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Parallax's motor/wheel combo and track's — Parallax Forums

Parallax's motor/wheel combo and track's

Brian_BBrian_B Posts: 842
edited 2008-09-08 00:07 in Robotics
Hi,·
·I've been thinking that the motor/wheel combo should be offered with tracks or as a add-on·.Would anybody else like to see this and if so what configuration would you like to see the tracks in. I've included 3 crude drawings of different track setups; any input would be greatly appreciated.
·
Brian
·

Comments

  • DgswanerDgswaner Posts: 795
    edited 2008-08-07 03:43
    I'd love to see a track version or track addon! I really want to build a bot for outdoors.

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    "A complex design is the sign of an inferior designer." - Jamie Hyneman, Myth Buster

    DGSwaner

    Post Edited (Dgswaner) : 8/7/2008 5:59:40 PM GMT
  • WhitWhit Posts: 4,191
    edited 2008-08-07 03:43
    Brian,

    I like the three wheel versions best.

    I have attahed a rotated version of one scheme.·A scheme like this would give the tracks some slight climbing abiltiy.

    See also the mattracks configuration attached

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    Whit+


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  • Brian_BBrian_B Posts: 842
    edited 2008-08-07 04:56
    Whit,

    ·I have never seen that track setup, looks cool. Do you think that they have a patent on that layout? Here is a little project I've been working on in my "spare time". It's to big for the wheel/motor combo but it might find it's way into somthing.

    Brian


    Post Edited (Brian Beckius) : 8/7/2008 5:04:51 AM GMT
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  • SRLMSRLM Posts: 5,045
    edited 2008-08-07 08:29
    Personally I like the two wheel design. It gives more grip to the drive wheel, and it takes up less vertical space. Of course, you could always design the system to have both options, but any tracked system that can be used outdoors will get my attention. Your version looks very heavy duty. What is the scale?
  • ercoerco Posts: 20,256
    edited 2008-08-07 13:38
    Brian: BEAUTIFUL track assembly, craftsmanship, and layout. Three questions for you:

    1) Is it NC'ed or are you a master machinist?
    2) The two bottom bogie shafts ride in slots. Are they spring-loaded?
    3) Where did you get your molded rubber tread from? Sometimes that's the toughest thing to get/make.

    Keep up the great work!

    Eric

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    ·"If you build it, they will come."
  • WhitWhit Posts: 4,191
    edited 2008-08-07 15:35
    Brain,

    I do not know if the Mattrack configuration is patented. Some of us have used a toy version (avaliable on some Radio Shack toy trucks) on the Boe-Bot (do a search on the forums). Real Mattracks are fitted on trucks and other equipment. See their site here - http://www.mattracks.com/·Be sure to look at some of the videos!

    I am with erco, your track set-up looks really well made. The suspension that erco speaks of is a good feature - I think. The Mattracks on the toy have no suspension themselves but are mounted with a suspension system. This allows up and down movement and some rotation. The real Mattracks are all about suspension. You will see on the website.

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    Whit+


    "We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney

    Post Edited (Whit) : 8/7/2008 3:46:09 PM GMT
  • Brian_BBrian_B Posts: 842
    edited 2008-08-07 18:50
    SRLM said...
    Personally I like the two wheel design. It gives more grip to the drive wheel, and it takes up less vertical space. Of course, you could always design the system to have both options, but any tracked system that can be used outdoors will get my attention. Your version looks very heavy duty. What is the scale?
    · Track is 4" wide and and has 17" on the ground.

    Brian
  • Brian_BBrian_B Posts: 842
    edited 2008-08-07 18:56
    erco said...
    Brian: BEAUTIFUL track assembly, craftsmanship, and layout. Three questions for you:

    1) Is it NC'ed or are you a master machinist?
    2) The two bottom bogie shafts ride in slots. Are they spring-loaded?
    3) Where did you get your molded rubber tread from? Sometimes that's the toughest thing to get/make.

    Keep up the great work!

