Hi All, I've browsed this forum for a few hours, and I am still confused about where to start my journey. Firstly, let me outline my 'wishlist'. I want to cut shapes out of aluminium sheet up to 1/4" (6mm) thick on a table bed of 48" x 24" (1200mm x 600mm) I've read about the C-Beam Machine Mechanical Bundle and the OX machine Where do I start? Do I need the C-Beam to make parts for the OX machine? Is either the best choice to suit my requirements? Looking forward to your replies!
Start here. This is a cross between the Ox and the C-Beam Machine and provides the best of both worlds. The C-Beam Machine is great for cutting aluminum but it doesn't handle large sheets well. The Ox handles large sheets well but not the best solution for aluminum. Mark's newest concept offers the large sheet capacity and smaller, more controlled movement that make it the proper choice for cutting aluminum. And please note, you don't have to have a machine big enough to cut the whole sheet at once. Through pin registration and tiling, large sheets are easily cut in sections.
While some aspects of Moag's design like the gantry assembly are workable, the moving build plate is not ideal for oversize sheets.
Thanks for all advice so far. I've learned so much in the last 24 hours! I have another question please. Say you want to build a machine with lead screws instead of the flexible belt. I know that there is well documented 8mm lead screws, but that isn't sufficiently rigid for (say) a 4' (1200mm) bed, so you would up the diameter to (say) 12 or 16mm. This may have a different pitch. So what do you change to correct for the change in thread pitch so that the software knows what to do to move (say) 1mm? I hope this makes sense.
Changing the software setting is easy and you can do it at the end. The tricky thing if you change the lead screw is that you can no longer use the standard linear actuator plates that make it so easy. The part store has end plates, bearings, shims, lock washers, and nut blocks that all work with 8mm lead screws. You would have to get (possibly more expensive) alternatives to all of these to make it work. But a larger issue with lead screws and large machines is that lead screws are much slower than belts or rack and pinion. I've got a 1m x 1m machine that is all lead screws and the low speed is my one regret so far. -D
Yes. I am using 1m lengths of 8mm acme screws. I've settled on 500mm/min as a reasonable top speed, though it is possible that I could tweak things or run less conservative speeds and still be ok. I can sometimes hear a bit of whipping at my top speed, but that seems to be minor and doesn't affect the accuracy as far as I can tell. Just remember that your working area will be less than 1m. My machine is built so that it can cut a 2' x 2' square with plenty of room to spare. -D
Oh. I should add that my target material is ABS which is much easer to cut than aluminum. So I don't think my exact design would work for you. But if you want to cut aluminum sheets, your greatest challenge will be making sure that it is a rigid machine. Small machines are much easier to make rigid than large machines. -D
I expect that it will all be about the cut depth. I'm not in a rush and would go for 0.5mm steps. Mainly routing out shapes from 3 or 4mm aluminium. I am lucky enough to have access to an aluminium workshop, so material etc is not an issue.
You can take a look at my build here: Contrariwise -- A C-Beam Router If you are planning on doing aluminum with something similar, you would want to do a lot to stiffen up the X-axis cross beam. Switch to the XLarge C-Beam plates that are now on the store, use high torque motors, and try using two C-Beams on opposite sides of the Z-axis so that it is completely supported rather than being cantilevered. Though I like my design, it might be simpler to start with one of ones designed for aluminum from the start mentioned above. -D
Spindle motors.... there doesn't seem to be a lot of info as to what people use. What would be some suggestions for a spindle router for aluminium. Do I need a VFD control?? and what specs would you recommend? Thanks
You will need a VFD if you use a spindle which does not have speed control. However, a lot of people use a VFD on their Router for the same reason. It enables a router to work at a lower speed than it was designed for.
All the squabbling has started now. The losers are like spoilt kids, throwing tantrums because they didn't win. And to be honest, the winners don't really know what to do. I, like everybody else, didn't think we would get out. Now we have loads of them wanting to get back in. What a bunch of Muppets! There's now't so queer as folk!
