The Kevin Post – Four, no, 28 months.. part 9 of ?

Trying to catch up as fast as I can. As of the last post I was caught up to December 21st, 2011 (today is May 16th, 2013). Let’s keep going.

Before I get to the heart of the post, let me get one bit about the snowflake from the last post out of the way. I had just finished printing a replacement piece for a snowflake ornament (one of the kids broke the last one) with my newly lathed heater barrel, fresh cut heater block, and PLA-printed (bad idea, I know) extruder. Here it the replacement:

Ornament fixed! Disaster averted!


Ok. Next, well, I considered not blogging about this next part for now, but I think it’s better to get it out of my system. As people who know me (and people who don’t but who’ve been reading this blog for a long time) know, my best friend Kevin Stearns died in a car crash back in February of 2010. Back then I posted about that, and one of the paragraphs of that post read:

Over the past year heโ€™d listened to more of my RepRap ramblings than anyone I know. He came up with a great idea for something fun thing to print on a RepRap, which he was going to share when I finished my Mendel. He designed software to create it, made incredible progress, and was just about done. Some day when I get my Mendel completed, Iโ€™ll share his creation.

Well back in December of 2011, with Chrismas and the anniversary of Kevin’s death approaching, I felt a self-imposed pressure to print that object before that anniversary. As you’ll see, I had a hardware failure that set that back, then some limited success, but an additional setback had me realize I wouldn’t get it done in time. That caused a great amount of stress, pressure, and pain (for obvious reasons) so I decided to pause work on the project.

Of course a month or two later, someone else on the internet finally had the same idea we’d had, and went ahead and posted it (which I’d like to say devastated me, but I think instead I became numb and wouldn’t let myself feel the pain, although I was underwater submerged in it). End of the story first: I never finished it.

As a result, I’ll blog about the attempts I made here, and post a video of his initial work, but I make no promises to myself or anyone else that I’ll ever go about trying to finish it (especially since someone else has already done it). (Please don’t post or personally say to me any attempts at motivating me to do it, even if I’m looking for something to print.. it brings too much pain and pressure along with it). Apologies to anyone who was waiting for some big post specifically dedicated to this with great happy results.

Ok.. So one day while at a Patriots game in Nov 2009, Kev and I were talking about one of my main topics at the time – “if you had a RepRap, what would you print?”. (Again, I didn’t have my Mendel built yet, although noone else in the U.S. did either). We talked about childhood toys, most of which were plastic. Then as we were talking, an idea came into both of our heads around the same time, but I’m pretty sure he thought and said it first. We thought about the Fisher Price record players that we had as kids, and how they had multiple discs you could put on and listen to songs.

We thought that if the resolution was good enough, you absolutely should be able to print those records.

Then Kev decided immediately what song it should play first, and his idea was the absolute, obvious, completely correct answer to that question. He said “it should play the first song it was ever exposed to!”. I knew exactly what he meant.

Kev was making a reference to a video I’d shown him by dbenoy (Daniel Benoy), where Daniel was testing some opto-endstops for his RepRap. He’d put firmware on the motherboard such that it spun the stepper motor to the tune of the Imperial March from Star Wars:

I completely agreed – the first Fisher Price record we needed to make was absolutely the Imperial March. If we could.

We bought a Fisher Price record player off of eBay since neither of our childhood ones were handy.

I sent Kev pictures one night with a few key measurements, including this pic:

and two weeks later, this:

and lots of other pics of images of the records and a video or two of it playing Jack and Jill.

While I worked on building my Mendel, Kev wrote software to simulate a Fisher Price record player. Since he wanted to give JavaFX a whirl, he downloaded it and whipped up a simulation, which he showed me (and it was glorious). He teased me that he knew how he’d motivate me to get my RepRap going – he’d post the record to thingiverse soon, and I wouldn’t be the one to print it first. I assured him I’d get the printer done soon.

I lent the record player to him the last night I saw him.

Again, Kev died before he could see the RepRap completed. Some time after his death at his house, his wife let me go through his computer to get the simulation and run it. I recorded a video of that:

Then (remember, I’m describing events from December of 2011) almost two years later in December, I was finally printing with good enough resolution that I thought it was worth trying.

At first I just tried making a blank record, with the grooves in the right place. I later tried a simple scale.

The print failed.

The extruder that I’d built out of PLA couldn’t withstand the pressure being placed on it by the M3 rods holding up the PEEK block on my new hotend. Here you can see the hotend is at an angle:

..and here you can just barely make out a bit of sagging of the bottom of the extruder where it wasn’t strong enough to hold up the M3 threaded rod holding the hotend:

Here’s a view from the back, again showing the bad angle of the hotend:

At least since I printed on glass I could convince myself that I had some of the dimensions right before the next print:

and I could try putting the peeled off failure onto the record player itself..

Taking a look at the bottom of my extruder confirmed that the PLA had failed:

Look at the left side of this pic – the plastic had softened up and the rod pulled through:

So I went back to my Wade’s Extruder.

Short term, I tried a few other prints for a change. An attempt at a bracelet:

some square thing that I can’t remember (edit: it was this):

an OpenX carriage (out of PLA again, still a very bad idea):


The carriage looked great.

Here it is assembled and snapped onto the x-axis rods as a test:

and here it is next to its brother from another mother:

The open-x carriage looks so good..

Surely it looked good enough to motivate me to try printing the record again.

It finished printing!

Here it is off the bed:

Here’s what the bottom looks like:

It looked so good near the record player..

On it went..

I tried playing it.. (this record try only attempted to do a few notes)

It fit. Tried printing another record with more notes.

I’d changed the grooves on this one a bit so each circle has two lines to it.. I like the look of the first one better but this was an attempt to get the notes better.

Time to try that one..

Playing that scale had me realize that our understanding of how the notes lined up was wrong (I hadn’t expected the double notes..). So that had me realize that Kev’s note as arranged might not even work. That discouraged me enough to postpone continuing work on this. ๐Ÿ™

Here were the two records (with slightly different sized grooves) side by side:

Done for the night (and since someone else eventually posted the same idea before I got back to it, done trying for the foreseeable future), I put the record I’d made in its new home:

I miss you Kev. Sorry I didn’t get it done in time. ๐Ÿ™

Stay tuned for a more cheerful next post. We’re now caught up to January 1st, 2012 (and I’m posting this on May 16th, 2013). Just over 16 months behind, but we’re gonna catch up soon. I promise.

One Response to “The Kevin Post – Four, no, 28 months.. part 9 of ?”

  1. nuttzy says:

    Amazing work! Totally respect if you decide not to move forward, but you should take some pride in acknowledging you actually got this thing to play music off a disc YOU MADE!! Incredible. Really, having the exact right algorithm to play the notes is less important than actually making the dream a reality. Back when first dreamed, you didn’t even have a 3D printer, and now you made some music, if only a few notes. SUPER COOL!!! I can’t speak for Kev, but I know I’m very proud of you!

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