Author Topic: Del Mar Bot Depot  (Read 10620 times)

daggius

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Del Mar Bot Depot
« on: July 05, 2016, 02:40:35 pm »
Sup guys, my name is Gordon.  I live in San Diego.  I love playing soccer but after tearing my acl I decided to get into bots.  I just got a 3d printer and am ready to bring it.  I hope there are some more competitions in Socal-- if you host anything in Los Angeles or South of there I will be there.  Just be real and post it on buildersdb so we can actually find it!  I am a big fan of the original battlebots from comedy central when I was a teenager.  I'm hoping to build a competitive beetle and fairy for RG 2017.  Here are my bots

Youtube:
https://www.youtube.com/channel/UC5in8z6mDp73iezc98zA2eg

Flex 2.0 (2-4)
clamper with increased lifting height and self righting
2018-present

Raise the Roof (9-7)
scissor lifter + wedge beetle
2017-present
Tournaments: 2nd place @ Seattle Bot Battles 15 (June 2017)

Flex (19-18)

2015-retired 6-18-2017; clamping lifting antweight
Awesome features: 1/4" ABS welded chassis (not printed).  UHMW wheel guards.  titanium back shield and front wedge.  new Nylon printed arm.  uses 4 bar linkage to clamp and lift with the same servo. 
Massive design flaws: vertical spinners destroy me and everyone is that
Tournaments: 2nd Socal MC 2015, 2nd RG 2016, 3rd @ DUTS 2016, Lifetime rumbles survived: 4

Particle accelerator (1-2)
2016-2016 (retired?? probably); fairyweight bar spinner
Awesome features:  my second 3d printed fairyweight but had some major design issues that require a total redesign
Massive design flaws: bar was too high and magnets too weak and weapon motor too weak and too long to spin up

Mr. Printybot (0-3)

2016-2016 (retired); fairyweight wedge
Awesome features:  really fast.  super compact. nylon 3d printed body with polycarbonate lid.  side charging plug and power switch. invertable.  3d printed wheel hubs.
Massive design flaws: not enough traction or torque.  too fast to control
Decided to retire this bad boy to necro parts for a better fairyweight.

Come at me Bro (2-2)

2012-2012(retired); antweight full body spinner
Awesome features: 4wd using 2 motors and lego gear/shafts drivetrain.  All lego chassis epoxied together for strength.  Shell is an aluminum frying pan hollowed out for weight reduction (with a file and hacksaw).  Direct driven shell with 3 oz brushed motor.
Massive design flaws: lego gears too fragile for impacts and shell deforms when you hit something hard.
« Last Edit: August 01, 2018, 01:18:15 pm by daggius »

tomchaps

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Re: Flex n Friends
« Reply #1 on: July 05, 2016, 07:26:39 pm »
My son and I are building our first antweight, and have been loosely modelling it after Flex. We've been freeze-framing stills from Robogames to try and figure out the dimensions of the clamp/lifter, (since I can't figure out how to get that four-bar lifter calculator to work for this...) So thanks for the images! If you don't mind my asking--what size/torque servo are you using? And is that hinge a rod of UHMW PE?

Thanks--it's my son's favorite ant...

daggius

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Re: Flex n Friends
« Reply #2 on: July 05, 2016, 07:40:00 pm »
hey tom,

this is the servo i use 

https://www.amazon.com/gp/product/B00URCJ6L0/ref=od_aui_detailpages00?ie=UTF8&psc=1

yes there is a rod of UHMW that just rides in some holes in the ABS chassis and it hasnt broken yet so its working pretty decent

i couldnt figure out the linkage program myself so i just tried messing around with legos, if you have some of these parts it is handy to figure out what lengths you want for the linkages


tomchaps

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Re: Flex n Friends
« Reply #3 on: July 07, 2016, 07:50:54 pm »
I've been trying my hand at CAD for the first time, and I'm actually hoping I can get Inventor to model the four-bar motion for me...

It looks like the bot is roughly 1" high? I've been having trouble figuring out how to get that big servo to fit!

How did you machine the nutstrip-like back to the lifter--it's a great shape, but I despair of being able to cut that out of UHMW PE.

Thanks again...

daggius

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Re: Flex n Friends
« Reply #4 on: July 07, 2016, 08:35:53 pm »
the nutstrip thing i made on the mill and the drill press.  the original one was abs (can see this in my cad pic at top) and i made in multiple parts then melted them together, but it was drum fodder. 

the battery or servo will be the thickest things in there so you can make it pretty slim, mine is 7/8".  the servo is not really exposed so you dont even need a floor or lid over it if you want to make it even thinner. for example, shazbot had his completely exposed


since most antweights are drums or vertical spinners i really recommend to try to design something more plow like on the front (also like shazbot has) too since it will get pummeled by drums.  mine has a 90 degree angle between the nutstrip thing and the wedge which is pretty horrible in that regard.  if you had some sort of curved sheet metal plow, but also the clamping arm coming down from above, that would probably be the best of both worlds

post pics of your progress!
« Last Edit: July 07, 2016, 08:44:57 pm by daggius »

Infernaltank

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Re: Flex n Friends
« Reply #5 on: July 07, 2016, 09:52:29 pm »
I was very impressed by Flex from the videos I saw of Robogames. It was really good at getting quick KOs.

tomchaps

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Re: Flex n Friends
« Reply #6 on: July 11, 2016, 01:27:02 pm »
Yeah, that's one of the reasons we're hoping to base ours off it!

daggius

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Re: Flex n Friends
« Reply #7 on: August 30, 2016, 11:39:44 am »
At Robogames Flex did really well but in the semifinals Pizza Slicer broke Flex's aluminum arm in half (pic below) with a great hit and then in the final The Bomb bent Flex's titanium wedge pretty bad and broke the servo.



