Wednesday, February 22, 2017

Light for Monoprice 3d Printer

Designed a bracket to hold an LED light on my Monoprice 3d printer. And I'm really happy with the results. I'm no longer printing in a gloomy shadow box. I can actually see how the print is going without using a flashlight.

An animated gif showing the difference the lamp makes to the illumination on the print bed. Also notice my high-tech printer enclosure (two trifold panels and a plastic bag.

The light from my studio's overhead light got blocked when I stood near the printer, and the desk-lamp still wasn't bright enough. I had to hold a light near the printer to really see what was happening with the print, or make the entire room blindingly bright just to see what the print looked like. So I decided to design a bracket to permanently attach a light to the printer itself.

At first I was going to do a simple squared-off S-hook and hang the light off the top rail of the printer. But no, that was too simple for a self-proclaimed designer. So I used the notches at the corner of the vertical and horizontal bars to create a pair of brackets. And I "just had to" decorate the bracket with mini-pilasters and notches and grooves. Hey, it may be a simple functional object - but that's no reason to not adorn every surface with decorations.

I had an old LED strip-light designed to go under kitchen counters. It's way too dim for my kitchen needs, but worked really well for shelves and the workbench. Plus, it was almost the exact size of my printer and the multiple LEDs gave an even illumination to all sides of the prints- no pesky shadow sides. So it had already become a sort of portable flashlight for my 3d-printing corner.

Finally, I had the brilliant idea to attach it to the printer and avoid the extra step of holding the lamp every time I wanted to check the progress of the print.
The lamp casts a nice, even illumination across the entire build plate. Really makes it easier to see how the print is progressing - even when you're printing with black filament on a black bed. Very happy with this enhancement.

The Monoprice i3 v2 has notches at the top of the vertical bar. Be careful - the notches on my printer were NOT THE SAME SIZE on both sides. I had to customize the tube that goes into the notch.

The bracket fits snugly at three points to keep to keep the lamp secure. There is a 30mm standoff for the filament to feed into the extruder. The post and flanges fit of the bracket into the notch at the corner of the printer's top and bottom rail. (Yes, I didn't level the bed, so my first layer is rough.)

The view from underneath shows the multiple LEDs on the lamp (providing evenly distributed light) and how the bracket clasps the beveled edges of the lamp. I printed the test piece at .20mm layer-height and a fast speed. It's ugly, but worked so well I decided to use this teat run instead of printing another, finer tuned one.

Here are some design captures from the 3d modeling program. I used attached pilasters for decoration and to add some thickness to the walls for added strength. I wanted to both hide the thickness of the walls and to make it to look like wrought-iron decorations. It does look less clunky than simple, thick walls - a little more delicate maybe. But the decoration doesn't read very well at this scale. It was good practice though.

Saturday, February 18, 2017

Diffusing Experiment

Played with some diffuser shields for NeoPixels using cheap E-sun PLA filament. I printed out copies of designs I had printed with Shapeways' Strong-and-Flexible materials. I wanted to compare the results. The PLA seemed very opaque and I thought it might block too much light, but I really liked the results

There is a difference between the two materials, but it doesn't show up very well in the photos. With a 1.0mm thickness, the S&F looked "grainy" - similar to Photoshop's add-gaussian-noise filter. The PLA was striated or slightly striped. Neither is noticeable from more than a few inches away however. A quick sanding on the PLA print's top layer would probably eliminate the stranding.

The PLA did seem to reduce the amount of light a little more, but it diffused the light more. Neither material significantly affected the colors. I probably wouldn't trust either to set my white balance, but for a rainbow light show with NeoPixels both materials work great.

Here's the case design. It uses a first generation Trinket from Adafruit, a 12 pixel ring and a potentiometer to change effects.

A pic with the cover on the case. This uses the Strong-and-Flexible material from Shapeways.

A close-up of the S&F material - notice the grain.

And a close-up using the cheap PLA. The camera grain almost hides the banding from the FDM printing process.

Overall, I'm very happy with the cheap PLA as a diffuser material. I will play around with other brands of PLA soon, and I understand some are much more translucent than the basic E-sun.