19-02-2011 19:36

O'Sancheski

Re: pic: Team 148 - 2011 - Raptor

I will be the first to comment and that is the coolest looking bot i have ever seen

19-02-2011 19:41

Matt704

Re: pic: Team 148 - 2011 - Raptor

Another year, another great Robot!! See y'all in Dallas.

19-02-2011 19:43

AndrewMorrison

Re: pic: Team 148 - 2011 - Raptor

Amazing again!

19-02-2011 19:43

seans341

Re: pic: Team 148 - 2011 - Raptor

Is that another nonadrive I see there?

19-02-2011 19:44

O'Sancheski

Re: pic: Team 148 - 2011 - Raptor

I was just looking closely at your drivetrain. Is that the same drive system you guys used last year?

19-02-2011 19:44

MrForbes

Re: pic: Team 148 - 2011 - Raptor

Beautiful! Hope to see it in person later this season...

19-02-2011 19:44

Hegemoni

Re: pic: Team 148 - 2011 - Raptor

I cannot wait to see this bot in action. Jaw dropping to say the least.

19-02-2011 19:46

BrendanB

Re: pic: Team 148 - 2011 - Raptor

Wow! This is one of the most beautiful robots I have seen!

Another quality machine from the 148 crew!

19-02-2011 19:55

Chris is me

Re: pic: Team 148 - 2011 - Raptor

Congratulations. That's really all I have to say.

19-02-2011 19:57

MattC9

Re: pic: Team 148 - 2011 - Raptor

Another great one I counting down the days to Alamo to see this bad boy in action. Just curious, why the name raptor after armadillo, tornado, tumble weed, ect.

19-02-2011 20:01

jwfoss

Re: pic: Team 148 - 2011 - Raptor

I for one am glad I live and compete in New England. Awesome job guys.

19-02-2011 20:01

DinerKid

Re: pic: Team 148 - 2011 - Raptor

Beautiful. Just Beautiful. I need to calm down before i can figure out what i am feeling...

~DK

19-02-2011 20:09

JaneYoung

Re: pic: Team 148 - 2011 - Raptor

Taking 1 guess: Birds of prey feel quite at home here in Texas. If you search for 'photos of Texas raptors' - you will see what I'm talking about. If 148 is choosing to stay true to their Texas theme, they are - beautifully.

Jane

19-02-2011 20:12

Zach O

Re: pic: Team 148 - 2011 - Raptor

Between the underglow and the engineering, it's mesmerizing.

Great video to go along with it. It's always fun to watch the videos.

19-02-2011 20:17

BJC

Re: pic: Team 148 - 2011 - Raptor

I really like the way you throw tubes out to the end of the lane instead of going up to the wall.

Oh ya, cool robot too.

19-02-2011 20:22

s_forbes

Re: pic: Team 148 - 2011 - Raptor

Killer mechanism, the extending linkage on the top is brilliant! The large gear/arm member on the bottom looks like a part that could cause a lot of headaches... did you have any strange issues to overcome with meshing a gear to the stacked aluminum plates?

I also love the way you implemented a telescoping mechanism with the rollers in the tube, I'm gonna have to play with that idea in the future. Lots of clever bits wrapped into your bot this year.

Fantastic robot as usual, and once again I'm super jealous of your fabrication abilities.

19-02-2011 20:24

thefro526

Re: pic: Team 148 - 2011 - Raptor

Wow.

That robot is amazing, I'm especially fond of the deployment system for the mini-bot.

Way to go 148.

19-02-2011 20:30

JVN

Re: pic: Team 148 - 2011 - Raptor

The low gearbox driving a high shoulder joint via a linkage (we call this the "hip joint") was inspired by the 67-2007 robot which had this VERY cool feature. We added our own twist by making it a 4-bar linkage. Now it is a double 4-bar (we've been making double 4-bar jokes ALL season).

The practice robot shoulder joint has been running up and down since Day 18 of the build. It "just works." No worries at all with the plate gear experiment. Lots of laser cut plate gears on Raptor...

Yes, we are proud of some of the more subtle features inside Raptor. I know there are some that most people totally ignore that will be impressive to a mechanical designer with a good eye...

-John

19-02-2011 20:42

sgreco

Re: pic: Team 148 - 2011 - Raptor

That right there is what FIRST is all about...simply inspiring...

19-02-2011 21:00

EricH

Re: pic: Team 148 - 2011 - Raptor

It reminds me of a certain dominating machine from 2007... with some very scary twists. Scary, that is, if you're behind the opposite glass. Looking good!

19-02-2011 21:34

Cyberphil

Re: pic: Team 148 - 2011 - Raptor

Wow. Thats all I have to say.

19-02-2011 21:35

Kevin Kolodziej

Re: pic: Team 148 - 2011 - Raptor

Very nice robot, 148. Much to learn from this one. Good luck to you this year, and you can be sure I'll be paying your pit a visit in St. Louis

P.S. Awesome musical taste, as usual

19-02-2011 21:41

Brandon Holley

Re: pic: Team 148 - 2011 - Raptor

Eh, looks decent....


Kudos on another terrific machine 148. The hard work your entire team puts in all season really shows in the final(ish) product.

-Brando

19-02-2011 21:54

R1ffSurf3r

Re: pic: Team 148 - 2011 - Raptor

how quick is that minibot

19-02-2011 22:07

Adam Freeman

Re: pic: Team 148 - 2011 - Raptor

Thank you, this is exactly what I needed after a long day in the shop.

Great design! I love the push link and the roller claw....seems vaguely familiar.

Thanks for the note

Can't wait to see it in person. I guess I will have to watch the video a few more times...maybe there's more hidden gems.

Awesome job 148!

EDIT: Didn't notice the first 10 times, but that is an articulating roller claw....just amazing!

19-02-2011 22:47

Aren_Hill

Re: pic: Team 148 - 2011 - Raptor

Not enough polycord for a Raptor john

http://www.chiefdelphi.com/media/photos/33501

19-02-2011 23:26

1086VEX

Re: pic: Team 148 - 2011 - Raptor

wow... i wish we could get the chance to play with you guys more often. your bots are always some of the most intricate and well designed machines out there. props on another insane bot!! best of luck this year!

