A separate router that connects to the cafe router would do it. That router can reach the Internet and share it with your tablet. Both the fluidNC and the tablet will be able to see each other. But no one outside your private router can reach those two devices without forwarding a port.
If you want remote access, you could also run cloudflare and have password protected access from the Internet. You would need a more expensive router or a second box.
BTW, I am jeffeb3 (from sandify) and this project is incredible. Thank you for sharing. Where is it?
Iām in New Hampshire. That cafe that Philipp linked to is not where the The Plot-a-ma-bob will be. Right now it is at my house. It will be at least a month or three before I have it ready and then it will be at Revelstoke Coffee in Concord, NH.
Jeff - This is one of my favorite Sandify plots. I have been told it looks like a pile of sh!t. I can verify that it actually does share a remarkable resemblance to a pile of black bear sh!t, as I have had several visit my property that have left gifts in my back yard. However, the reason I like it so much is that it is actually 260 concentric circles, of constant scale, with Perlin Noise applied to the contour. Iām sure you can appreciate that as well. Itās very therapeutic (for me) to watch it being drawn. If I find a video of it on my phone, Iāll upload it to my youtube channel.
If there is interest, I can start a thread in the āThings Youāve Madeā section of this forum with build details. It will be several months though, because itās fall in New England and I spend as much time as possible outside enjoying the season. When the bleak midwinter arrives, Iāll have more time.
The Perlin noise was added by @bobnik and I agree it is beautiful. The circle wiper base is a great choice. I love the math involved with taking something so consistent and regular and ammending it with a smooth bit of math to make something natural looking.
When I started sandify, I did not think of plotting at all. But it does lend itself well to ink and paper. Watching it work is so incredibly different than just looking at the result. I would never watch an hp plotter print that pattern, but if your plotter was making that in the same room as a TV, I would watch the machine.
If I get near New Hampshire after you install it and before it gets taken down, I will have to visit. More details would be great in a new post. We are getting some good fall weather too (in Colorado) and I have a hard time getting off my bike long enough to get on the Internet.
If you look closely, this video shows two issues I have had to deal with. The first is drawing surface inconsistency. In this case, the back board (I use 1/2" MDF) has a very slight crown in the center (warp was caused by water based primer), so as the pen gets further from the center, the pressure (the penās tip to paper) decreases. The result is a lighter line as it approaches the edges. Combine this with the second issue - felt tip pens donāt hold much ink, so they run out on larger prints - and it becomes noticeable. I redesigned (increased) the amount of pen travel (float in the Z-axis) and am currently experimenting with ball point pens (they hold a lot more ink) to address these issues.
So I think the 90 degree is not going to help the pen/ink scenario, as they are made to work 180 (downward)
The only thing I was thinking was having the pen on a 45, but with your changer, I do not think that is possible. for the mdf, maybe acrylic, or even Glass, I know that people use Mirrors for plates on the printers as they have to be completely flat so that your reflection is true. Maybe see how much a mirror would be from a glass store?
Fine liner pens do well at 90 and there are a few ballpoints with pressurized cartridges (I am using UNI-Ball) that write upside down. I have pondered, and may eventually try, an angled pen holder. I think the ideal pen would be a gel-pen. Unfortunately they are all gravity fed. Need to test to see what the minimum angle would be - I think 45 is a bit much. There are plenty of solutions to the ābackboardā issue. I think even 3/4" MDF would address the problem significantly. Comes down to a tradeoff with weight and cost. My current build is 6" less in the horizontal (uses 30" paper roll instead of 36") and it looks like that small decrease in size eliminates a lot of the pen travel issue.
