RVing Here and There

Thoughts, news and information about the world as seen through RV windows
RSS icon Email icon Home icon
  • Hacking the 101Hero: Cooling Fan

    Posted on January 6th, 2017 admin 1 comment

    One weakness of the 101Hero 3d Printer is the lack of a cooling fan.   Most users have compensated for this with bed-mounted fans.    But wouldn’t it be neat to add a cooling fan to the head, to direct cooling air right onto the recently-printed layer, just like on a more expensive printer?

    Where to Mount the Fan

    There are two likely places for such a fan:

    • In “front”, under the filament access door.
    • At “back”, under the hump of the stepper motor

    I thought the front location might interfere with access to changing filaments, and the shape of the duct would be difficult due to the need to fit in the yoke between the struts.   I also briefly considered mounting a fan on the top, beside the wiring and the filament tube, but thought that would be awkward.  Because of that I chose the “back” position.

    Choosing a Fan

    The 15 mm fan (for Raspberry Pi)

    The 15 mm fan (for Raspberry Pi)

    In either location, there isn’t much room.   At the front, there might be space for a  20 mm fan, while at the back, the most likely size is 15 mm.  I got a tiny 15 mm fan on Ebay for $10 plus $7 shipping, and found a 20 mm fan at Aliexpress for $10 with shipping included.

    The little 5V fan came within two weeks from Las Vegas.  It pumps 12 litres/minute at 15.7kPa, a fraction of the amount from the 40 mm fan I have mounted on the print bed.  Still, directed through a duct, that small amount of air might be enough to cool the PLA.

    Besides,  this is just a fun project, intended to help me learn to use 123D Design and to do 3D printing.  It is not expected to produce any really practical result.

    Fan specs.  Sprechen sie Deutsch?

    Fan specs.  Sprechen sie Deutsch?

    Developing the Design

    I wanted something with minimal curves, with minimal interference with the airflow.  I dismounted the head, did some measurements, made some sketches.  The first prototype was made of stiff paper from a 2016 calendar, taped together.   The idea was that the fan, at the top, could blow down through a duct and the air be directed downwards beside the extruder.  I taped the fan into the top, hooked it to a battery, and decided that maybe….

    Crude paper prototype

    Crude paper prototype

    It fit well onto the print head, and it looked like the design might work.  Now all I had to do was turn that paper model and my concept into a 3D print using strange software such as TinkerCad and 123Design.

    Iteration After Iteration

    This part was enjoyable, if a bit tedious.  I would figure out make a design (which often involved a lot of Google work), then print it out.  Then I had to play with the print settings or the part orientation to get a decent print.  Then I’d try it, see what was wrong with it, which also often involved Internet research on “3D printing problems:.  Then repeat.  And repeat.  And repeat.

    A few of the many tries.  I went through five major designs with up to 12 iterations in each.

    A few of the many tries. I went through five designs with up to 12 iterations in each and used many meters of PLA

    One obstacle was that I couldn’t really measure or fit with the head mounted in the printer.  With the head off to measure and fit, I couldn’t print.  Once I put the head back, it often took hours (in one case a full day) to get it readjusted to print properly.

    fan-concept

    First two-part prototype, joined and sealed with green vinyl tape. Early versions included a screw mount for the fan but a press-in flange worked fine.

    Still, the early printed prototypes snapped securely onto the print head, and were encouraging.   Problems with printing led me to cut the part into two, a motor housing and a duct.

    Early prototype clinging to the print head

    Early prototype clinging to the print head

    v5-6-cooling-fan

    A mid-series Image from 123D. Motor housing at left bottom on plenum; duct at right.

    So, change this, extend that, find that this didn’t print properly — why not?–move this, try again.  I learned about support, orientation, bridging, wall thickness, stringing, retraction.  I switched from Cura 15.02 to 15.04 because the latter gave more accurate slicing (in between two Cura versions, I tested KISSlicer, Repetier Host, Craftware, and ICEsl) .  I changed setting after setting and kept track of all the changes in a spreadsheet, so that eventually I could identify what worked well and what didn’t.   One thing that caused problems was support – Cura insists on putting support inside the duct, which was impossible to get out and which left the inside rough instead of smooth.  I wound up using Support “Touching build plate” as it worked the best. printing-v5-12

    The semi-final version was printed using the best quality I could achieve given my limited knowledge and skills.  There may be further modifications to indent the motor housing just under the motor, to allow space for the suspension struts during wide prints.