19-02-2011 23:31

ratdude747

Re: pic: Team 148 - 2011 - Raptor

wow... you guys seem to love the the robot lights.

looks sweet, thats for sure. performs well.

Good luck!

19-02-2011 23:58

Pat Fairbank

Re: pic: Team 148 - 2011 - Raptor

Totally awesome. I've been following the blog all season, and the finished product definitely exceeds the high expectations I developed from that.

Can't wait to see it in person at CMP (and maybe get a guided tour of the subtleties?).

20-02-2011 00:19

AdamHeard

Re: pic: Team 148 - 2011 - Raptor

It's a great machine, I loved the intro! Love the four bar even more, especially combining the rotation of the claw into the four bar.

I hope it does better than the last two robots named raptor (973 in 09, and 254 in 07), both fell in the semis at champs.

20-02-2011 00:28

Akash Rastogi

Re: pic: Team 148 - 2011 - Raptor

I wish we competed down in Texas.

Looking good 148.

And remember, don't let them haters hate.

20-02-2011 00:48

robodude03

Re: pic: Team 148 - 2011 - Raptor

John and 148 Members,

This is a beautiful machine and excellent intro video as always. We hope to see you in champs and good luck this season! I absolutely love the physical stop you placed on the arm to articulate the tubes into the right position.

20-02-2011 01:07

Flyer522

Re: pic: Team 148 - 2011 - Raptor

Absolutely Awesome!

20-02-2011 01:27

SteveGPage

Re: pic: Team 148 - 2011 - Raptor

JVN and crew:

You are more than engineers, you are artists!

(or maybe that should read - you are more than artists, you are engineers!)

20-02-2011 01:44

Arefin Bari

Re: pic: Team 148 - 2011 - Raptor

Dear team 148,

You are giving me nightmares. I admire your capabilities and your teamwork. Thank you for sharing the video with us and I sure hope I get the chance to see this robot in person. You all are an inspiration to the young generation.

- Arefin.

20-02-2011 01:47

Jacob Paikoff

Re: pic: Team 148 - 2011 - Raptor

Great video, awesome robot.

I hope that I have a chance to see it in person in St. Louis

20-02-2011 02:28

flippy147852

Re: pic: Team 148 - 2011 - Raptor

Wow... once again 148 has produced a stellar bot.

Can't wait to (hopefully) see it in person in St. Louis!

20-02-2011 03:05

Leav

Re: pic: Team 148 - 2011 - Raptor

What can I add beyond what has already been said? I am quite simply floored.

If you are making a pamphlet which explains your robot mechanically (I'm thinking of this one from simbotics in 08), I'd love to see it.

I'm constantly sharing great designs with my team and, well, let's say your design "qualifies"...

Yet another reason for us to strive for st. louis...

-Leav

20-02-2011 08:10

Chris Fultz

Re: pic: Team 148 - 2011 - Raptor

Very cool.

Great work 148.

20-02-2011 08:26

Tetraman

Re: pic: Team 148 - 2011 - Raptor

Can you imagine what they can do if a "feeder robot" was on their alliance?

20-02-2011 08:52

MagiChau

Re: pic: Team 148 - 2011 - Raptor

They probably don't even need a feeder robot if there is a human player chucking tubes over at them to hang.

20-02-2011 11:54

kgzak

Re: pic: Team 148 - 2011 - Raptor

Video has been blocked by Sony Music Entertainment

20-02-2011 12:30

Alex.q

Re: pic: Team 148 - 2011 - Raptor

Wow. I love robots like this where everything is planned out and fits together perfectly. I'd love to work on a robot like yours.

I'm interested in how you guys operate during the build season. How long does your team take to design before you begin to build the robot, when do the programmers get their hands on it, how much time do you leave for drivers to practice?

20-02-2011 12:38

Bjenks548

Re: pic: Team 148 - 2011 - Raptor

Glad this beast in down in Texas. Unfortunately I'm going to have to deal with its Green twin probably. Any specs on the Mini bot speed? Looks to be magnetic. Robot looks awesome, hope you aren't on the blue alliance too much.

20-02-2011 12:49

Greg Needel

Re: pic: Team 148 - 2011 - Raptor

There are no twins of this robot besides our practice bot.

20-02-2011 13:01

Amy Yznaga

Re: pic: Team 148 - 2011 - Raptor

JVN blogged about 148's entire build season. you can read it here: http://blog.iamjvn.com/

20-02-2011 15:07

Bjenks548

Re: pic: Team 148 - 2011 - Raptor

Was there any collaboration between 217 and 148 this year?

20-02-2011 15:16

Greg Needel

Re: pic: Team 148 - 2011 - Raptor

148 did not collaborate with any teams, if there are any similarities between us and any other teams that share our sponsor it is because we are all friends and share manufacturing capabilities, but there was no direct design sharing this year.

20-02-2011 15:30

ks_mumupsi

Re: pic: Team 148 - 2011 - Raptor

nice looking, though I wouldnt expect anythin gless .. hope to see you guys in St. Louis.

20-02-2011 16:32

pacoliketaco

Re: pic: Team 148 - 2011 - Raptor

One of my favorite videos this time of year is always the final display from 148. yet again i am not disappointed. you guys amaze me in what you are capable of. One thing id like to know is how you train your students to make such amazing robots. The design alone must take many many hours of CADing. as a sophomore meche with a considerable amount of design experience i know I'd have quite a challenge making something like your robots.

20-02-2011 18:05

Andrew Schreiber

Re: pic: Team 148 - 2011 - Raptor

Eh, it is ok, I think it will get better as the season progresses.


Seriously though, nice video can't wait to see how this thing works by the time Championship comes around.

20-02-2011 18:24

bcharbonneau

Re: pic: Team 148 - 2011 - Raptor

Great job again RoboWranglers. We look forward to seeing you in San Antonio.(Team 1296).

20-02-2011 19:35

Tyler Hicks

Re: pic: Team 148 - 2011 - Raptor

I noticed there is a 217 sign in the background of the shop.

Hmmmmm.

