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Parallax's 12V Modular Wheel and Motor Mounts - Feedback Requested! - Page 15 — Parallax Forums

Parallax's 12V Modular Wheel and Motor Mounts - Feedback Requested!

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Comments

  • WhitWhit Posts: 4,191
    edited 2009-01-26 21:12
    @TCIII - Sounds like your making some good progress. No Smoke is always good. Good luck with phase II of the testing and your code. I downloaded your code to study and see if I understand it.

    Sounds like you need a conditoned work space! By the way, it has been cold here too. I spent the weeked at camp with 50 teenagers. Even they got cold!

    @erco - sorry to hear you are suffering so...

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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) : 1/26/2009 11:59:17 PM GMT
  • Tom CTom C Posts: 461
    edited 2009-01-26 23:08
    Whit,

    I leveraged a fair amount off of Steve Norris' Spin code, but the speed and distance input code and conversion from an ASCII string input to a long variable is my own.

    Somebody with more Spin code experience than me can probably improve upon the ASCII string input to long variable and I hope that they do so I can improve on my Spin coding.

    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!
  • Tom CTom C Posts: 461
    edited 2009-01-26 23:21
    erco,

    Nice to see that you are taking an interest in bigger robots. You can see some of my bigger robotic rovers on the following Lynxmotion threads:

    http://www.lynxmotion.net/phpbb/viewtopic.php?p=38251&highlight=tciii#38251

    http://www.lynxmotion.net/phpbb/viewtopic.php?p=35682#35682

    The two robotic rovers in the threads above are intended for outdoor use while the robot I have shown pictures of in this thread is intended for indoor use. The dimensions for this robot are the same as the Hero 2000.

    I have built a base for a·torso and have constructed a gripper arm with 3 DOF for the indoor robot in this thread. The gripper arm sholder·can apply·approximately 20ft-lbs of torque. I will provide some pictures next weekend when I have the gripper arm attached to the·torso base. The torso is motorized and can swing +/- 90 degress from the center line of the robot base. I plan to add a small turret to the top of the torso that will contain a camera, TSA-81 thermal tracker and a Maxbotic long range ultrasonic sonar.

    If we had as much 70F+ weather here in North Texas as you have had in California, I would be much farther along with all three of my robots!

    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!

    Post Edited (Tom C) : 1/26/2009 11:34:18 PM GMT
  • SeariderSearider Posts: 290
    edited 2009-01-27 01:58
    Tom C,

    I looked at your pictures on Lynxmtion.net. Very neet work. I did not see any articulation. Am I correct that these are skid steer Bots? Meaning that the wheals will drag sideway slightly when turning. If so, has this caused any problems?

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    Searider
  • Tom CTom C Posts: 461
    edited 2009-01-27 02:57
    Searider,

    You are correct. Both of the robotic rovers on the Lynmotion Projects Forum use skid steering and not articulation for directional control. So far this has not caused any steering problems and appears to work well from my experience with both rovers.

    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!
  • robobillrobobill Posts: 12
    edited 2012-12-23 21:32
    Has anyone measured full load current draw yet? ... Thanks Bill
  • Matt GillilandMatt Gilliland Posts: 1,406
    edited 2012-12-25 16:36
    Has anyone measured full load current draw yet? ... Thanks Bill
    Hi Bill - here's the latest data we have from some internal testing:
    -MattG
  • robobillrobobill Posts: 12
    edited 2012-12-27 08:44
    Thanks Matt... Great videos
  • photomankcphotomankc Posts: 942
    edited 2012-12-27 10:33
    Is it possible to get just the motors? The other bits I can make on my own but having a heavy drive motor and encoder and not having to mix 'n match from Ebay would be nice for my planned outdoor rover.
  • robobillrobobill Posts: 12
    edited 2013-02-14 12:27
    I just mounted a motor kit on my robot... but had to retap the four 1/4-20's.... you've got a nice big chunk of aluminum with minimal tapped holes... why??? you've got room for more depth or at least have the mfr bottom tap the threads.... just sayin
  • Matt GillilandMatt Gilliland Posts: 1,406
    edited 2013-02-15 10:58
    but had to retap the four 1/4-20's.
    Hi robobill -
    Which holes are you having issues with? Could you post a pic? I think they should have been at least 1/2" deep (if it's the one's I'm thinking of.
    -MattG
  • robobillrobobill Posts: 12
    edited 2013-02-25 20:03
    I'm referring to the 4 1/4-20's two of which are shown at the bottom of page 2 of 6 of your instruction sheet. Sure its 1/2" worth of thread, and great if you have the exact lenght screw... but with all the material... heck make it 1" deep and bottom tap it.... its just a suggestion... NBD
  • Ken GraceyKen Gracey Posts: 7,365
    edited 2013-02-25 20:06
    Yep, I know what you're talking about. Those 1/4-20 mounting holes are kinda shallow, forcing the selection of a screw that is about the exact length and not an 1/8" too long. We could simply dive the drill an inch and use a bottom plug tap to give you more threads to work with.

