I need to be able to cut standard plywood thicknesses form 1/4" to 3/4"
I also need to cut up to 4" thick foam.
I currently have an LR2. (before you say it, I am considering the LR3, but I have limited hobby budget funds so it won’t be immediate. maybe something over the winter)
I just updated to the jackpot board and in the process started to have an x axis drift. I do not believe it is related to the jackpot, but just discovered it now.
I also have a crack in one of my parts and will need to disassemble the LR2 to replace it.
here is my misplaced post.
I chose the LR2 (this was before the LR3 was released) because of the potential wide range of Z. I was hoping I could use a 10" Z travel which would allow stability for cutting wood, but understood I would loose some strength when raised higher, but I was only cutting foam.
After talking with Ryan what I should have do is lift the cnc on risers which would allow for the 4" foam cutting and then use platforms to bring the wood to the gantry when I need to cut wood.
I recently built a torsion box table that allows for the clearance of the LR2
this will make lifting it on risers difficult and the main reason why i’m considering the LR3.
So first I’m looking for ideas on making risers for the LR2 to keep me going while I look into the LR3.
Preferably these risers would work for the LR3
the second thing is what to do for lifting plywood up to the raised gantry height.
I want to make it easy to pull in and out.
Another way to think of this is to make the risers height adjustable, but that seems complicated.
I remebered this video of a guy building a co2 laser and uses a belt drive system for raising and lowering the bed. Maybe could be used for something here.
go to 7:59
Not 100% on what to do for the risers for the LR2, but if you are cutting foam, and then want to cut ply, you could get varying thicknesses of the foam sheets used for insulation. You can put this down under the ply to raise it up to the height you need. It is relatively in expensive, light weight (easy to move), and can act as a sacrificial piece when you do through cuts. I have used this on a couple of projects before and it worked well.
So most the community uses drop tables. This is where the workpiece can be adjusted up or down but the riding frame stays the same. This works but if you want to do super deep cuts you’ll need a special bit like what is posted here Cutting styrofoam, a work in progress
Now also talking about that same post he modified the files to make his LR3 have much more clearance. This does take some CAD and programming (firmware) skills to accomplish.
I also like what @c00nphrog said about stacking or vertical tiling (not sure the technical name) where you take multiple smaller pieces, stack and glue them together to get your archived piece. You can also see this method in that thread as well.
I don’t think adjustable is worth the effort. Other than foam, how often would you need anything in between? If you don’t want a giant 4" riser block the size of your table, make it 2-4 smaller boxes. If you always put them back in the same location, they should stay relatively flat.
Would it be the same if I extended the Z tubes up and have the gussets above the gantry?. I’d have to modify the printed parts to remove the lip but that would be easy enough. I’d still loose some X dimensions but not too bad. This would keep as much Z as possible.
I think you are right. My thinking was that it would be the reverse of a drop table. But it would be more complicated then the gusset approach.
I like this idea. the only issue is that foam sheet is not perfectly flat. I could oversize some, surface it and then skin it with 1/4" ply. basically a torsion box.
Yep. The top pushing the way you are trying to prevent but still strengthens it, the bottom shortens the lever arm and pushes the opposite way. I am sure in practical terms it is closer than in my head.
If you make your riser blocks the right dimensions, it would still work without those. Something like a 2x4 “T” beam mounted on top of your table might be just right.
would supporting unistrut on PLA printed supports be supportive enough - the PLA I mean?
if it is, it would be fine for the LR3. I could make feet that mount to the table and support the unistrut at the correct height
I could even cut tubing that would do the actual supporting. The PLA feet would simply provide a means to secure it to the table.
One thing I like about this option is it visually is not as bulky looking. the supports can be space a part.
For the LR2 I could use spaced out plywood supports like sketch below.
I’m only raising this 4 3/4’ (forgot about the spoilboard in previous dimensions)
Yeah, extended an extra 50mm to use 200mm MGN12 rails. TallLR3 YZ PlateV2.zip (5.2 KB)
This is the one I have jn acrylic. Sharp corners rounded, and I put a slight arc on the bottom of the Y drive, but I think that didn’t import for the laser, so my parts have a flat bottom (which worked fine.)
TallYZPlate.zip (3.1 KB)
This is the original, sharp corners preserved, and a flat bottom of the Y drive opening. (The rounded corners are better for acrylic, I think.)