Quadcopter! Four, no, 32 months.. part 14 of ?

August 28th, 2013

Before I get into this next post, let me mention that I’ll be exhibiting again this year at Makerfaire NY 2013! I’m booth #10895. It’s on September 21st and 22nd. I’ll be at the 3D Printer Village. I hope to see you there! For those who don’t remember it, here was my post last year about my Makerfaire NY 2012 experience: Makerfaire NY 2012: Booth 8736 (My RepRap!).

Still trying to catch up on the blog. Yes I know how absurd it is that I’m talking about past events (from over a year ago) in the order that they happened, hoping to “catch up” like getting out of debt. I don’t care that it’s absurd. :) But want to know how absurd it is? The link I just gave above about last year’s Makerfaire (2012) is AFTER the events I’m describing here, yet I blogged about it because Makerfaire was cool enough to blog about out-of-sequence, and I’m now just getting close to catching up to that point (which I’ll then not cover, since I already did), and then in the present I’ll actually go to the 2013 one! That’s in 4 weeks from today, so I’d like to catch up before that if I can. What a byzantine mess!

Ok. Today is August 28th 2013 and I’m describing events from April 3rd of 2012. Here we go.

The next thing I just HAD to print was a quadcopter.

At work they had let us borrow a quadcopter (an AscTec Pelican) and it was incredibly fun. Two coworkers of mine (Reed and Neil) borrowed it with me, and we flew it enough to get a serious taste for it. I wanted to print one.

I decided to print the PL1Q Vampire (thing:17612), but with a bunch of alternate parts.

First I tried printing the regular center piece (“body”). That has some really challenging bridging, and I wasn’t using a fan. I didn’t have much luck.

I’m not completely sure on the order of these, but the first (aborted) fail I had (according to image number) was this:

Then I printed a bridging stress-test piece, thing:9804 (I still didn’t have a fan):

I also briefly tried a filament guide clip (thing:20663) on the center of the bar (which I later stopped using):

Another failed attempt (which looks particularly messy – I must have left it unattended) was this one:

So instead I printed this version from thing:18106 which split the top and bottom parts into two pieces.

Here they are together (I didn’t break off the circular pads that were only there to hold it down on the bed yet):

Next up were the arms. I couldn’t print them vertically, so I found this variant (thing:17803) that printed them on their sides:

I printed 3 more arms, and put them all on for show:

Then I printed one of the most solid, serious, strong looking pieces I could remember printing on my RepRap – the dome from thing:18106 (pl1qvampiredome_fixed.stl):

Here it is placed over the rims of the arms, holding them in place:

…and here’s what that looks like from below:

Next I printed the landing feet, which I now realize were the only parts directly from the original thing:17612 model:

The last parts were the combination motor-mounts-and-propeller-guards for each of the four arms. I used the ones from thing:18106. Here was the first one:

I was able to print two more..

Man that looks cool..

That picture of the three attached propeller guards was taken on April 9th 2012. Then I started running into problems, and I didn’t know why. Little did I know that some of these problems would stick with me for the next year or so. (By the way, it’s good for me to go through this history as I blog about it a year later, as I can start to see from a 30,000 foot view what actually happened).

REMEMBER THIS POINT IN THE POST!

Two days later I took these next two pictures. What was strange was that there was a shift in both the X and Y axes (which also happens later in the year but for a completely different reason). I think this time was a one-time problem:

As often happens after a failure, I got a bit sidetracked. You see, my favorite band is Rush, and within one week they were about to release another single from their yet-to-be-released album Clockwork Angels. In previous singles we’d seen this interesting clock face, and I decided I wanted to model it (I figured someday it might make a nice actual clock). I modeled and successfully printed it:

I used Google Sketchup for this, and because of how I pulled up the symbols, it ended up with a weird quirk that I decided to keep – not only were the symbols raised, but holes were left below it, so if you look at the back you see the symbols clearly too.

A week later I uploaded that to thingiverse on April 19th 2012 (here) on the release date of the single Headlong Flight, and someone later even created a derivative (remix) of it to make it bigger.

I tried printing the fourth propeller guard again, and had another failure. This time the extruder pushed out of the old-style PTFE insulator that I was using. (Always take pictures of your extruder during failures.. this is really the only way that I have of tracking which extruder type I was using when, and when problems started).