20-02-2011 19:49

ahollenbach

Re: pic: Team 148 - 2011 - Raptor

It's beautiful! Everything is so fluid and an excellent design!

20-02-2011 19:53

EricH

Re: pic: Team 148 - 2011 - Raptor

And there was a Simbotics sweatshirt on one of the students in a picture...

20-02-2011 20:00

Nick Rixford

Re: pic: Team 148 - 2011 - Raptor

Sick bot as always! hope to see you at St. Louis!

20-02-2011 20:08

ouellet348

Re: pic: Team 148 - 2011 - Raptor

nice bot, I'll be curious to see what 217 and 1114 look like this year though, either way this is a very well engineered bot

20-02-2011 21:09

James Tonthat

Re: pic: Team 148 - 2011 - Raptor

Not claiming I have a good eye, but really impressive. I love how you guys keep outdoing yourselves.

Can't wait to see it in San Antonio.

20-02-2011 21:21

Norman J

Re: pic: Team 148 - 2011 - Raptor

Echoing the sentiments of many before me, I congratulate 148 on an awesomely impressive robot. Your designs are inspiring and your videos extremely cool.

20-02-2011 21:54

Karthik

Re: pic: Team 148 - 2011 - Raptor

I was going to post a funny joke, but it may not have been appreciated. Either way, awesome robot once again.

20-02-2011 21:58

samir13k

Re: pic: Team 148 - 2011 - Raptor

Karthik took down his funny joke so i took down my funny response :/

on the other hand though, Oh dang...

20-02-2011 22:08

xSAWxBLADEx

Re: pic: Team 148 - 2011 - Raptor

i wanna hear, i wanna hear

20-02-2011 22:28

nuggetsyl

Re: pic: Team 148 - 2011 - Raptor

The mini bot alone will win most of there matches. Great job guys.

21-02-2011 03:30

PaW

Re: pic: Team 148 - 2011 - Raptor

I really have to commend your media crew. The insane amount of hours it must've taken to compile all the pictures and edit the video footage... that is A LOT of work. And every year, the reveal video is breathtaking, and just a bit better than the previous year. Nice work!

The robot looks pretty good too.

My jaw has become quite adept at self-healing, even with all the repeated drops to the floor.

21-02-2011 12:40

SuburBot

Re: pic: Team 148 - 2011 - Raptor

Hello Robowranglers,
Very impressive robot!
This year, I'm hosting a Robot video unveiling competition. More info can be found here:
http://suburbots2115.wordpress.com/ruv-comp/
I believe your video fits all the requirements. Would you consider joining for the chance to win bragging rights and a PNG image file badge? All you have to do is post your team name and number and a link to your video on this CD thread:
http://www.chiefdelphi.com/forums/sh...threadid=88184
Thank You

21-02-2011 14:35

JesseK

Re: pic: Team 148 - 2011 - Raptor

Great music selection and a front-contending bot as usual. I got some interest in creating an offseason nonadrive based on this video, but I'm still fairly certain it's beyond our fabrication abilities. Maybe we'll do a 12fps+ slide drive instead.

Those of us who never saw 67's linkage are left to ponder the way the 148 linkage works. Is it like the locomotive linkages on old-school trains?

21-02-2011 16:07

Chris is me

Re: pic: Team 148 - 2011 - Raptor

I've got a question. This question isn't a criticism disguised as a question.

What reasons would a team want to deviate from the "standard" method of powering an arm by bolting a sprocket to it and chaining it off a high reduction gearmotor? Basically, what are the advantages of the cool linkage pushing up on your arm as opposed to driving the rotational joint of the arm?

I've never learned much about arms and I don't understand the advantage or disadvantage of either system, other than CG placement.

21-02-2011 16:13

Bochek

Re: pic: Team 148 - 2011 - Raptor

I had the same thoughts, and can't seem to find a reason besides CG.

Defiantly interested to know.

- Bochek

21-02-2011 16:51

JVN

Re: pic: Team 148 - 2011 - Raptor

CG isn't reason enough?

One other reason is my hatred of chain, but mainly for CG reasons.
I would also suspect this is lighter than an equivalent low-gearbox + chain + sprocket...

Plus... c'mon... DOUBLE FOURBAR!

21-02-2011 17:10

Jonathan Norris

Re: pic: Team 148 - 2011 - Raptor

HOOWWW DOESS IT WORK??!?!?

21-02-2011 17:33

Bochek

Re: pic: Team 148 - 2011 - Raptor

Now I must ask, where does your hatred of chain come from? Honestly The only time i have ever had problems is when it is very very poorly tensioned.

-Bochek

21-02-2011 17:45

AdamHeard

Re: pic: Team 148 - 2011 - Raptor

You hit a point in design where you almost get bored, and you have to go further and try new things.

Chain is functional, 148's goals are higher than achieving functionality. There were some benefits (some may say they're small, I disagree) to this design over chain and they designed for that. I imagine never having to break chain, tension chain, deal with chain growing, etc. are pretty nice. I would imagine their goal is to keep making cool, great performing stuff, while never having to do repair or maintenance.

21-02-2011 17:49

MasonMM

Re: pic: Team 148 - 2011 - Raptor

Oh, my god. Double fourbar! What does it mean?!

Its so vivid!

21-02-2011 17:51

Akash Rastogi

Re: pic: Team 148 - 2011 - Raptor

Lololololol

21-02-2011 18:14

Adam Freeman

Re: pic: Team 148 - 2011 - Raptor

When we did it in 2007, it was specifically for CG purposes. I did not want to mount a gearbox near the top of the arm. I also did not want to run chain from the gear box to a sprocket at the top of the arm.

There is also a design elegance to doing something different than running chain.

I can tell you there are advantages and disadvantages to it. CG is probably the biggest advantage...other than 4 bar linkages are always cooler. In my mind the biggest disadvantage is the amount of packaging room required to allow the push link and connecting link to swing in the bottom of the robot.

In 2008 we wanted to use a double 4 bar, but could not get it to package... so we mounted a sprocket to the arm and ran a long strand of chain.

21-02-2011 18:33

MrForbes

Re: pic: Team 148 - 2011 - Raptor

If they don't have to repair or maintain the robot, they can spend their time and talent improving it. I like that idea.