    Anyone interested in duplicating or better yet improving this project will find the files at the 101Hero forum (101user.com).

    Is it Safe?

    I’m printing in PLA and perhaps having the blower close to the extruder is not a good idea. I am considering sending the part out to be printed commercially, or waiting until I get my Trinus so the duct can be printed in ABS (the blower housing can be PLA).   Though, in point of fact, the thing hasn’t melted yet.

    An early version, not quite straight and a bit close to the extruder nozzle

    An early version, not quite straight, not the best print, and a bit close to the extruder nozzle.

     

    In Conclusion

    In the end, I came up with a design that seems to work as well as it’s going to work.  I’ll print another Eiffel Tower to see the result.  Does it function and adequately cool the part as it’s printing?  Probably not.  It seems that 12 L/m of air at 15.7 kPa is not really a lot of movement or pressure. I can feel air coming out the vent, and that’s about as much as I can say for it.

    Still,  the project taught me a lot about using design software, principles of good design, and some basics of 3D printing.   Which was, after all,  the main goal.

    Further Reading

     

     

  • Five Tips for Video Presenters: Lessons from Live TV

    Posted on January 3rd, 2017 admin No comments

    Since getting my 101Hero 3D printer, I’ve been watching a lot of  how-to videos.  Generally speaking, I loathe amateur instructional videos on Youtube.   I’m not talking about camera technique, video quality, smoothness of editing or any other technical topic.   I’m talking about the person in front of the camera, telling  (instead of showing) me something that I want to know or learn or do.

    If a video can’t hook me in the first 30 seconds, I’m gone.  Lost as an audience now and probably forever.

    I used to work in live TV (a show called “Homework Hotline”) . I got that job because as an Advanced Toastmaster,  experienced public speaker and award-winning teacher, I was able to present well on air.   Not that I didn’t occasionally goof; I’m human.   Yes, there was a seven-second delay, and yes, a mistake would be edited in the video for distribution, but when you’re on live transmission, dead air and wasted time are a no-no.  A lot of what I’m talking about in this post came from lessons learned on that show.

    I’m not going to embarrass anybody by linking to flawed presentations… but ooh, it’s tempting! If you’re a video presenter and you want me (and others) to watch your work, here are five things I wish you’d pay attention to when you do your video.

    1.  Show some life

    Please don’t be just a talking head.  Show some animation.  If you look and sound bored, the chances are pretty good that your video will be boring.  But the chances are also pretty good that I won’t know or care, because I’ll be gone within the first 10 or 15 seconds.

    The Hotline hired teachers who could put some pizzazz into a lesson.  You need to do that for your video.

    2. Get Right Into Your Topic

    Our producer used to stress that “Air time is money! Don’t waste it.  Get right to your material!”  Perhaps as a result of that,  I have come to hate presenters who waste a lot of time with long and irrelevant introductions.

    A guy bored by your video presentation.

    How I feel about  your video presentation.

    “Hi, guys, how ya doin’? This is Greg the curizan specialist comin’ to ya from Upchuck South to tell ya all about how to dilate your curizan. If ya got a curizan that don’t dilate and ya wanna know how to make it do that, I’m the man to tell ya. I picked up my latest curizan at a flea market in Upchuk North for ony a buck, but it didn’t dilate right — ya always gotta be careful with what ya buy in a yard sale, don’t ya? So I had to figure it out and now I’ll share that with you.”

    And on, and on, and he’s wasted several minutes telling me NOTHING but what I already knew about the video just from the title.   If you’ve picked your title well — “Dilate Your Curizan by Greg”, or “Greg Shows How to Dilate a Curizan” — you needn’t say much more.  You don’t even need “Hi, how ya doin’?   Greg here again to talk about Curizans.”  I know that already.

    Save me the trouble of fast-forwarding to where you say something important.  Get right into your topic.

    3. Have Your Props Ready

    For heavens sake, if you need props or samples, have them right at hand.   Our floor manager used to rips us a new one if we didn’t have our lesson materials right where we wanted them and right when we needed them.

    You’re your own producer and director and floor manager, so this is all under your control.  Your items can be off to the side just out of camera range, or on a small table beside you (also out of camera range) or even on the desk in plain sight.   Do some preparation, know what you’re going need at each point in your presentation, have your props ready and in sequence.

    Above all, please, don’t be dodging off camera to get something.  Especially don’t make a comment while you disappear, “Shoot, where did I leave that?”  At the very least, edit the break for a smooth transition before posting your video.

