27-08-2009 11:25

Jared Russell

Re: pic: 6WD Chassis

1) Great job! Thanks for sharing.

2) You could probably eliminate some of those vertical supports and still have sufficient frame rigidity.

3) 59 lbs sounds a little heavy for what is pictured (are you including the battery in this weight?). What kind of material, e.g. wall thickness, is your structural tubing?

27-08-2009 12:27

Akash Rastogi

Re: pic: 6WD Chassis

The vertical supports in the rear of the frame can be reduced/ be placed in larger increments depending on what goes on top. Also, based on the game, you'd always have the chance of removing the front cross rail and replacing it with an opening.

EricH suggested 1/8" wall tubing, but this was when Rion had a single tier frame (no vertical supports and no top half) so would 1/16" wall be sufficient in this two tier frame?(vertical supports with top half)

27-08-2009 12:35

Rion Atkinson

Re: pic: 6WD Chassis

Thanks for the supports advice. I will definitely pull some out.


Ya.. i was thinking it was a little heavy... Yes the battery is included. The wood board... Inventor thinks that is Aluminum 6061, I can't find a wood option and it was originally going to be that.

The frame is made of 1" extruded aluminum(sides are 1/8").

27-08-2009 13:29

Tom Line

Re: pic: 6WD Chassis

You're going for the wide chassis footprint rather than the narrow.

You don't need 6 wheels to rocker a wide chassis - it turns fairly well with 4.

27-08-2009 13:33

sanddrag

Re: pic: 6WD Chassis

I would definitely keep 1/8" wall for the outside perimeter, and I would question the need for that upper deck. I like the battery box. You may consider flipping the battery around, and putting a mounting tab to hard mount the Anderson Powerpole connector to the box.

Having the middle wheel could be useful for games with ramps, such as 2006. 696 did a design similar to this, and it allowed them to use 3.5" wheels and have only 3/16" ground clearance, and still negotiate the ramp without high centering.

27-08-2009 13:54

Rion Atkinson

Re: pic: 6WD Chassis

Actually. I will be designing a narrow as well. I figured I would "perfect", so to speak, the wide chassis first.

The upper deck is actually what I used to mount the AM SS....

27-08-2009 16:36

BrendanB

Re: pic: 6WD Chassis

One suggestion, I wouldn't have the C'rio up against the front in case you get a hard it. It happens a lot. I don't think any team wants to have the most expensive piece of there robot be destroyed.

27-08-2009 19:31

Dillon Carey

Re: pic: 6WD Chassis

What is the indent in the front for?

27-08-2009 19:44

Rion Atkinson

Re: pic: 6WD Chassis

Nothing really.. I could move it forward, but there is really no need.. Save weight! (Even if only around .5 lbs...)

27-08-2009 20:58

Akash Rastogi

Re: pic: 6WD Chassis

Actually, many teams mounted their cRIO that way and even perpendicular to the ground. Even without zipties, I don't think any team had loose modules or a broken cRIO. It can take impacts pretty well.

27-08-2009 22:17

Dillon Carey

Re: pic: 6WD Chassis

Ok, i was thinking you were trying to plan ahead for some sort of pick up system.

28-08-2009 12:19

Taylor

Re: pic: 6WD Chassis

I assume the tabs along the sides are for bumper attachment. Given the limited hand space there, are you thinking cotter pins through bolts to hold them on?

28-08-2009 14:10

kramarczyk

Re: pic: 6WD Chassis

Yeah, the cRio has been known to take a beating.
http://decibel.ni.com/content/docs/DOC-6176

We used some quick release pins from McMaster-Carr (p/n 98320A140) on two robots this year. No bottom access required. We had zero perfomance issues and zero inspection issues (some of the inspectors actually liked them).

28-08-2009 16:49

AndyB

Re: pic: 6WD Chassis

Very interesting. I knew the cRio could take a hit, but that's unbelievable.

I would have no concerns about moving your cRio. Just make sure it's easy to access.

You'd be safe using 50 lb/ft^3 density for your wood panel. Aluminum is about 3 times that (I just looked up the densities for for particle board and 6061 aluminum for these numbers). http://www.engineeringtoolbox.com/wo...sity-d_40.html has a list of densities for various types of wood.

28-08-2009 16:56

BrendanB

Re: pic: 6WD Chassis

WOW!!!!

That really does take a beating. Guess I now know what is the strongest part of the robot.

28-08-2009 17:10

Rion Atkinson

Re: pic: 6WD Chassis

That was the original plan, but there isn't really enough room... I could always make the chassis bigger than 35 x 25...

Pretty much yes.

28-08-2009 17:19

Rion Atkinson

Re: pic: 6WD Chassis

The only problem is wood is not an option to choose from.. And I don't if you can manually change the density in Inventor...

28-08-2009 21:19

EricH

Re: pic: 6WD Chassis

You can. I forget how, but you can. And if wood isn't an option, then I just lost respect for Inventor. You go into the properties, and pick your type of wood--pine or oak should do the trick. (It doesn't have "wood" as an option because every wood is a different type of wood, and has a different density.)

28-08-2009 23:20

MrForbes

Re: pic: 6WD Chassis

Somehow we modeled ours in Inventor last winter...huh....

http://www.chiefdelphi.com/forums/sh...ad.php?t=71902

29-08-2009 13:19

Rion Atkinson

Re: pic: 6WD Chassis

I went through all materials. Not a single type of wood. In the 2009 Inventor There was. They were listed as "Wood (Pine)" or "Wood(Oak)". But when they upgraded to 2010 they must have take it out...

It is possible to just change the texture (As I did). But odds are you made it in 2009.

29-08-2009 14:15

Akash Rastogi

Re: pic: 6WD Chassis

Are there certain add-ins that you don't have enabled? I don't use Inventor but just a suggestion.

29-08-2009 15:34

GUI

Re: pic: 6WD Chassis

I don't remember exactly where it is, but in the iProperties of a part you can change the density to a custom value.

29-08-2009 16:39

Rion Atkinson

Re: pic: 6WD Chassis

No. All the other add-ins not enabled are just converters for other CAD programs..

I went through all the IProperties.. Couldn't find it...


I think its time to switch to solidworks..

29-08-2009 17:08

MrForbes

Re: pic: 6WD Chassis

You definitely want to be using a wood friendly modeling program. Wood is where it's at.

29-08-2009 17:13

Rion Atkinson

Re: pic: 6WD Chassis

Maybe I'll switch back to Inventor 2009 until I can get solidworks somehow....

29-08-2009 19:25

R.C.

Re: pic: 6WD Chassis

Just to Support Solidworks. One of the main benefits with Solidworks is that it is used more in the industry. In our area 12 out our 15 sponsoring (Engineering Companies) companies use Solidworks. Most of their partners use it also.

Also Solidworks has a wide range of add ins and the workflow is Fantastic. If you want a Copy of Solidworks, Marie Planchard would be the person to contact, Solidworks Rep for FIRST.

-RC