21-02-2011 18:50

JaneYoung

Re: pic: Team 148 - 2011 - Raptor

While true, when at the actual competitions, 148 can be found spending their time helping other teams. That's another way of spending their time and talent, improving.

It's going to be fun seeing the looks on a lot of rookies' faces when they see Raptor and 148 in action for the very first time.They'll wonder just what this FRC thing is all about and they'll want to learn more.

Jane

23-02-2011 12:02

JVN

Re: pic: Team 148 - 2011 - Raptor

I just put up a blog post highlighting how the linkage works:
http://blog.iamjvn.com/2011/02/insid...hip-joint.html

-John

23-02-2011 12:06

Akash Rastogi

Re: pic: Team 148 - 2011 - Raptor

Very cool. Thanks for explaining.

What's driving the hip joint on your robot?

23-02-2011 13:51

Brandon Holley

Re: pic: Team 148 - 2011 - Raptor

If you can't appreciate cool mechanisms like this, you probably can't appreciate anything!!

I especially like the use of sheet metal for everything, including the stacked plates to create the gear teeth on the smaller arm driven by the gearbox.

Thanks for sharing JVN.

-Brando

23-02-2011 14:25

JVN

Re: pic: Team 148 - 2011 - Raptor

The shoulder joint is driven by (1) Banebots 775 motor, and (12) bands of surgical tubing.
You can see the 775 in this pic:
http://1.bp.blogspot.com/-rFQ0CRqTKR...0/IMG_8024.JPG

-John

23-02-2011 15:45

Brandon Holley

Re: pic: Team 148 - 2011 - Raptor

You guys obviously rivet a lot, I assume you have a pneumatic rivet gun.

Any recommendations on one that is pretty reliable?

-Brando

23-02-2011 16:00

JVN

Re: pic: Team 148 - 2011 - Raptor

We buy the crappy ones from Harbor Freight -- they last about a season before they break. We replace them every year. Students are hard on riveters.

-John

23-02-2011 16:18

Garret

Re: pic: Team 148 - 2011 - Raptor

This robot is amazing.

I would think that the double fourbar linkage would actually simplify the arm's joint design (at least in my mind it seems so much easier to deal with weight and taking loads) in that you would have to worry less about powering the pivoting point (gearboxes and chain) and instead focus on the making the actual joint stronger and more stable. I also could see it as isolating the motors and gearboxes from the abuse (as in side loads) the arm could take in a match, which I see as beneficial seeing how much defense this robot will likely have to put up with. Those are some of many potential benefits that I thought of when I first saw it.

24-02-2011 11:17

JVN

Re: pic: Team 148 - 2011 - Raptor

After receiving a number of requests in response to this post, I decided to highlight some of the subtle parts of this year's design on my blog as part of an "Inside Raptor" series.

Here is a glimpse at one of the SIMPLE subtle features that I think makes Raptor special... press-on CIM pinions:
http://blog.iamjvn.com/2011/02/insid...ion-gears.html

-John

24-02-2011 11:22

thefro526

Re: pic: Team 148 - 2011 - Raptor

Wow, that's a really good idea. I can't tell from the picture, but does the pinion have the Key Shape cut into it, or do you just rely on the press fit to transfer the torque?

24-02-2011 11:26

IKE

Re: pic: Team 148 - 2011 - Raptor

Wow. The press on pinions are very elegant. Did you guys do any slip calcs or tests?

24-02-2011 11:26

Brandon Holley

Re: pic: Team 148 - 2011 - Raptor

Hell. Yeah.

Awesome idea Greg. Kudos to team 20 for producing the parts.

-Brando

24-02-2011 11:28

Chris is me

Re: pic: Team 148 - 2011 - Raptor

That's a cool idea! I wish we had the resources to try cool things like that.

What's the easiest way for Low Resource Team to get press on CIM pinions?

24-02-2011 11:32

Aren_Hill

Re: pic: Team 148 - 2011 - Raptor

Well it works for dewalt pinions, why not elsewhere, great idea

24-02-2011 11:38

MrForbes

Re: pic: Team 148 - 2011 - Raptor

If you had the right size reamer, you could do it that way....

Press fits are a reliable way of holding gears onto shafts. Getting the fit right is sort of critical, but even if you can get it within a thousandth of an inch or so you should be ok, if it's a tight enough fit.

Drills don't work too well for this.

Also the dewalt gear is IMHO too small to fit reliably on the CIM shaft, there just isn't enough meat there. Others will disagree...

24-02-2011 12:04

JVN

Re: pic: Team 148 - 2011 - Raptor

We rely on just the press fit to transfer the torque. It works fine -- no problems after hours of aggressive use.

24-02-2011 12:11

Travis Hoffman

Re: pic: Team 148 - 2011 - Raptor

Bring the idea to Andy Baker's attention?

Identify potential sponsors in your area who have EDM capability, and ask nicely.

...or reach out to a team in your region who already has an EDM-capable sponsor, then see if you can barter with them. We'll machine X parts for you if you give us Y extra parts or machine Z for us in return. Bartering is fun around these here parts. Our NEOFRA teams trade materials and sponsor services all the time. Example: I submitted some lexan from 379 to our waterjet sponsor along with all our parts; in return, the RoboCats gave me their unused KOP accumulator.

24-02-2011 12:53

Andy Baker

Re: pic: Team 148 - 2011 - Raptor

Huh, what, did someone mention me in the same thread as this beautiful and effective robot?

I will be sure to bug John and Greg about this in San Antonio next week.

Andy

24-02-2011 12:57

thefro526

Re: pic: Team 148 - 2011 - Raptor

Hmmm, I really, really hope this makes it into the AM Product line. Now that I think about it, Press Fit Pinions would make transmission assembly way easier.

24-02-2011 14:39

MrForbes

Re: pic: Team 148 - 2011 - Raptor

And pinion/motor disassembly more difficult.

Not that WE've ever lost a gear due to lack of lubrication....just sayin.....but I suppose having a couple extra motors with gears pressed on would be a reasonable thing to do.