If you look closely at the angle of the extruder motor in this pic you can see it raised off the rails:

…which you can see far more clearly from the front:

What makes this failure particularly mysterious is that not only did it come off of the rails (which usually indicates a knot of some kind in the filament spool), but the extruder barrel also pushed out completely, and Wade’s Extruder just kept on pushing filament through (which implied that it WAS able to move plastic – there was no knot at that time):

In this one you can see the further cracking of the front oval piece of the OpenX carriage, holding a bearing:

At the end of the filament is the culprit – a plug – which pushed out the barrel (or, maybe it’s just the innocent piece of melted plastic that came out after the PTFE failed on its own):

All I can think is that maybe after the heater barrel pushed out, the solid 3mm filament then pushed straight into the glass, and the continued pressure pushed the extruder off of the rails (made easier because of the weakened oval piece on the front).

There WAS also a slight problem with the filament in the spool, but it wasn’t necessarily a knot.. It looks like the plastic here went over the side of the filament guides and around the end of the spool, which might have made extra tension which perhaps then relented. Who knows.

My brother Jon came up from Brooklyn, and while he was here I gave him his share of the large McMaster order (which had included nuts, bolts, washers, and rods for RepRaps for him, the Museum of Science, Joe Werther, and myself). Here he is cutting steel rods on my chopsaw, for one of my RepRap’s children – Jon’s RepRap:

Next up – here’s some advice: don’t wind a coil of PLA off of one spool and onto another. You’ll see why below. I decided to give this a try after seeing Ross (TINYenormous) successfully use a Home Depot extension cord spool with his RepRap. At first I set it up like this, with the filament going through a hole I drilled in the handle and straight over the back top bar on the RepRap:

I later put some PTFE tube between the handle and Wade’s extruder. Unfortunately I didn’t have a good “stop” on the Wade’s side and it later pulled the PTFE tube in and chopped up the end of it.

I printed a Greg’s Accessible extruder out of PLA (again, bad idea using PLA for this):

Then I had yet another extruder failure while trying to print that fourth propeller guard. It pushed the nozzle out of the PTFE again.

That was infuriating (if I remember correctly) because I had just made another extruder.. it shouldn’t be failing this soon..

What was particularly messy about this failure was that the solid filament then happened to go towards the back of the RepRap, and went back and tangled inside the spool of plastic.

Not yet knowing why my RepRap had started causing PTFE-based extruders to fail, I became frustrated with the PTFE-insulator design and wanted to try to make my Adrian’s Extruder Nozzle work from before. Last time my problem had been that the two bars holding up the PEEK bar had warped the holes in the Greg’s accessible extruder. I thought that if I had something strong below the extruder, maybe it could support those bars. I went to Home Depot and found some shelving bracket made of metal, brought it home, cut it to size, and drilled holes in it.

The first print with this setup was not a great success.

Three days later I tried printing an idler piece for the extruder for the Museum of Science’s RepRap. This went rather poorly too, at least in part due to the x-carriage.

That yielded this unusable part:

I also recorded this reminder for myself about what I’d started doing with the x-belt, which might have explained the extra vibrations that caused the carriage to come apart:

(or maybe it was heat from the metal plate melting things.. but I hadn’t figured that out yet).

That was at the beginning of May 2012. A month went by where I didn’t touch the RepRap at all. Then on June 10th I got up and printing again. I had stripped a PLA large extruder gear, so I replaced it with another from somewhere (not sure – maybe the one I’d made for the Museum of Science? or for my 2nd RepRap?). While trying to print a replacement, I made these videos, which were pretty important (I caught a pretty serious error on video):

If you didn’t watch that video (you should have), you missed that: A) the printer wasn’t making it to the temperature that I wanted it to go to, and B) it totally hung in the middle of a print – it stopped, didn’t do anything, and then eventually resumed printing all on its own, but now it was offset (it missed steps, making it look like an axis had skipped or something, which it absolutely had not). From a forensic point of view (and from a historical one as well), this was excellent to capture on video.

Despite what I guessed about in that video though, the ‘new software’ had nothing to do with it. Here it hung again:

Note that in that video I guessed that maybe since it was a hot day the temperature had affected the board, or maybe I wasn’t giving enough power to the board.

