EVERYONE, ANSWER THIS PLEASE!!!

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Posted by Rob DeCotiis at 03/18/2001 1:50 PM EST


Student on team #504, RoBUCtics, from Red Bank Regional High School and Jesel.



what types of drive systems is everyone using??? im trying to figure out next year's bot so we can get working on it, then change it so it fits next year's specs... first thing's first - drive system!!!

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Posted by nick237 at 03/18/2001 5:41 PM EST


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


In Reply to: EVERYONE, ANSWER THIS PLEASE!!!
Posted by Rob DeCotiis on 03/18/2001 1:50 PM EST:



We have the regnott turbo system. It has a one jewel megger nerts with duel flange's.
The regnott's turbo system is not your usual run of the mill regnott's but is diffused to except the brundbury hop scotch link control. this of course is all deflambulated over a grundge swidget. but you possibly could use the reverse mondulation grab poker.
we have plans if you would like a copy.
nick237


: what types of drive systems is everyone using??? im trying to figure out next year's bot so we can get working on it, then change it so it fits next year's specs... first thing's first - drive system!!!

[archiver]

Posted by Ken Leung at 03/18/2001 7:45 PM EST


Student on team #192, Gunn Robotics Team, from Henry M. Gunn Senior High School.


In Reply to: Re: EVERYONE, ANSWER THIS PLEASE!!!hmmmm
Posted by nick237 on 03/18/2001 5:41 PM EST:



When I finish my Mechanical Engineering Degree, will I be able to understand what you are saying?

Or do I have to take another language to do that?

"mill regnott's", "brundbury hop scotch link control", "deflambulated", "grundge swidget", "reverse mondulation grab poker"...

[archiver]

Posted by nick237 at 03/18/2001 10:31 PM EST


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


In Reply to: regnott turbo system
Posted by Ken Leung on 03/18/2001 7:45 PM EST:



All of these parts are available in the first proto-type of "IT", except for the snozz-walloper those are custom made and are only available through team 237
So to order a parts list send $19.95+$4.50 s/h to team 237.
nick237
P.S. No team should be with out one of our MkII-III-IIIIIII drive systems.


: When I finish my Mechanical Engineering Degree, will I be able to understand what you are saying?

: Or do I have to take another language to do that?

: "mill regnott's", "brundbury hop scotch link control", "deflambulated", "grundge swidget", "reverse mondulation grab poker"...

[archiver]

Posted by Ryan McElroy at 03/19/2001 4:05 AM EST


Student on team #492, Titans, from International School and KPCB.


In Reply to: Re: regnott turbo system
Posted by nick237 on 03/18/2001 10:31 PM EST:



Stop, please, I'm hurting from laughing!

~ryan

: All of these parts are available in the first proto-type of "IT", except for the snozz-walloper those are custom made and are only available through team 237
: So to order a parts list send $19.95+$4.50 s/h to team 237.
: nick237
: P.S. No team should be with out one of our MkII-III-IIIIIII drive systems.

:
: : When I finish my Mechanical Engineering Degree, will I be able to understand what you are saying?

: : Or do I have to take another language to do that?

: : "mill regnott's", "brundbury hop scotch link control", "deflambulated", "grundge swidget", "reverse mondulation grab poker"...

[archiver]

Posted by Patrick Dingle at 03/18/2001 9:14 PM EST


Coach on team #639, Red B^2, from Ithaca High School and Cornell University.


In Reply to: Re: EVERYONE, ANSWER THIS PLEASE!!!hmmmm
Posted by nick237 on 03/18/2001 5:41 PM EST:



You sound like a politician trying to explain the state of the economy.

Patrick

: We have the regnott turbo system. It has a one jewel megger nerts with duel flange's.
: The regnott's turbo system is not your usual run of the mill regnott's but is diffused to except the brundbury hop scotch link control. this of course is all deflambulated over a grundge swidget. but you possibly could use the reverse mondulation grab poker.
: we have plans if you would like a copy.
: nick237

:
: : what types of drive systems is everyone using??? im trying to figure out next year's bot so we can get working on it, then change it so it fits next year's specs... first thing's first - drive system!!!

