperCam turns the output of diptrace to G-code
3. and of course Chillpeppr to talk to my controller.

I have successfully used it to create a very simple PCB and mill it out, the circuit was nonsense but the process worked.
search youtube for CopperCam

Regards

Michael

 

You're all brilliant. Right, just been pricing this up, and have hit one snag - didn't realise you guys are based in the US! Shipping is a killer (unsurprisingly).

Do you have any authorised UK distributors? I've found two places that seem to sell your stuff - Ooznest and Robocutters. A few pages back there were some negative posts on Robocutters so I'll rule them out. If Ooznest are legitimate then I'll order via them .

Planning on the kit, with motors, 4x limit switches, xPro board, and 24V PSU. Excited!

Thanks for all the help in the last few posts.

 

try ooznest.co.uk

 

Also, if your in the uk and cutting aluminium, try gbrengineering.co.uk for endmills and aluminiumwarehouse for plate and other ali..

michael

 

Hi all! First off, I wanted to say thanks to OpenBuilds for existing and to Mark for coming up with the Ox and C-Beam! All very inspiring.

I've been wanting to build a CNC router of some sort for ages and finally happened across the C-Beam which looks perfect for what I'm after at this stage.

At this point, I'm a complete noob when it comes to CNC routing although I've had plenty of experience with aluminium extrusion framing that I used to build a simracing rig and I'm adept with learning software packages and have quite a bit of experience with SketchUp (and a bit with Autodesk's 123 Design).

I figured that a stock C-Beam build with a CNC xPRO board and 24V PSU is a good place to start learning. Initially I plan to just stick a pen on it to get my head around the software side of things before switching to a router (probably the Dewalt D26200 as I'm in the UK and that seems to be the recommended choice).

I've no idea at all what I'll end up using it for, but I figured that inspiration will arrive at some point and really the journey is as important to me as the final destination. It would certainly be nice to be able to create aluminium plates for projects as well as carving decorative things out of wood.

I've read through this entire thread and will be watching Mark's build video before I start building but I plan to place an order with Ooznest very soon.

One question I've had, and please forgive my ignorance here - but why is MDF so commonly used as the bed vs. a flat aluminium plate with tapped holes for holding work pieces? I get that MDF is cheap and easy, but I'm sure there are other reasons I'm missing.

Also, am I right in thinking that people tend to use another sacrificial MDF spoiler board on top of the bed? I presume the idea is that these get switched out once they get too badly messed up?

Finally, is the CNC xPRO a solid option? I don't mind the fact that it's more expensive than an Arduino+Grbl Shield if I'm getting something which is going to be reliable, well supported and last me some time.

Thanks in advance for any feedback!

 

I bought a Dewalt DWP611. Less complicated than a Chinese spindle set up...at least to me anyway. Also have a SuperPid on the way which I'm super excited about. The reason people use mdf is because it is cheap. To add a 12mm plate as the base would add a lot of cost...but there are a few that have done it. Also you are right it also works as a sacrifice surface to into. The other reason is because you can mill the surface perpendicular to the cutter to remove any but of small misalignment between x and Y. You set up sounds good. I haven't used the xpro but there are a lot of people that have. You are ahead of me on being able to use sketch up. Every time I try and use it I get frustrated and just go back to my old stand by. You will need to learn about hold down methods and think about cutting things differently than when you are using hand tools but it one of the most exciting things to me anyway to design and cut a complex part and watch it happen. Being able to do things in your garage that were either too complex or time consuming to take on by hand before cnc and then being able to bang it out design to finished piece in just a few hours is f-ing awesome.

 

Thanks for the replies guys - I'm in touch with Ryan at Ooznest so will hopefully get building soon!

 

Something I just asked Ryan via email, but may as well ask here as well:-

The standard C-Beam kit appears to use V-Slot throughout which I understand is 20mm based profile.

I’ve used standard 30mm Aluminium T-slot extrusion quite a bit in the past (also have a load left over) so I did wonder if there was any benefit (ie. cost saving and extra rigidity) to using standard 30mm (or 40mm) T-slot extrusions rather than the 20mm VSlot to mount the C-Beams on.

I suspect I'm probably best just sticking to the standard kit initially though.

 

Sorry Rick, I probably wasn't very clear in my question.

The C-Beams would still be V-Slot based for the wheels to run in - I was just thinking of replacing the other parts where wheel tracks aren't required (ie. the structural pieces) with cheaper and bigger 30mm or 40mm T-slot profiles.

 

Yeah, it was more a case of whether I'd be barking up the wrong tree going down that route - perhaps there'd be no real benefit. Probably something I'd have to experiment with myself to get a better handle on.

 

When I ordered mine I started thinking about all sorts of ways to improve it but decided to just go with the standard kit and them see what if anything really needs some tweaking. To me I bought this as a machine to make machines with. So keeping it simple and as cost effective as possible is the path I decided to try and stay on. I have mentioned it in other posts but the things I did splerge on was the router and the SuperPid. The SuperPid should help out a ton when milling aluminum. Better surface finish, less noise and better bit life and wider bit selection. Once the machine is up and running it will be making parts for itself I'm sure . Right now I think I have about $800 in to the whole project.