I tried again and failed at printing the 4th propeller guard (I won’t bore you with the long printing video that showed that).

Two weeks later, made a big discovery – finding the culprit of several of the problems that I’d had (all covered during the duration of this post). I ruled out my guess about the temperature of the board with a fan, and then found the real problem. Watch these two:

Key point from that last video: during a print, I saw the pausing/hanging happen again, but while that happened I noticed that the fan I’d put on top of the electronics (which was wired straight to 12V input) was OFF. So the power supply was clearly not providing power at all at that point – it had nothing to do with the RAMPS board. I planned to swap out that power supply with another, to see if that fixed it. That’s when I found this:

That was a scary but extremely revealing bit of info. Prior to this I had been taking all of the power for my RepRap from one molex cable from the computer power supply. I fed those wires to both the 5A and 11A inputs on the RAMPS board (which I knew was wrong when I initially did it, but at the time I thought it would be super temporary, then I just forgot about it since things worked).

My theory about what happened is that since I was pulling so much current through just one connection, it heated up, and at some point a slightly loose connection caused sparks that burned that connection. The molex connector would still conduct electricity though, so the RepRap would still function, but enough of a power draw would cause it to go dead.

Rather than replacing the power supply, I replaced the connector (and added a second one). I take one set of power from one rail, and another set from a totally different rail (that is, I don’t use two molex connectors that are on the same wire from the power supply.. I use one molex connector at most from one wire, and connect the other molex connector into a completely different set of wires coming out of the power supply).

Intermittent loss of power was clearly causing these skips, but could also have been causing the temperature to drop too low, possibly contributing to the multiple PTFE insulator extruder-pushing-out failures.

Remember that point above where I said “REMEMBER THIS POINT IN THE POST!”? I think everything from that point until this point was negatively affected (or completely caused) by that power issue. I’d also lay some serious money on THAT being the point where the burning of that molex cable happened, but I didn’t notice it for two and half months.

Here are the new connectors I made:

I describe what I’ve done:

and there’s an immediate improvement:

Results: “super good”:

Alicia confirms its “super good” status:

and more progress:

Then I noticed something that justifies my earlier statement warning you not to wind PLA off of one spool and onto another. I looked over at the yellow external spool and saw this:

The plastic had probably weakened from being rolled from spindle to spindle.. The inside part of the plastic (which was used to having a smaller circumference around the spool) was now on the outside, and the outside part of the plastic was on the inside. Add to that the fact that PLA is brittle and mine is completely exposed to humidity etc, and you get it cracking in several places.

The print continued:

And then, after three and a half months of printing (most spent trying to print the 4th propeller guard), I finally finished my quadcopter’s printed parts!

I placed the fourth propeller-guard/motor-mount on my quadcopter, and it looked glorious!

Nope, I still haven’t bought the electronics for the quadcopter, nor the propellers, nor wiring, nor a transmitter, nor a receiver (even at the end of August 2013). :( But I will!

Coming full circle to reminding you about coming to see me at Makerfaire NY 2013, here I was holding up my completed quadcopter at Makerfaire NY 2012:

There’s still enough material between this point (July 17 2012) and Makerfaire for one more short post between then and when we skip past the 2012 Makerfaire. Getting more caught up! Again, today is August 28th 2013, so I’m about a year behind. This sure feels like debt. :)

Four, no, 32 months.. part 13 of ?

August 19th, 2013

Flying along trying to catch up on my year-and-a-half-behind blog. Today is August 19th 2013 and I’m describing events starting from February 26th of 2012. Maybe I’ll make this one short. Ha!

(This will sound like a bunch of detached unrelated paragraphs, because it is).

First up, at the New England RepRap 2012 meetup that I talked about in the last post, I tried again at printing the Hemi-demi-sphere.

