Re: Standard vs. Custom Frame
 

I anticipate using the kit frame next year with our young team, but we'll see. We are engineering resource limited (although we have a "Tytus" which makes up for it) so we'll use every available asset we can.

Here's another process that I have applied to components in general - treat the kit chassis as the prototype chassis, and test out your prototype mechanisms on it. As resources become available to design & fabricate the actual "production" components (including the chassis), replace the prototype component with the production component. If any production component doesn't get completed, you have the prototype to compete with.

Re: Standard vs. Custom Frame
 

In 2005 (that time I was mentoring team 134) team 134 decided to use the kitbot frame, rather than replicating our 2004 chassis (which was sweet).

What did we gain?
- A fully drivable base within the first week, to evaluate and for testing.
- A solid base for the rest of our super structure.
- Cheap Cheap Cheap.

Now albeit the results for the year were not spectacular, the robot base and frame did what it needed to, with no problems. And after the 05' season, we compared the results from 04' to 05' and we had came to the conclusion that neither one was any superior than the other.

As far as I know, a robot chassis is not judged on "sex appeal", and I'm sure the kitbot frame is comparable in weight to your frame. Please elaborate on why its not possible or practical to do "things" with a kitbot frame? You seem to always know everything, and I'd like to be enlightend.

Re: Standard vs. Custom Frame
 

I've got no ideaw what Dave thinks the kitbot's shortcomings are, but here are mine-

No easy/good way to directly output to the center wheel in a 6wd format

No way to tension chains by sliding the wheels

No easy way to use live axles

No easy/good way to run your wheels outboard of the frame.

That list isn't meant to be a complaint. The kitbot is great for a number of teams, and anything that keeps teams from showing up to a regional with a robot that doesn't drive is great in my book. It's just not very optimal when you move on to more advanced designs.

Re: Standard vs. Custom Frame
 

i would go custom, in the end it ends up being easer because you can diesgn it to fit the robot and not the other way around. and who needs CAD, i do everything to a 1cm for complex to 10cm for big simple components on graph paper, and the best part...you still have the design at 3:00 am ship day when the power goes out. another helpfull thing is full-scale cardboard mockup, you can never go wrong with cardboard and duct tape.

Re: Standard vs. Custom Frame
 

I'll concede all the points except live axles--I remember 1293 switching Ockham (which was originally kit frame and dead axles) to a live-axle setup in a leisurely-paced Saturday during the off-season. They used the bearings and blocks (and wheels, for that matter) from 2004.

Re: Standard vs. Custom Frame
 

I was refering to not being able to just bore the frame out for a bearing. You could mount your own pillowblocks for sure.

Re: Standard vs. Custom Frame
 

For several years, we've used a "custom" frame made from 1" x 1" x 1/8" square aluminum tube. We just cut, drill and bolt it together with quality bolts and nylock nuts or nuts and lockwashers. Nothing special, but it has never failed us. We've learned to do this because we have a low budget and nearly zero access to machining and welding facilities. Besides, it is really inexpensive and durable.

Re: Standard vs. Custom Frame
 

http://joemenassa.com/Images/ROBOTIC.../IMG_3865.html

That is 121's chassis, I believe it was live axel, it was definitely 6 wheel drive, and they tensioned the chain with out using sliding wheels. This drive system proved to work out very well for them with regional wins both years that they used the kit frame. 121 certainly used it for more than just showing up with a driving robot. I would say that their designs were certainly effective. The kit bot doesn't seem to limit what you can do.

Re: Standard vs. Custom Frame
 

We have used the kitbot frame with different wheels for the past 2 years.
That is mainly why we have used it.
In 2006 we won our regional, and had a good bot (i think). However were not able to collect balls as well as some teams with a different frame. It can limit your robot's ability and quality, but it doesn't require any designing, is easy to build and is is strong.
Although a custom frame is more versatile it can be hard to design and more complicated to build.

Re: Standard vs. Custom Frame
 

I never said you couldn't make a good robot using the kit frame. Just that it's my personal opinion that I wouldn't if I had the resources to do otherwise.

Re: Standard vs. Custom Frame
 

Looks like there are sprockets attached to the wheels to me. Dead axle drive.
Hmm.. seems like they tensioned the chain by pushing in the slack in the middle of the chain run. It looks tight in this picture, but remember this is a picture from the build season. In my experience FIRST robots get about a link and half of chain stretch over an event. Having an adjustable, simple tensioner may (or may not) prove to be worthwhile.

Re: Standard vs. Custom Frame
 

I am almost positive it is live axle, I know I talked to Rob from 121 about it, if you look at pictures of the robot from the year before you can see the drive system better, the design is almost Identical, other than the addition of more clearance this year.

Re: Standard vs. Custom Frame
 

They used bushings.

If you want to use bearings (which most people do), you can't do it without mounting pillowblocks on the top of the frame.

Re: Standard vs. Custom Frame
 

Touche

Re: Standard vs. Custom Frame
 

This thread has started to drift a little, but I will pull it back towards the original focus.

The kitbot frame is one of the best things FIRST has done to help rookie teams. Teams that don't have access to machine shops or lack the engineering support to design their own frames can use the kitbot frame easily. It is robust, comes with a fairly good drive train already, and is already designed and fabricated. There may be a weight/customizability/quality trade off, but if you have the choice between having your not-so-hot self-made frame breaking and you being dead for the rest of the competition and using a less-than-perfect kitbot frame, I think the decision is easy.