Still a noob here, so I would appreciate any advice on how to start ripping plywood. Thus far I’ve only leveled my table and built my struts.
I built my machine and table big enough to handle whole sheets, but for the life of me I cannot figure out how to go from a whole sheet to cutting (4) 11” x 7’ planks from this sheet. I have an assortment of bits, and am using repetier with a raspberry pi for connectivity.
Just plain rectangles?
Buy a circular saw and a straight edge?
Honestly a cnc is not really the right tool for this it will do it but it will be a slow cut.
Simplest way to do it:
Load up ESTLCAM draw a rectangle tool path and cut with 1/8 up it bit at 4mm depth per pass at 8mm/s. You could probably go faster but that’s a very conservative cut on an unknown machine.
Save the gcode to disk and run from repetier or sd card.
I’d really start with Ryan’s basics first, using small scrap to practice on but this will get you your rectangle.
Thank you. I dont mind it taking longer, I built the lowrider so I never had to rip plywood again.
In that case I’d get yourself a notebook and start a notebook with bits, feeds, and speeds and try to find the sweet spot for your machine.
Figure out a DOC that is a multiple of your material and experiment with feed rates until you get one that’s reliable and reasonably fast. Personally I just set up a ton of identical bits in ESTL cam on for each type of material.
for example
1/2" plybond birch plywood - Speed Tiger 1/8 2F Upcut - Cutting
6.5DOC, 10mm/s cut speed, Router speed 4/6, .25mm finish pass at 13mm, 20mm/s
Fine tune these values to fit your machine. Experiment on scrap until your success % is acceptable.
If you use holding tabs make them partial depth and a multiple of your DOC to minimize z-moves. for 1/2 I normally have my tabs @6.5 if I’m cutting 13mm deep.
Also get a 220grit sanding block for cleaning up the fuzzies.
I just barely started building my lowrider and have almost zero experience with a cnc so sorry if this sounds stupid but maybe there’s a way you could attach something like dewalt dcs571 4.5 inch circular saw to the machine. I don’t know if it’s sturdy enough to handle something like that and could be dangerous so this is not advice. Would be pretty cool though. Just make sure it’s perfectly straight and only moves along one axis.
I think Doug build a panel saw with parts of the Primo.
So my little machine there doesn’t cut very deep, it’s a 7 1/4" circular saw, and I set it up as a panel saw. The panel that I mounted to is 12mm plywood and has a pocket milled for the saw to mount in, so it loses less than 1/4" cutting depth, but add in a bit of clearance and it adds up to significant reduction in depth. I could probably still cut studs or other 2X? lumber, but only just. So far I have only used it for sheet lumber.
Have any details or plan on how I could make something similar?
Not a super difficult project. I took measurements of the bottom plate of the circular saw so that I could design the pocket, with room for the blade protector and with the screws that hold the saw down. I then figured on a safe distance to allow my saw to tilt to 45° and determined a spacing for the rails. Draw in CAD, cut with the CNC. I took the spacing for the bearing holders off of Ryan’s 611 plate.
Then I made a couple of end plates with 25.4mm holes (Plus a very slight allowance, I think they’re 25.6mm in CAD) spaced exactly the same as I did for the holes that mount the bearing holders.I cut a couple of templates from each out of plywood, with an endcap for each end with no holes.
The tricky part is making the whole thing square to the support.
My end caps have holes for #8 wood screws to go into some dimensional lumber (I used 2X8s) that will have the base at just the right height that the saw blade can reach the bottom. I positioned the 2X8s using a sheet of plywood that I trust the lumber mill to have cut square. If the mill is off, then my square will be off. I did check with a framing square.
You lose about 9" with this setup where the saw can’t reach the bottom. I can cut a 5’ sheet with this, and I have a peg that lets me set the width as accurately as I can measure with a tape for length. (I let the saw cut the peg, so it’s exactly where the saw kerf will end.) The panel saw sits at a slight angle against the wall, and is about 6’5" tall. I plan at some point to make a support structure instead of the sheet strips it currently has which I expect to warp at some point.
