Wednesday, November 30, 2016

More Monoprice MP Select mods

I just found this site:

If you have an MP Select printer, you should go check it out.

I updated both my LCD and motion firmware from that site this evening, it has already fixed some bugs (the biggest one was that gcode contained in SD card subdirectories didn't print correctly).

It also adds PID Autotune, which was BADLY needed, especially if you have replaced your hotend with an E3D as I have.  Follow the directions on that link, it's very straightforward.  However, it still doesn't seem to be nearly as good as my old RepRap was. It still varies by as much as 4 degrees.  The RepRap would go to temp and stay there for hours without budging. More experimentation upcoming. I'm probably doing something wrong.

There are also a bunch of great mods and ideas on the site, including a clip to reset the Z endstop height if you want to add a glass printbed. I could have used that, I just mangled the switch to do the same thing. I was thinking about designing a clip like that but it's nice that it's already done.

They have Slic3r, Simplify and Cura profile packs for the printer, 

I've also printed this knob, which is WONDERFUL compared to the junky knob it shipped with.

I just finished installing this lower profile E3D adapter. The original one which is widely touted starting on the Hackaday review is OK but offsets the printhead significantly, losing about a centimeter of print volume in the Y direction.  This still has some offset, but much less.

Also this fan shroud, which uses a 40mm fan and provides part cooling as well.

Here's the hotend and fan shroud as they are now:

Pretty prints

The Monoprice MP Select can produce really nice prints if the slicer is set up well:

Saturday, November 26, 2016

Building the 8x8x8 LED cube from BangGood

I bought this LED cube, I've always wanted to put one together.  This one was a bit frustrating because there were NO instructions to speak of whatsoever.  In the end I made to errors - I had the polarity of the matrix reversed (I originally wired positive to the grid points and negative to the horizontal planes, and it wasn't working well at all.  Reverse of that is correct).

In the end it's a pretty cool toy for < $30.

Here's the link to the product on BangGood's site.

Here's the video I made of how to build it.

I also made this quick dumb little guide for properly spacing the planes before soldering in the wires to fix them in place:

Here's a link to the STL if you want to print one.  Or you can just hacksaw slots in a hunk of wood or plastic or something every 20mm, whichever.

Saturday, November 5, 2016

Updates to Monoprice MP Select Mini printer

A couple of months ago I bought the $200 Monoprice mini 3D printer.  I really like it.  It has some warts but in general it's nice, small, portable, and just does the job.

Things I wouldn't mind seeing improved:

  • Temp control isn't as good as it was in my PID tuned RepRap. They may be using bang-bang not PID.
  • Arm stability is just a little wobbly.
  • The Z axis endstop could really stand to be adjustable, for trying different print surfaces.
  • The hotend is fragile
The Z axis switch is just fixed in place. When I decided I wanted to put glass on top of the print surface, the surface couldn't be cranked down far enough so I had to bend the arm on the switch. I will try to come up with a better solution to this later.

The hotend works well at first, but as soon as I had the first trouble with it, it became very cranky and started causing a lot of trouble,  The 30mm fan failed which led to a bunch of jamming because I was too dense to notice the fan not running. Once the fan was replaced I still had issues, and the little springs like to go flying around the room when you disassemble it.

I had already ordered a new hotend to go with it. I decided to try out one of the $10 E3D all metal clones out of China.  When it came in, I was very impressed with the quality. I actually owned a legit E3D a while back, and I don't think I could really tell the difference.

In any case, I used the hotend adapter that Benchoff posted on Hackaday and Thingiverse.

It works very well, and I got a bag of 0.4 and 0.5mm nozzles to play with.

I have some PETG filament coming which prints at 235 degrees, so the all metal hotend