    It's free for us, since we've already got the darned metal sandwiched in the Kurt vise. We'll follow-up on this.

    Send more comments, anytime.
  • Ken GraceyKen Gracey Posts: 7,365
    edited 2013-02-25 20:07
    photomankc wrote: »
    Is it possible to get just the motors? The other bits I can make on my own but having a heavy drive motor and encoder and not having to mix 'n match from Ebay would be nice for my planned outdoor rover.

    Of course, just drop me an e-mail and I'll take care of your request. I realize you posted that message a long time ago, but if you're still interested I'll get you the motors.
  • ajwardajward Posts: 1,118
    edited 2013-03-05 02:39
    Ken Gracey wrote: »
    Hey all, I'd like to answer some questions and maybe ask a few more.

    Tracks are in the near future. They're already designed, in fact. All you'll have to do is replace the wheel with a track sprocket, and you're all set.

    Ken·Gracey
    Parallax, Inc. ··

    {I trimmed a lot of Ken's post to focus on the track comment!} :smile:

    Wow! This thread started before I'd joined the forums.

    ANYway, are the tracks mentioned above still in the works? I do like tracked vehicles and have built a couple, but the tracks are problematic.
    I've used the Tamiya molded plastic tracks and those are okay for small, light 'bots, but when you add weight to the vehicle or add track sections for a bigger platform, you start throwing the track on turns.
    Looking for something sturdier than the Tamiya offering, I found the Vex and Lynxmotion tracks. I didn't see the Vex product as much of an improvement over Tamiya (also, green tracks seemed silly) and went with the 2 inch track from Lynxmotion.

    I got a sturdier track for sure and I got TRACTION!!!!! The Lynx' track puts so much rubber on the ground turns are darn near impossible... even running the 7.2 volt motors at 9.6 volts. I have a couple of 12 volt Pololu 131:1 motors with about 3-1/2 times the torque to try out, but haven't found time to reassemble that 'bot.
    @erco - I tried the 131:1 motors on Orville and the slower motor is =way= better.

    So yeah... I hope you're still working on some kind of track. I'd love to see what you've got!

    Amanda
  • Ken GraceyKen Gracey Posts: 7,365
    edited 2013-03-06 10:32
    ajward wrote: »
    {I trimmed a lot of Ken's post to focus on the track comment!} :smile:

    Wow! This thread started before I'd joined the forums.

    ANYway, are the tracks mentioned above still in the works? I do like tracked vehicles and have built a couple, but the tracks are problematic.
    I've used the Tamiya molded plastic tracks and those are okay for small, light 'bots, but when you add weight to the vehicle or add track sections for a bigger platform, you start throwing the track on turns.
    Looking for something sturdier than the Tamiya offering, I found the Vex and Lynxmotion tracks. I didn't see the Vex product as much of an improvement over Tamiya (also, green tracks seemed silly) and went with the 2 inch track from Lynxmotion.

    I got a sturdier track for sure and I got TRACTION!!!!! The Lynx' track puts so much rubber on the ground turns are darn near impossible... even running the 7.2 volt motors at 9.6 volts. I have a couple of 12 volt Pololu 131:1 motors with about 3-1/2 times the torque to try out, but haven't found time to reassemble that 'bot.
    @erco - I tried the 131:1 motors on Orville and the slower motor is =way= better.

    So yeah... I hope you're still working on some kind of track. I'd love to see what you've got!

    Amanda

    Hey Amanda,

    The update isn't very promising. Although we're working with a great design, I don't think it's cost-effective to deliver the tracks we've considered (an aluminum extrusion system).

    Tracks are a challenging system to deliver. First, there's an expectation from the user that they're going to be more capable than all wheeled systems. Tracks get very dirty if used outside, and sprockets must be self-clearing. Friction is high and break-free torque is required, making a real tradeoff in speed/power. Bottom line is that if we provide tracks, it'd have to be on a complete robot where everything has been designed: chassis, idler wheel location, track style, etc.

    Right now, we're in a holding pattern.
  • ercoerco Posts: 20,160
    edited 2013-03-06 10:58
    Amanda: Keep this on the QT, whatever you do, don't post about it in the forum.