    4. Don’t Um and Ah.

    Speech hesitations, unnecessary interjections, false starts –”Um, man, like, you know, I, uh, got this curizon, and, like, it didn’t work, you know”  ARRGH!

    You’ll notice that professionals don’t do a lot of this.   If you have your own Youtube channel and do a lot of videos, please review a few of your posts and take a count of the number of speech stumbles.    If there are more than a couple, plan to do something about it.   Take a speech class.  Join Toastmasters.  Get a friend to slap your face with a dirty sock whenever you do something like this.   For Canadians, it’s that unconscious “eh?” at the end of our sentences that we don’t even notice until our American friends tease us about it.

    It takes a little practice and training to break these speech habits,  but you can learn to speak fluently.

    4. Pay Attention to Pacing

    blah-blah-blah-clipart-1-jpgThis is a toughie that comes with practice.  I find that the average video presenter talks so slowly that I want to shake him (or her) and say, “Go! Get on with it!”  On the other hand, if you’re rattling along like an auctioneer, I’m going to be missing some of what you say.

    Many sources give the average conversational speech rate as about 110 to 140 words a minute, but our listening comprehension goes much higher.  Trained professionals — motivational speakers, newscasters, advertising readers–tend to be at the higher end, up to 160 words per minute (one study of Ted Talks found the average rate was 163 wpm).  With crisp, clear delivery and good enunciation, a speaker may be understandable at a faster rate, up to around 220 or even 240, but that’s the upper limit for effective listening.

    Your goal is somewhere between the used car salesman’s rapid-fire pitch and the kindergarten teacher explaining to the slowest students in the class.  Of course, the best speakers also vary their rate, just as they vary their inflection, for greater emphasis on certain points.  You can also do this in your video.

    But here’s the rub:  Average reading speed is 200 to 300 words per minute, and faster readers can easily hit 500 or more. To a reader, your talking video is incredibly, frustratingly, annoyingly   s….l….o….w.   This is the main reason I hate videos: I can read your material in a fifth of the time it takes you to say it.

    5. Don’t Tell Me — Show Me

    “Show, don’t tell” is a writer’s dictum that also applies to videos. Most Youtube videos are telling me something (slowly) that I’d rather read (quickly).  The value of a video is when you can show me a process or skill or operation that can’t easily be described in words.  If you’re just telling, you can video a text screen that I can scroll past after I’ve read it.  Saves us both time.   But talking heads?  Pfui.

    I like Instructables because they generally use words and tagged images.  I can take those at my pace, as fast as I can  handle them.  But Instructables also sometimes include short video clips that show or demonstrate some particular point or process.   Those are truly worthwhile use of the video format, especially if they’ve been tightly edited to show only the essentials.

    Conclusion

    Much of what I’ve written here is basic to any public speaking class, or is covered by a year in Toastmasters or a similar organization.  However, if you’re doing instructional videos, you can improve your product — your presentation–not only by taking courses or training but also by paying attention to what you’re doing, being prepared, and simply working at being better.

    Further Reading

  • 3d Printers For Beginners…Or Not

    Posted on December 29th, 2016 admin No comments

    Just before Christmas, on Dec. 22, 2016, TechJoint (TJ) published a youtube video titled  “5 Amazing 3d Printers For Beginners”.   It was nothing but a compendium of promo videos from Kickstarter campaigns  with no original content, review, or comment.

    Still,  I was a bit surprised by some of their choices.  Let’s take a closer look.

    OLO 3D SLA Printer

    OLO campaign photo

    OLO campaign photo

    First up, OLO.  The OLO was intended to be a mini  SLA printer powered by your cell phone.  I had looked at it and decided to stay away.  The original Olo 3d Printer video and campaign have been criticized because

    1. it glosses over the fact that your phone will be tied up for hours by a print
    2. it shows alleged light-sensitive resins in clear plastic bottles, which is seen as deceptive
    3. it claims cost-equality with FDM printers, yet the resin is far more expensive than filament
    4. the fundraising goals have been seen as far too low for product development

    The printer has been panned by Maker’s Muse, KickScammed, Quora,  and elsewhere (the Quora discussion in particular has considerable detail) but apparently is technically feasible and may eventually come to fruition.  But don’t hold your breath — in the KS comments section, backers have been reduced to chatting about Mexican food.

    101Hero 3D Delta Printer

    101Hero’s campaigns on both Kickstarter and Indiegogo were well-fulfilled, with some 3700 backers.   The unit is simple and cheap, made of injection-molded plastic   The blue production model isn’t nearly as pretty as the white prototype shown in their campaign video, but it has started shipping (I have one working on the desk beside me).

