28-02-2005 10:49

Josh Hambright

Re: pic: ThunderChicken Transmission Teaser

YAY! Sweet looking transmission.

Everbody give it up for Fish & Chips! Best combo ever

28-02-2005 12:05

marccenter

Re: pic: ThunderChicken Transmission Teaser

Did you find that the extra motors weight was necessary for the
torque required to implement your game strategy? We found that
we were close to our weight limit and didn't need the extra two
CIM motors for driving, so we removed them from the FIRST
transmission and placed one on our elevator-style arm.

28-02-2005 12:13

Paul Copioli

Re: pic: ThunderChicken Transmission Teaser

Marc,

We determined early on that we wanted to be a fast capper so we wanted a pretty decent top speed (9.5 ft/sec). We also knew that teams would want to block us after we received a tetra from the auto loader, but before we actually left the auto loader. Given this assumption, we also wanted to maximize our pushing power without shifting gears.

Given our desired top speed, desire not to shift, and our pushing force desire we calculated that the 6 motor drive would give us what we wanted.

If we eliminate the FP from the drive, we would either need to reduce our top speed (increase gear ratio) to about 6.5 ft/sec or change tread material to decrease our coefficient of friction with the carpet in order to not trip breakers in a pushing match.

By the way, our practice bot is only using the CIM motors for drive because we are not getting in many pushing matches during practice.

-Paul

28-02-2005 12:35

Rick TYler

Re: pic: ThunderChicken Transmission Teaser

What kind of budget do you have to have to pay for a practice bot?

28-02-2005 12:53

Paul Copioli

Re: pic: ThunderChicken Transmission Teaser

We actually do not use that much money to build a second robot. We are a veteran team so we have many victor 884s and spike relays already on hand. We had last years controller already and just loaded the firmware to get us the required updates. We have acquired a few inexpensive machines for student use, because we allocate $1,000 each year that the mentors help raise in order to purchase tools/machines:

1. A mini mill for around $300 from Harbor Freight (acquired last year).
2. A mini lathe for $350 from Harbor Freight (acquired 2 years ago).
3. A combination Lathe/mill for larger jobs for $650 (acquired over the Summer).

All shafts, small parts, brackets, spacers, etc. are made by the students in our "mini-shop" and we only pay for material.

Our arms are made from PVC that you buy at Home Depot, so they are inexpensive.

Our wheels (CNC machined), transmission housings (CNC machined), and sheet metal (laser cut and manually bent) are donated from two sponsors that we solicited four years ago and cost us no money (a few trips to their plants and some demonstrations).

Since we are only using one pneumatic cylinder this year, both cylinders were free from Bimba.

We spent another $500 for sprockets, gears, etc. for both robots that the students modified/lightened.

We require our students to raise $1,000 by soliciting sponsors. We are pretty fortunate that we live in an area with a lot of technology companies that the students can solicit.

I say we spent about $1,500 in hard cash for both robots. Not as much as one would think.

Ford Motor company provides us with a home (Ford Van Dyke Plant), pays for our first regional entry fee, and gives us another $1,000 to spend on robot parts. All other monetary donations come from donations solicited by students and mentors.

28-02-2005 14:34

sanddrag

Re: pic: ThunderChicken Transmission Teaser

I like the fully enclosed box. Was that cast?