    I'm working on tracks made from cable carrier. Cheap and plentiful in numerous sizes: http://www.ebay.com/itm/Cable-drag-chain-wire-carrier-10-10mm-R18-1000mm-40-/261172228907?pt=LH_DefaultDomain_0&hash=item3ccf13f32b

    We're RPing some sprockets to try. Now these "treads" are slick nylon, not rubber. Not much traction. Prolly not ideal for all situations, but likely good for some.

    Remember, this is our little secret, that's why I'm PMing you only.

    Edit: oops...
  • Ken GraceyKen Gracey Posts: 7,365
    edited 2013-03-06 11:31
    erco wrote: »
    Amanda: Keep this on the QT, whatever you do, don't post about it in the forum.

    I'm working on tracks made from cable carrier.

    Edit: oops...

    erco/ajward, maybe you could also look at food conveyance plastic belting. This material has sprockets and drive systems to accompany the "track".
  • W9GFOW9GFO Posts: 4,007
    edited 2013-03-06 11:57
    I have a box full of stainless steel conveyer track. It was used in the Red Hook brewery for transporting kegs. I think I have over a dozen or so feet of it - enough for a tracked vehicle. Each segment is about 7" x 2".

    I can bring it to UPEW OPC if anyone is interested - and if I attend this year.
  • Matt GillilandMatt Gilliland Posts: 1,406
    edited 2013-03-06 13:51
    food conveyance plastic belting. This material has sprockets and drive systems to accompany the "track".
    In one of my former lives, I designed and built some food conveyor systems - the ones I used to use seem like they'd be perfect - especially with attached cleats.

    great. another project with no time allocation...
    -MattG
  • JasonDorieJasonDorie Posts: 1,930
    edited 2013-03-06 14:26
    Erco / AJ - I'm not sure what size you're looking at, but this is an option too: http://letsmakerobots.com/node/30942

    This guy is using a pair of tracks from small snowmobiles, with custom sprockets cut from delrin. Those would be expensive, but if they were made of HDPE they'd be just as smooth, but much cheaper. Snowblower tracks work well too.

    Also, these look pretty cool:
    http://letsmakerobots.com/node/21908
    http://www.instructables.com/id/How-to-make-custom-and-strong-tank-tracks-for-very/

    And these would be way too big, but the method they use to build them could easily be scaled down to use bicycle tire tubes as the belts, and something else as the treads.
    http://www.youtube.com/watch?v=zrWx8yxtsWo#!
  • Roy ElthamRoy Eltham Posts: 2,995
    edited 2013-03-08 13:00
    Rich,
    I hope you go to OPC, we might even end up being a convoy! :D

    Why have I been in Bellevue for over 6 months and we haven't met up?

    Ken,
    I would love a good solid tracked bot solution made by Parallax. Something a bit larger like in the Eddie/Madeusa catagory I think would be best.
  • W9GFOW9GFO Posts: 4,007
    edited 2013-03-08 13:25
    Roy Eltham wrote: »
    Rich,
    I hope you go to OPC, we might even end up being a convoy! :D

    Why have I been in Bellevue for over 6 months and we haven't met up?

    I didn't think you were around here anymore since your "location" switched from Bellevue back to SanDiego. Been to SRND yet?
  • Roy ElthamRoy Eltham Posts: 2,995
    edited 2013-03-08 16:01
    W9GFO wrote: »
    I didn't think you were around here anymore since your "location" switched from Bellevue back to SanDiego. Been to SRND yet?
    I don't think I ever changed my location on the forums here, oops. Fixed now.
    What's SRND? (google is not giving me anything that seems right)
  • ajwardajward Posts: 1,118
    edited 2013-03-09 14:24
    W9GFO wrote: »
    I have a box full of stainless steel conveyer track. It was used in the Red Hook brewery for transporting kegs. I think I have over a dozen or so feet of it - enough for a tracked vehicle. Each segment is about 7" x 2".

    I can bring it to UPEW OPC if anyone is interested - and if I attend this year.

    Any chance you could put up a picture of a section? :-)

    @
  • ajwardajward Posts: 1,118
    edited 2013-03-09 14:32
    Ken Gracey wrote: »
    Hey Amanda,

    *Snip*

    Bottom line is that if we provide tracks, it'd have to be on a complete robot where everything has been designed: chassis, idler wheel location, track style, etc.

    Right now, we're in a holding pattern.

    Well, a complete, tracked 'bot is way out of the ballpark financially. I have 'decent' tracks, but need a set of "stump puller" motors to drive them.
    The current plan is to add a half section of Lynx' tracks per side and adapt a set of r/c car wheels to function as road wheels. This will reduce the footprint (ground friction) and improve the obstacle climbing ability.

    I'm digging out the old Ted 3 chassis to test the 131:1 motors this weekend.

    @
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