    101 Hero printing a benchy

    101 Hero printing a Benchy

    The early round of deliveries suffered from failed stepper motors and missing parts; the company is focused on shipping and has been ignoring customer complaints (perhaps not the best of strategies) until shipping is completed.  Lack of communication from the creator is also a constant complaint.  The official Facebook group is static and unhelpful, but there is an active unofficial FB group for users.

    Angus at Maker’s Muse backed the 101Hero but has not yet received it at the time I write this.  I’d have thought that the company would take care to get a unit to an influential backer.   Since I backed mine late through Indiegogo yet was among the first to receive one, I suspect that they are pushing retail sales to generate cashflow — not fair to backers, but not uncommon.

    Kodama Trinus All-Metal 3D Cartesian Printer/Laser Engraver

     Trinus set their standard as being a solid, all-metal, streamlined industrial design.  Their polished campaign video was humorous and catchy, attracting over 3,000 backers and $1.6 million.  The unit was well reviewed and backed by Maker’s Muse, which apparently attracted backers.   The bare-bones printer was $299 with add-ons (heated bed, laser engraver, enclosure, LCD screen, filament pack) driving the price as high as $900 USD with shipping.

    Like many KS campaigns, development was behind schedule, and shipping fell several months late.  However, the company has started shipping with units to reach most backers in early 2017. Users and potential users have both an official forum and an active official FB group.

    Kodama Trinus prototype

    Kodama Trinus prototype

    Minitoy

    minitoy

    A MiniToy campaign shot

    Minitoy’s approach was, like 101Hero, push-button simplicity.  However, the Minitoy is specifically aimed at children and schools, and stresses safety (in that it prints only PLA).   The video seems to focus on toy production.   Early criticisms cited

    • lack of a locking door,
    • lack of ventilation,
    • problems with filament loading
    • lack of USB connection

    The company has promised to find a solution to the door issue, but object that a lock would significantly increase costs.  They’re considering sensors that would halt the print and retract the head if the door is opened during a print.

    The product has had the usual holdups but may ship to their 600-odd backers in early 2017. Comments on the KS site are of the “Please show some videos of real prints?” and “When are you going to ship?” variety. Their FB group, like that of the 101Hero, has little of value to users, and presently has few user/backer comments.

    iBox Nano

    As for the iBox Nano, apparently it quietly disappeared.

    Conclusions

    It seems odd that TJ should recommend for beginners at least three printers that have significant issues.  OLO and iBox seem to be non-starters.   Minitoy is working through their issues and plans to ship in 2017.   101Hero has yet to address their lack of customer service, but has begun shipping (mostly) working printers.   The most expensive of the lot, the Kodama Trinus,  is shipping now, with most users due to receive their units in early 2017.

    Further Reading

  • 101Hero 3D Printer: Glow-in-the-Dark Filament

    Posted on December 28th, 2016 admin No comments

     A couple of nice companies have provided free sample filaments for me to play with.    Now that I have at least a vague idea how to set up my 101Hero 3D printer so I get mostly decent results, it’s time to look at some of the more exotic and interesting of these samples.  First up: a phosphorescent filament.

    Testing RepRap Glow-in-the-Dark Green Filament

    Typical projects for glow-in-the-dark prints include stars and other galactic subjects; these filaments are also popular for Hallowe’en decorations.  The more dense the print, the brighter the glow, it seems, so thick walls and heavy infill are recommended.  I had a  three metre sample of RepRap’s glow-in-the-dark green PLA so I wanted a small project.

    Sun ornament by MicrosoftStore

    Sun ornament by MicrosoftStore

    For several reasons, I chose the Planet Ornament series by Microsoftstore from Thingiverse.

    1. First, they’re a suitable subject.

    2. Second, they appear to have enough mass to give a bright glow.

    3. Third, I could print two of them from the sample filament supplied by RepRap Warehouse.

    4. They’ll be a good little gift item for grand-children (problem:  I have three grandkids and can make only two ornaments).

      Sun ornament by MicrosoftStore

      Sun ornament by MicrosoftStore

    The filament measured at five different spots with a digital caliper:   1.71mm, 1.72 mm, 1.73 mm, 1.71 mm, 1.74 mm.  Using the “throw away the extremes and average the remaining three” method gives an average of about 1.725.  Is that really important?   In Cura 15.02.1 I left the filament set to 1.75 and the flow at 100% because changing those settings seems to have NO effect on the 101Hero.

