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3D Printed 28BYJ48 Stepper Moter Actuator ( Low cost EcoRobo Series) — Parallax Forums

3D Printed 28BYJ48 Stepper Moter Actuator ( Low cost EcoRobo Series)

GarethGareth Posts: 278
edited 2014-04-23 09:54 in Robotics
Here is a custom 3D printed Linear actuator for activating a lever or push/pulling something or other.

It uses a Cost effective Stepper motor (we all know which one).

From a previous static test i knew that the motor in this worm screw configuration could push close to 2Kgs of force (as measured against my kitchen scales)

The bugbear was thinking of a way to attach a feedback potentiometer to the worm screw...

....I tried linear potentiometers however they were limited in length...
. .... instead I used a 10 turn Linear Pre-set Potentiometer and geared it further down with spur gear.

I designed It using "Blender" ... sticking to a general 0.2mm for clearances so everything slotted glove-like together.
IMG_1049.png


Printing took a 2 hours, plus 2 more for tweaking .

Eco_Friendly Note :- When my print is under-way I place heat insulating foam around the print piece ...
..this stops the cooling fan dropping the temperature of the Heat-Platform unnecessarily, conserving Watts.
.. It also reflects heat back into the Heat-Platform and helps maintain a stable base heat.
IMG_1037.png
IMG_1039.png


Close-up of the Feedback pot .... its the key to the miniturisation . I have left circa 5mm room for adjustments.
IMG_1036.png


I am pleased with the design (although I plan a few upgrades to add extra performance)
IMG_1048.png


I have wired up the system and after a test run I am pleased with how precise the feedback potentiometer is. YAY

Assembly Walkthrough :-
[video=youtube_share;0WFP2zGRc9E]
IMG_1036.png
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IMG_1037.png
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IMG_1039.png
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IMG_1048.png
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IMG_1049.png
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Comments

  • Bill HenningBill Henning Posts: 6,445
    edited 2014-03-29 14:37
    Looks great!

    Nice work.
  • macrobeakmacrobeak Posts: 354
    edited 2014-03-30 05:55
    Yes Gareth, I must congratulate you on some good design and engineering here. 3D printers are often underutilised, but in this case you have really used it to capacity. Well done
  • mindrobotsmindrobots Posts: 6,506
    edited 2014-03-30 07:49
    Very clever! Your threads and gears look like they really turned out well.

    At first I read this as the "Low Cost ERCORobo Series" but ECO works too!! :lol:
  • ercoerco Posts: 20,256
    edited 2014-03-31 23:55
    mindrobots wrote: »
    At first I read this as the "Low Cost ERCORobo Series" but ECO works too!! :lol:

    No, Gareth has long surpassed me with his robotic prolificity and he can name his manifold creations as he sees fit.

    Well done AGAIN, Brother Gareth. Do you ever sleep? :)
  • GarethGareth Posts: 278
    edited 2014-04-01 06:33
    macrobeak wrote: »
    3D printers are often underutilised....
    Tnx ... much appreciated....
    Indeed this is so.... there are many things to be be designed out there.....it only needs a "tad" extra effort..... (ie not to get stuck in the .... lets print me a new printer that will print me a new printer loop ...which is often the case).
  • GarethGareth Posts: 278
    edited 2014-04-01 06:34
    Bill Henning wrote: »
    Looks great!...
    tnx.... it even works....YAY...
  • GarethGareth Posts: 278
    edited 2014-04-01 06:43
    mindrobots wrote: »
    "ERCORobo Series" ....
    Hmmm could be a whole new line there.... better patent the name before some well know appreciated celebrity "takes the biscuit"...

    The design was my first go at combining many things together in one part....the centre screw bit has four parts .... and was a "Pig" to knit the interfaced layers (gears) together ....
  • GarethGareth Posts: 278
    edited 2014-04-01 06:58
    erco wrote: »
    No,.....sleep? :)
    Welll....Sir Erco of the Round Think Tank .... I should have checked my flippant ecorobo name before unleashing (there are too many google references) ...... may have to add the extra "r" to avoid losing all the biscuits.....
    ....sleep...yes ..however the coolio designs happen unfortunately just before sleep onset.....
    regards Sir Gareth of the round table.
  • ercoerco Posts: 20,256
    edited 2014-04-01 10:47
    Such a beautiful finish on that leadscrew! Did you have much cleanup work to do?

    I know these steppers are slow, so I must assume that this is not a high speed device. Aiming a telescope, or tracking, perhaps? Gotta see some video!
  • GarethGareth Posts: 278
    edited 2014-04-01 13:53
    erco wrote: »
    Such a beautiful finish on that leadscrew! Did you have much cleanup work to do?
    I ran the 3D print with the Z axis set to 0.1mm steps and the lead-screw built flawlessly with the constant climbing overhangs to the top "40mm" ... no after shave_ing required... YAY
    Next print I will increase the infill ie much more than the 10% I used in the prototype you see...

    The Stepper chastity belt was an easy clean up .... except for these neat furry bits..... I could not resist taking a photo :-
    IMG_1045[1].jpg
    IMG_1047[1].jpg


    Specs :-
    40mm (1.5") linear motion (It uses only 25% of the feedback pot ... meaning the leadscrew could be extended to 160mm (6 and 5/16")
    Travel time 40mm = <3 minutes
    Working Torque :- 1Kg continuous (although I know this stepper will achieve 2Kgs)
    IMG_1045[1].jpg
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    IMG_1047[1].jpg
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  • NWCCTVNWCCTV Posts: 3,629
    edited 2014-04-01 20:39
    Nice work. Which 3D printer are you using?
  • ercoerco Posts: 20,256
    edited 2014-04-01 21:21
    Of course, since you are using the the pot for position feedback, you really don't even need that slow, low torque stepper motor. You could use a faster and torquier DC gearmotor driven by two SPDT relays, which would only use two I/O control lines instead of four.

    Hmmmm... maybe I'll rapid-fabricate my own linear actuator using the all-too familiar purple Hot Wheels track clamp that holds orange track to a tabletop. You know the one!
    clamp.jpg
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  • GarethGareth Posts: 278
    edited 2014-04-02 01:27
    erco wrote: »
    Hot Wheels track clamp that holds orange track to a tabletop. You know the one!
    That looks a neat clamp calling out for a new destination in life.....Yes Hot-Wheels ....the loopty_loop part needed it badly.
    As Great "Bros" think alike ..... here is what is already sitting in the background .....all bases are covered.....there is something awaiting in the shadows......
    Intheshadows.jpg
    Intheshadows.jpg
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  • ercoerco Posts: 20,256
    edited 2014-04-02 09:26
    Yes, great minds run in the same ruts. :)

    That's just the Solarbotics motor I was thinking about.
  • ajwardajward Posts: 1,130
    edited 2014-04-02 12:51
    That is pretty darned cool Gareth! Great work!

    Amanda <green with envy>
  • ercoerco Posts: 20,256
    edited 2014-04-02 13:17
    Amanda, you could use one of those on your telescope for tracking.
  • GarethGareth Posts: 278
    edited 2014-04-23 09:54
    Update :- 20140423
    Added assembly Video in main description.
    Now looking for deployment possibilities...
    Window_Example.jpg
    Window_Example.jpg
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