24-02-2011 16:15

Manoel

Re: pic: Team 148 - 2011 - Raptor

One of those d'oh! moments... We've been wire EDM'ing all gears for our gearboxes since 2007 and that stupidly simple idea never occurred to me! In 2012 we won't be fighting with keyways, let me tell you that!

24-02-2011 16:42

Greg Needel

Re: pic: Team 148 - 2011 - Raptor

The easy answer is find someone with a wire edm to make them for you. You can do pressfits with a reamer on a lathe, but the issue with these is that every gear that I found that was off the shelf 11tooth already had a bore which was over the pressfit size. So you would need to find a source for some gear stock (if you find it let me know I couldn't find any. )

24-02-2011 18:36

Cory

Re: pic: Team 148 - 2011 - Raptor

You can get 12T 20DP gearstock. Obviously not quite what you have, but if a team were to be satisfied with a 12T already and just wanted to press it on, that would be a solution.

24-02-2011 23:08

Meredith Novak

Re: pic: Team 148 - 2011 - Raptor

Awesome robot, 'Ranglers. Can't wait to see it in person next week!!!

We will be up against a Raptor and a Dragon...and we look like a duck...a mighty duck...

25-02-2011 13:40

JVN

Re: pic: Team 148 - 2011 - Raptor

Another in this series, discussing the one of the reasons we chose to build the design we did, and some more detail on the wrist joint:
http://blog.iamjvn.com/2011/02/insid...st-joints.html

-John

25-02-2011 14:04

Madison

Re: pic: Team 148 - 2011 - Raptor

John -- thanks for taking the time to do this series of blog posts. I often wonder if the way I conceptualize and design things is "right," or if I'm off in my own corner of the world somewhere doing weird things that are crazy.

The manner y'all use to extend the upper part of your four-bar is exactly like something I'd conceptualized a few years ago after I was unhappy with the telescoping mechanism on our 2005 robot. It's awesome to see that someone else had a similar idea and even better to see it implemented so well.

26-02-2011 17:14

JVN

Re: pic: Team 148 - 2011 - Raptor

Here is another in this series describing our use of aluminum plate gears this season:

http://blog.iamjvn.com/2011/02/insid...ate-gears.html

-John

26-02-2011 17:56

Cory

Re: pic: Team 148 - 2011 - Raptor

John,

I'm curious how you avoid misalignment of the teeth relative to each plate after assembly. Do you bolt both plates together and then cut the teeth? Do you use pins to align them and then clamp them with bolts? is it just "good enough" that you can bolt them together without any alignment aids?

26-02-2011 18:29

sgreco

Re: pic: Team 148 - 2011 - Raptor

I'm curious as to why you chose to stack plates instead of just cutting a thicker plate? I can understand if it was really thick for cost purposes, like over a half an inch, but wouldn't it be easier for a 3/8 piece to just cut one from a thicker piece of metal? I suppose if you're laser cutting then thicker aluminum isn't an option on all lasers because of aluminum's reflective properties.

I've also always been curious, are your parts lasered of waterjetted?

26-02-2011 18:56

JVN

Re: pic: Team 148 - 2011 - Raptor

It is just "good enough."

We align the plates (using a mating gear + eyeballs) and then clamp them with c-clamps before riveting.

These are aluminum gears, and we figured they'd wear in happy.

Again -- we were surprised how well this worked. We were expecting more hassle... but... it just works.

-John

26-02-2011 18:57

JVN

Re: pic: Team 148 - 2011 - Raptor

Our parts are lasered. We use 1/8" plates stacked instead of thicker plates for two main reasons:

1. The laser does have some "blow out" which will affect the tooth profile in thicker materials.

2. Our shop stocks 1/8" 6061 aluminum, so we can get it without a special order. When I'm trying to get 24 hours turns, I try not to make our shop do anything they don't normally do for production.

-John

26-02-2011 22:59

s_forbes

Re: pic: Team 148 - 2011 - Raptor

Cool stuff, John!

Maybe you guys need to start up a Robowranglers R&D division to test more neat ideas like this... you can attempt all kinds of weird projects that would normally be foolish to try during a build season*. Though it sounds like your offseason work already accomplishes this.


*cough* walking robot *cough* *cough*

27-02-2011 11:32

LBseale

Re: pic: Team 148 - 2011 - Raptor

If you dislike chain so much, why did you choose to chain together your omni-wheels and traction wheels? From your models it looks like you have enough CAD experience to space and use timing belts. SolidWorks (at least, maybe Inventor does too) comes with a tool for calculating belt lengths that's very handy. Belts are quieter and don't need tensioning.

27-02-2011 11:59

JVN

Re: pic: Team 148 - 2011 - Raptor

Maybe next year.

We dislike chains that we need to worry about. This low-load application is pretty happy the way it is.

27-02-2011 12:02

sdcantrell56

Re: pic: Team 148 - 2011 - Raptor

We've used laser cut gears in manipulators before when a small range of motion was desired but Ive never thought about using them in a drive application. Be sure to post up at the end of the season about any wear issues you encountered because otherwise it is a very simple solution to custom gears. I'll be sure to check them out at alamo.

27-02-2011 12:22

JaneYoung

Re: pic: Team 148 - 2011 - Raptor

I wonder if there is any maximum allowance of people/teams per pit. Looks like 148 is going have a crowd. Non-stop. Again.

27-02-2011 13:18

Ian Curtis

Re: pic: Team 148 - 2011 - Raptor

How do you generate the tooth profiles? Does IFI just have a piece of software that spits it out, do you do it by hand , or is there a handy SW feature that I've missed that does it for you?

27-02-2011 13:28

MagiChau

Re: pic: Team 148 - 2011 - Raptor

Well 148 would be nagged about the safety issue of too much people crowding your pit.

27-02-2011 13:41

JaneYoung

Re: pic: Team 148 - 2011 - Raptor

Actually, it's always a pleasure to notice how planning committees work to make the pits efficient and, at the same time, a showcase for teams like 148 and 118, allowing space where there is some to be had. It's also nice when rookies are placed between veteran teams or are placed in an area together where they can be accessed and helped easily by veteran teams and volunteers who will help. Teams like 148 are very aware of their draw and they work hard not to infringe on other teams' space. I've seen it on Championship level and Regional level. It's also the job of the pit volunteers to help keep things orderly and running smoothly.