    Sun ornament on the 101Hero print platform

    Sun ornament on the 101Hero print platform

    The filament printed just fine with standard settings (layer height 0.2; shell/top/bottom thickness 1.2; fill 20% (but could be solid); print/retraction/travel speed 12 mm/s @ 200C.

    Ah, But Does it Glow?

    A few seconds in the sunlight to charge it up, then into the main bathroom (only room in the house without a window!) to test it out.

    Left: Charging in the winter sun; Center: Normal exposure; Right: Low-light exposure

    Left: Charging in the winter sun; Center: Normal exposure; Right: Low-light exposure

    That was about 30 seconds in the sun, not even tipped up perpendicular to the sunlight, and enough glow to see and photograph.   The glow lasted for quite a while, and the medallion seems to have recharged under the incandescent lighting above the bathroom vanity.

    Conclusions

    The RepRap glow-in-the-dark PLA printed easily, needed no special twiddling of settings,  and did indeed glow in the dark.  Is it worth paying $30 CAD plus shipping for a kilogram of this filament?  Not entirely sure yet.  Probably my grandkids will twist my arm a bit and persuade me to buy some.

    Further Reading

     

  • 101Hero 3D Printer: Filament Samples

    Posted on December 28th, 2016 admin No comments

    Although I haven’t had any luck at all with the failaments (deliberate misspelling) that came with the 101Hero, filaments from other companies have printed with no issues.  RepRap Silver, Botfeeder Opaque Red, and RepRap Translucent White, the only ones I’ve tried so far,  have done well.   I had wanted to order samples from eSun, but it turned out that shipping costs were prohibitive.

    Prints showing RepRap Silver, BotFeeder Opaque Red, RepRap Translucent White

    Prints showing RepRap Silver, BotFeeder Opaque Red, RepRap Translucent White

    Sample Filaments From Kind Suppliers

    BotFeeder PLA, BotFeeder Canada, Ontario

    • Opaque Red – a particularly bright red
    • Transparent Natural  – a clear filament, should make a pretty vase or window ornament
    • Gold – a metallic
    • Flex Natural – a flexible filament, not sure what to do with it

    RepRap PLA, RepRap Warehouse, Edmonton, Alberta

    • Glow-in-the-Dark Green
    • Thermal Color-Changing
    • Wood
    • Flex Blue

    Handling Samples

    Each set of samples came in a single zip-lock bag.   I separated them, and put each filament into its own sandwich bag, labelled with the supplier and type of filament.   It’s dry in the Alberta winter so was not too concerned about desiccant.  Nor was I particularly neat in my labeling, not being too obsessive about such things.   In the future, however, I will print up a business-card sized label showing the manufacturer, supplier, color, recommended extrusion temperature, and whatever other information I can find about the filament.  This will save me having to look it up every time I want to use a sample.

    sample-filaments

    The box in which the 101Hero 3D printer was shipped is sturdy and turned out to be just the right size for storing filament, both spools and samples.

    The 101Hero 3D printer shipping box used for filament storage

    The 101Hero 3D printer shipping box used for filament storage

    Guess I’m as organized as I’m going to get.    Next step is to start testing some of the more exotic sample filaments.   I think I’ll start with the glow-in-the-dark green.    Oooh, I’m so excited!

    Further Reading

  • 101Hero: Changing the Levelling Screws; Screw Holder

    Posted on December 26th, 2016 admin 5 comments

    One thing about the 101Hero 3D printer is that I seem to be almost always screwing around… uh…fiddling with screws. Here are a couple of screwy little hacks.

    Replacing the 101Hero 3D Printer Z-Axis Adjustment Screws

    I thought that once I got the 101Hero levelled, that would be it.   Turns out you have to do it whenever you change filament, or temperature, or whatever.

    After about the tenth time of powering down the printer and pushing the print head to the bed to adjust this, I had had enough.  I had to use a little Phillips screwdriver, and there really wasn’t enough room with the rods and pylons right there to get my fat hand in easily.  And often the screwdriver wouldn’t bite and would slip out, so I couldn’t tell if I’d turned the screw or not.

    The 101Hero 3D printer is certainly hackable.  So I hacked.   I removed the little Phillips screws and threaded in some 4-40 x 10 mm hex-socket head bolts that I had on hand.  Actually, they were 4-40 x 30 mm but I cut them down.  I could have re-threaded the holes with a 4-40 tap, but the plastic was soft enough that I just screwed the bolts in and let them cut their own threads.  They went in easily and grip firmly.  However, since the bolt head is thicker than the screw head, the bolts had to be driven in almost all the way.