[archiver]

Posted by Patrick Dingle at 03/18/2001 9:26 PM EST


Coach on team #639, Red B^2, from Ithaca High School and Cornell University.


In Reply to: EVERYONE, ANSWER THIS PLEASE!!!
Posted by Rob DeCotiis on 03/18/2001 1:50 PM EST:



Our drive system was one of the things we were most proud of at New York city. Not once did we ever have any traction or torque problem. We didn't even need to groove the wheels. We were easily able to go over bridge, even when pushing another robot. The only problem we had was a lousy flexible coupler (plastic) that shattered during practice. We machined some aluminum replacement pieces that afternoon, and never had a problem again.

My main advice:
1) Use drill motors! They simply have the most power.
4) Power all four wheels! If you have unpowered wheels, you are wasting an amount of traction proportional to the force of the wheels on the ground. You may have noticed many of the robots with castors did not get over the ramp that easily.
2) Don't go for too much speed. Gear the drill motors down enough (use two sets of gears if necessary) so that the robot goes about 4-5 ft/sec. The speed vs torque needed generally changes with every game, but this game torque was very important.

Patrick

: what types of drive systems is everyone using??? im trying to figure out next year's bot so we can get working on it, then change it so it fits next year's specs... first thing's first - drive system!!!

[archiver]

Posted by George at 03/19/2001 12:19 AM EST


Coach on team #180, S.P.A.M., from None and UTC Pratt Whitney.


In Reply to: EVERYONE, ANSWER THIS PLEASE!!!
Posted by Rob DeCotiis on 03/18/2001 1:50 PM EST:



well... that is if you're looking for traction

that's what we've had for the past 3 years... best traction of any team we've gone up against.

it also helps to have 4 motors driving your chassis =-)

feel free to stop by at nationals and take a peek at out gearboxes.

just a quick word of advice for ya if you do decide on treads: make sure to have a set of spring-loaded guide pulleys (aka "boogey wheels&quot placed under your CG. they help ALOT with turning.

designing the chassis ahead of time is a good idea... you know you'll need it and you can pretty much guess what you'll be able to use to make it.

well, whatever you decide, best of luck.

George
SPAM Team 180
"The burned hand teaches best. After that, advice about fire goes to the heart"
-- Gandalf, Lord of the Rings

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Posted by P.J. Baker at 03/19/2001 1:19 PM EST


Engineer on team #177, Bobcat Robotics, from South Windsor High School and International Fuel Cells.


In Reply to: EVERYONE, ANSWER THIS PLEASE!!!
Posted by Rob DeCotiis on 03/18/2001 1:50 PM EST:



I uploaded a picture to the gallery to help answer your request. This year, we are using the two drill motors to power all four wheels with tank style steering. If you get the gearing right, there is plenty of power available and the steering isn't as bad as everyone makes it out to be.

I posted the picture of our frame and motor mounts to illustrate how I would go about planning for next season. GET FAMILIAR WITH 80/20!! (or some other "industrial erector set&quot If you make some motor mounts that can just bolt in, you'll be able to experiment with a number of different drive set ups in a very short amount of time. When you're set on what you want, you can build your machine out of 80/20 or weld up a frame with your desired layout if weight is a concern.

This year, we were able to use 80/20 for the entire frame. Once we had all of the pieces cut, it was possible for myself and one student to assemble the complete frame from its components in a little more than an hour. This meant a lot more sleep for all of us this year. I can't imagine that we'll go back to the old way unless they take this stuff out of the additional materials list.

Follow the link below to see a picture of the completed fram 80/20 frame (sans drill motors and wheels). Stop by our pit in Florida and we'll gladly give you a more in depth tour of the machine.