    Eric

    Eric,
    ·I have a CNC mill, the bottom 2 shafts are used to tighten track and are stationary once they are set. The tracks came from a most unlikely source :-), I am working on this system for another project, but I believe it could be scaled down to fit the wheel/motor combo.

    Brian
    ·
  • Brian_BBrian_B Posts: 842
    edited 2008-08-15 03:11
    ·Here is the first set of tracks that I had made to fit the motor/wheel combo , the supplier and I·are still fighting about why the drive lugs go all the way across. If you guys are interested in these you better pipe up,my wife is seeing no humor in me buying stuff that does not work :-)


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    Thank's Brian



    ·"Imagination is more important than knowledge..." ·· Albert Einstein

    www.PropelX.com








    Post Edited (Brian Beckius) : 8/15/2008 3:16:58 AM GMT
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  • SRLMSRLM Posts: 5,045
    edited 2008-08-15 05:58
    Nice. Looks like you could build some pretty heavy stuff on that. I'm a far cry from an expert on tracked vehicles, but it looks like the tracks could just slip off sideways... Please say I'm wrong!
  • Brian_BBrian_B Posts: 842
    edited 2008-08-15 11:04
    SRLM,
    Your right ,the track will slip off sidways . They where suppose to have only a 1" wide drive strip in the center ,not all the way across. I'm trying to get the supplier to remake them the right way.

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    Thank's Brian



    ·"Imagination is more important than knowledge..." ·· Albert Einstein

    www.PropelX.com
  • SRLMSRLM Posts: 5,045
    edited 2008-08-15 16:38
    Well, I was right but ultimately wrong. Yay! Should be a little bit cheaper too, without that extra material. How is the track reinforced? Are there steel cables or does it use nylon/plastic reinforcement? Also, how is the junction between ends reinforced? (or do you make it in one loop?)
  • Brian_BBrian_B Posts: 842
    edited 2008-09-04 00:08
    Okay,
    Here is V1(really v2) of the motor/wheel tracks . Tell me what you think, Please! :- )

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    Thank's Brian



    ·"Imagination is more important than knowledge..." ·· Albert Einstein

    www.PropelX.com








    Post Edited (Brian Beckius) : 9/4/2008 3:43:33 AM GMT
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  • Tom CTom C Posts: 461
    edited 2008-09-04 00:39
    Brian,

    Nice work, but the drive sprocket is too narrow and concentrates the vehicle load only in the center of the tread width. In other words your design is not making use of the full load bearing capability of the tread width.

    Hope this helps.

    Regards,
    TCIII

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    If you are going to send·a Robot·to save the world, you·better make sure it likes it the way it is!
  • Brian_BBrian_B Posts: 842
    edited 2008-09-04 01:02
    Thanks' for the input Tom,
    The little drive was going to be used for the top wheel on a triangle drive, the wheel/motor would sit to low to the ground with that small of drive. I was thinking of doing a just a straight track and that would make the drive wheel adout 5" in daimeter(and wider) the wheels would be about 7 inches center to center. That would work good for a 2 motor crawler type robot with skid steer. This is really up to you guys what you would like to see ,the cheaper way will be to go with the straight crawler,the most expensive would be the mattrack's design.

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    Thank's Brian



    ·"Imagination is more important than knowledge..." ·· Albert Einstein

    www.PropelX.com
  • DJSandbergDJSandberg Posts: 56
    edited 2008-09-08 00:07
    Brian,

    Great design. I didn't realize when I first looked at the picture that the drive lugs are separate. Great way to keep costs down and add flexibility.

    I have a tracked robot and one of the difficulties is turning. With 17 inches on the ground, that's going to take a lot of force to turn the robot and that same force tries to rip the track off the wheels. I used a Delrin guide on the bottom to reduce the surface contact on flat surfaces.·· I hasn't reduced the ability of the robot to climb or move.
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    Yikes, not sure what happened there.· Must have leaned on the return key?

    Daryl

    Post Edited (DJSandberg) : 9/8/2008 12:13:07 AM GMT
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