Speed vs. Torque?

FIRST General Forum
1

Posted by colleen at 12/27/2000 7:54 PM EST

Engineer on team #190, Gompei, from Massachusetts Academy of Math and Science and WPI.

A long running question on my old team was always… ‘What’s better to have, speed or torque?’

So how 'bout it… what are some individual thoughts…

Speed vs. Torque?
Offensive vs. Defensive?
Good 'n Plenty bot vs one that can do one/two things REALLY great?

(good 'n plenty = can do many things good… nothing ‘great’)

The more you travel around to different teams… you’ll be amazed by what people think… and joining my 3rd team… i’m finding plenty of different opinions…

so let’s hear it… 9 more days!

2

Posted by nick237 at 12/28/2000 12:06 AM EST

Engineer on team #237, sie h2o bots, from Watertown high school ct and sieman co.

In Reply to: Speed vs. Torque?
Posted by colleen on 12/27/2000 7:54 PM EST:

Good question but hard to answer. Its a fine ballance between the two with a bias to the needs of the game plan.
This year we felt torque or push power was important in order to fight our way to the bar but this proved to be not needed as to the way many of our games played out.
Only in two of our games we needed our bot to have a lot of push and that was against the Aztechs, but while their bot and ours were tangled in combat for one game our alliance was racking up the points, then when they broke from us to go after our alliance we were left free to climb the ramp and grab the bar.
So the real answer is flexability and a faith in the drivers, coaches and the machines ability…
For what it`s worth the Aztechs in one game not only stoped our bot dead in its tracks but moved us backwards faster than our bot moved normaly alone. Amazing.
nick 237.

: A long running question on my old team was always… ‘What’s better to have, speed or torque?’

: So how 'bout it… what are some individual thoughts…

: Speed vs. Torque?
: Offensive vs. Defensive?
: Good 'n Plenty bot vs one that can do one/two things REALLY great?

: (good 'n plenty = can do many things good… nothing ‘great’)

: The more you travel around to different teams… you’ll be amazed by what people think… and joining my 3rd team… i’m finding plenty of different opinions…

: so let’s hear it… 9 more days!

3

Posted by Raul at 12/28/2000 8:33 AM EST

Engineer on team #111, Wildstang, from Rolling Meadows & Wheeling HS and Motorola.

In Reply to: Speed vs. Torque?
Posted by colleen on 12/27/2000 7:54 PM EST:

Colleen,

Ah yes, the old question of tradeoffs. You have brought up the subject that most often gets engineers in trouble. In my opinion, the tradeoffs and compromises that one makes are the most critical in determining how good your robot will perform. Actually, I believe this is the essence of engineering.

Our team has always chosen to not specialize in one or two areas. We prefer to have a flexible design that can do many things. Our philosophy is that if you do only one or two things really well and cannot do much else, then it is easier to find a strategy to beat you. However, it is not easy but possible to find a robot concept/architecture that does a couple of things really well and yet do many things.

Unfortunately, some inexperienced teams will rush to decide on a concept so they can start building their robot right away. They start looking at the details without understanding the weakness of their overall concept. My advice, especially to rookie teams, is to not be intimidated by the short time you have (6 weeks); make sure you really analyze the implications of the strengths and weakness in the overall concept you choose.

Some times we get confused and make tradeoffs that are not necessary. A simplistic example is your Torque vs. Speed tradeoff. You can get both if you really want; you just have to dedicate several motors to that cause. You can use the 6 most powerful motors and have a very strong and speedy vehicle. But it might not be able to do much else well.

The last thing I want to say about Torque and Speed, which is probably stating the obvious, is that each has its pitfall. High speed usually implies less control of fine movements. High torque implies that you need a lot traction to make use of it. That is why most teams choose a middle ground, unless of course you use the Technokat’s gear shifter.

Raul

4

Posted by Dodd Stacy at 12/28/2000 9:49 AM EST

Engineer on team #95, Lebanon Robotics Team, from Lebanon High School and CRREL/CREARE.