Here’s a comparison of the old failed ones that I’d tried printing before (on the left) and the new excellent ones that I printed at the meetup (on the right):

Here they are assembled. Obviously, the new ones are on the top:

Here’s a closeup of the good one.. Looks like a baseball:

A coworker had asked me once long ago if you could just print anything on thingiverse – why didn’t I just go print this Debian logo, for instance. I finally got around to it at the meetup, and gave it to Tim later:

Later some of us at work were trying to motivate ourselves to work on some project, and tangentially it lead to me picking one print from thingiverse (a “protobot” – a small arduino-based robot with a breadboard on it) and saying “guys if we can’t come together and build, say, THIS, in just a few days, then something else is wrong..”. So we divided up tasks (I did the printing from home), and got it built in about a day or two, tops. Little did we realize at the time that the object it was derived from was done by a bunch of boy scouts for a merit badge, so if we failed it was laughably embarrassing that we’d be beaten by a bunch of kids.

The frame (x2):

Other parts:

The wheels (you put large o-rings around them):

These really remind me of the reel-to-reel tapes that we used to use on our old old old tape recorder when we were kids:

Here are the parts laid out:

..and then they were ready to take into work (I didn’t have a 3D printer on my desk at the time):

One of my jobs was to get the servos, so I stopped by a local hobby shop and picked these up:

Then we got it working and doing simple movement!

Woohoo!

Ok back to my RepRap. I printed out some more heart boxes..

And then I printed another “K” block:

I tried printing a small twisted bottle (thing:12278) but it failed, I’m guessing at least partially because I had no fan:

One of the things I’d wanted to print for a while was a tool for my mini-lathe that would let me hob bolts on my lathe (I’d done it before with a tap in a drill, but I’d rather do it on my lathe now that I had one). The only downside is that my lathe is a mini-lathe (7″x12″), and the largest tool it can handle is 5/16″. So I took one of the good looking tools out there and modified it to fit on my mini lathe (while writing this post I finally uploaded my modified version to thingiverse: Bolt Hobbing Tool for Mini Lathe ).

Here is my lathe tool to make hobbed bolts (modified to fit my lathe):

Here is video showing me hobbing the bolt:

…and here is video of the resulting hobbed bolt, which I made for the Museum of Science’s RepRap (those two videos are technically out of order, from December of 2012, but they go with the hobbed tool I printed):

I’ll leave it to a later post to show you what I got in exchange for some of the hobbed bolts I made for others with this tool. :)

Here is the earlier hobbed bolt (not the newer one in the last video) inside an extruder. When I took the photo (on March 28th of 2012), I was happy with the quality of that bolt. Now (over a year later, in August of 2013) I’m not as happy with the quality of the bolt in this picture – I’ve done better (as you can see in the video above). :)

I don’t really want to end it there, because that just seems like a collection of things I printed without any great punch to it, but the next bit deserves its own post, so I’ll end it here. We’re now caught up to March 28th 2012 (and again I’m posting this on August 19th 2013). Look at that! It WAS a (relatively) short post! :)

Four, no, 32 months.. part 12 of ?

August 8th, 2013

I started the last post by describing how back in January of 2012 that we had solidified a date for the first meeting of the New England RepRap group: February 26th, 2012 (but I spent the post discussing my rush to create a RepRap for the Museum of Science in Boston between those dates). Now let’s cover the event – the first meeting of the New England RepRap group!

Actually we’ll start a few days before that.

While printing at the Museum of Science in Boston (with my Mendel, which I brought down for a day, not to be confused with the Prusa IT2 I made for them), it was printing horribly. I had multiple big y-shifts that helped contribute to this miserable print:

Later when printing at home I saw a similar shift in the first layers of this aborted print:

Here you can hear and see it:

I decided the y-belt was probably lose (and might have loosened up after the trip). Having just put an adjustable belt tensioner in the Museum of Science’s RepRap, I wanted to upgrade my Mendel as well.

I removed the bed, installed the tensioner, hooked up the belt, and set the tension correctly.

(Note in that picture and video you can see the old legacy stepper driver boards that I never bothered to take off, beneath the bed. Maybe someday I should use that space to mount a Raspberry Pi).

It was around then that I finally uploaded my first Thing to thingiverse.com – an OpenSCAD version of the arm to the OpenX carriage. Here it is in the Newest Things feed:

..and here is the page itself:

Ok enough of that.. back to the printer. With the Y-skipping problem fixed, I did a few prints.

