The Abacus – Four, no, 44 months.. part 18 of ?

August 3rd, 2014

The thing about my RepRap hobby (which might apply to all hobbies?) is I’ll sometimes go months without thinking about my RepRap at all, then I’ll use it for a month or two solid. As a result I’ll still be far behind on my blog, and the backlog starts to feel like work (which causes a feedback loop where the backlog discourages me from blogging, which causes more of a backlog, etc). So let’s try to get some of this covered and catch up a bit..

Last I blogged we were caught up to March of 2013 (whereas today is August of 2014). The Museum of Science’s RepRap was printing well. Let’s go from there.

At work I borrowed a Makerbot Replicator (#8640) for a work related project, and I was allowed to take it home (and use it for non-work related uses). On a Friday evening, I drove in to work with Cara to pick it up so I could take it home for the weekend.


We’d been using it at work and had created our own el-cheapo heated chamber for it with some cardboard boxes and some pieces of paper. Here’s what it looked like from behind:


I started printing any parts I thought I’d need out of ABS (since I didn’t want to clog my own nozzle by switching over from PLA to ABS if I didn’t have to). Here I printed a bunch of pulleys (there’s one failed one on the right):


Meanwhile, on the RepRap I’d printed and assembled for the Museum of Science, I started printing a set of RepRap parts for Joe Werther (he heard I was giving them a RepRap and asked if his parts could be printed from THAT RepRap, which I thought was a cool idea.. plus it would get the Museum of Science off the hook for one of the two RepRaps that this RepRap needed to print, since all RepRaps should print at least two other RepRaps for other people).

Here are a bunch of belt clamps:



In the last post I posted a picture of a happy Cara that also showed the power cord cable that I’d tried using as an alternate filament spool:


Once I had the clamps printed for a filament holder, I moved that yellow spool up onto it (until I could put a real spool on later).


Three posts before that earlier picture of Cara with the spool, I’d shown the bad results of trying to transfer brittle PLA from one spool to another via unwinding.. It had multiple breaks in it:


This was that same spool. So as I printed things, I’d have pieces of plastic falling out from time to time (with increasing frequency towards the end of the spool).



Occasionally I’d run out of a strand and have to pause a print long enough to switch to a long piece of filament. I really wanted to use as much of that plastic as I could. :)

Here’s a sadly truncated only-twenty-second-long video showing that:

I printed more parts. I’d seen a new adjustable Y-motor-mount that had a built in y-tensioner, and I wanted to try that.

I printed two out of PLA on the MoS RepRap, and then tried printing one out of ABS on the Makerbot, which I was going to use for a Mendel I was printing for use at work. Unfortunately the ABS one curled up because the homemade heated chamber isn’t that good.. ..but the PLA ones were fine.




Here’s a picture of a PLA/ABS y-motor-mount sandwich:



..and here are two of them side-by-side:


Here’s the next plate of parts I printed (I checked – it isn’t one of the standard 4 plates, I had arranged the parts I needed in OpenSCAD):


At the same time, on the Makerbot I printed an X-end piece out of ABS for the RepRap I was making for work. This came out pretty well.




3D Printing Class – March 10, 2013

My mother-in-law Barbara is always doing “sewing” class for my kids and their friends, and I wanted to be able to teach my kids about RepRap and 3D printing too (not just watching it print, but learning how to design parts of their own, learn OpenSCAD, and print things themselves). Alicia and Cara decided to join, and on March 10th 2013 we had our first 3D Printing class.

We did some standard stuff (cubes with spheres subtracted from them, a bunch of boxes of different colors combined with a large sphere (which we later printed as a multi-color print on the Makerbot, and in yellow it looked like an old disposable Kodak camera)), but the main thing we designed that day was Alicia’s Abacus.

For a long time Alicia had been asking for a 3D-printed abacus for her doll. We figured out what size we wanted it to be, found some nails about that size, measured them, and designed and printed this abacus.




I just now uploaded it to thingiverse, one year and five months after we designed and printed it.

After that, it was more printing to get Joe Werther’s RepRap printed, more printing to get the RepRap I was printing for use at work printed, and cleaning up of the wiring of the Museum of Science’s RepRap so I could give it to them for good.