In Reply to: Re: Speed vs. Torque?
Posted by Raul on 12/28/2000 8:33 AM EST:

: Our team has always chosen to not specialize in one or two areas. We prefer to have a flexible design that can do many things. Our philosophy is that if you do only one or two things really well and cannot do much else, then it is easier to find a strategy to beat you. However, it is not easy but possible to find a robot concept/architecture that does a couple of things really well and yet do many things.

: Unfortunately, some inexperienced teams will rush to decide on a concept so they can start building their robot right away. They start looking at the details without understanding the weakness of their overall concept. My advice, especially to rookie teams, is to not be intimidated by the short time you have (6 weeks); make sure you really analyze the implications of the strengths and weakness in the overall concept you choose.

Good advice from Raul. We try to spend the first full week of the 6 just settling on our play strategy, what capabilities the bot-to-be needs in order to execute that strategy, and what general mechanism concepts we will use to give the bot those capabilities.

As a very important part of the play strategy decision, we always have part of the team working on how to defeat our candidate strategies. We literally crawl around on the floor (trying to mimic robot speed/torque range) with dummy goals, balls, etc and try to work out how much strategic flexibility is needed to play a robust game.

A one-trick robot can do some pretty entertaining stunts, like tipping the puck to tumble off two opponents (;D), but it’s not a way to win a competition.

Dodd

5

Posted by Andy Baker at 12/29/2000 9:00 AM EST

Engineer on team #45, TechnoKats, from Kokomo High School and Delphi Automotive Systems.

In Reply to: Devil’s Advocates
Posted by Dodd Stacy on 12/28/2000 9:49 AM EST:

The TechnoKats have played this both ways…

We did many things well in '98, and we did very well. But, that was the last year without alliances.

In '99 we did only a few things, but we did them as good or better than anyone. Sure, this limited our strategy somewhat, but it still worked very well.

In '00, we went back to the ‘do many things well’ strategy, and we did OK.

If I had to pick… I like our robot to be a specialist, as long as we have alliances. We really like being the ally that many teams want to have on their side (like in '99).

As for torque vs. speed, we have a decent and simple way to get both with our gear switching mechanism, but there are better (and heavier) systems out there. Sure, we can switch gears, but we gotta stand still to do it. I admire the mechanical systems put together by teams 33, 65, and 157. Changing speeds on the fly is sure attractive.

Happy new year!

Andy B.

6

Posted by Brian Savitt at 12/29/2000 10:59 AM EST

Student on team #56, Robbe Xtreme, from Bound Brook High School and Ethicon Inc…

In Reply to: We’ve played both ways
Posted by Andy Baker on 12/29/2000 9:00 AM EST:

ROBBE 2K also had changing gears, but we had to do the standstill and then change, oh well we still changed them heh

Brian

7

Posted by Jason “JDoggyDog” Trotter at 12/29/2000 9:52 AM EST

Student on team #191, X-CATS, from Joseph C. Wilson Magnet High School.

In Reply to: Speed vs. Torque?
Posted by colleen on 12/27/2000 7:54 PM EST:

: A long running question on my old team was always… ‘What’s better to have, speed or torque?’

: So how 'bout it… what are some individual thoughts…

: Speed vs. Torque?
: Offensive vs. Defensive?
: Good 'n Plenty bot vs one that can do one/two things REALLY great?

: (good 'n plenty = can do many things good… nothing ‘great’)

: The more you travel around to different teams… you’ll be amazed by what people think… and joining my 3rd team… i’m finding plenty of different opinions…

: so let’s hear it… 9 more days!

Throughout my years on the X-Cats, we have always aimed at doing everything. Last year we wanted to be able to hold multiple balls, go under the bar, hang, deliver, and serve espresso. But after a review of that many team members thought that that was our downfall. We preformed our matches well, but we were never seen as an alliance partner.
As for torque/speed- we always set time aside to determine what we need. This year we went with more speed than torque, but in previous years it was vice versa. Last year, prior to Regionals, we did a trial run. Our robot was extremely fast. But one problem, couldn’t turn. So we lowered the speed raising the torque. Slower yes, but we regained the ability to turn.

Just my $.02

Jason Trotter

8

Posted by Peter Krumdieck at 12/29/2000 11:58 PM EST

Engineer on team #353, Pobots, from POB Central School District.

