Wild Thumper 6WD Chassis - Black (34:1 gear ratio)

Comments

• Bill Henning Posts: 6,445

  2016-10-05 16:23 edited 2016-10-05 16:24

  I have one of these chassis, and it is a very nice bit of kit... I hope to turn it into a nice robot this winter.
  
  Note the motor stall current ... you need a very beefy h-bridge or ESC to drive it.
  
  Parallax's HB-25 would be a good choice, even if you needed six of them.
• VonSzarvas Posts: 3,594

  2016-10-05 16:58

  That does look like a great platform! I'm envious!
  
  Parallax's DHB10 would also be a contender, and should handle a pair of wheels. The Thumper specs call for 2x stall current, ie.
  14 Amp per channel surge. I've had the DHB10 supporting more than that at continuous when doing load testing on a 12V supply.
  
  You could daisy chain the DHB10's, which each have a prop1 on board with maybe 6 cogs free for user code! No need for extra uc! As I recall, you can plug a standard rx receiver straight onto the dhb10 headers too. Just check the +ve level fits what you need.
• VonSzarvas Posts: 3,594

  2016-10-05 16:59

  Oh, and when you do this...
  PLEASE post photos and news
  ... would be great to see this project!
• George Sutton Posts: 180

  2016-10-06 00:43

  I have a 6WD WT... planning to use the older Propeller Activity Board to control it, so I can not yet actually provide info about using the P1 as a controller. But Parallax used to sell the 6WD WT and outfitted it with a P1 in the form of a Propeller Project Board and two HB-25 motor controllers, one for each side, providing for skid-steer (differential) steering by three motors at a time (Left vs. Right essentially). The HB-25 is very well-made and quite capable for the Wild Thumper setup.
• scandoslav Posts: 11

  2016-10-06 00:44 edited 2016-10-06 00:44

  Bill Henning wrote: »

  I have one of these chassis, and it is a very nice bit of kit... I hope to turn it into a nice robot this winter.
  
  Note the motor stall current ... you need a very beefy h-bridge or ESC to drive it.
  
  Parallax's HB-25 would be a good choice, even if you needed six of them.

  
  Dunno about needing six of them, as per Sparkfun's description:

  Each of the six motors are mounted on independent suspension and outfitted with 34:1 steel gearboxes (no more stripped gears!). The motors are wired together on a terminal strip inside the 2mm thick anodized metal frame and can be controlled on two channels (left and right).

  
  Is the 5.5A maximum stall current per motor, per channel, or sum total? I assume it's per motor. It's too bad you can't use brushless ESCs on brushed motors, otherwise two xRotor ESCs would be able to handle the current easily.
  
  Two hobby RC truck/crawler ESCs should be more than adequate; the one I chose, for instance, claims* it'll do 60A continuous / 360A peak.
  
  *(I have my doubts)
• Bill Henning Posts: 6,445

  2016-10-06 01:53

  VonSzarvas:
  
  I will post pics once I start the build...
  
  George Sutton:
  
  I'll use my RoboPi controller, and you are right, looks like two HB25's might be enough!
  
  scandoslav:
  
  Looks like six of them just might be overkill
  
  I've already ordered some crawler ESC's to try, and I share your doubts about the specs.
  
  
• erco Posts: 20,261

  2016-10-06 17:25

  If anyone is in the market for a Wild Thumper, Andy has one he may be selling for health reasons. So no lowballing.
  
  http://forums.parallax.com/discussion/165177/have-to-give-it-up-for-a-while#latest
• NWCCTV Posts: 3,629

  2016-10-08 15:44

  Thanks erco. However, unless I get close to what I paid that is one I think I will keep.
  
  I bought mine direct from Parallax. It uses 2 Ea. HB-25's. One for each side and it works great.