27-02-2011 14:00

JVN

Re: pic: Team 148 - 2011 - Raptor

There are lots of ways to do this. Some of my favs:

1. Pull out your handy Machinist's Handbook and sketch the tooth profile by hand.

2. Buy one of those gear profile generation programs and get it to spit it out for you.

3. Download the gear from somewhere online. bostongear.com has all their gears available online.

For this year's robot we used option 3. I downloaded the gear I wanted from Boston gear, then traced over the tooth in Solidworks (eliminating splines with simple arcs, so it would import cleaner into our laser cutter's NC program). I grabbed this sketch, dropped it into a new sheetmetal part and away we went...

-John

27-02-2011 16:17

Tristan Lall

Re: pic: Team 148 - 2011 - Raptor

A few more options:

1. It's surprisingly easy to generate a real involute using equations; this and this explain how to do it in Pro/E (but any CAD software ought to be able to do the same).
2. If you can make do with an approximation instead, either follow the second method in the link above, or get GearGen (I think it's shareware*) from here or here. (It's a DOS program, so the interface might be a little unfamiliar nowadays....) This makes a sort of segmented polyline when exporting, with arcs that (as near as I can determine) are approximate. But thanks to modern, fast computers, you can create an arbitrarily large gear and scale it down to whatever degree of precision you need—so this isn't a problem so long as your CAM software won't choke on the geometry. (Note that all of those facets will make 3-D CAD really slow to regenerate; use the equation in that case, or just approximate it for visual purposes.)

*Does anyone even use that term anymore?

28-02-2011 10:53

JVN

Re: pic: Team 148 - 2011 - Raptor

Another from this series which highlights the Drive Module layout.
http://blog.iamjvn.com/2011/02/insid...ve-module.html

-John

28-02-2011 10:58

MrForbes

Re: pic: Team 148 - 2011 - Raptor

Nice drive module!

for making that strange gear for the arm lifter....you could also get the arm gear from a door window regulator from a car, and trace it onto the aluminum

28-02-2011 12:47

sdcantrell56

Re: pic: Team 148 - 2011 - Raptor

Why did you decide to ditch the drop down perpendicular omni wheel this year? I would think strafing would be the only upside to this whole switching drivetrain

28-02-2011 13:28

hurtzmyhead

Re: pic: Team 148 - 2011 - Raptor

Im not sure that they did: Looks like they can go side to side

if im mistaken and it does not have a 5th omni to go side to side... here it shows the robot "auto magically" lining up to the pole.

28-02-2011 13:30

tim-tim

Re: pic: Team 148 - 2011 - Raptor

From the blog on the drive module, he states that there is a reduction through gears and another through chain. This essential provides a two speed transmission with two different driving characteristics. This will allow for a change of speed and torque. The omni-wheels still provide more degrees of freedom for the robot to move in, than IFI traction wheels.

There are plenty of advantages to this system. I really like this system and hope to develop something similar in the off-season.

-Tim

28-02-2011 13:57

Chris is me

Re: pic: Team 148 - 2011 - Raptor

If there is no powered movement in the lateral direction, they don't. However, I'm tempted to believe that 148 did put in the "kicker drive". I just don't see why they would choose an articulating drive like this if they couldn't strafe controllably.

I really like how the traction wheels are geared differently than the omni wheels. Simpler than shifting indeed!

28-02-2011 14:01

tim-tim

Re: pic: Team 148 - 2011 - Raptor

@ Chris, you do bring bring up a valid point. However, the omni-wheels will allow for a more maneuverable robot. This is what I was trying to say. Thanks for catching that

28-02-2011 14:10

Joe G.

Re: pic: Team 148 - 2011 - Raptor

I can imagine that the all-omni wheel drivetrain would create a nice "drift" effect when turning around during high-speed motion, a maneuver that can be seen at about 1:44 in their video. I can imagine that this will come in handy, due to the "back and forth" nature of driving in this game, and that this may have actually been hampered by the kicker wheel.

CAD drawings that flash by all feature a kicker wheel, as well as many practice bot pictures. But all footage of the final robot seems to place the battery in the center of the robot, in place of the mass of sheet metal that (presumably) supported the sideways wheel.

Also, John mentions a major change to subsystem 1 (the drivetrain) here. Coincidence? Or iterative design?

28-02-2011 14:45

JVN

Re: pic: Team 148 - 2011 - Raptor

You got it.
The original drivetrain was a full Nonadrive system, but we ended up removing the sideways wheels around Day 31 (see the blog post linked above). After a week of practice we decided it wasn't necessary. In my mind, all our work and testing since that point has confirmed we made the right decision.

When we removed the middle wheel our original plan was to swap out the 4 primary omni wheels with 6" traction wheels, however... well... we were impressed with what our driver Connor can do with it.

We call this configuration "Butterfly Drive." Which is a joke in reference to how this robot can be pushed sideways while on all omni wheels (obviously when we drop the traction wheels she stops floating like a butterfly and stings like a... you know.)

I don't think all of it's virtues are readily apparent. I assure you there are more reasons to do an articulating drive than moving sideways. Though I realize most other teams may not value the same things we do, and as such may not make the same tradeoffs we did.

We love "traction mode" and it's virtues in autonomous and driver control. We love the simplicity and modularity of this module design. We love how the drivetrain performs on all omni-wheels (super efficient geartrain + 4 omni wheels = smooth like butter). We're very happy with what we ended up with...

-John

28-02-2011 15:13

sanddrag

Re: pic: Team 148 - 2011 - Raptor

I remember way back to 2003, team 980 had a similar drive system in which they raised or lowered two different sets of wheels to essentially have two different final drive speeds/ratios.

28-02-2011 15:16

Manoel

Re: pic: Team 148 - 2011 - Raptor

Team 810 did the same thing in 2002, from what I remember.

28-02-2011 17:26

sdcantrell56

Re: pic: Team 148 - 2011 - Raptor

While I think its cool shifting wheels instead of shifting gears, I don't really see how it is simpler at all. A transmission is quite compact and requires a small amount of force to shift versus needing enough force to lift the robot to drop down the traction wheels. The only potential benefit I see of this system without the perpendicular omni wheel is the ability to change the center of rotation although the benefit of that wouldn't necessarily be worth the added weight of the system.

