Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect
hey brett about that runaway thing,
i can often replicate a similar situation by setting all the rates on the radio to 100% and just holding on full power for about 2 seconds and it seems to keep going for another second before stopping despite taking my finger off the trigger.
i suspected it was just some signals being bigger than 2.3ms or whatever the limit was hence i reduced the servo limiters etc and i havent noticed it anymore. _________________ www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz
Thu Dec 02, 2004 5:06 pm
Big AL Experienced Roboteer
Joined: 16 Oct 2004
Posts: 436
Location: roleystone perth. WA
with the post to remotly control the shut off of you robot. i thought you would need just a drill switch atached to a remote switch should be able to take care of your power problem. that is what i was going to use on budgo to control the failsafe as well as the weapon. _________________ For West ausies interested in robotics email me at: theoneshrug@hotmail.com
OR
dragoonarie@gmail.com
best quote ever:: "Those Gas-Turbine style warehouse heaters arent illegal, and neither is remote controlling one as far as I know."
Thu Dec 02, 2004 5:34 pm
andrew
Joined: 16 Jun 2004
Posts: 3110
Location: Castle Hill, Sydney. N.S.W
i dont understand sorry. is that a switch on radio that when u push it a servo mechanically pushes a off switch or something??
if so there sone problem and thats if your bot goes outacontroll that servo wont respond from radio anyway's
if i am wrong i apologise and please correct.
thanks. _________________ Andrew Welch, Team Unconventional Robotics
Thu Dec 02, 2004 6:09 pm
ffej Experienced Roboteer
Joined: 22 Jun 2004
Posts: 595
Location: Kurrajong, NSW
quote:Originally posted by Big AL:
with the post to remotly control the shut off of you robot. i thought you would need just a drill switch atached to a remote switch should be able to take care of your power problem. that is what i was going to use on budgo to control the failsafe as well as the weapon.
Er . . . .. failsafe ? Wouldnt that just be compounding the problem ? Im guessing your planning on using a servo to control the drill switch, and servo's dont failsafe when the RX looses signal or gets a crap pulse. So although you could use it to control the power to the bot providing the radio system remains intact, theres nothing to stop the power staying on after signal loss.
BTW, if you can run your whole bot / weapon through a drill controller without blowing it up, it must have bugger all power, as im pretty sure they would either melt (or current limit on the XU1's up to a point) with little more than 20A continuous, 20X12V = 240W in, less than 140W out . . . _________________ Jeff Ferrara
fb@ffej.net
ffej.net
Thu Dec 02, 2004 6:29 pm
kkeerroo Experienced Roboteer
Joined: 17 Jun 2004
Posts: 1459
Location: Brisbane
I wonder why they don't make servos with in-built faisafes? _________________ Get Some!!!
Secretary of the Queensland Robotics Sports Club inc.
Thu Dec 02, 2004 6:34 pm
Valen Experienced Roboteer
Joined: 07 Jul 2004
Posts: 4436
Location: Sydney
kkeerroo, probbly cost an extra 30 cents
andrew
have a big switch, connected to a servo, servo has a spring return on it so that if the servo isnt recieving valid data the spring will overcome it and push the servo horn back and thus the switch. All power to the bots *drive* and weapon systems goes through that switch. reciever presumablly runs off its own pack. _________________ Mechanical engineers build weapons, civil engineers build targets
Thu Dec 02, 2004 6:50 pm
Knightrous Site Admin
Joined: 15 Jun 2004
Posts: 8511
Location: NSW
If your going to put a return spring on a servo, might as well buy a servo with metal gears then, because the Razer Team tried that on Warhead to cut the motor back if it failsafed and just kept stripping gears. They eventually bought one of those $300 digital servos with titanium gears in them.
Joined: 16 Jun 2004
Posts: 3110
Location: Castle Hill, Sydney. N.S.W
because then your up for nearly 100 buckersroonies for 3. two for each drive and 1 for weopon.
