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 Organizations / Canada / rtlToronto / 15780
  Gear lash....
 
Well, it looks like in the 11th hour I'm going to have to abandon my differential drive for Project Y....there is WAY too much play in the differential gear train, which makes tracking the light with the whole bot virtually impossible... As my S.O. (...) (19 years ago, 2-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: Gear lash....
 
(...) I found with my trial adder/subtractor that the play in the gearing was just unreasonable--sure, when the 'bot travels a bit in one direction it's straight, but that initial few inches--not so much. no worries about hte AB--I didn't go with (...) (19 years ago, 2-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: Gear lash....
 
(...) Ever have one of those times where it's like "it ran outside the chassis!" then you actually install the bastard and put everything together and it stops working? Last night was one of those times. Sacha had figured out how to make the two (...) (19 years ago, 2-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: Gear lash....
 
(...) Can I ask a stupid question from a non-moving bot owner? Why do you need that much precision? The light readings are going to be pretty variable, and the robot targets and obstacles are all moving, so do you really need that much precision to (...) (19 years ago, 2-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: Gear lash....
 
In lugnet.org.ca.rtltoronto, Calum Tsang wrote: <snip> (...) I tried to make my wiring as tidy as possible--I only have 2 short wires left (without ripping apart my train layout) As well, you've seen the 'bot work on video, it's been tested numerous (...) (19 years ago, 2-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: Gear lash....
 
(...) This is the main reason I went with two light sensors--knowing that there'll be moving 'bots and such, I wanted to 'home in' using the best and easiest possible way. using the two ight sensors as a differential, you can steer right towards any (...) (19 years ago, 2-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: Gear lash....
 
(...) 'Cause in my (maybe no so) brilliant design I have a "probe" that is tied back to a touch sensor that needs to be inserted into the transfer opening. If the probe hits a wall/another bot, etc. then it will back off assuming it was a bad light (...) (19 years ago, 2-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: Gear lash....
 
(...) Are you thinking the robot could adjust its direction on the fly? In my limited experience, precision matters when the robot is close to the TO, especially if it can cover a lot of ground in the time it takes for the sensors to come back with (...) (19 years ago, 2-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: Gear lash....
 
(...) ... (...) Calum, Try turning around the wire on one of the RCXs. When connecting RCXs together this way, the polarity WILL matter. That would explain why something that seemed exactly the same would work outside the robot, but not when it's (...) (19 years ago, 2-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: Gear lash....
 
In lugnet.org.ca.rtltoronto, Wayne Young wrote: <snip> (...) Yeah, castors are harsh. I tried a nice little 2 wheeled beast with castors, thinking that I'd save room in the 'bot, but the castors threw the 'bot off so much, especially right after a (...) (19 years ago, 2-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: Gear lash....
 
(...) Hey Steve, Thanks-- I guess I should have clarified--it's the inter brick communication via IR that's not working. The touches were placed the same way on the test brick, and the "master" brick portion is running fine. The master has all the (...) (19 years ago, 2-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: Gear lash....
 
(...) But if you are "close" to the TO...then your precision usually is higher anyways--less movement, less slop? Here's some made up numbers to illustrate what I don't understand... If I read at time 0 at 30 degrees, a "contact". By the time I come (...) (19 years ago, 2-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: Gear lash....
 
(...) Hear hear on that. Castors are evil. If you rotate and get lined up then drive forward, the castors will twist just enough to pull you off line. ...that could be contributing to the drunken lurching effect... I might have to try 4 wheel skid (...) (19 years ago, 2-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: Gear lash....
 
In lugnet.org.ca.rtltoronto, Calum Tsang wrote: <snip> (...) <snip> Seriously, my code for scanning is as simple as it gets-- NQC'd-- task scanner_task() { while(true) { if (found_light == 1) //found light source--keep scanner on light source { (...) (19 years ago, 2-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: Gear lash....
 
In lugnet.org.ca.rtltoronto, David Koudys wrote: <snip> Forgot to mention where my issues are where the coding's concerned-- I wanted the setup routine to take care of, well, just about everyting--I didn't wnat to hard-code values into the 'bot but (...) (19 years ago, 2-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: Gear lash....
 
Thanks for sharing your source, Dave! I don't know about anyone else, but reading that added to my design and programming knowledge. (19 years ago, 2-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: Gear lash....
 
