Guys , check out the new products!!! This is going to be really great for new builds.. Thanks to OpenBuilds store / design crew for always bringing new innovating products for our building needs, lets us expand our imagination. Thanks guys & gals !!
That's funny. After reading some comments that were critical of v-slot and thinking about how the forces play out on the OX, I started doodling profiles for n 80x40 v-slot this morning. Came up with the same idea as the C-Beam profile. Basked in my brilliance for a bit, then thought about how I could make it a reality. I couldn't have been more thrilled to open up my email and see that you've already done it! Looking forward to seeing what people come up with for C-Beam. Also hoping it is eventually available in 1500mm lengths.
I have been determined to build a 4x4 format router but looking at how easy it would be to stack a few of these togather lets just say im softening up to the benifits of 1000x10000 ie 3x3. Heck thats three 1000mm kits (two y, one x) and a short 250mm for the z. Round that order off with xpro controller and power supply, hmm
Another vote for 1500! I am going to be building an approx. 4'x4' bOx ( bruce's Ox - it will also be square.) I can use a c-beam pack for the z axis and if they were 1500, I could use 2 for the Y axis. Am I missing something or can they NOT be used for X axis? I suppose the stepper could be on the end and the non-stepper ends of the Yaxis could attach, but that seems really wasteful. It also seems to be a $30 savings over the previous Z axis materials.
Outside of combinig (bolting various extrusions i do believe these c-beams are the stiffest in the parts store, so beyond the $30 savings in materials for a z axis it may also be stiffer, to bad those acme screws only go out 100 0mm hmmmmm a belt would look nice riding in that channel pop that delron nut off the inner side of the plate an mount the motor perpendicular with the shaft running through the plate pulley mounted on the shaft ridding under those v-wheels in the channel LOL thats a mouth full.
Newbie here. Need all the help and advice I can get, and not ashamed to admit it! RN by Calling x 20+ years. Spent a good part of the last decade down pretty low due to Crohns' Disease. Surgery last April gave me a new lease on life, and doing something different for ME! Started Machine Tool Tech at a local Tech College last August. (Should have seen HER reaction when I announced same!) Am Blessed to have my Tribe (Poarch Band of Creek Indians) pay for all books, fees, and tuition, but don't think they will fork out for a cnc machine. I know it will be my 1st build, but I figure why have a do-over later. So, I would like to do a 6-8x48x12 build, but need to know how to join the additional x rails, and where to procure the leadscrews for that kind of length. Electronics I have on hand are: NEMA 23 x3, with 425 oz/in each, and NEMA 34 x2 with 1050 oz/in each. Please advise as soon as possible. I am doing this primarily to get a better handle on cnc programming, which thus far I suck at!.
Has anybody got a cad drawing of the section for this c-beam? It comes right on time for the double x-axis for my 1.5 cubic meter 3d printer, but unfortunately, only 1000 mm lengths are available. Mark, please consider supplying these babies in 1500 mm flavour, you will do a huge favour to many of us. Thank you so much.
Bill, the useful length of screws maxes out around 4 feet unless you get them in a rather substantial diameter. Igus can supply the length you seek but they aren't cheap. You may want to consider rack and pinion for a system that size. Reference the Strong Ox for suggestions. (Skip down the page a bit). CNCrouterparts is also a good source of information. And while I understand your desire to just do this once, I suggest you start with a smaller system for the learning process. The larger the machine, the larger the problems tend to be. A table top macine will also be useful for cutting plates for a larger machine and you can sell it off when you no longer need it.
Hi Bill, You might want to try Nook Industries, I purchased four 16 mm diameter trapezoidal metric lead screws from them (60 inch each) for a reasonable price. Paid about 40-50 bucks a pop, and some 20 bucks per nut. Could you be a little more specific about the design of your machine, a drawing maybe?
Clynad, there's lots of lead screw manufacturers out there, you can find screws longer than 1000 mm, single or multiple travel, etc.
Great suggestions all! So, would it be feasible to get 2 of the larger axes, running them in tandem for the x with the NEMA 34's I have??
Don't see why it shouldn't work. Please have a look at the drawing enclosed, you will notice 4 axis on z, 2 axis on y and 2 axis on x. Also, you will notice the lead screws I was mentioning earlier, the yellow vertical bars running along each z-axis v-slot. For the record, I am using 4 nema 23 (425 oz.in) for z, two similar nema 23 for y axis (but with a 6 mm shaft) and two nema 17 for the x-axis. Also, you can have a look at how the various v-slot rails are held together. Hope that helps.
