Attempting to print my first Mendel piece

December 7th, 2009

After printing the K block (see my previous post) with the RepStrap, I immediately went ahead attempting to print my first Mendel part. I ambitiously chose the pinch-wheel-bracket-NEMA17_604-bearing_1off.stl file, which is the green part of the following picture:

The green part is what I need to print

The green part is what I need to print

I’ve had varying amounts of success and failure. I have several aborted attempts. Since these were aborted, most of these are just the bottom part of the above piece:

You leave the thing alone for one minute...

Multiple levels of failure

Almost good enough!

This was a very fast print, but it almost wrecked the extruder

The bottom of one of the failures before clearing away the raft

The one on the right is closest. I took a spare ruined PTFE rod and stuck it in the piece on the left (and then fed a piece of ABS filament through it) for illustration purposes.

So, the above one on the right is the closest I’ve come to a functional piece. Worst case, I’d drill through the top, sand off the rough parts, and make it work, but it’d feel better to print it correctly. Clearly I need to do some kind of configuration for this device that I haven’t done (I thought we’d calibrated it but I’ll try again).

Video:

Insanely lucky tangent – RepStrap/RepRap

December 6th, 2009

About two weeks ago I almost posted a blog entry titled “%*@$-ing surreal!!”, whose first sentence was “Ok, my head’s about to explode”. I decided to hold off posting it just a bit – here’s a bit of back story behind that, that post, then more..

(Quick glossary for friends reading this that don’t know the terms: a RepRap can print most of its own parts, and is made from parts printed by another RepRap. A RepStrap is a device you make out of whatever you have lying around, that works just well enough to bootstrap you into the system by letting you print out the necessary pieces for a RepRap (so a RepStrap might be made out of wood, or might be a modified existing machine you have, or you could theoretically make one out of Lego bricks, etc)). Darwin is the name of the first version of RepRap, and Mendel is the name of the 2nd version of RepRap.

First of all I’ve been acquiring parts for and building my Mendel RepRap since October 29th, when I threw my hat over the wall and ordered most of the 3rd generation electronics. I really wanted to make a Mendel at this point, not a Darwin, and since there were no Mendel-like RepStraps in the world, I was initially torn – I didn’t want to build a Darwin and then immediately go ahead and build a Mendel (cost and time).

So, I decided I’d throw caution to the wind and just plunge ahead acquiring parts for a Mendel, doing all of the assembly that I could before requiring RepRapped parts, and eventually I’d figure something out. The closest thing I had to an exit strategy was posting a picture of all of the purchased and assembled parts I had, and begging someone who wanted to grow our community to print me parts (with the true promise that I have a bunch of friends lined up behind me waiting for me to print them parts).

While building and not having any real access to RP parts, a rationalization started to build in my mind. Rather than feeling like I should have gone down the longer path of building a RepStrap of my own design (which would be destined to fail, by the way – I’m married, with four children, and it’s amazing I have any time at all for any of this.. my building experience is ok, but not great..), I’d convinced myself that it’d be even better to not build a RepStrap, my rationale being that the quicker I get on the actual RepRap platform, the sooner I’ll be able to apply my creativity and design to that platform, to make things better for everyone (rather than just designing, building, becoming attached to, and then enhancing my own tangent RepStrap design, which I’d only really needed to get on the RepRap platform in the first place). Some people have done amazing innovative work on their RepStrap platforms, don’t get me wrong, but I really wanted to get to a RepRap soon.

On Sunday, November 22nd, I was explaining my new rationalization to my dad and my friend Kevin on the way to the football game we were attending (Go Pats!). After describing my desire/justification to bypass the RepStrap process, I said:

“Don’t get me wrong, if someone dropped a MakerBot on my desk tomorrow, I wouldn’t say no, it’s just that I want to spend my time/energy on getting a Mendel.”.

Now, here’s the post I was going to post on November 24th, two days later:

Title: %*@$-ing surreal!!

Ok, my head’s about to explode.

Today after lunch, two coworkers returned from some talk and said…

…that there are MakerBots in the building, that we can go ask for. And take.

(For anyone following this blog that doesn’t know, a MakerBot is a RepStrap build by a company called MakerBot Industries in New York. It’s like a RepRap kit. It can’t print another one of itself, but it can print a RepRap, which could then print another RepRap).

The parts are sitting on my desk right now. They bought three, for groups to build. It’s part of a technology library they have here, to foster creativity/imagination/etc.

Chris and I picked it up, opened the box, and plan to build as much of it as we can on Saturday.

I still can’t quite believe it. It went from “yeah, no I think you can just walk upstairs and ask for one”, to “no, umm, really?”, to a bunch of discussion, to “why not, let’s go ask”, and then bam – parts all over the desk.

What’s really killing me is three (fully assembled) Stepper Motor Driver v2.3 packages, sitting right here, next to a window on my screen that’s checking the website every 30 minutes to make sure they’re still out of stock on Stepper Motor Driver v2.3 boards. >:(

I fully expect to wake up and wonder how I believed any of this was real.

🙂 Two days after I told Kev that I wouldn’t say no if someone dropped a MakerBot on my desk, and someone literally dropped a MakerBot on my desk.

That Saturday, at Chris’s house, from 11:30am until 4:30am, we built the MakerBot that will someday print out parts for many Mendels.

(BruceW, if you’re reading this, keep printing. 🙂 Larry and potentially I will still need them, as will others in the new england group. I’m not so good at reliably printing parts yet (after many, many attempts). And theoretically we don’t get to keep this MakerBot forever).

This whole thing has been a big (but useful!) change in direction for me. Before I was building. Now I’m printing, with a functional 3D printer. It feels a bit like reading the last chapter of a book before reading the rest. I’m now stuck figuring out what temperature to print what at, how to get something to print without it being destroyed by the printer (or destroying the printer), etc. But I’ll get back to that fire cement soon enough.

So, many of the blog posts after this will reflect my use of a functional RepStrap, and the problems involved in printing. Hopefully it won’t take long before I get enough parts printed (either by myself or from others) that I complete my Mendel and I’m talking about things I printed with my own instance of the Mendel RepRap. 🙂

p.s. After a few failed attempts to print whistles and minimugs, here was the first successful print. (I’m now going to save the minimug tradition for when I get my Mendel printing):

Protecting Your Thermistor

December 2nd, 2009

I’ve read about several people breaking their thermistor and having to purchase a new one, halting their progress for a day. I’d like to add my own tip to protecting your thermistor, lest your progress get halted too.

Step 1: Don’t lose your thermistor

That’s it – don’t lose it. I just got the coil wrapped around my heater barrel:

..and I was all set to dive into the world of fire cement. I got some plumbers tape out to wrap the thermistor and – boom – it was gone. 🙁

I think it was in this bag:

So I probably lost it when soldering these Opto Endstop boards last Friday night:

I then proceeded to spend at least 20 minutes combing around on the ground looking for the thermistor, at least five times thinking I’d actually found it, but then seeing it was actually a pine needle:

Not a thermistor

🙁