Danny's Corner

It's alive!

Created on Friday, November 18 2016 12:17

That right there is the result of a lot of tweaking and represents my first truly successful print with the new MKS Sbase microcontroller. Been a long road, but we're up and running. More tweaks to be made, but I'm really close now. Time to recap.

The MKS Sbase lacks a way to switch off power to itself. The commands are available, but there's no physical hardware like a relay or what not to do it. So, I tried to put one together with mixed results. Here, I'm trying to use an LM78xx 5v voltage regulator. In my tests with a 9v battery it did great. The temps creeped up, but topped off at around 104F or so. However, once i switched over to 24v, the temps went through the roof. I didn't bother to figure out how hot, it simply got way too hot to touch.

I then went and designed around a DC step down converter. Much better. But this too ultimately failed because my relay is blown. It seems to be stuck in a NC state on the NO side. Really weird. I'm going to try a few different things to it, but in the meantime I've got more 5v low relays inbound. The rest of the wiring was pretty uneventful and not worth writing about. Plugs were cut off and new ones crimped on.

Another hurdle was my hotend setup. I inadvertently snapped the all metal heatbreak I was going to use. The part wasn't made to spec and the shoulder of the transition zone was too thin. But, I do have quite a few (5) 4.1mm throughout heatbreaks and I'm going to be printing almost exclusively in PLA formulas, so I'm good right?  Turns out I was wrong.

A E3D style hotend seals itself when the heatbreak and the nozzle clamp against each other in a heater block. One of the two differing metals is going to yield and result in a nice seal. Typically it's the brass nozzle that yields against the stainless steel heatbreak. When the mating doesn't happen, you end up with leaks in two places. It didn't matter if I heated up the nozzle, or wrenched down on it as hard as I could, it kept on leaking. So, I dug a little deeper.

A 4.1mm throughout heatbreak leaves very little surface for the brass nozzle to mate against. That's a small problem but something to keep in mind. But since the heatbreaks I bought haven't gone through any meaningful quality control, I ended up with a bit of a mess. Only two of the heatbreaks had what I thought was a decent enough mating surface.

It also turned out that out of the 5 heatbreaks I had, only 3 had mating surfaces that were perpendicular to the vertical axis. One of these off balance heatbreaks was in the hotend assembly. All of the heatbreaks also weren't quite threaded properly either. In fact, really only one was up to par. The one in the middle above. It had the best 6mm threading, a nicely sized mating surface, and was perpendicular.

I can really see now why the argument exists about buying a real E3D v6. Their quality control saves quite a few headaches.

While I was diagnosing my hotend issues, I was using 3D Benchy as my test print. One of the small issues I also had to figure out was layer cooling. The print on the left had no layer cooling and suffered for it. The two others did have layer cooling, but suffered from the unpredictable nature of the leaky hotend. 

Things are looking up now for my Black Devil Overlord Pro. Configuring Smoothieware wasn't too bad. I got the simple bed leveling and the mesh leveling routines to work without much fuss with my microswitch Zprobe. I did have to cut off the roller wheel, but after that it was smooth sailing. I'm contemplating getting another Smoothieware based microcontroller for the Gem Blue Overlord Pro. We'll see.

Edit: link to what my blue printers SDcard contents look like.