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Robot Chassis (refresh to update)

Discussion in 'Robotics & Mechatronics' started by William At MyBlueRoom, Nov 26, 2006.

  1. William At MyBlueRoom

    William At MyBlueRoom New Member

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    I'm going to build a small project based on the Tamiya Twin Gearbox. Refresh and the image will update.
    [​IMG]
    [​IMG]
     
    Last edited: Nov 30, 2006
  2. dknguyen

    dknguyen Well-Known Member

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    Is it a segway robot? You should give it a shot with just two wheelks.
     
  3. William At MyBlueRoom

    William At MyBlueRoom New Member

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    That would be cool but beyond the scope of a wee robot. A little more detail, where the chassis is and the PCB.
     
    Last edited: Nov 26, 2006
  4. dave

    Dave New Member

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  5. Sceadwian

    Sceadwian Banned

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    That's not really much of a chasis, it's just a board tacked onto the gearbox.
     
  6. bloody-orc

    bloody-orc New Member

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  7. William At MyBlueRoom

    William At MyBlueRoom New Member

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    Watch it grow. To keep the costs down it'll be similar to the BOEBot.
     
  8. William At MyBlueRoom

    William At MyBlueRoom New Member

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  9. bloody-orc

    bloody-orc New Member

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    if you want i can send the nonrendered thing also. it is mechanically correct and tested with cosmos motion works and all other such things so everything works 100% (to make sure servos can lift the weight, that ball fits under the roller when it squeezes, and test how much it can squeeze the ball without lifting itself up.
    PS you can find the actual bot also on http://picasaweb.google.com/rellermaa/Robotex200602
     
    Last edited: Nov 27, 2006
  10. William At MyBlueRoom

    William At MyBlueRoom New Member

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    That's a cool robot. Mine is real simple, even the power supply will be very simple to keep the costs low. The prototype fits in my hand. Too ugly at the moment so it's camera shy :)

    It uses 4xAA for all motors including servos. The CPU got an upgrade to a 18F2525 (needed the dual PWM, and 18F has a free C compiler student edition) The PIC is driven via a LM78L05 100ma regulator and a 9V NiMH and will be located on the front! I'll post the drawings soon, and maybe a photo...
     
  11. bloody-orc

    bloody-orc New Member

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    hhe... the system is fairly similar to mine... 4AA,s 9V krona, PIC and servo+DC motors. 1 H-bridge without PWM do drive the CD motors. only the pic i use is 16F88 with bootloader (picaxe 18x). sensor is one sonar module and 1 laser sensor + 2 touch sensors. nothing more. fairly simple. it just seems "complex" but it really isn't
     
  12. William At MyBlueRoom

    William At MyBlueRoom New Member

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    How do you find the 9V and AA combo?
     
  13. theinfamousbob

    theinfamousbob Member

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    I like the latest update (Nov. 29, 06)...I've used the caster you put on the front, the only thing I'd say against it is that sometimes it doesn't work as well on hard, painted surfaces. It seems to drag/skip once in a while. Perhaps I didn't have enough weight over it.

    The only other thing I'd say (although it would make the kit bigger) is to shift the drive wheels to the center of the robot. That way it'd have a zero-turning radius and make a lot of simple projects (maze bots, etc.) easier to implement, based on personal experience.
     
  14. William At MyBlueRoom

    William At MyBlueRoom New Member

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    Actually the caster is on the rear, I'm adding a 9V battery to the front.
     
  15. theinfamousbob

    theinfamousbob Member

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    Ah, ok.

    That looks really nice so far...are Sketchup models exportable?

    I'm assuming the AAs are going to be in holders, too.

    I like the huge proto area, much bigger than the BOEBot. A lot of possibility, too. As far as the second caster goes, I'd see how it runs so far, maybe make some sudden direction change/jitter programs, just to test and see if it'll fall easily. Maybe an incline test/uneven terrain test. I'm guessing that the batteries might make it just a bit easier to tip, so a second caster might be necessary.

    I can't wait to see the actual proto pics!
     
  16. William At MyBlueRoom

    William At MyBlueRoom New Member

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    The AAs will get holders, just have to draw them.

    Found some 3mm x 1mm round rare earth magnets. Seems they might be just right for squeezing in to the crown gear (in the Tamiya Twin Gearbox)
     

    Attached Files:

  17. bloody-orc

    bloody-orc New Member

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    is there a possibility you could share your 3D file with us/me. or maybe make more views than just 1 so we/I could see more details about this thing ;) seems interesting

    i don't use combo, there is a 1 4xAA pack and one 9V krona battery (kinda like yours). one driving motors and one for electronics...
     
  18. William At MyBlueRoom

    William At MyBlueRoom New Member

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    I've used the Hypercosm viewer on my page, neat stuff. Lets you get a look at the models in 3D.
     
  19. bloody-orc

    bloody-orc New Member

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    ok but send the file so i could look at it more detail ;)
     
  20. theinfamousbob

    theinfamousbob Member

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    I like the Hypercosm viewer...

    I think the battery placement and second caster were both good ideas.

    Are the leads on the hall effect sensor going to be long enough?

    I found an old Tamiya twin gearbox at my school, and a chassis with treads attached already. I'm using it with a BotBoardPlus for a rough-terrain robot. The gearbox sounds pretty bad though, even after replacing a bent axle. Oh well, hopefully it'll work.
     
  21. William At MyBlueRoom

    William At MyBlueRoom New Member

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    I'm experimenting with a simple two flat identical plate design. I'll draw the holes (a few at 5mm spacing). I think tank treds are a little hard on the twin gearbox. They should be far superior to modified servos though.

    The hall sensors have nice long leads. The will be mounted on the bottom side of the PCB. They are south sensitive only and those little 3mm x 1mm magents only have about a 4mm range, just right.
     

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