Note I was now printing one piece at a time because I was estimating how long a stretch of filament I needed to print each part. In this next picture you can see two small coils of contiguous plastic on the keyboard that I’d rescued from the broken spool, that I used in later prints:


Here are two boxes being filled with parts (Joe’s parts on the left, and the parts for use at work on the right):


(Joe, if you’re reading this, consider this post a nudge to remind you to assemble your RepRap! :) )

Once I was done printing parts for Joe and for use at work, I cleaned up the wiring on the Museum of Science’s RepRap. I mounted the RAMPS board in a Sliding lid RAMPS 1.4 box that I printed on the Makerbot (due to its height), and mounted that on this mounting board. (come to think of it I may have modified that mounting board to accommodate the extra nuts and washers on the top rods.. note to self: look that up and upload it).


I put black hose around the zip-tied wiring on the rods:




…and here’s the final cleaned-up version, pretty enough for final delivery to the Museum of Science (although that wouldn’t happen for another month and a half):


Here are three other pictures that I want to throw in at this point. First was this piece of paper – notes from Alicia while I was redoing the wiring on the RepRap destined for the Museum of Science:


The second picture was my grinder, which I believe I had just finally set up at this point for the first time:


(I now use that grinder every time I cut any rods for any reason.. I can’t believe I got along without it before.. way better than filing down the edges to wear off the sharp parts)..

And the third picture was what Jimmy Astle gave me in exchange for using the above grinder (and my chop saw) to cut rods for him for his first RepRap. A 6-pack of home-brew beer:


Ok that seems like a good breaking point to end this post.

By the way, I’m going to exhibit at Makerfaire NY 2014 this September, for my third time! (Although, tragically, this blog is so far behind that I haven’t even covered Makerfaire NY 2013 yet! I’ll do that soon.. I hope to be fully caught up before Makerfaire this year.. ha!). Buy your tickets now and come see me! If I can drag two RepRaps down in a car from the north end of Massachusetts to Queens, New York, you can drag yourself down there.. it’s a great time!

mf_newyork_seemethere_125x125 mf14ny_badge

Don’t make carriages out of PLA – Four, no, 39 months.. part 17 of ?

March 18th, 2014

Last post, I had us caught up to January 23rd 2013. Let’s keep going. Today is March 18th, 2014. Just over a year behind.

So I was working on the child RepRap that MY RepRap had built, so I could give it to the Museum of Science. During the last post I’d done its first print and the traditional minimug toast. Now I had to get the endstops working.

This was my first Prusa Mendel (IT2) build, so I didn’t know how the endstops would go on (in the original Sells Mendel the optical endstop mounts were all integrated into the build, but on the Prusa Mendel you have a lot of “flexibility”). I decided that I still wanted to use opto-endstops (vs mechanical ones), but that made it more difficult to figure out where the endstop flags should go (and I don’t like the idea of using glue for anything).

For the Z axis, I wanted to design a small opto-flag holder for Z (adapted from the endstop holder for Z). I set up the opto-endstop in a helping hands aligator clip to help measure what the piece should look like, and put the original z-endstop-holder (that I was adapting) on the X axis:


I measured it, designed what I wanted, and printed it on the Museum of Science’s RepRap (it printed its first enhancement part).


Here was the resulting part:







..and here is the new piece on the x-axis where the old original piece I adapted from had been:



This next video was horribly truncated (probably because my phone ran out of space or battery life) and I usually wouldn’t include it, but it feels a bit historic so I’ll include it for the 24 seconds that it lasts for:

I had more work to do on the opto-flag holder (more on that later), but first I wanted to make a proper filament spool holder. I tried printing 4 of these new-style rod holders (I’d later realize I needed two of these and two of the old style), but then I ran into the new problem that my prints were slanting on X and Y (not individual skips, but full slants for every layer):


I guess I tried printing something else hoping the problem would go away, because the next picture I have is of that effect getting far far worse:



It was at this point that I started to suspect that my X-carriage had just melted…

Yup.. Your x-carriage should NOT do this:



Here was that gear attempt that had failed because the nozzle was lifting up and back left:



What’s the lesson to be learned here? Don’t make carriages or extruders out of PLA.