NO thanks. if it can be done cheaper than ill choose that. if u can come up with a cheaper way then i am all for it.
@Jake- good idea, costs u a servo, maybe a few 100 grams and some extra work but if it failsafes then cool. what about something similar then having your on/off switch idea also so servo hits it and kills everything. that could have been what u were implying if so sorry.
i thought u meant a on/off toggle switch dealyo.
ALso could u post or send me a wiring diagram for that switch and what bits i need etc etc. thanks.
u rock. _________________ Andrew Welch, Team Unconventional Robotics
Thu Dec 02, 2004 7:36 pm
Glen Experienced Roboteer
Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect
im personally not 100% concerned on making you get a real failsafe on the drive welch, but for all our sakes PLEASE buy a working off the shelf failsafe for the weapon. _________________ www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz
Thu Dec 02, 2004 7:50 pm
Ajax Experienced Roboteer
Joined: 17 Jun 2004
Posts: 298
Location: Sydney
It is worrying that there are some people that don't take safty seriously in this sport.
These robot (not all,) have the ability to cut, rip, break limbs..
Isn't that enough to have a failsafe that every one know's works and works well.
The one thing everyone needs to remember, is that the arena is a safe place for a robot. Out side of the arena is where the danger is.
The owner of the bot may know what they are doing, but there are others around the robot that has no idea. there is the biggest danger.
and what if something does go wrong. You need to have a safe reliable way to turn the robot off.
I would much rather spend $100 on failsafes knowing that when I want the robot to turn off it is, than having to go to hospital because the robot hit me, or even worse hit some one else _________________ It's all about the destruction.
Thu Dec 02, 2004 8:33 pm
andrew
Joined: 16 Jun 2004
Posts: 3110
Location: Castle Hill, Sydney. N.S.W
agreed there ajax and very good point and i am certainly having a failsafe on the rebuild of orbit whether it be a off the shelf or purpose made one.
The times when scraps saw blade got triggered i made sure that nobody was near it when i tested it and it got stuck or twitched and bumped the switch etc etc.
Glen u dont need a off the shelf failsafe.
I plan just one failsafing deadly that shuts off the series connection between the two batts or one wire in teh one batt. _________________ Andrew Welch, Team Unconventional Robotics
Thu Dec 02, 2004 9:31 pm
Big AL Experienced Roboteer
Joined: 16 Oct 2004
Posts: 436
Location: roleystone perth. WA
that is what i was getting at one on-off switch to disconect the battery from the robot. by using the controler to turn it on off in the arena it save people from having to go near it (pretty bloody good idea when budgo is fully operatonal) and so if you lose signal a spring mearly has to push it in to place to switch it off. _________________ For West ausies interested in robotics email me at: theoneshrug@hotmail.com
OR
dragoonarie@gmail.com
best quote ever:: "Those Gas-Turbine style warehouse heaters arent illegal, and neither is remote controlling one as far as I know."
Sat Dec 04, 2004 11:31 pm
cerberus3112
Joined: 05 Dec 2005
Posts: 497
Location: Mt Druitt,Sydney,NSW
Can anybody please repost the servo wiring diagram please preferably soon??? I dont want to go soldering anything until I have instructions and a diagram. _________________ A journey of a million miles begins with a single step followed by a hell of a lot of other steps so get walking
Thu Apr 26, 2007 1:11 pm
prong Experienced Roboteer
Joined: 19 Jun 2004
Posts: 839
Speedbump ran home made spring return failsafing.
It had a custom servo setup with large rubber bands that would return the servo's to centre. It worked fine, and I never had a problem with it, but if I was running anyhting more than an 8kg robot with no weapon I would look at building something a bit more engineered. Though it did work better than most electronic ones I have tried.
Thu Apr 26, 2007 4:33 pm
Woody
Joined: 07 Oct 2004
Posts: 202
Location: UK
Here's a selection of servo /switch based motor control options.
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