Image Discuss: TechnoKat-45 Teaser 45

[Madison]

Yes, yes -- I know this thread is two years old. I have a good memory.

I had a question about the tensioning cam and am hoping someone from 45 sees this soon.

Specifically, I was wondering what the chassis side of things may have looked like here. Is there a matching tensioning cam on the other side of the pulley, or was one sufficient?

Also, any insight into the practical operation of this idea would be appreciated. Did it work as advertised, so to speak?

I'm looking into a cam like this for a similar use, though primarily as a means of relieving belt or chain tension.

[Clark Gilbert]

Originally Posted by M. Krass

Yes, yes -- I know this thread is two years old. I have a good memory.

I had a question about the tensioning cam and am hoping someone from 45 sees this soon.

Specifically, I was wondering what the chassis side of things may have looked like here. Is there a matching tensioning cam on the other side of the pulley, or was one sufficient?

Also, any insight into the practical operation of this idea would be appreciated. Did it work as advertised, so to speak?

I'm looking into a cam like this for a similar use, though primarily as a means of relieving belt or chain tension.

Since, I took that picture let me see if I can find any more.

EDIT:
It's been awhile, but here's what I remember (I think). It was the same on the other side. I think I remember that we tightened by the inside/outside with our hands at first, then used a hammer (and maybe a flathead screwdriver) to tap them tight.

http://img140.imageshack.us/img140/2496/dscf17814tp.jpg
http://img140.imageshack.us/img140/1521/dscf18471wy.jpg
http://img140.imageshack.us/img140/2302/dscf17153we.jpg

Did it work?
If I remember correctly it worked pretty well. (Hopefully, Baker will correct me if I'm wrong). I want to say I remember breaking off atleast one of the small tabs while adjusting the cams, but I can't remember one ever coming loose during a match.

EDIT#2:
I now remember that we changed the shape of the cam for the Midwest Regional, but I can't remember why.

In this bad picture you can sort of make out the new shape.
http://img138.imageshack.us/img138/3299/dscf21954gw.jpg

[Andy Baker]

If I recall correctly, this aluminum sheet cam was replaced by a steel sheet. Only one cam tensioner was used on each tread. The back wheel was stationary, as it was the driven wheel. The front wheel is the one shown in this pic, and its axle was mounted in a slot and tensioned by this cam.

I suggest a wider cam. Our sheet steel cam was probably .06-.09 thick. Give yourself a break and go with a 1/4" thick cam for this type of tension adjustment.

Looking at this thread, I laugh. 2003 was the 4th year out of 5 of which we did treads and we have not done them since. I don't miss those treads, that is for sure.

Andy B.

[techtiger1]

Originally Posted by Andy Baker

If I recall correctly, this aluminum sheet cam was replaced by a steel sheet. Only one cam tensioner was used on each tread. The back wheel was stationary, as it was the driven wheel. The front wheel is the one shown in this pic, and its axle was mounted in a slot and tensioned by this cam.

I suggest a wider cam. Our sheet steel cam was probably .06-.09 thick. Give yourself a break and go with a 1/4" thick cam for this type of tension adjustment.

Looking at this thread, I laugh. 2003 was the 4th year out of 5 of which we did treads and we have not done them since. I don't miss those treads, that is for sure.

Andy B.

Woot! Tkats do treads very nice loving it Mr.Baker, this was for the 2003 game forgive my lack of reading?

[David Guzman]

I had never seen this one. Definitely very nice and the cam idea is very cool.
I never saw this robot in action and I'm wondering how good it was at turning and does it have and offset middle pulley or something to help it turn?

Just Wondering
Dave

[Clark Gilbert]

Originally Posted by David Guzman

I had never seen this one. Definitely very nice and the cam idea is very cool.
I never saw this robot in action and I'm wondering how good it was at turning and does it have and offset middle pulley or something to help it turn?

Just Wondering
Dave

Here is a list of videos and photos of the 2002-2003 TechnoKat robot. The videos show off various driving and the pictures are mostly of the drivebase.

