gametechmods

Off-Topic => Real Robotics => Real Robotics Discussion => Topic started by: Somebody on March 31, 2012, 09:40:00 PM

Title: Somebody's Senior Project
Post by: Somebody on March 31, 2012, 09:40:00 PM
Well I present on April 11th, so I figure its about time to start.

I am planning to CAD a 30 lb robot for my senior project. Doesn't have to be super beautiful and doesn't have to be amazingly accurate, because I'm pretty much the only kid who knows a damn thing about robots in my school AFAIK, and there is only gonna be a few people at the presentation anyways.

My plan is a 30lb robot with an eggbeater weapon. Haven't decided much after that, but thats not too important. I need to basically know what parts are the best to use in this, and a place I can get a sheet metal quote and the eggbeater weapon.

FYI, the project is to make a CAD Robot and to do some stuff about combat robotics in general, probably editing together a video of some bots (hence my earlier thread on the subject). I will be using Autodesk Inventor 2012 Student Edition (is free), which I am somewhat familiar with already.

Thanks
~Somebody
Title: Re: Somebody's Senior Project
Post by: SKBT on March 31, 2012, 10:14:03 PM
Come on and really build a robot...
Title: Re: Somebody's Senior Project
Post by: Somebody on March 31, 2012, 10:16:50 PM
I caaannnn't

No money no time. It will most likely be built someday, just not now. Or I'll go to WPI and get to play with Professor Chaos instead. They wait-listed me but there is still a chance.
Title: Re: Somebody's Senior Project
Post by: SKBT on March 31, 2012, 10:19:00 PM
I caaannnn't

No money no time. It will most likely be built someday, just not now. Or I'll go to WPI and get to play with Professor Chaos instead. They wait-listed me but there is still a chance.

uhh I'll convince one of my friends to go Drexel instead of WPI... that should free up a space for you.
Title: Re: Somebody's Senior Project
Post by: Somebody on March 31, 2012, 10:35:19 PM
Don't tell me that there is a limited space for the club... pleease you'll crush my dreams lol
Title: Re: Somebody's Senior Project
Post by: haz on April 01, 2012, 06:28:04 AM
eggbeaters are awesome
Title: Re: Somebody's Senior Project
Post by: Somebody on April 01, 2012, 11:17:27 AM
Due to my laziness I have just decided I'm going to do something simpler with no active weapons. Just need motor ideas now probably.
Title: Re: Somebody's Senior Project
Post by: R1885 on April 01, 2012, 11:19:48 AM
Dewalt power drive kits.
Title: Re: Somebody's Senior Project
Post by: SKBT on April 01, 2012, 12:07:10 PM
I was bored and made a beater (https://gametechmods.com/uploads/images/42461Beater_SKBT.png). If you want to use it feel free to ]download (https://gametechmods.com/uploads/files/Beater_SLDWORKS_SKBT.rar) it
Title: Re: Somebody's Senior Project
Post by: Somebody on April 04, 2012, 08:17:37 PM
Would you happen to know the amp draw of the dewalt motors? I need it to choose batteries and speed controllers.
Title: Re: Somebody's Senior Project
Post by: R1885 on April 04, 2012, 08:24:21 PM
With four inch wheels, a Dewalt power drive on "high" speed and at 24 volts would draw 23.5 amps, and 47 amps peak, and have a five minute Ah requirement of 2.742.
If locked in "Low" speed, the power requirements would be even less, having only about 16 amps peak.

In that case, the Victor 883 is a good option, and a simple team NightMare NiCad pack at 3 Ah would work wonders.
Title: Re: Somebody's Senior Project
Post by: Somebody on April 04, 2012, 08:31:06 PM
Now would the amp draw change at all if the motors were set on low power?

Edit: didn't notice the part in your post answering my question, thanks
Title: Re: Somebody's Senior Project
Post by: SKBT on April 04, 2012, 08:36:17 PM
a simple team NightMare NiCad pack at 3 Ah would work wonders.
who still used NICad these days...

http://www.hobbyking.com/hobbyking/store/__8582__ZIPPY_Flightmax_5000mAh_6S1P_20C_.html (http://www.hobbyking.com/hobbyking/store/__8582__ZIPPY_Flightmax_5000mAh_6S1P_20C_.html)

http://holmeshobbies.com/product.php?productid=274&cat=2&page=1 (http://holmeshobbies.com/product.php?productid=274&cat=2&page=1)

Basically Nyx's drive setup. Mike ran these in all 3 of his bots at moto. The esc's handled enough amps to desolder the motor leads on Nyx.