JVN given that you ended up taking out the 5th omni wheel would you stick with this drive if you could do it over or go with a more conventional 6 or 8wd with shifting transmission?

28-02-2011 17:32

AdamHeard

Re: pic: Team 148 - 2011 - Raptor

From a fabrication standpoint for a team with limited resources, it is far easier. Having worked through the "fun" of getting the speeds right for multiple gearboxes, it is also nice in that it is easier to change the difference between high and low gear.

Utlizing COTS gearboxes and wheels, a team with a drill press (or even a hand drill), could make such a drivetrain.

28-02-2011 17:37

Chris is me

Re: pic: Team 148 - 2011 - Raptor

While it can be done with less resources, I'd be worried about these low resource teams trying this, mainly because wheel pod side loading is a pretty big concern with this style of drivetrain.

By the way, the above blog post refers to large performance gains with the removal of the 5th wheel. What are those gains?

28-02-2011 18:53

Andrew Schreiber

Re: pic: Team 148 - 2011 - Raptor

Depends on the way you place your wheels. Obviously if you use omni wheels as your dropped wheels you will slide rather than break the pods. If you use traction wheels the problem becomes more significant.

28-02-2011 18:57

Chris is me

Re: pic: Team 148 - 2011 - Raptor

Yes, but the system is designed around giving the traction wheels a higher reduction, so they aren't the natural choice to be directly driven / the pivot point.

Unless, of course, you've put the CIM on the module... like 148 does...

28-02-2011 18:58

JVN

Re: pic: Team 148 - 2011 - Raptor

This was something we learned last year, which is why the Generation 3 & 4 drivetrains have stationary traction wheels and actuated omni wheels. When we're in traction mode if we take a hit, all the load gets transferred straight into the chassis.

This layout comes with its own set of challenges and constraints, but we like it a lot more.

-John

28-02-2011 20:32

Dad1279

Re: pic: Team 148 - 2011 - Raptor

Not to hi-jack, but that's how we did it, Drill press and bandsaw. Only machined parts are the two plates. Traction wheels direct drive, larger mecanums raised and lowered. 1-CIM 1-775 per module.


Side loading is not a problem, as the traction wheels are mounted conventionally with a bearing on both sides of shaft, and the mecanums are braced with sideplates/slides. Obviously not all is shown in this rendering.

01-03-2011 09:34

JVN

Re: pic: Team 148 - 2011 - Raptor

Another in this series:
http://blog.iamjvn.com/2011/02/insid...retainers.html

Want to retain a flanged bearing? Drill some holes and rivet a washer over the flange.

-John

01-03-2011 10:29

Alex Cormier

Re: pic: Team 148 - 2011 - Raptor

Did you also replace the bolts in the AM omnis with rivets?

01-03-2011 10:47

Greg Needel

Re: pic: Team 148 - 2011 - Raptor

Yes we did and they haven't failed us yet. Not sure how much weight we saved by doing this but anything we can do to save a little bit is worth the effort. Additionally by doing this it was and opportunity to check each roller to make sure it rolled freely.

01-03-2011 12:35

Madison

Re: pic: Team 148 - 2011 - Raptor

810 used 9" Bead-lok wheels for its main drive and lowered two absurdly wide belts to the ground for pushing. I don't recall the overall ratios, but the difference between the wheels and belts was 3:1.

01-03-2011 23:30

Captaindan

Re: pic: Team 148 - 2011 - Raptor

haha fusion answered the call for awsome funchional leds check it out at the bayou regional ladies and gentlemen

02-03-2011 01:02

lynca

Re: pic: Team 148 - 2011 - Raptor

I've noticed that our omni rollers eventually stop spinning. We have tried loosening the screws but sometimes we have to change the rollers completely.

How often do you guys swap out rollers ?

Did you notice any difference between riveting omnis instead of screws ?

02-03-2011 11:48

Akash Rastogi

Re: pic: Team 148 - 2011 - Raptor

On the topic of plate gears, I remembered that 1771 had plate gears integrated into their turreted shooter's hood. The entire thing was also turreted on a huge laser cut sprocket. Guess they should've published some documentation on their robots! What a dominant machine they had that year.

I'm hoping 1477 and 2415 also have some cool integrated components in the coming seasons.

For anyone interested, it was a simple but pretty cool application.

02-03-2011 11:52

Andrew Schreiber

Re: pic: Team 148 - 2011 - Raptor

For anyone who is feeling left out on the laser-cutty-goodness you can achieve a similar effect by taking a length of timing belt and wrapping your circular surface in it with the teeth facing out. It isn't as effective as having the teeth laser cut but for low torque applications it does work. 2337 use this approach somewhere on their 2009 robot (I'll snap a pic next time I am down there).

02-03-2011 12:31

jwfoss

Re: pic: Team 148 - 2011 - Raptor

The adjustable length four bar link is a really slick trick. I've had that sketched out in my engineering notebook since the first time I ever saw that done back in 2008 at FLR. They had an adjustable lower link to stay within the sizing rules and to tilt the gripper up, whereas you adjust your upperlink to actuate your wrist. Also I believe theirs may have been passive (gas shock) where your is pnuematically adjusted.

FRC67 - HOT from 2008
http://www.chiefdelphi.com/media/photos/30680

02-03-2011 12:52

pwnageNick

Re: pic: Team 148 - 2011 - Raptor

This robot is awesome. My first year of FRC was last year, and I remember being very frightened after seeing your promo video last year. I can't wait to see how you guys do at Alamo this weekend. Good luck this season 148, 2949 can't wait to see you guys perform at Worlds!

02-03-2011 21:00

Redo91

Re: pic: Team 148 - 2011 - Raptor

You guys always impress.

Are you not worried with getting pushed too easily from the side when your traction wheels are up?
How well does the robot turn when the traction wheels are down?

I wish I could see your robot in person.

