Published Time: 2017-12-09T17:32:39.402Z
my UV lamp is made from a UV led strip glued to a cardboard box, I just place the UV over the board not the board in the lamp.
The so called 1080p cheap projectors are actually 640x480 real resolution, or even 320x240, they are able to accept a 1080p signal and scale it down so are falsely advertised as FullHD. That was the state of things a year ago when I last checked. Much better to get a sh brand projector instead.
About resolution: FullHD 1920x1080 over a 150x100mm board gets you 10pixels/mm roughly, that is 0.1mm resolution, I don't know if that is good enough, also focusing at such a close range would require some lens hacking, from the factory they focus at 50cm at least and get you a 60-100cm diagonal size.
Correction: I should have said 0.5 mils.
That's according to altium.
However, I'm not sure if they're referring to wet film thickness or dry film thickness. I guess with uv cured paint it maybe would be the same either way?
I found that certain brands of Kapton tape are advertised to be 0.5 mils thick.
I've ordered some and will try using that to set the film thickness of the solder mask when I flatten it out between two very flat 1/2" thick panes of glass.
For purposes of solder masking, I compared a number of black markers for drawing on PP sheeting to see which would be the blackest and most opaque. I compared: Inkzall, regular Sharpie, Sharpie Oil, and POSCA (a Japanese paint pen). By reputation I had thought the POSCA would win, but by far the blackest and most opaque of the bunch was the Sharpie Oil. It appeared to be genuinely opaque. The Inkzall and the regular sharpie were not opaque at all.
Reporting back: After letting it dry overnight, I discovered that the Sharpie-Oil apparently shrinks and then flakes off of the PP film:
Not sure if it behaves better with other films or not.
However, before it dries, it performs great, as seen below.
Here I am squishing solder mask between two thick sheets of glass:
This technique seems to do a reasonably good job of producing a uniform thickness of the UV solder mask.
Here I use a Sharpie Oil marker to print the word OIL and place it over the flattened solder mask before exposure to UV:
I exposed it to UV for a full 99 seconds, which may have completely cured the non-masked solder-mask. Here is how it looks after I removed the "OIL" mask:
Here is how it looks after peeling back the top layer of PP film:
I then removed the uncured solder mask using IPA, after which I cured it some more under UV just to be sure:
As a first attempt, not bad! Using a high opacity mask probably helped quite a bit.
So, I guess now the question is: which inkjet ink/pigment or which laserjet toner has the highest opacity? For instance, there is this which claims to be:
or this:
From the looks of it, the answer will be some kind of inkjet black pigment, which is consistent with the results I got from comparing ink pens vs paint pens above.
I saw an YouTube video screenprinting. That guy noticed that semi transparent sheets work better than transparent sheets. Ink holds better or something.
I can actually try this one out. Because afteral. We want that 0.4mm pitch right?
I just need to find something to put the paint on.
Which thing are you planning to try? Sharpie-Oil on a semi-transparent sheet, or the uv resistant inkjet ink, or...?
For enhanced laser printing I found this:
though I have no idea how well, or even if, it works.
inkjet printing on semi transparent sheets.
I received some Sharpie-Oil "Extra Fine" pens. Testing them, they have a 1mm line width, so they'd be no good for filling in features smaller than that. AFAIK, they have the smallest tips in the Sharpie-Oil series.
I received the 16-bit closed-loop uStepper hardware from Denmark, so I'll be testing that sometime soon. I intend to use it on the z-axis, since accuracy on depth of cut is critical. If even this is still not enough, then I'll work harder to identify the source of the error and, if appropriate, consider stronger measures like low run-out collets, low-runout bits, ball-screws, tighter linear rails and/or tracking absolute position with a DRO and/or possibly a different spindle.
I've played around with the Ustepper-S now, and as near as I can tell, it is working correctly in closed-loop mode without issue. After the execution of each command, it shows error of 0.00, and it maintains closed loop operation to maintain its position even after the execution of the command, as it should. In my testing, Servo42A fails to do that, as well as having other problems, including lack of response to posted github issues.
Ustepper-S incorporates PID, so it should be able to do rapids and yet stop exactly where it should. Again, my initial impression is that seems to be the case.
I'm ordering UStepper-S for the x and y axis as well, which unfortunately will again take weeks to receive. However, I expect this will be the last stepper driver upgrade that I will ever need to do. If I later decide to upgrade to NEMA-23, the same UStepper-S can be used to drive it and only a different bracket would be needed to position it on the back of the NEMA-23.
I found a good "once and done" lubricant for my CNC called Krytox. It's made by Dupont, is non-toxic, never dries out, and is non-reactive with just about everything. It is more or less liquid teflon (PTFE). It comes in a wide spectrum of different viscosities. I'm using GPL105, but I think for a CNC one could argue for using a version that's a least slightly more viscous (i.e. GPL106 or higher).
There also exists grease versions of Krytox, so perhaps (?) that would be even better. In general, for any given lubricant, how does one decide what the right viscosity is to use?
Have you got your new 3020T yet? I intend to buy 3020 but there are a few variants in Aliexpress. Which site did you buy from? Can you share the link? Thank you for starting this thread.
This was my choice:
It already arrived and I started to play with it.
I decided not use its Chinese controller software or Mach3 with parallel port connection, so it needs some upgrade before I can make the first tests with it.
There are tons of upgrade options to make it work with open source stuff. I almost ordered a TinyGv2 controller, but it turned out, that that CNC can be GRBL controlled over the parallel port. In such case, original stepper and spindle drivers can be used as well.
The problem is, that the research I found behind this was misleading and it contains inaccurate / improper details (or at least not exactly applicable to my HW version), so I had to re-execute
