Hi guys, new to the forum but excited about building a CNC machine... I have looked at the OX, and it looks like a cool design, but I was also looking at the C-Beam Machine. I like it's design for the most part, the only thing I don't like is that the Y axis seems to be a bit flimsy. I don't like that the table is supported only by a very small area and any play in the carriage of the Y axis table or flex in the beam would be multiplied by the torque arm formed by the table. This may be OK for doing flat plates, but if you wanted to do any serious 3D shapes, or edge machining, I think it would distort too much. Also, the C-Beam machine seems to have a very limited Z axis capacity. C-Beam X and Z axes are great, and the lead screw construction is simple, cheap, and really adaptable. So I asked myself the question: Would it be possible to use the Z and X axes based on the C-Beam system, but use the Y axis configuration of the OX system. This should result in a stiffer system, with all of the capabilities of the OX, but with the much simpler and cheaper construction of the C-Beam for the X and Z axes. Do you think it would require custom side plates to do this, or would it be a simple modification to bolt the C-Beam X axis to the OX side plates?
I had planned to do what you mentioned. Basically, an Ox using Cbeam parts. I am using lead screws for everything. I had to make some modifications though due to lack of cbeam in longer lengths, which actually may make it a little easier to fine tune. I modified the Ox plates slightly by making them 10 inches higher due to using 2 20x80 vslot extrusions bolted together for the x axis rather than 20x60. Also, I made them wider towards the top to mount the stepper motor and lead screw. I wanted minimum 24 inches for the width so I went 1500 L x 850 W. The working are will be about 25 inches wide. I am still sort of working out the design. I am thinking of flipping the z cbeam around and fixing the beam directly to the x plate, so this drawing will change slightly. Having it the way I drew it limits my z axis, or I have to lower the bed and extend the z further than I would like potentially leading to deflection. I plan to do it like this: Cebu | OpenBuilds Also, I have not attached all the minor bits and pieces (screws, etc...) and I did not draw my own lead screws. I cheated and used 8mm (from the cbeam build) when in reality, I will be using 1/2 inch 5 start acme for Y and 3/8 inch 4 start acme for X and Z from McMaster Carr.
Here is an example of modification to the Ox plates to utilize c beam.Screaming Ox CNC Machine | OpenBuilds
Hi Guys: Is it actually possible to bolt 2 C-Beam linear actuators together at right angles to form the active part of a gantry system? I notice most of the c-beam builds utilize a plate system similar to the standard OX gantry with guide wheels outside the extrusion. Is the inside wheel system used on the C-Beam not stiff enough to use by itself, or is it just that it is physically impossible to bolt together?
I actually wanted to build a machine using a 250mm c-beam linear actuator for the Z axis, a 500 for the X axis, and 2 500's for the Y axis, using stock components if at all possible so I can just buy all the parts off the shelf from the parts store or from SMW3D.
Take a look at the Routy, more specifically the gantry risers on the Routy. You should be able to morph that design using the parts you list into what you seek. You haven't specifically noted what you plan to use it for so I really can't say how feasible the whole approach may be.
Hey Rick: I looked at the Routy, but I don't really like the belt drive system, nor the gantry system. I was hoping to use C-Beam Linear Actuator assemblies for all axes.
I mainly intend this to be used to cut or engrave plywood or plastic parts for projects, but I also want to be able to cut up to 3/8" aluminum for metalworking projects as well. Eventually, I would like to add a laser cutter for gaskets, cloth and engraving, and, possibly even a printing head to make large format 3D printed panels.
If you want to do the C-Beam build, you could run the Y axis on two C-beams with either 2 stepper motors, or with one motor in the middle. Somewhat like this: C-Beam Double X | OpenBuilds Then you would have more support for the Y axis table. If you want to do an Ox/C-beam hybrid, I would think you would need to make your own gantry plates like the Screamin' Ox I referenced above. The easiest would be to down load his sketch-up file, since he did the work for you, and print out the plates and use them to drill holes in aluminum. That is, if you do not have access to a CNC already. I have no access to a CNC machine, and so I am using my drill press. To make sure everything lines up right, I am screwing corresponding plates (slightly oversized) together and drilling through both at the same time. Then I will do the finish cutting of the plates on a saw and clean them up with a sander. The second comment, by Kyo (thanks Kyo!), in this thread shows how to flatten the sketch-up drawings to make templates Printable plate files | OpenBuilds .
You didn't follow what I was suggesting. You were wanting to eliminate special plates and make this happen with off the shelf components that work with the C-beam actuators. Look at the Routy and visually replace all the main rails with C-beam Actuators. Now look at the means the gantry beam is supported by the side risers. These easily connect to the C-beam Gantry Plates of the Y-axis rails. And with the X-axis rail attached to the rear edge of these risers, it balances the eccentric load of the spindle which sets forward of the X-rail. A perfect system, no. But it will get a system up and running to where you can easily cut plates of your own design. And the parts you would be taking out were not a significant initial expense and could also easily be re-purposed. I would however suggest upsizing these risers to 20x60 or 20x80 extrusions or maybe even C-beam off-cuts.
Hmmmm, I'll have to look closer. You are right, I thought you were just suggesting building a Routy, I didn't realize you wanted me to look closer at it's construction. Thanks, Rick.
Rick, that was what I was thinking of and now I see what you mentioned! Now if we can just get C-beam in lengths greater tha 250 mm and the assoc actuators as units.