P.J. Baker

Team #177

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Posted by Andrew wyatt at 03/19/2001 6:35 PM EST


Other on team #524, Alpha Omega Robotics, from South High School.


In Reply to: EVERYONE, ANSWER THIS PLEASE!!!
Posted by Rob DeCotiis on 03/18/2001 1:50 PM EST:



The drive system is THE single most important thing on the robot, which basically means you should take devote the most care, time, money and facilities to it.
I've come up with a few helpful tips/pointers for designing a good, workable drive assembly.

1. castors suck. Have you ever tried pushing a heavy cart around that has four castors? ever notice how hard it is to steer and reverse in close quarters?
better yet, try to push one up an incline. the front doesn't track straight and tries to lean over to one side or another, which puts you right off the incline or worse.

2. power all your wheels, all the time. having four wheels does you no good if two of them aren't powered,
because the unpowered wheels add to the amount of drag and add no traction.

3. don't use stock wheelchair wheels. the stock wheel chair wheels provided aren't the main drive wheels, and aren't really designed for maximum traction. We turned our wheels down to 5.75 inches diameter (to get rid of the "hump" and leave a nice, flat surface.)
we then milled 48 slots in the outer surface of the wheel , .05 inches deep and .125 inches wide at 200 RPM. Rubber doesn't machine well, so we were left with wheels covered in a soft rubber fuzz that gripped carpet like the hand of GOD.

4. Keep it heavy. the weight limit is 130 pounds, and there is very little reason to build a light, spindly robot that weighs 30, especially given the chance of incidental contact. We built ours up near the hairy edge of the weight limit (126.5 pounds) and we had to replace the rivets in our roll cage mounts because we were impacted several times.

5. keep your CG low. as low as possible. lower than floor level if you can. Having a low CG insures that you won't lose traction when you go over the bridge or flip coming down it, and it is essential if you have to do any kind of manipulation of said bridge. (if you'll notice, our robot lifted its front wheels of the ground. if we had a high CG, we'd have regularly fipped ourselves over.

6. Do your drive system FIRST. while manipulators are nifty, the drive system allows your drivers to gain valuable experience driving it around. Good drivers can overcome bad equipment, which gives everyone more points.

7. make sure you have a machinist on staff. machinists are handy people, and ours was quite invaluable, as he knew exactly what needed building, because he was there every meeting.

8. Don't switch drivers every round if you can help it.
have one driver drive EVERY round. having multiple drivers leads to inconsistent performance and makes it difficult to scout, in addition to the training problems inherent in training multiple people on one robot to high levels of proficiency.

I hope these help.
If you have ANY questions, requests, anything, please email me.

[archiver]

Posted by Warren Boudreaux at 03/19/2001 8:50 PM EST


Engineer on team #180, S.P.A.M., from South Fork & Martin County High School and Pratt&Whitney.


In Reply to: EVERYONE, ANSWER THIS PLEASE!!!
Posted by Rob DeCotiis on 03/18/2001 1:50 PM EST:



First, figure out what you can work make. Knowing your limits is the most important thing. A good machinist can make a mediocre design work great. Mediocre manufacturing can make the best design stink.

After that it's a team effort to figure out what the drive system is supposed to do. Speed? Traction? Light weight? Ease of maintenance? Reliability?

With unlimited money and unlimited manufacturing resources you can come up with a great design. Anything less than that is a compromise. Engineers call it "System Optimization".

Give up speed for traction? Make it heavy but reliable? The choices are many.

Pardon my drawn out oration, Rob. But your question is not nearly as easy to answer as to ask.

If you are really serious, I would recommend building several prototypes in the off-season and see how they work.

Snoop around the pits at Nationals to get some ideas. Bring a camera and lots of film. Ask questions. Some teams think of their designs as trade secrets and some have no problems explaining how their's work. Come by Team 180's pit. We'll be happy to talk to you. Assuming we aren't in the middle of a re-build.