View Full Version : pic: 6WD Chassis
Rion Atkinson
27-08-2009, 11:23
[cdm-description=photo]34214[/cdm-description]
Jared Russell
27-08-2009, 11:25
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?
Akash Rastogi
27-08-2009, 12:27
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?
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)
Rion Atkinson
27-08-2009, 12:35
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?
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").
Tom Line
27-08-2009, 13:29
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.
sanddrag
27-08-2009, 13:33
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. ;)
You don't need 6 wheels to rocker a wide chassis - it turns fairly well with 4.
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.
Rion Atkinson
27-08-2009, 13:54
You're going for the wide chassis footprint rather than the narrow.
Actually. I will be designing a narrow as well. I figured I would "perfect", so to speak, the wide chassis first.
I would definitely keep 1/8" wall for the outside perimeter, and I would question the need for that upper deck.
The upper deck is actually what I used to mount the AM SS....
BrendanB
27-08-2009, 16:36
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.
Dillon Carey
27-08-2009, 19:31
What is the indent in the front for?
Rion Atkinson
27-08-2009, 19:44
What is the indent in the front for?
Nothing really.. I could move it forward, but there is really no need.. Save weight! :D (Even if only around .5 lbs...)
Akash Rastogi
27-08-2009, 20:58
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.
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.
Dillon Carey
27-08-2009, 22:17
Nothing really.. I could move it forward, but there is really no need.. Save weight! :D (Even if only around .5 lbs...)
Ok, i was thinking you were trying to plan ahead for some sort of pick up system.
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?
kramarczyk
28-08-2009, 14:10
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.
Yeah, the cRio has been known to take a beating.
http://decibel.ni.com/content/docs/DOC-6176
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?
We used some quick release pins from McMaster-Carr (p/n 98320A140) (http://www.mcmaster.com/#98320a140/=3dy6cq) 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).
http://www.mcmaster.com/param/images/Pins/98404a365callout.gif
Yeah, the cRio has been known to take a beating.
http://decibel.ni.com/content/docs/DOC-6176
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/wood-density-d_40.html has a list of densities for various types of wood.
BrendanB
28-08-2009, 16:56
Yeah, the cRio has been known to take a beating.
http://decibel.ni.com/content/docs/DOC-6176
[/IMG]
WOW!!!!:ahh:
That really does take a beating. Guess I now know what is the strongest part of the robot.:]
Rion Atkinson
28-08-2009, 17:10
Ok, i was thinking you were trying to plan ahead for some sort of pick up system.
That was the original plan, but there isn't really enough room... I could always make the chassis bigger than 35 x 25...
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?
Pretty much yes. :D
Rion Atkinson
28-08-2009, 17:19
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/wood-density-d_40.html has a list of densities for various types of wood.
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...
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...
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.)
MrForbes
28-08-2009, 23:20
Somehow we modeled ours in Inventor last winter...huh....
http://www.chiefdelphi.com/forums/showthread.php?t=71902
Rion Atkinson
29-08-2009, 13:19
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.)
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...
Somehow we modeled ours in Inventor last winter...huh....
It is possible to just change the texture (As I did). But odds are you made it in 2009.
Akash Rastogi
29-08-2009, 14:15
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.
Are there certain add-ins that you don't have enabled? I don't use Inventor but just a suggestion.
I don't remember exactly where it is, but in the iProperties of a part you can change the density to a custom value.
Rion Atkinson
29-08-2009, 16:39
Are there certain add-ins that you don't have enabled? I don't use Inventor but just a suggestion.
No. All the other add-ins not enabled are just converters for other CAD programs..
I don't remember exactly where it is, but in the iProperties of a part you can change the density to a custom value.
I went through all the IProperties.. Couldn't find it...
I think its time to switch to solidworks.. :rolleyes:
MrForbes
29-08-2009, 17:08
You definitely want to be using a wood friendly modeling program. Wood is where it's at.
Rion Atkinson
29-08-2009, 17:13
Maybe I'll switch back to Inventor 2009 until I can get solidworks somehow....
Maybe I'll switch back to Inventor 2009 until I can get solidworks somehow....
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 (http://www.chiefdelphi.com/forums/member.php?u=22753) would be the person to contact, Solidworks Rep for FIRST.
-RC
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