(...) But suppose at time 20 your robot is pointed at between 10 and 30 degrees due to the steering defect. Then it has lost even more ground to the moving target. (...) Your thinking is probably correct if the robot can sample the light reasonably (...) (19 years ago, 2-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: Gear lash....
 
(...) One reason the sampling time can be high is a misguided attempt to "smooth" the times. I tried averaging out the last five values in a shift register and found it really slowed the thing down (my samples got really "steppy"). I switched to (...) (19 years ago, 3-Mar-06, to lugnet.org.ca.rtltoronto, FTX)
 
  Re: Gear lash....
 
(...) If I may comment on the castor issue. 1. Never put rubber tires on casters. 2. Use that funny boat hull piece as a caster whenever possible 3. Never put rubber tires on casters. The hole issue with casters messing up your direction control (...) (19 years ago, 3-Mar-06, to lugnet.org.ca.rtltoronto, FTX)
 
  Re: Gear lash....
 
(...) No, that made a lot of sense. I get it. I looked at Dave's code--that helped too. (...) I've never used them. I don't really know why one would. I've always used those little 2x2 round pads. I've got a couple worn down by a millimeter which is (...) (19 years ago, 3-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: Gear lash....
 
(...) Trying running a robot around the house, with quarter-inch steps between hardwood and rug. Sometimes, castors are a neccessary evil. Besides the "no rubber, minimize friction", there's also the idea of minimizing castor steer by offsetting the (...) (19 years ago, 3-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: Gear lash.... & casters
 
(...) I've been reading this, trying to figure out what you guys are complaining about. I use casters all the time. Often I'll change the caster design to adjust how the robot acts. The caster Rob used here is a problem because the (...) (19 years ago, 3-Mar-06, to lugnet.org.ca.rtltoronto, FTX)
 
  Re: Gear lash....
 
(...) Well, in the context of rtlToronto games... :) I guess it makes sense in the house, I suppose. Couldn't you just build curved shape out of slopes? (...) Yes! What if Lego made duct tape? Wouldn't be up to 3AM working on my robot... Calum (19 years ago, 3-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: Gear lash.... & casters
 
In lugnet.org.ca.rtltoronto, Steve Hassenplug wrote: <snip> (...) Steve!! Good hearing from you. I owe you a hug--coming up for this competition? Dave K (19 years ago, 3-Mar-06, to lugnet.org.ca.rtltoronto)
 
  results...
 
(...) No. For some reason, it just never captured my interest. Here's what I expect: Your two-part robot will do the best. It will have a big advantage for receiving blocks, because few people have done testing where the receiving robot is moving. (...) (19 years ago, 3-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: results...
 
(...) we can hope--the software checking last night--not so good... (...) I can't receive a block from calum... however, I did make the shell motorized, so maybe I'll jsut drive around randomly... (...) You know Chris so well.... (...) Oh there'll (...) (19 years ago, 3-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: results...
 
(...) This game didn't really capture my interest but I'm honestly been turned in the past two weeks. (...) Here's hoping. My greatest fear is how reliable the firing and turning mechanism will be. (...) All jokes aside, that's usually how Chris (...) (19 years ago, 3-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: results...
 
In lugnet.org.ca.rtltoronto, Calum Tsang wrote: <snip> (...) And I think that this competition, being a co-operative one instead of being pitted against one another is the most unique aspect of this game--the more our 'bots co-operate, the better (...) (19 years ago, 3-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: Gear lash.... & casters
 
(...) Thanks for the feedback, Steve. I did try one wheel, but found that the bot would either track sideways (if the L&R were on the same side) or drag (if both to the inside/outside). I think the problem in this case was way too much weight on the (...) (19 years ago, 3-Mar-06, to lugnet.org.ca.rtltoronto, FTX)
 
  Re: results...
 
(...) Turned? Or turned on???? ;) ROSCO (19 years ago, 3-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: results...
 
(...) and your point is? dont you need to figure out who sent you a GPS unit or something ? Chris (19 years ago, 4-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: results...
 
(...) OK GROUP VOTE!! do i punch him NOW or after the event? you can email your vote to me in utmost secrecy Chris (19 years ago, 4-Mar-06, to lugnet.org.ca.rtltoronto)
 
  Re: results...
 
(...) "one brick....one marble", now, thats harsh... We all know that even a broken clock is right TWICE a day. SO he should be able to strive for TWO, at least :) -Rob (not one to talk) A> (19 years ago, 6-Mar-06, to lugnet.org.ca.rtltoronto)

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