Need help in deciding the configuration for an off season chassis prototype

[pmangels17]

Just a reminder, off the subject of dimensions, make sure you test the base under full weight. If your team generally build way under the weight limit and is 30lbs underweight, make sure you account for that. If your team pushes the limit to 119.9 lbs like we usually do, then your base when being tested should be around 140 lbs total (robot, battery, bumper). If you don;t test with weight you will see dramatically different traction results

If you want to get fancy you should even raise the weight a bit to account for how high your Center of Mass will be. Accurate testing in the offseason yields predictable results in the onseason.

[Brandon_L]

Originally Posted by Abhishek R

Though I don't think it applies to this thread as much because your turning radius will be largely improved by having 2 omnis and 2 traction wheels.

While that is true, there is also the major downside of being spun around in every collision that teams usually try to avoid.

[Tim Lehmann4967]

Originally Posted by lamk

Please do!! My original plan was to exactly do that for the off season chassis but decided to try WCD because I feel WCD is likely more easier to configure and maintain.

I'm having some issues uploading the photographs from my phone due to the weird format it saves them in. I will have them converted/uploaded later this evening. Sorry about the wait.

[Abhishek R]

Originally Posted by Brandon_L

While that is true, there is also the major downside of being spun around in every collision that teams usually try to avoid.

Right, I was referring to 1625's setup this year, that it's not a standard WCD because of the two omni wheels they had.

[DampRobot]

Originally Posted by Brandon_L

While that is true, there is also the major downside of being spun around in every collision that teams usually try to avoid.

Personally, I'd much rather spin out of collisions than get locked up in a t bone pin by them. We had two omnis on front and 4 VersaWheels on back of our 6WD this year, and it was still much harder to get out of T bones than I would have liked.

[Tim Lehmann4967]

Originally Posted by Tim Lehmann4967

I'm having some issues uploading the photographs from my phone due to the weird format it saves them in. I will have them converted/uploaded later this evening. Sorry about the wait.

Okay, I put the best two I have in Google Drive and pasted the links here and here.
I also asked my teammates for more, as these two do not show of our chassis perfectly. If interested I can try to get a SolidWorks render of just the chassis also.

[lamk]

Originally Posted by Tim Lehmann4967

Okay, I put the best two I have in Google Drive and pasted the links here and here.
I also asked my teammates for more, as these two do not show of our chassis perfectly. If interested I can try to get a SolidWorks render of just the chassis also.

Looks excellent. I like how you guys make the cut out in the front for the ball collector and still comply with the bumper rule. Very clever.

[Tim Lehmann4967]

Originally Posted by lamk

Looks excellent. I like how you guys make the cut out in the front for the ball collector and still comply with the bumper rule. Very clever.

If you look closely you will see that it is not actually a cut out. There are two aluminum boxes in each front corner. These boxes sit in front of a aluminum frame rail, the same as seen in the rear of the robot, the only difference being the front rail is flipped backwards. The space in between is where our pickup forks lower. The boxes give us quite a bit of frame rigidity in those corners. This is a bit hard to explain so I would like to show you in photographs.

[lamk]

I can sort of glimpse that in the two image you posted. Love to see more picture

[aphelps231]

Originally Posted by lamk

We used the long configuration AM14u for aerial assist. It got us to St. Louis. As an off season activity I would like to prototype a 3 cim 2 speed 6 wheel west coast drive. I am leaning towards a 28 x 28 square configuration. My student wants to stick with the 23x32 long configuration. Any suggestions.

Team 1318 is working on a few summer projects, including an 8 Colson wheel, 4 CIM, West Coast Drive using dual speed WCP DOG shifters, and a modified 6 Colson wheel AM14U kit bot chassis outfitted with shifter upgrade kits. I reccomend moving out of the box and trying something new when it comes to summer projects (more below).

1318 (The IRS) has been known through out the PNW for their relatively simplistic, and well performing, designs. Last year we manufactured our own chassis, dimensions were based off of the 2013 kit bot chassis. This year, we decided to use the provided kit bot chassis in a 28x28 configuration, which took us up to Galileo division finals (although the front cross brace extrusion is bent in about an inch after division semifinals). By branching out this summer we hope to educate our team about a higher performing level of drive train, and comparing and contrasting different designs (6 wheel vs. 8 wheel, kit bot vs. WCP drive base, etc.)

[tr6scott]

As another design constraint to consider....

Can it get through your room door with bumpers on?

Being slightly under this dimension when you are driving out the door, saves a lot of time when you want to go show off your hard work in the gym, cafeteria, etc...

(AM14U, two speed upgrade, 28x28 configuration, number 4 alliance captain on Archimedes, 1st year not designing WCD base)

[DampRobot]

Originally Posted by tr6scott

As another design constraint to consider....

Can it get through your room door with bumpers on?

Being slightly under this dimension when you are driving out the door, saves a lot of time when you want to go show off your hard work in the gym, cafeteria, etc...

(AM14U, two speed upgrade, 28x28 configuration, number 4 alliance captain on Archimedes, 1st year not designing WCD base)

IIRC, the rules are designed to make sure any rectangular robot can fit through a door with bumpers on in at least one dimension.

[tr6scott]

Depends on your door... but it is better to be a long bot to drive through the door, as to be wide, and have to pick it up and carry it sideways.

Just saying, it's a demo, make it easy on you....

[Andrew Schreiber]

Originally Posted by tr6scott

Depends on your door... but it is better to be a long bot to drive through the door, as to be wide, and have to pick it up and carry it sideways.

Just saying, it's a demo, make it easy on you....

Y'all need a cart with caster wheels then.

[lamk]

Originally Posted by aphelps231

Team 1318 is working on a few summer projects, including an 8 Colson wheel, 4 CIM, West Coast Drive using dual speed WCP DOG shifters, and a modified 6 Colson wheel AM14U kit bot chassis outfitted with shifter upgrade kits. I reccomend moving out of the box and trying something new when it comes to summer projects (more below).

1318 (The IRS) has been known through out the PNW for their relatively simplistic, and well performing, designs. Last year we manufactured our own chassis, dimensions were based off of the 2013 kit bot chassis. This year, we decided to use the provided kit bot chassis in a 28x28 configuration, which took us up to Galileo division finals (although the front cross brace extrusion is bent in about an inch after division semifinals). By branching out this summer we hope to educate our team about a higher performing level of drive train, and comparing and contrasting different designs (6 wheel vs. 8 wheel, kit bot vs. WCP drive base, etc.)

Agree! That's why I will go with the WCD 28 x 27 to get away from the am14u.
Will also buy different vex wheels and colson wheels to try out.