In Reply to: Speed vs. Torque?
Posted by colleen on 12/27/2000 7:54 PM EST:

: A long running question on my old team was always… ‘What’s better to have, speed or torque?’

: So how 'bout it… what are some individual thoughts…

: Speed vs. Torque?
: Offensive vs. Defensive?
: Good 'n Plenty bot vs one that can do one/two things REALLY great?

: (good 'n plenty = can do many things good… nothing ‘great’)

: The more you travel around to different teams… you’ll be amazed by what people think… and joining my 3rd team… i’m finding plenty of different opinions…

: so let’s hear it… 9 more days!

Last year our bot was FAST and light. we couldn’t pick up more than one ball at a time. We eventually changed our strategy and fed the black ball over the top of the operator station and dumped it for a quick 5 points. Then we did a little d-fense!

During one match our claw became disabled so it was total defense. (we won the best defensive play award for that round).

One of our teammates / opponents didn’t have any engineering help. so they focused on one aspect and did it really well. They came to us and said (and I quote),’ Hey man. All we do is hang.’ And they did it very well. (except for the round where our claw broke and we kept them away from the bar and off the ramp all together.

Their focus due to the limited resources, earned thm a quick selection by one of the highly seeded teams. Hey 10 points is 10 points.

You really want to have a flexible bot but you do what you can.

Most of all, learn something and have some fun!!

-pete

9

Posted by Travis Covington at 12/30/2000 3:16 AM EST

Student on team #115, MV ROBOTICS, from Monta Vista High School and Hitachi Data Systems - 3com - NASA Ames.

In Reply to: Speed vs. Torque?
Posted by colleen on 12/27/2000 7:54 PM EST:

Why not both??

Do like some teams and have a reliable gear switching mechanism. Then you get the best of both worlds.

In all reality i would have to say it depends on the circumstances.

-DJ CHAVEZ :wink:

10

Posted by Steve Prairie at 12/30/2000 1:45 PM EST

Student on team #173, RAGE, from Rockville High School /East Hartford High School and UTRC.

In Reply to: Re: Speed vs. Torque?
Posted by Travis Covington on 12/30/2000 3:16 AM EST:

: Do like some teams and have a reliable gear switching mechanism. Then you get the best of both worlds.

Worked great for us (RAGE 173). We had great speed to get the black balls across the field, and the torque was usefull in pushing our way onto the ramp/bar.

Torque was probably the better of the two to have though. Even in low gear we could out-run teams, but our pushing power was very handy.

Steve Prairie
RAGE 173

11

Posted by Jessica Boucher at 12/30/2000 2:52 PM EST

Student on team #237, Sie-H2O-Bots, from Watertown High School and Eastern Awning Systems & The Siemon Company.

In Reply to: Speed AND Torque, good combo
Posted by Steve Prairie on 12/30/2000 1:45 PM EST:

After Bash at the Beach, our mechanical team raved about your robot for weeks. It was a wonderful combo and a wonderful robot.

Hope your next season is as good or better,
Jessica B, #237

: Worked great for us (RAGE 173). We had great speed to get the black balls across the field, and the torque was usefull in pushing our way onto the ramp/bar.

: Torque was probably the better of the two to have though. Even in low gear we could out-run teams, but our pushing power was very handy.

: Steve Prairie
: RAGE 173

12

Posted by Kate at 1/2/2001 11:39 AM EST

Engineer on team #190, Gompei, from Mass Academy of Math and Science and Worcester Polytechnic Institute.

In Reply to: Speed vs. Torque?
Posted by colleen on 12/27/2000 7:54 PM EST:

Both for everything!!

Even though our on-the-fly shifter didn’t work that great until the after competiton competitions, it made the post-season great for us…

We’re also into the being both offensive and defensive thing… It helps that we were able to shift gears so we could do so… Quick for offense and torque for defense…

In general, we also try to make sure we’re decently good at everything… But be wicked good at one or 2 things… But we don’t usually totally throw one option out and not have quality…

We just like to multi-task and excel at everything… We also don’t really like to keep it simple either… Even though some new people on our team want to make the machine simpler… We’ll see what happens…

T190 XO
Kate