    4-40-hex-socket-bolt-arrow

    These bolts are far easier to adjust using a 1.5mm hex key (aka Allen wrench).  The hex key provides

    • Easier Adjustment, because the wrench handle is away from the pylon
    • Positive insertion – it’s easy to tell when the hex key is properly inserted
    • No slipping – the hex key does not pop out like the Phillips screwdriver sometimes does
    • Finer adjustments – with greater leverage, it’s easy to make adjustments a degree at  a time.

    easy-adjustment-with-hex-key

    Collecting Loose Screws

    When I remove the screws from the filament gate, and set them down on my desk, they always run away.  They fall off and bounce under the desk.  They scoot under the printer.   Enough, already.  I took a small magnet and set it on the top of the printer.   When I remove the screws, I put them on the magnet.  They stay put and are always right there when I need to re-insert them.   Maybe I’ll fasten the magnet to one of the pylons.    But for now, it works fine.

    20161226_113531

    I wish all my 3D printing issues could be solved so easily.

    More Fun Hacks and Tips

  • 101Hero: Vertical Print Limitation

    Posted on December 22nd, 2016 admin 2 comments

    How high can a little printer reach?

    The 101Hero 3D delta printer was launched on Kickstarter  at $49 USD and continued on Indiegogo for as low as $79 USD (S/H extra for both).   One of many billed as “the world’s most affordable 3D printer”, intended to retail at $99 USD, it was certainly inexpensive.

    The printer promised to deliver simple assembly and simple operation from either an SD card or computer via USB.  Some of the early deliveries suffered from stepper motor failures, while others required considerable tuning, hacking, and fixing.   Mine was one of the latter, but by about the third week, I was getting very nice prints.

    The first vase, 75 mm tall

    The first vase, 75 mm tall.  Octopi not included.  Love the single hair on the little guy on top.

    Today I decided to see how high I could print.   The 101Hero claims on its Indiegogo page: Print size: Height 100mm (3.93″) Base Print Area φ150mm (5.9″).  Having just printed a very nice spiral vase from Thingiverse at 75 mm, I decided to do the same print at 100 mm high and 45 mm wide.

    The larger print suffered three flaws, pointed out in the image with arrows.  The first two were entirely my fault.  When I loaded the print spool, I didn’t notice that I had the filament crossed over itself.  Twice, the filament got trapped briefly, which caused minor layer shifts.  They’re only noticeable if you look for them, and don’t really affect the quality of the print.  In fact, on looking closely at the smaller first vase,  I see that this might have happened to that print as well.

    large-vase-small

    The major issue is that before the vase reached 100 mm,  the print head began mushing against the print.   Possibly the 101Hero can print an Eiffel Tower to 100 mm (I read somewhere that the actual print area of a delta printer is conical)  but it couldn’t print this vase at 45 mm wide and 100 mm tall.

    The maximum height for the vase:  95 mm

    The maximum height for the vase: 95 mm

    Had I set the height of the design to 95 cm, I expect the print would have been just fine.   The next step, I suppose, is to see how wide a bowl I can make.

     

  • 101Hero: Reversed Prints

    Posted on December 21st, 2016 admin 4 comments

    When I got my 101Hero, I assembled it according to the directions… but all my prints were backwards!

    The three pylons were identical, except that one had a much longer wire from the limit switch.  There is no mention of this in the instruction booklet so I assumed it was just a change made mid-production, where somebody realized that money could be saved by making the wires shorter.  So I figured it didn’t matter what pylon went where, and the instructions didn’t say anything on the matter.  As it turned out, maybe it did.

    Connecting the wiring to the controller seemed straightforward.  On page 7 of the instruction booklet was a nice diagram of Step 3 Connect the Controller.   Each wire was labelled with a letter, and the diagram showed where each plug should go.  One plug appeared to have read “C” but was over-written by hand to read “J”.   I also noted which connections were to the print head.

    Connection diagram in the instruction booklet

    Connection diagram in the instruction booklet

    I connected the wires as per the diagram, and went on to have some terrible prints.

    Eventually, I got things sorted out.  One of my test prints was an XYZ calibration cube from Thingiverse.  It printed nicely, if with a few holes on the top where fill didn’t quite reach the walls (since adjusted by increasing the Infill Overlap).  It was only some time later that I noticed that the “Z” on the top of the cube was printed backwards.  Since “X” and “Y” are symmetrical, they looked just fine.

