Wednesday, July 23, 2014

A 3d printer hot end. Everyone's favorite late night project.

Going on two years ago, I got a kit to build a hot end for my 3d printer. It's sat in my car since then. DrD kept pushing me to get my 3d printer going.. so step one, is make something hot.

The hot end I have is a Makergear V2 hot end.  Hopefully they'll read this, and take my recommendations to heart.  They're on the V3, but the issues I ran into, still stand.  (I think.)

At about 11pm last night, I spilled the contents of the bags out on shop rag and got to work.
Digging in, I started to build the actual hot end.  I expected that my kit would have cohearant start to finish instructions.  As it turns out, there are two separate sets, and a lot of "uh.. what's this?" bits in the baggies.  A chart identifying what the bits are would be useful.  For instance, the teflon tape comes wrapped on a little plastic spindle, that looks like a teflon tube.  Nothing about it said "this is the teflon for your hot end" so I ended up using my own teflon tape. 

As I was following the hot end instructions, I ran into a step that said "install your ceramic hot end."  And.. that was really about it.  No link to those instructions.  And no further detail.  Just suddenly a grey blob with wires showed up in the directions. 

It turns out, that the other baggie, with the brass threaded inserts was the ceramic heater kit.  I found the page on how to build that, and went about building my two heaters. 

Here's my wound heater.  What would be nice, is if they told you what the orientation of the core was.  As later on, when you're trying to attach the hookup wires, it starts to matter a little bit.  Also, the insulation on the nichrome wire, is wound on, so you can futz with it and unwind it.  The first few times I went at it, I tried a wire stripper.  ... don't use a wire stripper.

The next step is to protect, and insulate the leads.  Here's where things got a little wacky.  At these steps, knowing that you next move is to fold them back up onto the sides of the heater core, would be useful information.  Also, knowing they need to clear the teflon sleeve would have helped. 

The wiring setup, is on the next page, which doesn't have a well indicated link.  That means I didn't know there was a second page until I got there.  

At least it looks good.  Now they tell you to cure the core.  They don't hint that it will need a second curing until the next page.  Knowing there's a second cure coming, would have helped a bit.

I managed to get over those hurdles.   Here's what it's supposed to look like before the second curing.

Now that it's all encased in Cecobond, it's time to make sure it's all working.  6.0ohms... right on the money.  I then went an made the second ceramic heater core. 

I didn't take any shots of the rest of the mechanical hookup.  The two copper wires go to the thermistor.  The thermistor is held on with Kapton tape.  Oh, and it's now 2am.

 Next?  I need to get a x-y-z table set up so I can test this thing out.