pic: OH GOD! WHAT HAVE I DONE???

[EricH]

Originally Posted by JVN

Eric,
As noted by the "FTW" I was referring to their WINNING robot, not it's ancestors.

I've been a huge fan of the super-elegant 2005, 2007, 2008 Beachbot robots. In 2005 & 2007 in particular I loved the 4-bar designs my teams utilized, but then saw that 330 could score as well or better with just a single joint. Simplicity yields elegance.

-John

Actually, I can only think of 2 330 robots with more than 1 degree of freedom. It's just that 1999-2002 had lifts. 1998 had 2 degrees; 2004 was as shown. (2003 was a 4-bar.)

[FoleyEngineer]

Originally Posted by Kevin Sevcik

One CIM puts out about 25 in-lbs of torque at 40A.

Hi Kevin,

Where do you get this figure from? I'm looking at the performance curve for the CIM and it looks like at 40A it's generating about .8Nm of torque which works out to .59 ft-lbs, or about 7 in-lbs - not 25 in-lbs as you suggest.

Maybe I'm mistaken. Wouldn't be the first time! Anybody?

Thanks!

[AdamHeard]

Originally Posted by Jonathan Norris

I would have to say this looks like a fun CAD project to work on, but very unpractical to combine those two systems in real life. By adding a telescoping section to a poof style 2-jointed arm you are basically adding a redundant system to achieve the same goal. The whole point of the lower joint on the 'poof' style arm is to extend the arm to reach farther, higher ect. which can also be achieved by a 'pink' style telescoping arm with a lower joint. So unless you really can't achieve your goal with a 'poof' or 'pink' style arm, I guess this system could work... but that's very unlikely and makes this kind of system unnecessary.

The one advantage I can think of is having to reach up, and far over a large object. However, can't remember too many times this would be beneficial.

[Jonathan Norris]

Originally Posted by FoleyEngineer

Hi Kevin,

Where do you get this figure from? I'm looking at the performance curve for the CIM and it looks like at 40A it's generating about .8Nm of torque which works out to .59 ft-lbs, or about 7 in-lbs - not 25 in-lbs as you suggest.

Maybe I'm mistaken. Wouldn't be the first time! Anybody?

Thanks!

Looks like he is taking about stall torque, which is a bit less then 25 in-lbs. Yes we run 40A breakers, but the amperage will spike a lot higher then 40A before the breaker trips. From my rough understanding with 40A breakers on a CIM we can get all the torque out of the motors. The only time I can remember hearing the breakers trip is stalling our drive against a wall...

[joshy1323]

congrats im very impressed with your cad work. do u have any other completed designs? and how long did this take to draw this up? im sure u included all the measurements and materials in your design or you wouldnt have been able to calculate the weight and also to do that i am sure u were able to calculate the load it can take in different directions. if so what type of aluminum do u intend to use? is this design just an after thought that u wanted to get opinions about or is this something u want to use? if you are planning to use it idk if u should show the needy eyes all us competitors ur plans like this. again i wanna stress that i am very impressed with ur cad.

[EricH]

Originally Posted by joshy1323

congrats im very impressed with your cad work. do u have any other completed designs?

He does. He's actually one of the three most shown Solidworks designers on these forums. One of your teammates and another Northern California member are the other two. Search CD-Media by the uploader using these three members' names and you'll find plenty.

[roboticWanderor]

Originally Posted by joshy1323

congrats im very impressed with your cad work. do u have any other completed designs? and how long did this take to draw this up? im sure u included all the measurements and materials in your design or you wouldnt have been able to calculate the weight and also to do that i am sure u were able to calculate the load it can take in different directions. if so what type of aluminum do u intend to use? is this design just an after thought that u wanted to get opinions about or is this something u want to use? if you are planning to use it idk if u should show the needy eyes all us competitors ur plans like this. again i wanna stress that i am very impressed with ur cad.

I DO THIS STUFF FOR FUN.
Really, I do. I ran into a snag trying to figure out the gear ratio it needed for the design, so I decided to post it up here looking for help. I do most of my calculations using the JVN calc to make it easier, then optimize the ratios for part availability, machining complexity etc.

And yes, I have many other designs posted up here, and yes I put in all of my materials as I CAD my parts, this one in particular is made of 6010 (correct?) alum, and steel axles, sprockets, gears etc. what you saw is what SolidWorks did it's mass calculations from.

Also, i realize this design is completely, and utterly complex. I would not really even consider building something like this. But CAD allows us to dream right?

