pic: Team 100 Prototype Base - Underside

[Jeff K.]

This is a really nice example of a modifiable prototype chassis. 55 lbs ain't bad, our mecanum base last year was 80 lbs, while the arm was 30 or so. With all the weight down low, we never were close to tipping over. The method of tensioning is also a pretty slick idea. How heavy are the wheels? Will you be using a similar chassis layout with the box extrusion?

[Cory]

Pretty cool guys. I agree with Travis. Looks extremely well designed. Wish we had ever had our acts together enough to have an offseason project as nice as that when I was on the team

For those criticizing the weight, there's all kinds of weight they could easily remove. The sprocket hubs can be turned down. The gears in the AM shifters can be lightened. The big CIM's can be swapped for small CIM's.

Even without swapping the CIM's, I'd say they could cut 2-5 lbs pretty easily.

[Brandon Holley]

I would not worry about the 55 lb drivetrain you got there. With electronics that is a PERFECTLY acceptable weight. I like the whole setup you got here. Good job.

[Blue_Mist]

It's organized and simple, and very light for a drive train and frame and electronics and pneumatics. However, as Squirrel said, weight down low isn't a bad thing. We try to keep a low center of gravity and almost never tip, although the ramps were sometimes a problem and we aren't considered fast. I like how neat and clean the chains are- no tensioners. If I may, I think the motor wires might do better tied against the frame to keep them out of the way. Just my opinion. I do like the frame extending to protect the wheels in the front and back. That would be a nice place to put bumpers; mount them with bolts on either side of the wheels. And good looking welds, too, from what I can see.

Sorry for bashing the weight. I spent too much time thinking about that one number. It is quite the nice system. How quick is tensioning?

Also, do you happen to know around how much the electronics board in whole weighs? I'm curious as to whether or not this thing would be lighter with a less hefty board.


Very nice, and props on getting something together before the season! I know it's not easy, as all of my attempts at doing this have been shut down.

Props!

[MrForbes]

A piece of plywood can be kind of heavy, or not....depending on what you use. 1/8" lauan plywood is fairly rigid, light, and not very expensive, usually available in part sheets from big building supply places.

[=Martin=Taylor=]

Originally Posted by 114ManualLabor

Sorry for bashing the weight. I spent too much time thinking about that one number. It is quite the nice system. How quick is tensioning?

Also, do you happen to know around how much the electronics board in whole weighs? I'm curious as to whether or not this thing would be lighter with a less hefty board.


Very nice, and props on getting something together before the season! I know it's not easy, as all of my attempts at doing this have been shut down.

Props!

Its a sawed off piece of our 06 ramp, I believe its 0.5" thick. We also used four different fuse boxes because that was all we had. I think the major weight came from the Big CIMs. As Cory said, those big CIMs weigh significantly more than the small CIMs. We used them because we didn't have any of the small pinion gears that are needed for the small CIMs in the AM shifters.

Tensioning is really easy. You just loosen three bolts and slide the bearing block into place and tighten it down. And no, the blocks don't slip. The chains will stay tight until they begin to strech.

Originally Posted by Cory

For those criticizing the weight, there's all kinds of weight they could easily remove. The sprocket hubs can be turned down. The gears in the AM shifters can be lightened. The big CIM's can be swapped for small CIM's.

Even without swapping the CIM's, I'd say they could cut 2-5 lbs pretty easily.

Yes, there are many things we could have done to lighten it. But it all would have taken time and money and the purpose of this system is to create a simple prototype base.

For the competition version we may use 7075 or 7068 aluminum for the axels. Any advice on that?

[Cory]

Originally Posted by Hachiban VIII

For the competition version we may use 7075 or 7068 aluminum for the axels. Any advice on that?

Nothing too special you need to do. ours are just plain old 7075 1/2" main diameter, with 7/16" hexes on either end. No heat treatment or hardening necessaary

[Ross340]

340's proto frame weighs somewhere around there made of 3/4 bar stock. it's so bulletproof. We love it.

[team2061]

What is being used to hold down the electronics and other stuff because in the 2007 season we screwed and bolted everything down.Bad idea it bit us in the butt big time.I heard zip ties are the best way to go.

[caraddicted101]

I have seen some teams use zip ties as they are easy to cut and replace, I have also seen some teams use strong Velcro, as it is even easier to change a component then zip ties. As for me, we had a little room and just put a few extra spikes on the robot unwired that way we would only have to pull the wires off the bad one and we would be good to go.

[Andy Baker]

This is a great drivebase. Kudos to you for not only getting a prototype put together in the off-season, but also having the guys and GP to post it on this site, for all teams to see.

The only advice I can think of at this time (for your competition version) is for a different material for the electronics board. The plywood is lightweight and easy to use, but a perforated sheet material (aluminum or gray PVC) works great. If you use this sheet, there is no need to drill holes when you mount your electronics and route your wires. I would suggest 3/32" thick aluminum or 1/8" thick PVC perforated sheet with 3/16" dia holes to start with. McMaster-Carr, MSC and other places sell this stuff.

Andy B.

[lukevanoort]

This looks really solid guys! Doesn't quite have the intimidation factor of those massive pneumatic wheels that your last drive base had, but I imagine it'll serve you guys much better! In the last couple of years, we finally abandoned big pneumatic wheels as well, and we'll probably never go back; it is so much simpler not to have to worry about whether wheels are equally pressurized, if anyone packed the tire pump, whether the tire is leaking air, and so on. (much lighter too)

Originally Posted by Andy Baker

I would suggest 3/32" thick aluminum or 1/8" thick PVC perforated sheet with 3/16" dia holes to start with.

I was planning on using the perforated aluminum on our robot next year, but I'm curious about how well it (and PVC too, which actually sounds like a more attractive material to me) handles the weight of the circuit breaker panels and the distro block. Have you experienced any issues with tearing or extreme bending with the heavier parts?

[AdamHeard]

Allways good to see teams being productive in the off season.

55 Lbs isn't bad at all, especially with the possible weight savings of a lighter board and the small CIMs.

Also, I'm liking the very minimal amount of fabrication that had to be done.

Overall, great job. I'll be sure to look out for it at silicon valley.

[=Martin=Taylor=]

Originally Posted by Andy Baker

The only advice I can think of at this time (for your competition version) is for a different material for the electronics board. The plywood is lightweight and easy to use, but a perforated sheet material (aluminum or gray PVC) works great. If you use this sheet, there is no need to drill holes when you mount your electronics and route your wires. I would suggest 3/32" thick aluminum or 1/8" thick PVC perforated sheet with 3/16" dia holes to start with. McMaster-Carr, MSC and other places sell this stuff.
Andy B.

We usually use 1/8" ABS plastic for the board. But its kinda expensive to waste on something that will never see competition.

Originally Posted by team2061

What is being used to hold down the electronics and other stuff because in the 2007 season we screwed and bolted everything down.Bad idea it bit us in the butt big time.I heard zip ties are the best way to go.

Yes, all the components are held on with zip-ties. This is a great way to attach stuff IMO. We just drill one hole, stick a zip tie through, and stick another zip-tie on the bottom. This creates a little plastic bolt that can be cut and replaced as needed.