    ZYX Cube.  Note the Z inverted on the top.

    ZYX Cube. Note the Z inverted on the top.

    I continued to tune the printer and refine settings, and eventually I got a really nice Benchy in silver PLA.  On the bottom of the boat it is supposed to say “CT3Dxyz” to show whether you’ve got the first layer “squished on” properly.  On my Benchy, these letters were a mirror image.

    This is a common enough situation with delta printers, apparently, and the solution is to reverse two of the leads from the stepper motors and the corresponding limit switches.   So I interchanged A with C, and H with J.  This should swap the X and Y axes.  I noted the change in the instruction diagram, and also ran a strip of label tape to remind myself of the change for the next time I’m hacking the controller.

    Controller connection labels

    Controller connection labels

    Time for another XYZ calibration cube to check that everything is good and proper and that I didn’t screw anything up.

    xyz-cubes-3

    ZYX and XYZ calibration cubes. First (inverted) cube on the left, revised (correct) cube on right. The SD card was nearby so I included it for scale.

    The odd thing is that for most prints, I hadn’t even noticed the inversion, or if I did notice it, I didn’t much care.  Does it matter if a cute little octopus waves a left or right tentacle?  It’s still a cute little octopus.  The Benchy is symmetrical, so no problem.  It’s only for prints where the orientation is important that this becomes critical.

    You may have got your pylons in the right order and your prints are the right way.  If you didn’t and your prints are coming out backwards, it is a simple fix.

     

  • Hacking the 101Hero: Strut Tighteners, New Plate Clips

    Posted on December 20th, 2016 admin 1 comment

    There’s a very helpful crew on Facebook Groups sharing ideas about making this little $50 printer into a real machine.  Here’s one hack that came from the group, and an update on one of mine

    Tighten the Ball Struts

    The ball joints used on the connector arms are very loose and sloppy, which allows the print head to move up to 1 mm or more in any direction.   Users have recommended a three fixes for this:

    1.  Replace the struts and ball joints with higher quality parts.   The radio control industry supplies ball joints and connectors in various sizes, configurations, tolerances, and prices.  For example, Stefano Marcon found a good quality aluminum strut with what appear to be metal ball joints.  Some users wonder if the expense of these parts is justified given the low overall quality of the printer, but replacement is an excellent option.

      Ball strut by Stefano Marcon

      Ball strut by Stefano Marcon

    2. Connect the arms with a light-weight spring.  It doesn’t take much tension to pull the arms in together, and too much may stress the poor weak little stepper motors and wear the ball joints prematurely.  Possibly even a spring from a ball-point pen would work?  I used three identical springs that I had in my junk box, and stretched them out so they had less tension.  I didn’t measure the force, so don’t ask.

      Spring retainer by Stéphane Keep Hérault, from a UTube video

      Spring retainer by Stéphane Keep Hérault, from a UTube video

    3. A small elastic band will do the job too.   Simply remove the struts at one end or the other, slip the rubber band on, and reassemble.  It is enough to keep the sockets tighter on the balls at each joint.

      Elastic band retainer by Stefan Gautsch

      Elastic band retainer by Stefan Gautsch

    Two of these are cheap and simple and appear to do the job of tightening up the ball joints.  Does this simple strut-tensioning hack work?   Well, here are photos of two Benchy prints, almost identical in settings (the one on the left used top/bottom 0.8 while the one on the right used 1.2, had springs, and had a fan running for the top half of the print.  Oh, and I wound up hanging the spool of filament on the holder above the printer, which may have twisted the Benchy just a little.  Gotta fix that).

    Left:  Benchy 1 Right: Benchy 2

    Left: Benchy 1;  Right: Benchy 2.   Dang, the photos looked sharp enough on my phone.

    Clip Down the Build Plate

    One of the first hacks I did was to replace the metal binder clips that were supplied to hold down the round glass print platform. There is nothing wrong with them; even some higher-end printers use this simple and economical retention system.   However, I found them a bit awkward to get at, and they tended to fall off my desk or scoot under the printer.  For a while, I clipped them to the top of the printer or to the edge of one pylon, but I soon saw that having one turnbutton at the front would be superior.