[techtiger1]

I agree with John V Neun simplicity is elegance and it works. This is me comming from a team thats made an award winning 8 wd 6 motor 2 speed drive system and a 5 axis arm. I like the fact that its CAD work practice and your asking really vaild questions instead of arguing why or why not this is needed. This is what should be happening on Chief Delphi people. Good work keep it up.

-Drew

[AdamHeard]

Originally Posted by roboticWanderor

I DO THIS STUFF FOR FUN.
Really, I do. I ran into a snag trying to figure out the gear ratio it needed for the design, so I decided to post it up here looking for help. I do most of my calculations using the JVN calc to make it easier, then optimize the ratios for part availability, machining complexity etc.

And yes, I have many other designs posted up here, and yes I put in all of my materials as I CAD my parts, this one in particular is made of 6010 (correct?) alum, and steel axles, sprockets, gears etc. what you saw is what SolidWorks did it's mass calculations from.

Also, i realize this design is completely, and utterly complex. I would not really even consider building something like this. But CAD allows us to dream right?

I think you mean 6061 Aluminum . Most hollow extrusion is most commonly available in 6061 alloy.

Originally Posted by EricH

He does. He's actually one of the three most shown Solidworks designers on these forums. One of your teammates and another Northern California member are the other two. Search CD-Media by the uploader using these three members' names and you'll find plenty.

However flattering that may be, I don't deserve any credit for Solidworks. I know how to use it, but I'm much more adept in Inventor right now. If you want to see some really nice CAD in solidworks, check out Madison's stuff; she's quite skilled in that department.

-Craig

[Kevin Sevcik]

Originally Posted by FoleyEngineer

Hi Kevin,

Where do you get this figure from? I'm looking at the performance curve for the CIM and it looks like at 40A it's generating about .8Nm of torque which works out to .59 ft-lbs, or about 7 in-lbs - not 25 in-lbs as you suggest.

Maybe I'm mistaken. Wouldn't be the first time! Anybody?

Thanks!

You're correct, that was a typo on my part, or some such. I intended to use the 100 oz-in at 40A figure you can get from the CIM dimension sheet, which puts it at 6.25 in-lbs. I used that figure in the rest of the math, however, so the ratio still stands.

Originally Posted by Jonathan Norris

Looks like he is taking about stall torque, which is a bit less then 25 in-lbs. Yes we run 40A breakers, but the amperage will spike a lot higher then 40A before the breaker trips. From my rough understanding with 40A breakers on a CIM we can get all the torque out of the motors. The only time I can remember hearing the breakers trip is stalling our drive against a wall...

You can't get anywhere near stall torque out of the CIMs. The circuit breakers, Victor/Jaguar, and motor will all eventually prevent you from doing so. In the past, FIRST has arranged things so it's the circuit breaker that keeps you from using stall torque for any length of time, to protect your investment in your motors and speed controllers. Rest assured, that circuit breaker trips somewhat before your Victor would melt, and that your Victor would melt before your motor did. But the motor would most certainly do so if you stalled it for too long.

The 40A breakers we use will trip in at most 0.6 seconds at the 133A that stall torque would draw, so it's not really available for a useful amount of time, beyond stating up.

[Triple B]

pink uses alot of 6063 AL tubing also.
nice cad work wanderer.
mike d

[joshy1323]

thank u erich i am relatively new to CD and im very good friends with RC. i see his designs before this site does usually and he is training me on how to use solidworks right not but im already used to his work im more interested in what others have to show. i did not kno that he was so well known on here btw i guess it adds up though since im often making fun of him for always being on here. btw i see ur kind uf well known on CD and im curious as to how to make a name for myself. RC says just start posting but i feel like i have no voice as a new member. any advice?

[EricH]

Originally Posted by joshy1323

t btw i see ur kind uf well known on CD and im curious as to how to make a name for myself. RC says just start posting but i feel like i have no voice as a new member. any advice?

Follow RC's advice. We all start from the same place. If you aren't comfortable, try the Chit-Chat forum until you get a feel for the site. Also, if there's a forum that interests you, that can also be a good place. (For me, it was Rules/Strategy.)

[Akash Rastogi]

Originally Posted by joshy1323

thank u erich i am relatively new to CD and im very good friends with RC. i see his designs before this site does usually and he is training me on how to use solidworks right not but im already used to his work im more interested in what others have to show. i did not kno that he was so well known on here btw i guess it adds up though since im often making fun of him for always being on here. btw i see ur kind uf well known on CD and im curious as to how to make a name for myself. RC says just start posting but i feel like i have no voice as a new member. any advice?

As a good friend of RC's, welcome to CD
Post if you have a valid question that hasn't been found through the "search" feature up top. Seems like we share a common teacher.