There have been a number of designs and ideas for easily changing between the different tool heads. But not really for the bed itself. Personally I don’t have that much of a problem with switching the tool heads (just 4 screws) but I don’t like to change the bed which is a lot more work than the tool head.
The only idea I know of (so far) is the use of magnetic strips like posted here: Easy way to switch build plates
But I’m not sure that would work good enough for CNC. I had some concerns about how “flat” it would be in the case of 3d printing, but that would be just a matter of creating a slot in the build plate with the cnc so the magnets are countersunk/flush with the buildplate.
My ideal solution would be something like:
- prepare a “premounted” board for all toolplates. so one for the printbed, a cnc wasteboard that can actually be wasted and one with the laser plates mounted.
- “click” that prepared plate in place and just go.
Before trying to build something myself I thought I’d first try and pitch my ideas here and get some feedback.
What have I tried already:
Mill flat the cnc wasteboard and put my printbed on top of that to get a surface as flat as possible. I was a little bit concerned about the heat so I had put a heat resistant silicone mat in between which actually had the nice side-effect I could use the screws to “squish” the mat to finetune the flatness of the bed even more. I didn’t take a good picture of that but you can more or less see it on this one:
So new and (hopefully improved) idea:
- keep a cnc wasteboard permanently mounted on the carriage and use that as the easy attachment layer: This should allow to use something else than the screws to connect it to the carriage and provide more flexibility
- have a piece of MDF to which all buildplates can be mounted. For CNC I actually already have been screwing a sacrificial plate between the wasteboard and my workpiece. Although that was mostly because I needed peg holes for double sided milling. See below
*. The peg holes did provide a lot of “fixation power” to the workpiece which gave me the idea.
- the above premounted MDF board could use carriage bolts (completely countersunk obviously) which go all the way through. 4 should be sufficient.
- these could be tightened from the bottom with just 4 wing-nuts. Or if I wanted to do it more fancy things like these threaded cam levers: https://www.wdscomponents.com/en-us/cam-lever-cam-clamp-female-thread-red-aluminum-handle-wds-369/c-400/p-2097. Or maybe the combination of magnets and 4 peg holes with steel pieces of steel bar that I used for my cnc project would already be sufficient. but I’m a bit worried that those might be more susceptible to wear and would get loose over time. Hence I would put a bolt through that can be tightened from the bottom. And by using carriage bolts, they won’t spin and lock in place.
I’m having some problems so far finding a supplier for those fancy lever clamps, but it should be possible to make those myself by using some barrel nuts and 3D printing the rest of it, and glue a washer to the bottom of the wasteboard to make it easier to flip them.
- “easy” mounting with only 4 screws/wing nuts/clamps from the bottom.
- always flat surface, only once to mill the base plate flat and from then on, no more worries.
- some work to make all this
- you lose some build-height.
- Some extra weight on the carriage, but that shouldn’t be a problem
I would love to hear some feedback on this.
* I needed to do double sided milling to create a tablet wallmount. Needed to cut parts from the back as well for the cabling). (Tip: use painterstape on your plate and workpiece and superglue to connect those together, works really well!)
Front: (cutout is for a magnet to fix the tablet in place)
finished product after painting and mounting:
The tablet can be removed and is “attached” by the magnet in the wallmount (and sticker on the tablet). Charging is done with a magnet charging cable that connects/disconnects as you mount/unmount the tablet.