Here are some more pictures of the melted carriage:






I printed a carriage out of ABS on a Makerbot Replicator that I’d borrowed for something else. I wasn’t about to muck with mixing ABS and PLA in a nozzle of my own RepRap (or the Museum of Science’s RepRap) at this point:


I also printed out an idler:


…two extruder parts with bottoms designed for the Budaschnozzle, two spare Open-X carriages for me:




…and the both gears for the extruder:


Since I was printing ABS extruder and carriage parts, I decided to print some for my brother as well (whose RepRap parts were printed by my printer), since I now knew the PLA carriage I’d given him would melt. :)


Here is what I mailed him:



Around this time my brother had mailed me a picture of the frame he’d built from the parts I’d given him:


Jon, if you’re reading this, here’s more motivation for you to finish up and get your printer printing! :D

Ok back to the Z opto endstop.. At first I mounted the opto endstop board on a standard holder printed out of PLA, which you can see in the upper right-hand corner of this picture:


I really wanted that to be adjustable though. I found this “Really High accuracy adjustable Z Endstop for Prusa” piece, printed it, and attached the opto-endstop board to it, and mounted it on the RepRap:


(Actually I mirrored the arm part, since I wanted to mount this on the right side of the machine instead of the left. The mirrored arm piece is now on thingiverse here).

Back to my Z-opto-flag holder, here it is with the tin cut and with tape on it:


…and here it is installed and ready to swing down in place:


…and here is the first homing of the Z axis with these parts:

I just uploaded it to thingiverse finally, while writing this post. :)

So then I mounted the Budaschnozzle in the new ABS X-carriage. It got stuck at first, and after I managed to remove it I filed the edges of the inside of the circle a bit so it was more easily removable.



Then I assembled the new ABS extruder:


Then I realized what I was going to do for an X endflag.. I don’t know if it was by design or chance, but when you’re using a Budaschnozzle mount on the Prusa IT2 x-carriage I was using, a piece of tin right between the plastic part of the Budaschnozzle mount and the extruder is at exactly the right height for an opto endstop board mounted on a standard Prusa IT2 endstop holder.

I modeled them with paper then cut them out of tin after (I say “them” because not only did I put the X endflag beneath the left of the extruder, but I put another shim of metal beneath the right of the extruder so it was evenly balanced).





Cara was downstairs and help me attach the new X-carriage to the LM8UU bearings:



..and here she is describing it (again, a truncated video – sorry for missing her saying goodbye):

Cara is a really good RepRap helper.


Here she is, telling us what the RepRap is doing.

The four new-style clamps turned out great, although as I said before we only needed two of them.



Then we started two of the old-style clamps for the top (I put two long bolts through diagonal holes, pointing up, and use those as guides to hold the threaded rod that goes inside the spool).




and my favorite picture of the whole post:


Well that catches us up to March 8th 2013, leaving me still just barely over a year behind. Clearly I need a combination of blogging more often and to stop using my RepRap. :)

See you in the next post.

Four, no, 37 months.. part 16 of ?

February 9th, 2014

Time for another blog post. At first I was been unable to post anything for about a month as I waited for my webhosting company to migrate my domain to some new servers. Then I’d finally got the blogging software caught up-to-date etc. But then this very post stretched across many months due to laziness.

As you all remember and are probably sick of reading about, I’m about a year behind on my blog. My last post led up to the events of my booth at Makerfaire NY 2012, which I had already covered out-of-sequence way before that, and after posting that I exhibited again at Makerfaire NY 2013 (real time). I’ve decided I’m not going out of sequence again – you can read about Makerfaire 2013 when I catch up to it.

But for now, we’re still at October of 2012 (even though as I’m writing this, today is actually November 15th, 2013 February 2nd, 2014 February 9th, 2014).

I got back from Makerfaire NY 2012 and unpacked.



After that, I did nothing RepRap related for about two months. Next up was finishing the Museum of Science’s RepRap. As I’m sure you remember, earlier in the year I built the beginnings of a RepRap (no extruder or endstops yet) for the Museum of Science in Boston. I brought it into the museum where they used it as a non-functioning prop for a 3-week exhibit.


Then took it home to finish it (where it sat untouched for half a year). It was now time to finish it.

First I needed to figure out where to mount the opto-endstop flags. I cut a piece of thin cardboard to use as a template for how I wanted to mount it, then once it was good I cut the same shape out of a flattened tin can.



I wrapped the opto-flag part in blue tape so it didn’t reflect, and mounted it beneath the bed.




Here you can see the mount screws coming through the top of the bed:



I cut an opto-endflag for the X-axis, and got a bit frustrated about how the raised belt on the Prusa design has the potential to touch the extruder.