I think there was an offset somewhere between 0.25 - 0.35 inches from the bottom of the outermost pulley to the middle one.

EDIT: I'll add the link when my internet starts behaving...

http://web.ics.purdue.edu/~cagilber/files/Tkat0203/

I'll leave these up for a few days.

[David Kelly]

Originally posted by Solace
our team decided not to use tracks this year for one overriding reason. with tracks, you can't really straddle anything. When you reach the top of the ramp, the front half will stick out a couple inches in the air. If another robot is coming from the other side of the ramp and slams into you when your nose is in the air, you're gonna get tipped. hasn't this bothered anybody else?

no offense meant to team 45, those tracks look awesome - this is just an observation on tracks in general

this is the TechnoKats 4th season using treads. i remember them using treads in the 2001 competition where we had to balance on the bridge. they never got tipped. and im sure they know to put their CG down low so that they dont even risk tipping. and.... intentional tipping is illegal. wedge robots designed to do that specific thing are also not legal.

[T967]

Hey What about lateral forces. Like the side of the robot? How is a track going to help you there?
I my like tires thank you.

Originally posted by T967
Hey What about lateral forces. Like the side of the robot? How is a track going to help you there?
I my like tires thank you.

As David kindly said, we have been working with treads and track drives for 4 years (out of our 12 years of existance). This has been taken into account.

[Jnadke]

Originally posted by David Kelly
this is the TechnoKats 4th season using treads. i remember them using treads in the 2001 competition where we had to balance on the bridge. they never got tipped. and im sure they know to put their CG down low so that they dont even risk tipping. and.... intentional tipping is illegal. wedge robots designed to do that specific thing are also not legal.

He's referring to when they approach the top of the HDPE platform. The first 1/3 of their robot will be up in the air since the last 2/3 will be weighted down toward the meshing... If a robot came and pushed against the part sticking out hard enough (pushed against them: defended the ramp), the TKats could essentially be tipped using this as leverage.


And no, this wouldn't/shouldn't be intentional tipping. It's a design flaw. The other team would be merely defending their position as King of The Hill. I can see this definately happening if the TechnoKats try to go forward as a team pushes against them. I don't mean anything harsh to the TechnoKats, but they shouldn't be able to hide behind this to gain advantage. If they get tipped by a team that has enough power/torque to do this, then so be it.


On a positive note, looks like this will be another wonderful TechoKats robot. Every year they make it harder to be better than the last. Must be tough. At this rate, next year they're going to have to have a 6 motor CVT powering their robot.


Keep up the good work. You never fail to impress us.

[Clark Gilbert]

We've thought about it...looked at it....and tried to work around it. I know exactly what your talking about, and thing it could very easily happen, but i seriously doubt it will.

Actually, my design team came up w/ this "military 1/2 track design" that tilted to conform to the ramp when you are going up it and when you reach the top, but after thinking about it and working around with our other designs we didnt really find it necessary.

[sevisehda]

In defense of the Kats, its not like ther the only ones making a tread system. The problem of it not conforming will happen with anyone who has more than 4 fixed wheels. Why, if you have 6 wheels the middle wheels will pick the front ones up as you go over the ramp. So its not like the Kats are facing this problem alone. If you consider a low CG and treads in general should anyone get in there way they may just drive on top of them.

Instead of a half track I'd of considered 2 per side like some of those arctic vihicles, but then again is it worth all the additional weight and work?

[Solace]

actually, our team solved the problem by having one of our axle's rotate vertically around the middle point. that way - no matter what angle we approach or exit the ramp from - we always keep all 4 wheels on the ground.

[Jeff Waegelin]

Surprise, surprise, the Technokats are using tracks. I think I could've guessed that one. You guys are just too predictable

[Andrew Rudolph]

Looks like you guys are using the brecoflex self tracking pullies and timing belt. i always wanted to use that stuff for a tracked system, it will be very difficult to push this robot from the side to dislodge the tracks. congrats 45 on another sweet drivetrain