I decided to build the Maslow CNC frame using aluminum extrusion profiles. Its my first CNC project but I envision making lots of modifications in the future to accommodate my curiosities and get the most out of the machine. I know AL extrusions are expensive but I like the way they look. Hopefully it will be rigid enough for my projects.
The frame concept uses two 1500mm C beams bolted and (possibly) welded together as the basis for the stepper motor mounting on the topside
I’ve also included a cool looking cart that runs on the V slots of the extrusions to help me later with cable and dust evacuation management.
My kit ships in June and I should have the parts for this frame within a couple of weeks. I’ll update this thread with the build process.
@Mikey . Welcome to the group. I’m a brewer in Southern California. I like what you are doing with this design. I am looking forward to seeing how it performs for you.
20x20mm extrusion is too weak. you will need minimum 25x25mm (1x1") or better yet 1.5" extrusion.
I honestly don’t have much experience with aluminum extrusion, can you elaborate a bit more on the 20/20 profile, do you reckon that it wont be able to support the weight of a spoil board and workpiece as shown in my model below without considerable deformation?
Do you have any resources that could help me simulate or calculate wether or not the 80mm x 20mm pieces will be strong enough for the horizontal or the “C Beam” 40mm by 80mm for the vertical?
Consider that I plan to attach a piece of spoil-board across the frame across the front (thinking it will increase rigidity)?
I used to buy tons of t slot aluminum. 20x20mm extrusion is going to bend/deflect a LOT over 10 feet. Now it looks like you are using a custom weird extrusion that is several 20x20’s put together and that will be substantially stronger. But those custom extrusions are also extremely expensive. keep it simple just use the 1.5" x1.5" square extrusion, much stronger and cheaper than some custom weird shape extrusion.
or just save a lot of money and use plan old 1.5x1.5 square aluminum tube about half the cost and in reality you will wind up doing very little modifying IMHO.
you can get the stuff off ebay for a good price. especially if you have a 10% off coupon.
Could you estimate what it would cost to build this frame in aluminum? Just ballpark?
well if you have a local aluminum supplier then it will be about twice the cost of making it out of wood. If you dont’ have a local aluminum supplier and have to get it shipped then it will likely cost 4x to 8x more than wood.
(regardless of the cost, you will not suffer wood warping or twisting which can cause chain jumping and skipping)
I really like the idea of a cart at the top… I have been considering some way to use the chain tailing movement to guide a bracket that carries the dust capture tube so that it follows the sled position. With my stock frame and the extraction tube on the floor, when the sled gets to the outer extremes of the bottom corners, the suction tube must be managed so it does not pull the sled off it’s course.
Your design does not seem tall enough for 8x4 plywood… on my stock frame they are 17” above the top edge of the ply. Also keep in mind that for the sled to cut to the edges, a 9” apron at the same thickness as the workpiece is needed to support the sled. I find this essential at least at the top and bottom.
FWIW, a lot can be done with the stock set-up, and once you have made that work, you will have all sorts of new ideas you can use with that aluminum frame.
Keep us posted on you progress.
I really like the idea of a cart at the top… I have been considering some
way to use the chain tailing movement to guide a bracket that carries the dust
capture tube so that it follows the sled position. With my stock frame and
the extraction tube on the floor, when the sled gets to the outer extremes of
the bottom corners, the suction tube must be managed so it does not pull the
sled off it’s course.
I’d be interested in seeing what you are thinking of to manage the cart. I can’t
see a good way to tie it to the chain position
Your design does not seem tall enough for 8x4 plywood… on my stock frame
they are 17” above the top edge of the ply. Also keep in mind that for the
sled to cut to the edges, a 9” apron at the same thickness as the workpiece is
needed to support the sled. I find this essential at least at the top and
you need a few inches, but you do not need 9" off each edge.
A couple people, including myself, have put a board sticking out on the top of the frame to hold the z-axis cable and power cord for the router. This helps get them off the work piece and out of the way. I was planning on using a bearing (like a lazy Susan) so that that board could rotate slightly and “follow” the sled. Adding the hose to the existing cables on that board was what I had in mind. I just need more hose…
Interesting idea. I have my z-axis cable (and future z-axis zero cable) attached to a board sticking out above the work area with three of those key chain extendable cords such that they pull the cables up and out of the way (I’ll try to get a picture soon) with about a 12" look that hangs down off of each extender.
It would be cool to rig something similar for the router power cord and vacuum tube, but for now I am having those hang from the sled (power to be run from an outlet at the bottom of the work area controlled by the arduino to give spindle control).
I am also intending to put my emergency stop at the end of the board at the top which will cut power to both the motor board and the router (DPST). I have the parts, now just need the time to put it all together.