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-   -   quick question to all about why using KOP metal. (http://www.chiefdelphi.com/forums/showthread.php?t=63423)

artdutra04 06-02-2008 21:11

Re: quick question to all about why using KOP metal.
 
Quote:

Originally Posted by CuriousGeorge (Post 693539)
well if u have one high torqued robot pressing against a KOP bot (which happened in 06 for me) it could break, i did it myself.. i drove the robot.

ive also see some KOP robots run str8 into walls and fall apart

what im trying to figure out with this thread is why people use KOP bots.. i personally dot understand it

It seems like these observations are skewed by a confirmation bias. Because one thinks that the Kitbot is inherently weak, their attention will automatically be driven towards Kitbot failures and will often overlook contrary evidence (non-Kitbot robots breaking).

I've seen just as many non-Kitbot chassis robots bend/break as Kitbot ones.

No matter what choice you go with (KOP or custom), if you don't build it right it will break.

Torboticsmember 06-02-2008 21:21

Re: quick question to all about why using KOP metal.
 
Our team used the KOP chassis last year, and were fine with it. Which is why we are using it again this year.
We weren't very aggressive but the few times we were it held up for us fine.
If you put it together properly than it is very strong.
Time is a big reason for us, knowing our team it would be a week and a half to design the chassis and another week to actually build it (exageration of course)
and finally money is a big issue with so much other things that don't come in the kit we don't have the money to go buy another frame to be made.

GaryVoshol 06-02-2008 22:03

Re: quick question to all about why using KOP metal.
 
Quote:

Originally Posted by CuriousGeorge (Post 693485)
why not just buy stock and weld?

Lack of money, facilities, time or expertise are good reasons.

A few days after Kickoff, one group from our team was drawing out plans for a custom made frame. We would have someone machine it for us. The other half of the team, for lack of anything better to do at the time, decided to put the kit frame together for prototyping until we got our real frame made. Without looking at the instructions (because we didn't have internet hooked up in the room at the time) we managed to put it together in an hour or so. Then got some old wheels out of the closet and put them on axles through the kitbot frame. We looked at it and thought, "Hmmmm - it might work." We've gone with it, made a couple minor modifications, and it looks like it will work out well for us.

With a tower made of 8020 attached. :rolleyes:

EricH 06-02-2008 22:56

Re: quick question to all about why using KOP metal.
 
Here are some reasons: Cost. Time. Resources. Strength.

The team I am currently mentoring is a "low-resource" team. No welder. Hand tools only. It's taken us long enough just to get the thing running...imagine if we made a custom frame. Also, it's free, and I personally have NEVER seen one break. Not even bend. (I did tell the team to loctite the bolts for the final build. Hopefully they will, so no robot droppings.) Plus, it's extremely versatile--I can think of three different drivetrains that would just slap in in about 10-15 minutes.

dtengineering 07-02-2008 01:40

Re: quick question to all about why using KOP metal.
 
You've seen a kitbot frame BREAK?

I won't contradict that evidence, but will agree that with the vast majority of posters on this thread that... properly assembled... the things are darn near indestructible when used in FRC applications. We've used them ever since they were part of the KOP... and while we chop them, mill them, weld them and flip them upside down, they always come out far stronger than we need.

I guess you can make anything break if you build it to break (although the kitbot frame is pretty hard to screw up), but anything that breaks a kitbot frame is probably breaking most custom frames of similar weight, too.

Jason

Jimmy Nichols 07-02-2008 07:44

Re: quick question to all about why using KOP metal.
 
Quote:

Originally Posted by CuriousGeorge (Post 693566)
we broke one robot at the joints (this i know was bolts and such)

and one robot snapped at the front KOP bar trying to run into us as we ran into them

also made one robots side KOP bar bend severly from the side

This thread seems to be going in cirlces. CuriousGeorge doesn't seem to me that he will be convinced that the KOP frame is a great frame, when biult and reinforced properly.

We have been using it for 3 years now and have not had any issues, when it was biult properly. We chopped it up a little for Aim High and had some bowing issues. Last year no problems and we were beat on pretty heavy last year, and I foresee no problems this year.

We have the facilities and resources to make whatever we want and we have used welded frames and bolted frames and we prefer the bolted. One big reason, if a weld breaks at competition and there are no welding facilities, your robot may not operate the same. I've seen that happen to welded frames at competition and the robot was never the same again.

I think it is time to agree to disagree.

Brandon Holley 07-02-2008 08:35

Re: quick question to all about why using KOP metal.
 
Quote:

Originally Posted by CuriousGeorge (Post 693539)
well if u have one high torqued robot pressing against a KOP bot (which happened in 06 for me) it could break, i did it myself.. i drove the robot.

ive also see some KOP robots run str8 into walls and fall apart

what im trying to figure out with this thread is why people use KOP bots.. i personally dot understand it

fortunately for you, people dont need to justify their robot design to yourself.

in all seriousness though, the KOP frame is surprisingly strong for what you get. Its there on day 1 ready to build (unless your in brazil, sorry guys) and it gets you moving right off the bat.

some teams don't have access to a welder to weld box beam together. bolting a frame together can also turn into a mess if your not doing it right/ don't know exactly how to do it.

we do not use the KOP frame on our robots because we have the capability to make something better suited to OUR needs, it doesn't mean other teams do as well.

dragoonex 07-02-2008 12:26

Re: quick question to all about why using KOP metal.
 
Our team found the KOP frame to be quite strong. We built our 2006 and 2008 bot out of it. Our 2007 bot was built out of 10-10, and 20-10. Regardless, both bots have held up well. We've jumped roadside curbs, ramps, pulled wheelies, and hit lockers and walls at full speed with our 2006 bot and besides losing a few screws which weren't loctited, it hasn't sustained any damage.

The KOP frame is useful for us, because it's light, easy to assemble, and it is easy for new team members to build. Of course, it's strength depends on how it's built, but we haven't had any problems.

Jon Stratis 07-02-2008 12:53

Re: quick question to all about why using KOP metal.
 
We've been using our robot from last year for test driving this year, and while many things have gone wrong with it (we've lost some bolts and other pieces, the main circuit panel popped off and pulled out a few wires, etc), the frame is still as good as it was when we went to our competition last year. And trust me - our drivers have driven it straight into cement walls and pillars... one even almost too a door off it's hinges with it!

The frame is definitely strong enough - I would attribute any breakage to "user error" - bad nuts and bolts, improper mounting of other pieces to it, etc.

s_forbes 07-02-2008 13:13

Re: quick question to all about why using KOP metal.
 
We've never used it, but I have seen plenty of teams use it at regionals that have had no noticable problems. It's quick and easy to use. This is the only kit frame I've seen break, and it wasn't caused by another robot...


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