I will have to get back to you for the side view, don't have one handy right now. The reason I sent you this isometric is to get you an angle on all three directions. I am a bit concerned that my two y axis, 6 mm shaft, nema 23's will wreck the small pulleys attached to them, but I will go easy on it in the beginning. If 425 oz.in of torque proves too much for the 6 mm shaft, I will upgrade to the next available. For now, I'm sticking with this because the pulley is GT2 and the smaller the number of teeth on it, the better the resolution. Without doing any math, the only way to check if your motor is too much or too little for the design, is to trial and error, methinks.
Ok..........so, since some say use r&p, and others screws/belting; if get the belting you describe with the 16t, I should still have decent resolution. Still having a tad of difficulty with (mind-viewing) the belting connections with the actual axis mount. Is this some kind of a clamp-in fastening, or am I really way off? And I gather the break strength of most any of that belting is fairly high, is it not? In thinking on some of the original replies to my initial posting, I see the possible issues with drivescrew wobble at extended lengths. So, the ADD brain formulated a POSSIBLE solution: What if there were 1/2 nuts along the bottom and top of the longest axis? These (not that I pretend to be an engineer; like I said, I am an RN) could be mounted on small N/O solenoids, with a screw-type pressure adjustment. They would retract (ideally) if set up through a proximity sensor or microswitch. When the carriage got within a few inches, they would momentarily disengage from the screw, and re-engage post-passage of the carriage. Thoughts?
Bill, I am only using GT2 belts for the 2 y axis and the 2 x axis. Going lead screw or ball screw is overkill for a 3d printer, imho. Obviously, it's not the case for a CNC. The reason you may have difficulty picturing it is because the y axis plates for the nema 23's and the idle pulleys are custom made by me, at the time openbuilds didn't have a plate for nema 23 done yet so I had to come up with my own vitamins. Please see attached drawing, I put something together for you real quick.
Understood. I see McMaster-Carr has trapezoidal leadscrews, but smallest they show is a 10x5. These are 1750 mm long. So, given that is outside the given parameters of the things I see listed in the store, how hard would it be to rethread the stock items?
Bill, try Roton. Apologies, in an earlier post I said I purchased my lead screws from Nook. Sorry, it should read Roton. They also have some nice tools for picking the right one. The ones I bought came in 60 inch length, which was fine by me since my screws are some 55-56 inches long, end to end. Why re-thread? Just go find yourself the right one, plenty of lead screws out there. Also, depends on where you are, if in North America, it should be fairly easy for you to find screws.
A very interesting idea Bill. They would need to be supports on the O/D of the screw rather than half nuts (having a thread) but it could make for an interesting project. Tweakie.
Thanks for being able to decipher what I was TRYING to say! No, I really wasn't speaking of the clamp-over type that are on a lathe; rather (perhaps) 2 pieces of delrin (?) of the same dimensions clamped together, drilled, tapped, then used as said imaginary supports.
You'll actually want the supports to slide freely along the screw rather than be tapped and move with it. Here are a couple suggestions: Connect the intermediate supports to the carriage with belts or chains such that the carriage drags them into place as it moves away. Granted they will not move uniformly or be uniformly spaced but no matter where the carriage is, the unbraced length of the screw will never be more than half the span as the carriage will pull one to the middle as it moves to one end. Alternatively, you could connect the guides with a bar half the length of the rail. As the carriage bumps them, it repositions them to where no matter what, no more than half the span of the screw is unsupported. (Note, the bar is only connected to the guides, the carriage moves freely between them.)
Yes, just a smooth hole in a guide block. That is all that's required to provide support. If you tap them, they move with screw movement and the screw would force them to the end fairly quickly and lock up the screw.
Rick, Please have a look at the following 3d printer: http://3dpunlimited.com/features/ Notice the horizontal lead screw along the x-axis? This printer has a footprint of 1000 x 1000 mm, and I don't see any additional supports along the lead screw. Just thought you guys might be interested.
Those are no different than the 1000mm C-beam kits where you won't see a support either. The discussion here is in regards to much longer lengths. The 8mm screws are good to about 1000mm and 1/2" diamter screws are good to between 4 and 5 feet. But if you intend to get up into the 7 to 8 foot range, you'll either need a fairly massive screw or a means of bracing a smaller one. A massive screw however won't fit within the confines of the C-beam extrusion.
Ok...that is what would determine the biuld for me. Also, do the v slot and t track use the same general fittings?
Didn't know we're looking at 7-8 feet here. I'll have a look at our cnc at work on Monday, it's pretty massive, see how they did the x axis. Pretty sure I've seen a ballscrew there.
I too am waiting and wondering about 1500mm lengths and 10-12mm screws. I was ready to purchase today until I saw they were limited to 1000mm with a working distance of 900mm. I'm working on a hybrid CNC/3DPrinter similar to the 3DP1000.
10-12 mm diameter screws might not work at 1500 mm. such unsupported span requires at least 16-18 mm diameter lead screws.
