pic: Team 1983 Fall CAD Project

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[Jamie Kalb]

I've been out of this competition a little too long to really comment on the overall design (although it looks very solid). Two quick things, though:

1.) I like the built-in follower wheels. Just so you know, VEX nows sells "dualie" omni wheels in that size, too: http://www.vexrobotics.com/products/.../276-1902.html

2.) Any particular reason the drive motors are up so high?

Keep up the good work!

[Akash Rastogi]

Originally Posted by Jamie Kalb

2.) Any particular reason the drive motors are up so high?

Keep up the good work!

It keeps the gearbox footprint out of the bellypan. Might be easier to work with things on there, but could also interfere with maintenance on the drive wheel below the gearbox.

Definitely looks solid though, what are the specs? Why the odd perimeter/flange on the edges?

[AllenGregoryIV]

Very nice design.

1. What pneumatic solenoids are you using? They look different than any I have seen but it might just be the angle.

2. How are the wheel shafts mounted to the frame? It looks like a 1/4-20 bolt.

[Jamie Kalb]

Originally Posted by Akash Rastogi

It keeps the gearbox footprint out of the bellypan. Might be easier to work with things on there, but could also interfere with maintenance on the drive wheel below the gearbox.

Hmmm... sounds like one of those "engineering tradeoff" things! I'm just wondering about the effect on the COG.

Also, the easy-to-access main breaker is major plus.

[Ninja_Bait]

The follower wheels are nice, but you could probably have mounted it upside-down so there's a little less metal under the belly and give yourself a little more clearance.

I always think that if you're going to build a robot in CAD you should at least figure out the correct center distance for a chain run, so I'm not a huge fan of tensioners. Just remember that the sliding one will probably slide, and often inopportunely.

Those are my only qualms, and it's really just an opinion thing anyway. Otherwise, it looks pretty solid and well thought-out. Very nicely done!

[Justin Montois]

Looks awesome. Great Job.

[Chris is me]

You'll definitely want to spring load those follower wheels for accurate tracking. Other than that, looks like you've put quite a lot of thought into this design!

[akoscielski3]

Sorry i'm asking this but what is the point of Follower wheels. What do the improve and how? I've never seen them before so i'm just wondering

I just finished my 7th Chassis in CAD (this year), im gonna put up the one that we are currently building for a prototype and the one I like the most in a different thread soon.

[Chris Fultz]

A follower wheel can have an encoder type of device connected to it to track distance traveled. Since it only rotates if the robot is actually moving, any wheel slip does not corrupt the distance measurement.

These were valuable in a game like the Rigolith game, where there was significant wheel spinning.

[Ninja_Bait]

Originally Posted by Chris Fultz

A follower wheel can have an encoder type of device connected to it to track distance traveled. Since it only rotates if the robot is actually moving, any wheel slip does not corrupt the distance measurement.

These were valuable in a game like the Rigolith game, where there was significant wheel spinning.

I imagine it is also very useful for mecanum, where it can be hard to predict exactly how the robot will move based on encoder values coming directly from the wheels, especially when strafing at odd angles.

[O'Sancheski]

Are those 4in AM Plaction wheels you are using or custom?

If they are the Plactions, did you make them or download them? Because I cannot find where to download. If someone can tell me where they are located I would be very appreciative.

[thefro526]

Originally Posted by O'Sancheski

Are those 4in AM Plaction wheels you are using or custom?

If they are the Plactions, did you make them or download them? Because I cannot find where to download. If someone can tell me where they are located I would be very appreciative.

http://www.andymark.com/product-p/am-0198.htm

Click the 'Files and Documents tab'.

[O'Sancheski]

Originally Posted by thefro526

http://www.andymark.com/product-p/am-0198.htm

Click the 'Files and Documents tab'.

Thanks,

For some reason that tab wasn't loading on my computer. (Tried on another and works.)

[JamesCH95]

The CAD looks nice, the only comment I have is that you seemed to have placed a lot of mass near the outside of the frame (motors and battery). Having that inertia out there will slow down your robot's turning speed. Maybe it's a problem, maybe it's not, just something to keep in mind.