Color Swatch

Here's a color swatch of our PLA in Spocktapus form.

In other news, we're still working on our custom printer design as well as the MendelMax 2.0 beta printer. We'll have more detailed updates soon.

Mendel Max Custom Build

We're having a lot of fun with the 3D printer and ended up ordering a Mendel Max 2.0 beta (more on that later) as well as another Mendel Max 1.5. This time around our plan is to really customize the MM1.5 printer and see what we can do to reduce the part count, improve the looks, and perhaps improve some functionality. The main thing that annoys me with the MM1.5 and most Reprap printers is the triangle top.  It's not really needed, adds extraneous parts, and makes the printer feels more cluttered. Everyone that's seen our printer likes to watch it print, so it'd be nice to open it up and improve viewing angles.

The first step was to get rid of the triangle top. While it's completely possible to just remove the entire top section of the printer frame and have the Z travel rods attached only to the bottom frame with no connections up top, we decided to borrow from the design of the MM2.0 and went with vertical extrusions to support the Z rods up top. I designed some custom brackets to attach the rods at the top, and some right angle brackets to support the vertical extrusions along the base. Here's what we've got so far. (Custom parts are purple.) You can get the right angle bracket model from http://www.thingiverse.com/thing:59398

Modifications and Additions Part 4

We finally got around to redesigning the back mounting clip for the power supply. We have 1 back clip, 1 side clip, and 1 foot holding the power supply under the printer. You can download all the parts from http://www.thingiverse.com/thing:57765  Here's a shot of the mountings from underneath the printer. Back clip is green, side clip is blue, foot is grey.

Colin made some clip mounts for the 2020 extrusions in OpenSCAD so I decided to create a filament guide that clips on to the top of the printer frame. http://www.thingiverse.com/thing:55776

He also bought a LED light for the extruder and a rocker switch to turn it on/off. Seemed like a good idea to make a clip on housing box for the switch. http://www.thingiverse.com/thing:57849
Here's the rocker switch we used https://www.sparkfun.com/products/8837?

We'll probably replace the LED light with something else, but here's what we currently have http://dx.com/p/39mm-2w-9-smd-led-126-lumen-6500k-white-dome-light-dc-12v-51002?rt=1&p=6&m=1&r=4&k=1&t=1&s=&u=51002

PLA

So far we've only printed with PLA filament. It prints at lower temperatures than ABS, has no odor while printing, and supposedly is stronger than ABS. We've gotten most of our filament from Ultimachine and have printed in red, silver, black, yellow, green, and purple. They all print extremely well, have consistent diameter (~2.85mm) and most stuck to the bed easily.

We started off printing straight to our glass bed (it's plain old glass not borosilicate glass). Our hot end was set to 185C - 190C and the bed to 55C (we measured the bed with a thermal gun and got 60C with the software setting of 55C).  Things went well for a while but then we started getting curling as we started larger prints. We pulled out the temp gun and the bed was reading all over the place +/- 10C. We turned the bed setting up to 60 - 65C with a little improvement. The silver was giving us some grief not sticking to the bed very well. 

Example of curling, the right side came up off the bed during printing.

Around that time we bought some blue PLA off eBay. It's a great color with a little translucency and it was a lot cheaper than Ultimachine. It has a diameter of ~3.0mm so we had to make a new materials setting in KisSlicer (one for the eBay, one for Ultimachine). We were excited to start printing with our new color but that excitement quickly soured. We could not get the blue to stick to the bed with any consistency. We started playing around with the temperatures and made a little progress but still very inconsistent results.

Underside of a print with the eBay PLA. The bumps are were it didn't stick to the bed.

Eventually we covered the glass with Kapton tape and that seemed to help out with the blue and it solved most of the problems we had with the silver as well as the curling.  Currently we're printing the eBay blue PLA at 210C for the first layer, 190C after that and a bed temp of 75C-80C.  Our Ultimachine PLA prints at 185C with a bed temp of 65C.

Regardless of the temperatures you end up with, proper cooling is extremely important. You want the PLA to cool as soon as it's out of the hot end. We have two 40mm fans blowing at the hot end but are still planing to try some fan ducts to focus the air better.

I won't say the PLA we got from eBay (which most likely came from China) is bad but it's definitely more fussy than the Ultimachine PLA. If you're just starting off, go with filament you know will print easily, get your printer dialed in, then experiment with the cheap stuff.

2 New Blog Pages Added

I've added 2 new pages to the blog. The tabs are located at the top of the page. One page for all the custom printer parts we are designing and one page for just fun stuff we print.

Modifications and Additions Part 3

Like most Reprap printers, our kit wasn't designed with any way to mount the power supply. But having it sit on the desk next to the printer was uncouth, made it difficult to transport, and was a potential shock hazard.  The obvious place to try and mount the power supply was underneath the printer but there wasn't enough clearance. The first thing we need to do was raise the printer about 3cm.

We started off printing some feet we found on Thingivers (http://www.thingiverse.com/thing:15880) to raise the printer, but with 4 of these in place it didn't provide much stability.

With my handy dandy new OpenSCAD skills, I designed some basic legs that would attach diagonally across each corner. These provided much more support and we were able to adjust the back left leg so the power supply could rest on it.

Here they are mounted to the printer.  They're a bit slippery on the bottom so we may add some rubber feet to them. Download the files from http://www.thingiverse.com/thing:51895

Again, here's the power supply and relay prior to mounting.

Here's a shot below the bed so you can see where the power supply is going. The cutout leg is in the back corner and blue parts are printed clips that screw into power supply and clip on to the extrusion frame. Currently only the side clip is being used. After attaching the back riser we realized the back clip won't fit so we'll need to make a slight design change.

A few pictures of the power supply and relay mounted. The relay is attached to the front leg with double sided tape.

 

  

After mounting the power supply we rerouted all the wires and used cable ties to keep things a little more tidy. Here's where we're at now.

SCADBot 1.0

I just started working with OpenSCAD this week and so far it's a lot of fun. I don't have the patience to work with 3D graphics editors so it's a great alternative if you know even the most basic programming concepts.

You can download OpenSCAD from http://www.openscad.org/ and here's an online manual
http://en.wikibooks.org/wiki/OpenSCAD_User_Manual/The_OpenSCAD_Language

Here's my first attempt at a miniature robot, meet SCADBot 1.0! His butt is a little saggy in this print, but we're still trying to figure out the best temperatures to print this blue PLA.  You can download this little guy from http://www.thingiverse.com/thing:50858

On another note, we just finished mounting the power supply to the printer and have cleaned up the dangling wires.  A detailed post with lots of pictures will be coming in a few days.