02-03-2011 21:55

Adam Freeman

Re: pic: Team 148 - 2011 - Raptor

Unfortunately our 2008 adjustable lower link design never made it passed our practice field. The mechanical implementation on that design (PVC and gas shocks) had a serious transition phase that caused our programmers fits. We ended up re-designing the lower arm and replacing it with a solid link as soon as it came out of the crate Thursday morning @ FLR.

Raptor's adjustable arm is much more elegant and functional than that HOT '08 adjustable arm ever dreamed of being.

02-03-2011 22:15

JVN

Re: pic: Team 148 - 2011 - Raptor

Another post in this series, my last before we take her out of the bag tomorrow morning at the Alamo regional:
http://blog.iamjvn.com/2011/03/insid...ntiometer.html

Our programmers accuse me of having a mental block which keeps me from designing sensors into the robot. To them I say: "BAGH!"

Good Luck to everyone who competes in week 1!
Raptor has one more big surprise up her sleeve which is ready to go. See you on the field

-John

03-03-2011 12:22

JesseK

Re: pic: Team 148 - 2011 - Raptor

Hmm. More compactness (potentially):

1. Fix 2 long VEX metal pieces to the dead axle of the arm such that one of the square holes is concentric with the axle. The hole will have to be enlarged of course. The two pieces of metal should be far enough apart that the slop is minimized, regardless of whether the potentiometer gear is cantilevered or dual-supported.
2. Attach the VEX gear to the arm, as shown.
3. Attach the potentiometer and the potentiometer gear to the VEX metal using appropriate spacing for the chosen gears. The spacing is built-in since it's VEX.
4. Profit.

We've always had issues with potentiometers since we can't seem to keep them from slipping in the shafts we directly mount them to (thus needing to recalibrate them). Or the rubber band / polycord belts we make slip. It results in a bad calibration. Maybe we can try VEX this off season. Right now we use limit switches with encoders -- not too bad coding-wise, but man that's a lot of little wires to run.

03-03-2011 12:32

Travis Hoffman

Re: pic: Team 148 - 2011 - Raptor

Quite evil, that.

Cross-drill a hole through the pot shaft and the mechanism shaft, and secure with a cotter pin or other suitable clip, bolt, whatever.

04-03-2011 17:24

ChuckDickerson

Re: pic: Team 148 - 2011 - Raptor

148 just scored 2 uber tubes BY THEMSELVES in autonomous during match number 55 at Alamo! Now folks, THAT defines just how uber cool 148 are!

04-03-2011 18:11

waialua359

Re: pic: Team 148 - 2011 - Raptor

Nice job!
That's two teams now that can score 2 in auto.
The other being that one Michigan team that posted a video of it.

04-03-2011 18:23

Tom Bottiglieri

Re: pic: Team 148 - 2011 - Raptor

Hey John that's a pretty cool piece of SOFTWARE you've got there.

07-03-2011 11:31

JVN

Re: pic: Team 148 - 2011 - Raptor

Some video of Raptor in the elimination rounds of the 2011 Alamo Regional:
http://blog.iamjvn.com/2011/03/san-a...011-video.html

Check out Final 1 for a glimpse of the week 1 national high score, and our 2 tube autonomous mode.

22-02-2012 22:02

tim-tim

Re: pic: Team 148 - 2011 - Raptor

The 2012 release should be in the near future.

Correction, the much anticipated 2012 release should be in the near future, and I can't wait.

22-02-2012 22:05

Re: pic: Team 148 - 2011 - Raptor

Aww. Got me excited over last year's robot.

22-02-2012 22:06

stundt1

Re: pic: Team 148 - 2011 - Raptor

http://www.youtube.com/watch?v=g3jeR...eature=channel

There human player has skill.

22-02-2012 22:09

its da PAT!!!

Re: pic: Team 148 - 2011 - Raptor

I know right? I saw that and got so excited. lol

22-02-2012 22:10

V_Chip

Re: pic: Team 148 - 2011 - Raptor

Isn't he from 118 Robonauts?

22-02-2012 22:11

s_forbes

Re: pic: Team 148 - 2011 - Raptor

I see a robot in the background that may be of interest.

22-02-2012 22:13

Peyton Yeung

Re: pic: Team 148 - 2011 - Raptor

Looks like a wide base

22-02-2012 22:13

V_Chip

Re: pic: Team 148 - 2011 - Raptor

I see a wide config bot

22-02-2012 22:16

CalTran

Re: pic: Team 148 - 2011 - Raptor

I'm thinking the same thing.
Replay of the last few moments:
148 released their robot already?? *reads thread* I got played.

22-02-2012 22:16

Walter Deitzler

Re: pic: Team 148 - 2011 - Raptor

It is definetly a wide base.
I almost mistook it for the Raptor when I first saw it, becuase of the triangular frame. I wonder how it looks...

22-02-2012 22:21

V_Chip

Re: pic: Team 148 - 2011 - Raptor

http://s1199.photobucket.com/albums/aa476/V_Chip/

22-02-2012 22:22

tim-tim

Re: pic: Team 148 - 2011 - Raptor

Sorry for the false hope guys. It is not unusual for 148 to release their robot soon after the ship/bag&tag deadline.

I will agree that it does appear to be a wide based robot. However, I would not put it past JVN and Greg to have placed a 'fake' robot in the back corner to create discussion...

I am just waiting on how simple their design will be (as always, simple, clean, and effective).

22-02-2012 22:25

Walter Deitzler

Re: pic: Team 148 - 2011 - Raptor

It looks as if they have a tall bridge lowering arm or ball manipulator running up the front, then a shooter tower behind it. The image is too fuzzy to make out anything from there.

22-02-2012 22:51

ChristopherSD

Re: pic: Team 148 - 2011 - Raptor

Would it upset you all if I mentioned that this is their 2011 robot?

22-02-2012 22:57

BrendanB

Re: pic: Team 148 - 2011 - Raptor

The picture in the video is not their 2011 based on the bumper configuration but i would laugh if they put a hole in them as a joke for the video!

22-02-2012 22:57

akoscielski3

Re: pic: Team 148 - 2011 - Raptor

No cause you would be wrong. Their bumpers had to be all the way around last year and had numbers in the middle of bumpers. This clearly isnt.