Replacements for the y-belt tensioner pieces that I borrowed from my future RepRap parts:

Heart boxes that I had failed to print in time for Valentines day, 10 days earlier:

A flimsy mount piece for the Museum of Science’s RAMPS board (which I later replaced):

Then I wanted to print out more of the garbage bag holders that I’ve printed before. I started the print:

but then an hour and a half later, another knot in my filament spool again hurt an X-carriage by once again pulling the extruder and carriage off of the x-axis and into the air. (Everyone that I’ve endlessly lectured about not letting go of the end of filament on a spool, take note!) Note in this first picture that the extruder is way up at the top while the X-axis itself is much lower (also note the knot in the spool):

On the front of this next picture you can see where the small oval plastic piece that holds the front bearing on was severely bent. The bend is between the top and bottom screws.

Here were the partially printed parts. Note how good they looked before the failure.

The carriage wasn’t damaged much except the bend on that front part, but even then it still functioned.

I fixed it all up, and brought the RepRap upstairs to our “pinball room” for the New England RepRap 2012 meetup the next day.

I had the Museum of Science’s RepRap (just taken back from the Museum so I could do more work on it) on display too, even though it didn’t have an extruder yet:

Then I started a long print. Alicia couldn’t figure out what it was when it started printing, so I referred to it as the mystery print. I posted two pictures on Google+ asking if anyone had any guesses what it was..

This was the first picture I posted. “Who can guess the mystery print?”:

Twenty minutes later and I posted this, saying “Here’s a little more progress. Again, who can guess the mystery print?”. This picture was enough to get the author of the print to guess what it was:

(I think the above picture and views before that had Alicia guessing “the front part looks like a cave from Star Wars” and someone else (Laurie?) guessed maybe that part of it was Florida so perhaps it was the United States).

Then after a bit more progress..

This next part almost looks a bit like the Enterprise from Star Trek: Next Generation (someone else said the same thing to me recently):

Progress continued..

Here’s a shot of the whole RepRap printing it (with a light behind it):

I started becoming aware of the Z-height and how close my extruder was getting to the top:

…but, I pressed on..

Good video of it printing:

And then I got really worried about Z-height:

I think this picture is where my Z-height started to actually matter:

I hadn’t yet figured out (I realize that in this next video) that Z has already stopped going up. I must have set a maximum Z-height in the firmware, and it reached that. There’s no code yet to say “hey wait this print is taller than your build area” though, so it just kept right on going, but it was such a small piece of the print that I still consider the print an amazing success.

It finished! I give you, the head of Tony Buser!

I looked it up.. My 2nd Google+ post said “Here’s a little more progress. Again, who can guess the mystery print?”, and here was Tony’s response:

I really liked this print, so here are a few more pics:

But a view like this one:

makes me really aware of the butchering I did to the top of Tony’s head, leading me to use other prints as hats. :)

Here’s a picture from earlier in the print that I didn’t want to use above (because the computer screen gave it away):

With everything ready for the next day, I went to bed.

The next day, everyone showed up. We had lots of people, lots of printers, and a lot of really good discussions. Everyone had an incredible time and wanted to know how long until the next one.

At one point I went outside and saw we had at least 10 cars parked.

I didn’t have much space on my phone (because I’ve been behind in this blog for so long!), but here are the two videos I took:

Some more pics:

Katy Hamilton, one of the attendees, took a lot of great photos. Here are some (used with permission):

To organize the group we’d used our Google Groups mailing list, but we all realized we needed something more. So the next day I created the New England RepRap Google+ page (go follow it!). While I’m on both Facebook and Google+, it seems Google+ is where all of the RepRap activity is. The downside to a Google+ page is that the only person who can post is the owner.. But then things really got better in February of 2013 when Google+ allowed Communities (which is basically like a forum – people can post their own threads and others can comment, etc). Be SURE to join the New England RepRap Google+ Community.. At the time of this post (August 8th, 2013) we have 128 members (597 people have the page in their circles).

tldr; GO FOLLOW THIS AND JOIN THIS! :)

That seems like a good place to stop. This catches us up to the events of February 26th 2012 (whereas today is actually August 8th 2013). For anyone that’s particularly confused by the delay – future spoiler: we just had our SECOND New England RepRap meetup in July 2013.. but the blog hasn’t caught up to that yet! :) ).