I have wondered about how much of the error is error on sled construction.
A few (dozen) posts up I posted a process to cut a sled that did not require
that the maslow be accurate with the temporary sled first. It’s more work than
just loading the g-code and letting it go, but the result is far more likely to
have the router centered.
David Lang
Agreed, glad we are aligned 
I also like the idea of simply shrinking the pattern if the endoscope ends up being too close to the board.
Glad we got this definitively resolved. Thanks for making the diagrams! We can point people back to them if they ask why rotation doesn’t matter.
Yeah definitely important since we’re focusing on the router axis instead of the camera axis. I kinda wonder if we could mount the camera permanently off-axis and correct for the image skew in software. Then we’d have the side benefit of a nice camera angle to watch our cut. Definitely too much to think about for now though.
Woo sign me up
I fired up the plotter today and tried to dial in the dimensional accuracy. Interestingly, I was able to get it perfect in the 36" dimension (within my ability to measure anyways) but the 48" dimension came up 1/32 too short out of 42" (0.074% error). That’s the spooling direction, so I’m not totally surprised it’s a little bit off. Any sort of slippage or variation in diameter of the wheels that are pushing the paper could probably result in dimensional error.
I scaled the dimension in Illustrator and printed a 96"x36" banner with the calibration pattern, but it came up 1/16" short on the 90.5" measurement. Not sure why my software scaling didn’t seem to have an effect. I changed the paper between these runs, so I guess it’s possible that different paper types cause different amounts of dimensional error.
But overall I think it’s good enough. @madgrizzle we probably just need to add an advanced setting for configuring the dimensions of the test pattern.
I like the idea… Phase 2!
Definitely… I’d be shocked if the 4x8 banner I ordered arrives with precisely 1/2-inch squares.
Except it’s not available in most countries. It’s a great router if you can get it (or the ?AEG?? equivalent) but if you’re in Oz or a kiwi, say, not so good.
one can get 44" wide format inkjet pritners, used for cheap like an Epson 9600 with a clogged yellow nozzle might be $300. normally they are really slow, but if all you are printing is tiny black squares they will be pretty fast.
The R22000 is no longer listed on Ridgid’s products site either…
Papers are hygroscopic. Grow and shrink with different humidities.
If you are going to use paper “long term” then I think you need to get it laminated.
or use some nonwoven material like Tyvek (house wrap)
I dont think you could print on tyvek. Kinda waxy
Now if you could use the pattern thats on tyvek, writing… that would solve the problem.
Can you get 96”x48” laminated? Where would you go or what would you buy?
Good to know! My basement is kinda humid so maybe that’s what’s happening.
Sounds hard! But if you think of something with a grid on it, that might we workable
How much did the 4x8 banner cost? Did you say it’s vinyl?
I haven’t found anyone that would laminate 48x96 at least at reasonable cost (<$100). Office Depot laminates ARCH-E sheets (36x48) for a few dollars (total cost I think was $12? per sheet). You could piece together three of them to cover the whole board, but you’d need a means to align the sheets and then deal with the overlap if there is some.
The vinyl banner from Vista Print was $60 + shipping… It was “on-sale” for 20% off… but they could be one of those places that have permanent sales. The problem was the image was limited in resolution and at 75 dpi so, iirc, I made the squares 0.6 inches so each square came out with consistent number of dots… at least that was the plan. We will see tomorrow.
If you were up in the $100 range, that’s about what it would cost to have a 4 x 8 CNC machine cut you a custom sheet. Then you can keep that for reference. If you have a file showing exactly what you want cut, I can take it to my local CNC shops and get some relative pricing for you.
I would pay $100 for a perfectly sized durable sheet to calibrate on. Would you use some kind of multilayer multicolor plastic sheeting and cut into that to get two contrasting colors? What is that kind of sheet called?
I’m hoping we can definitively solve this part of the puzzle with something we can all easily order or source! Pegboard was initially so promising!
For this option, you are going to have to find someone local with a CNC that will cut if for you. Shipping a single 4x8 sheet will cost hundreds of dollars. I’m crossing my fingers the VistaPrint banner works because that can be ordered online and shipped in a tube. If it doesn’t work, we might be able to find a print shop that will do a group order for laminated 4x8 sheets at a reasonable price.
I was thinking either a black or white melamine particle board. You can get at the big box stores. I make my work table tops out of the stuff, with dog holes everywhere.
