Society of Robots - Robot Forum

Mechanics and Construction => Mechanics and Construction => Topic started by: Spiffyguy on March 20, 2008, 05:35:28 PM

Title: $50 robot design
Post by: Spiffyguy on March 20, 2008, 05:35:28 PM
I wanted to get some opinions on my design before I start putting it together.  Experience is always the best voice.  Basiclly I am doing a revered trike.  Battery is underslung green board on top will be my electronics.  I a have not started that part yet.  The rear caster has me a bit worried, mainly because it is cheap and may lock up.  Will not really know until I try it though.  And I had them so no cost there.  I plan on putting the photoresitors in some sort of case and then mount them.  Maybe a ball point pen case?  Something along those lines.  What sort of angle do they need to be at?  I figure it is trial and error but a place to start would help.  Anyway if you see anything blatantly wrong please let me know.  I plan on starting construction next week.  Oh do I need to use a breadboard to zero out the servos or can that be done once all the electronics are completed?

Thanks

Front
(http://spiffyguy.com/images/robotics/images/slides/chassis_front.jpg)

Side.  the caster does rotate.  I am just not that good at sketchup yet
(http://spiffyguy.com/images/robotics/images/slides/chassis_side.jpg)

bottom
(http://spiffyguy.com/images/robotics/images/slides/chassis_bottom.jpg)

(http://spiffyguy.com/images/robotics/images/slides/chassis_angle.jpg)
Title: Re: $50 robot design
Post by: airman00 on March 20, 2008, 09:36:28 PM
angle of the photoresistors doesn't really matter , just make sure they are pointing slightly upwards to see light from above


to modify the servos you need to give them a pulse to "zero" or center them

You could center the servos after the circuit board is made ,you just need to change the code on the microcontroller
Title: Re: $50 robot design
Post by: Spiffyguy on March 20, 2008, 09:53:24 PM
ok cool.  I figure eventually I will a sharp IR or something else on the front end.  I will work on the circuit and get that done first.  Then center up the servos.  So the chassis looks ok though?
Title: Re: $50 robot design
Post by: airman00 on March 20, 2008, 09:55:45 PM
chassis looks good

is everything done to scale?
http://www.societyofrobots.com/member_tutorials/node/70
Title: Re: $50 robot design
Post by: Spiffyguy on March 20, 2008, 10:03:13 PM
yeah everything is pretty close.  I think the back wheel will need a spacer or two to keep the deck level with the front tires.  Kinda hard to tell with sketch up.  I wish it had a 3 pane view like some other modeling programs I have used.  But I got out my ruler and measured everything.  Deck is 4" wide and 8" long.
Title: Re: $50 robot design
Post by: airman00 on March 20, 2008, 10:05:37 PM
if you really want a 3 pane view then save it as a .dwg file from sketchup

and use a free DWG viewer to open it up. Vola , 3 views
Title: Re: $50 robot design
Post by: Spiffyguy on March 21, 2008, 08:38:03 AM
I may just have to do that.  just to get a figure on how far the back wheel is off the ground.  Sketch is not that bad to use.  I still have trouble with the move tool, getting it to go the right way.  which is why a 3 panel view would be cool.  Maybe they will add it one day.