Also if you are budgeting parts as part of your project both of these things are cheaper.
Title: Re: Somebody's Senior Project
Post by: R1885 on April 04, 2012, 08:39:25 PM
NiCads can suffer more abuse that LiPos, and don't burst into flame when mistreated. I like NiCads more.
And to answer your question, Gary Gin's Original Sin uses NiCads.
Title: Re: Somebody's Senior Project
Post by: MikeNCR on April 05, 2012, 10:31:31 AM
while true, NiCad's are much heavier for the same power. I used a 6 cell 2650mah Turnigy Nano-Tech pack in Nyx and it worked great. As long as you don't short it and protect it well, you'll save a ton of weight vs. NiCads.

Also, the Nano-Tech's are cheap. http://www.hobbyking.com/hobbyking/store/__20756__Turnigy_nano_tech_2650mah_6S_45_90C_Lipo_Pack_USA_Warehouse_.html (http://www.hobbyking.com/hobbyking/store/__20756__Turnigy_nano_tech_2650mah_6S_45_90C_Lipo_Pack_USA_Warehouse_.html)

Also, on Nyx, I used 4" wheels in high gear with a slight chain reduction (15t on drive, 19t on wheel, 1.267:1 ratio) making it perform closer to a 3" wheel (drive speed would match a 3.16" diameter wheel directly mounted to the dewalt shaft)
Title: Re: Somebody's Senior Project
Post by: Somebody on April 07, 2012, 03:22:38 PM
I am planning a 4wd bot, because looking cool and POWERRRRR will probably help me more in the project than a real effectiveness.

I forget where you wrote it mike I think it was in the instructable for Nyx that you said that the two drive motors drew about 1300 mAh. I figured with 4 I would need 2600 and then a bit of breathing room so I chose a 3300.

http://www.hobbyking.com/hobbyking/store/__17261__Turnigy_nano_tech_3300mah_6S_45_90C_Lipo_Pack.html (http://www.hobbyking.com/hobbyking/store/__17261__Turnigy_nano_tech_3300mah_6S_45_90C_Lipo_Pack.html)

Same brand but I just wanted to verify.

Also, what does 45-90C stand for?

Edit: And also, what does 6S stand for?
Title: Re: Somebody's Senior Project
Post by: haz on April 07, 2012, 04:01:52 PM
6s is 6 cell, so 22.2v
Title: Re: Somebody's Senior Project
Post by: MikeNCR on April 07, 2012, 04:33:43 PM
This should be really handy for pulling numbers-

http://www.killerbotics.com/kbtools/TentacleTools/ (http://www.killerbotics.com/kbtools/TentacleTools/)

(drive train calculator)
Title: Re: Somebody's Senior Project
Post by: R1885 on April 07, 2012, 04:49:10 PM
Team Run Amok has a more up-to date version.
Title: Re: Somebody's Senior Project
Post by: Somebody on April 08, 2012, 12:20:12 PM
Every other part is modeled, and I was about to do the OrangeRx Receiver. I noticed that the listing for it mentioned nothing about a failsafe. Shouldn't it have one?

Edit: And does it need a receiver battery? I don't see one in Nyx.
Title: Re: Somebody's Senior Project
Post by: SKBT on April 08, 2012, 12:27:27 PM
When it looses signal it defaults to the position the transmitter's stick were at when Rx/Transmitter were bound. So as long as your sticks are "zeroed" it will failsafe correctly.
Title: Re: Somebody's Senior Project
Post by: haz on April 08, 2012, 12:31:03 PM
wheather or not it needs a rx battery depends on what escs you are using and if they have a BEC or not
Title: Re: Somebody's Senior Project
Post by: Somebody on April 08, 2012, 01:19:15 PM
The Speed controllers have a BEC, so that's all set and thanks for all your help everybody.
Title: Re: Somebody's Senior Project
Post by: Somebody on April 08, 2012, 08:11:56 PM
Oh my god.
Oh my god.
Oh my god.
Oh my god.
Oh my god.
Oh my god.
Oh my god.

I had it in the proposal and everything to build to Robogames rules, and they aren't running a 30lb class this year according to their website. 6WD LW Time?
Title: Re: Somebody's Senior Project
Post by: SKBT on April 08, 2012, 08:14:49 PM
60lb multibot... Or go NERC...