So I decided to 3d print some nylon replacement parts including a trilobyte-style front bumper.  My thought behind using nylon instead of metal is that although the material is weaker, it is more flexible for absorbing impacts as well as it will break into small pieces when hit so it is kind of like ablative armor.  Here is the bot with the new arm and front wedge.



I took the bot to Destruction Under the Stars, an insect event in Pomona last weekend.  Great turnout with 18 antweights, no entry fee, and way more competitive bots than at RG this year.  The printed parts worked really well as far as absorbing impacts and protecting the bot from being hit really high in the air or breaking internals.  However it was still a brutal competition and with no pushouts my bot was basically getting a full 3 minutes of being totally shredded by spinners and trying to win a judge's decision.  And the new parts didn't exactly survive either. Damage pic:



The aluminum bar has never been dinged up like that before and also the UHMW side skids got totally twisted.  I also forgot to put the soft jaws on my grabber so I didn't really get any good lifts during the whole tournament.  But defensively the bot held up and kept battling the whole tournament, winning 4 matches plus a forfeit win and losing 2 to get 3rd place overall. So it was a good experiment and hopefully I can keep developing the front lifter a little more to be both defensive but still get some lifts.
« Last Edit: August 30, 2016, 04:59:09 pm by daggius »

VBT_Robotics

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Re: Flex n Friends
« Reply #8 on: August 30, 2016, 03:13:45 pm »
Hi, can you explain the welded ABS your using and why it would be better than 3d printed nylon?
Also I can't see the pictures in your latest post. edit: I can see them now, thanks!

Thanks

-Tom
« Last Edit: August 30, 2016, 06:18:12 pm by VBT_Robotics »

daggius

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Re: Flex n Friends
« Reply #9 on: August 30, 2016, 05:05:48 pm »
Thanks, I fixed the pictures I think.

I made the welded ABS about 2 years ago before I had a 3d printer so that's why I chose that.  nylon would do just fine
« Last Edit: August 30, 2016, 05:10:34 pm by daggius »

daggius

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Re: Flex n Friends
« Reply #10 on: August 31, 2016, 02:26:28 pm »
here's footage of flex's best battle (vs little overload, a vertical disk bot)

https://www.youtube.com/watch?v=Ixu0MKY52Rg

tomchaps

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Re: Flex n Friends
« Reply #11 on: September 06, 2016, 03:27:19 pm »
What do you use for the "soft jaws" for the grabber? Are you allowed to make it a bit tacky?

daggius

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Re: Flex n Friends
« Reply #12 on: September 08, 2016, 05:39:14 pm »
adhesive backed foam

daggius

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Re: Flex n Friends
« Reply #13 on: November 28, 2016, 05:45:36 pm »
Quick update, i went to socal maker con, another quality event in pomona.  I took apart my old fairyweight and built a new one that is a horizontal spinner.  it has magnets on bottom and a big spinning bar but in the end it was underpowered due to small motor and went 1-2.  I need to redesign this.  wasn't happy how it turned out

Flex worked really well and clamped and lifted many bots but only went 3-2 and lost to the vertical spinners as usual. I was happy how it works but the vert spinners are just too powerful that you don't get a chance to do much before going upside down or flipped out of arena.



I had anew 3d printed flexible top arm (orange thing) that can absorb some impacts and protect the servo.  it worked nice.  the lower nylon printed wedge also held up pretty well despite fighting spinners in every match.  I'm going to try to add self righting to the bot again with a new antenna, and also do some more repairs (servo came loose again, fingertech gearboxes came loose also, i need to loctite these, abs chassis is cracking everywhere, carbon lid is cracked).

But long term I think it is time to design Flex 2.0 which will be more user friendly for working on it, and try to have some features that make it more competitive against spinners and less failure points.  I watched some of emmanual's stream on twitch and really saw how much better pizza slicer second version was when he redesigned it from the first version, and i want to get my bots to that next level also.  since when you design something the first time, at least for me, i always end up with a bunch of hacked together crap that i just did to make things work, and you don't really get any refinement until you do it for the second time and bring together all of your ideas in a better package.

some features I want to have in flex 2.0:
  • hardened steel or ti wedge/front plow that can be rammed into spinners fearlessly
  • skids hidden under wedge so they don't take abuse
  • self righting
  • print chassis parts with alloy 910
  • external charging port
  • have the arm lift higher (at least 4") so it can put bots over the walls (to end matches with no pushouts)
  • servo can connect to lifting mechanism with a timing belt so that it is isolated from impacts

But first.. i must finish my beetleweight.
« Last Edit: November 28, 2016, 05:53:17 pm by daggius »

irobotchuck

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Re: Flex n Friends
« Reply #14 on: November 28, 2016, 09:31:19 pm »
Keep in mind that if you are using lipo batteries, some competitions require you to charge the battery in a lipo bag.  So unless you can fit the whole robot into a lipo bag the external charging port would not be of much use. :)