pic: One-day Minibot

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[Jim Wilks]

Looks Great!

Any details on the switch at the top?

JW

[DonRotolo]

It takes a whole day to reach the top? I think that might be too slow

[Chris is me]

I'm very surprised that this minibot took 1.6 seconds to go up. My guess says it should go up in about 1.2.

Good job with the minibot. I expect this on every robot by the end of the year...

[PhilBot]

OMG... I started building that exact same robot yesterday.

My design had the magnets above and below the rollers as I didn't know if your configuration would provide enought vertical allignment. I even have that same top switch from Lowes.

I see that you have a limit switch to turn the bot on when it contacts the pole. I was planning to turn it on as it left the robot, but your's is probably more universally interchangable.

Too Cool.

Phil.

[Chris is me]

Originally Posted by PhilBot

I was planning to turn it on as it left the robot

It may be worth it to spin up the robot before you touch the pole. Play around with it and find out

[jvriezen]

Originally Posted by PhilBot

OMG... I started building that exact same robot yesterday.

My design had the magnets above and below the rollers as I didn't know if your configuration would provide enought vertical allignment. I even have that same top switch from Lowes.

One of our early minibot designs had magnets above and below drive wheels but we found that if deployment wasn't good, the bot would attach with one magnet in contact with the pole, which works very well at increasing friction and helps in the production of smoke signals. Putting the magnet between the rollers assures there is no way the magnet can touch the pole.

John Vriezen
Team 2530, "Inconceivable"
Mentor, Drive coach, Inspector

[VKP]

What material did you use for the rollers? It looks like some sort of rubber. Did you take it off of the Tetrix wheels? Or is that electrical friction tape?

[JB987]

Originally Posted by Chris is me

I'm very surprised that this minibot took 1.6 seconds to go up. My guess says it should go up in about 1.2.

Good job with the minibot. I expect this on every robot by the end of the year...

He said 1.6 seconds from the base. Maybe he is referring to time it takes from breaking the plane at start of deployment to the trigger? Anyways, this looks much like our new iteration. Wonder if he left the pinion on and used set screws not visible from the front view to hold or if this is a straight press to the motor shaft. Nice work.

[BIGWILLI2081]

how did you connect the motor shafts to the bigger shaft?

[216Robochick288]

Honestly, you don't even need the magnets. you could go a similar design with PVC that is just slightly bigger than the diameter of the pole then cut about 60 degrees out of it to hold to the pole with the motors under... its a brilliant design. Simple too.

[TEE]

can't see the battery

[VKP]

Originally Posted by BIGWILLI2081

how did you connect the motor shafts to the bigger shaft?

Our team began making a minibot like this. We took the Tetrix axles and used a lathe to bore a hole in them the diameter of the motor shafts, and then press-fitted them on.

[undefined117]

I have found that magnets make the minibot slower becuase they add friction, If you have any extra time you may want to work on getting some pvc to snap onto the pole. Our minibot can get up in 1.2-1.3 seconds.

[Nikhil Bajaj]

Just a note: you are correct in stating that the magnets can potentially add to the damping in the system and slow the mini-bot down. However, this is not friction, unless you are rubbing the magnets or something else on the pole.

http://en.wikipedia.org/wiki/Eddy_currents

This is a very common high school physics class demonstration, taking a vertical aluminum tube and sliding a magnet down it towards the ground. It can take longer than one would expect.