    Low-quality prints in black 101Hero PLA

    Low-quality prints in black 101Hero PLA

    The first ones were in the way for larger prints, so for this batch I moved the LED mount behind the screws.   They still illuminate fine.  I wrapped an elastic band around the one without an LED mount to serve as a gasket or cushion. This was a fast, low-quality print; the clips don’t have to be all that sturdy or pretty.  I didn’t oversize the holes, so you’ll have to drill them out to fit the screws, and if you want to recess the screw heads so they go further into the base, you’ll have to drill the recess wider too.  Layer height 0.2, shell/top/bottom 0.8, fill 0%, print speed 12 @ 200C.  They’re installed and working fine.   Here they are lighting up a Benchy:

    Clips serve to hold and illuminate the print bed

    Clips serve to hold and illuminate the print bed

    Note the little arrow showing how the front one rotates. When it’s swung out of the way, the glass will slip out of the other two and can easily be removed.  Put the plate back in, swing the clip back into place, and the build platform is locked down and ready to go.

    You’ll find the .STL files for these clips here, here, and here.

    The hacks are fun and the sharing is a great way to make the most of this little printer.

  • A Look at the Lumos Bike Helmet

    Posted on December 19th, 2016 admin No comments

    A couple of weeks ago, in the middle of a spell of really cold (-35C) weather, my Lumos bike helmet arrived.    I was excited to see it but not at all motivated to go cycling, so it sat there for a week before I even got to unboxing it.

    Mistimed Marketing

    The thing was originally supposed to ship last summer, which would have been nice, but KS projects seldom deliver on time (you’d think they’d learn to underpromise).  Oh, and they included a bunch of discount cards for referrals — guess what, they expire Dec 31!  So instead of having a few months to show off my helmet and give my friends a discount coupon,  I have… NO TIME AT ALL because none of my cycling friends are going to see this helmet until next spring.   Nice bit of marketing, but badly timed.

    Ah, well.  The weather’s supposed to be nicer this week, so I might get out on a bike to ride through the snow; maybe not right now with winds up to 70 km/h, but some time this week.  At any rate…

    Helmet from the back

    Helmet from the back, showing switch and charge port

    A Nice-Looking, Well-Made Helmet

    The helmet looks well-made, nicely finished with all the parts fitting together well, no gaps or blemishes.  As might be expected, it’s a bit hefty, massing 436 g.  Compare this to my Specialized helmet at 250 g and a cheaper Bell Micro at 346 g.  Still, it fits my head well enough and doesn’t feel that bad as I sit here typing with it on.

    Lumos helmet showing front lights

    Lumos helmet showing front lights

    The switch at the back cycles through three flash patterns for the tail light and headlight in synch, and they both seem plenty bright.

    Turn Signals on the Lumos

    The turn signals show in four places:  on the helmet back, on the front, on the handlebar switch, and in a kind of “eyebrow” panel under the front of the helmet.  This latter I guess is supposed to show in your peripheral vision, though I can’t see it unless the helmet is tipped dangerously forward instead of being two fingers above my eyebrows.  Perhaps it will reflect on the top of my sunglasses when I’m riding, though I doubt it.  It’s one of those features that looks cool but isn’t really useful.  There is something else in the center of this little panel, perhaps an ambient light sensor or a low-battery warning light.

     

    Left turn signal

    Left turn signal at rear

    Controller

    I was impressed with the sturdy handlebar remote which snaps nicely into both the wireless and wired holders.  I don’t think it will bounce out and be lost on the road, but I can still click it out and pocket it when the bike is parked.  A firm push on either the L or R button will turn on the appropriate signal light on the helmet; the button also flashes to let you know the signal light is on.  Another push turns the signal light off.

    Handlebar remote

    Handlebar remote

    Lumos Brake Lights in Beta

    Unfortunately, the brake light is iffy.   Lumos promised “integrated lights, brake, and turn signals” but delivered only two of the three.  The accelerometer that detects braking is mounted in the remote, rather than in the headgear. According to Lumos, “this feature does not work perfectly and is still being refined”.  It works, sort of, but is incredibly sensitive and twitchy.  I think the brakes will go on every time you hit a bump, drop off a curb, or jog around a pothole, which suggests that on a rough route they would be on almost constantly.   All sets of lights — both turn signals, the tail lights, and the headlights — come on for about two seconds every time.  Lumos warns that this can “lower the battery life of your helmet and remote significantly” which is why the brake lights are off by default.  Too bad Lumos can’t use the LucidBrake technology.

    Storage bag

    Storage bag

    Except when we have a chinook happening, the Lumos will sit in storage  until spring.  I guess they foresaw this, as they included a bright yellow storage bag.

Supporting your fulltime RV adventures and aspirations