Since I was giving the RepRap to the Museum of Science and knew they’d be using it on a regular basis, I wanted their hot-end to be one they could purchase commercially if something went wrong (rather than making them one on my lathe). I asked around as to which hot ends people were using that had few problems. Chris Connelly had been using a Budaschnozzle without problems for months, so I decided to go with that:




Then I spent some time trying to debug what was wrong with the opto-endstops I’d set up.


Meanwhile, I got MY RepRap up and running again, for the first time since Makerfaire.


My own RepRap was still having horrible problems with the carriage and my new extruder which required reinforcement. Three days later this abomination came out of my printer:


Well, back to the Museum of Science’s RepRap. I started putting together the extruder (not the one I’d just failed to print, but the one I’d successfully printed long ago when printing the parts for the RepRap).



..but then I found that I’d drilled the holes a bit off and needed to abandon that particular piece..

I decided that for the time being I’d instead try using a red ABS extruder that my friend Chris Connelly had previously printed for me on his RepRap (even though I’d ultimately go with a different extruder altogether). But first I needed a hobbed bolt.

I took an existing bolt, put it through the red extruder, and marked off where the exact center was with a black fine-tipped Sharpie (if I was using 4 washers on the gear side of the extruder).


That turned out to be exactly 26mm from the head of the bolt.


I marked 26mm on a new bolt, lined it up in my Bolt Hobbing Tool for my lathe, and proceeded to move the bolt 56 notches on the dial (which should be 1.4mm) into a 5/16″ spinning tap. I showed these next two videos a few posts back, but here they are again (since this is when they were actually recorded).

Here is video showing me hobbing the bolt:

…and here is video of the resulting hobbed bolt, for the Museum of Science’s RepRap:

Here it was lined up in the extruder:


Here is just the bolt itself:



The red extruder had a hole on the bottom for a PTFE insulator, but since I was using a Budaschnozzle, there would be nothing to fill that hole (and I worried about the filament sliding to the side before entering the hole). I took an old spent PTFE insulator, put it in the lathe, and cut this small insert:



(Sorry that video cut off at the end)

I inserted the insert, and connected the cold end to the hot end.


Yes, I now had an extruder!

I added the bolts and springs to hold the idler against the filament:


Then I mounted the extruder on the X-axis, and connected it up with the Extruder Pluggable Wiring Convention like my own RepRap and extruders use:




Again, here’s what the hot end looked like beneath the x-axis:


On Sunday January 6th 2013, at around 6:17pm, the Museum of Science’s RepRap had it’s first manual (and then first powered) extrusion:




Now, for no particularly good reason (other than that this happened around the same time), at this point I’d like to go on a super-brief tangent and post a picture of the best hamburger I’ve ever had in my life:


It was from a place called Tucker Duke’s in Valparaiso Florida. It was their signature burger. Those are onion rings in the middle, and the pink dressing was something about marmalade – I can’t remember. The whole thing is held together with a knife until you’re ready to eat it, at which point you scrunch it down and then start eating (I immediately wished I’d rolled up my sleeves first, because you can’t put the burger down after that). Sadly, that is very far from me, and I don’t know if I’ll ever have that burger again. I’m haunted by the picture I took of it. Mmmmmm..


(Jeff snaps out of it)

Ok, where were we? :)

Now we needed the heated bed.

Here I am talking about using tiny PTFE tubing over the leads for the thermistor for the heated bed, and then heatshrinking it all up nice.



Here’s the beautiful result of my careful work on the thermistor for the heated bed:


…and then proof that the thermistor was working:


and here’s the heated bed fully installed, working, and moving:

(I’ve said it before, but I love the fact that with my first RepRap it was a LONG time before I ever got around to having a heated bed, and then after that, I don’t even consider a printer finished until it has one. We keep raising the bar. :) )

Continuing on the rapid progress, on Wednesday January 23rd 2013 at 6:22am, the Museum of Science’s RepRap had it’s FIRST PRINT!


…and the result!


All of this was on its first try!




And guess what? It was water-tight on the first try too!



Fulfilling tradition, here I am toasting the successful completion of another RepRap, this one for the Museum of Science in Boston!

That’s all for this post. Today is February 9th 2014 and I’ve now brought you up to the events of January 23rd 2013.. so I’m a tiny bit more than a year behind, but that’s okay because I really will catch up. Honest.

Thanks for reading.