OCCRA
Go to Post 1114 is the definition of what a FIRST team should be. For anyone to say otherwise is disgusting to me. - Andrew Schreiber [more]
Home
Go Back   Chief Delphi > CD-Media > Photos
CD-Media   CD-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

photos

papers

everything



Mean Machine's 2018 CAD Release

Trevor

By: Trevor
New: 05-03-2018 12:57 PM
Updated: 05-03-2018 12:57 PM
Views: 1842 times


Mean Machine's 2018 CAD Release

Here is the CAD for our 2018 robot "Atlas" if you have any questions leave a comment or you can email use at team2471@gmail.com

CAD download
https://team2471.files.wordpress.com/2018/05/atlas-cad.zip

Recent Viewers

  • Guest

Discussion

view entire thread

Reply

05-03-2018 01:06 PM

nuclearnerd


Unread Re: pic: Mean Machine's 2018 CAD Release

Awesome robot. Thanks!



05-03-2018 01:23 PM

Noodles


Unread Re: pic: Mean Machine's 2018 CAD Release

It's about time

xoxo <3



05-03-2018 01:37 PM

Skyehawk


Unread Re: pic: Mean Machine's 2018 CAD Release

Thanks for the CAD!

Also 600th post



05-03-2018 01:38 PM

Landon K


Unread Re: pic: Mean Machine's 2018 CAD Release

I could be missing something, but what is the cylinder on the winch shaft for? and how did you actuate the disc brake? Also, I didn't see any pulleys/sprockets for the drive train? What was the set-up for the power transfer to the outer wheels? Thanks for the great CAD to dig through!



05-03-2018 02:14 PM

mman1506


Unread Re: pic: Mean Machine's 2018 CAD Release

Very cool, any details on the layup of the lifter forks? I was hoping to do something similar but I never got around to it.



05-03-2018 02:36 PM

Francis-134


Unread Re: pic: Mean Machine's 2018 CAD Release

Trevor,

If you add the cad files to grabcad.com, you can submit the link to TBA, so the CAD is always linked to the team's page TBA page for 2018.



05-03-2018 05:24 PM

Rafi Ahmed


Unread Re: pic: Mean Machine's 2018 CAD Release

Great robot this year! Always fun to see what you guys come up with.

Did you current limit or slow down your drive gearboxes any? Anything you would change with them?



05-03-2018 05:30 PM

mman1506


Unread Re: pic: Mean Machine's 2018 CAD Release

Are those custom omni wheels?



05-03-2018 06:06 PM

SnapDragon


Unread Re: pic: Mean Machine's 2018 CAD Release

Aw yes, it's here! I saw your reveal video and your update videos, and now I'm so happy the CAD is released!



05-03-2018 06:10 PM

Munchskull


Unread Re: pic: Mean Machine's 2018 CAD Release

Quote:
Originally Posted by mman1506 View Post
Are those custom omni wheels?
Yes they are.



05-03-2018 06:38 PM

Trevor


Unread Re: pic: Mean Machine's 2018 CAD Release

Quote:
Originally Posted by Landon K View Post
I could be missing something, but what is the cylinder on the winch shaft for? and how did you actuate the disc brake? Also, I didn't see any pulleys/sprockets for the drive train? What was the set-up for the power transfer to the outer wheels? Thanks for the great CAD to dig through!
The Cylinder on the winch shaft is there because the gearbox running the elevator is 2 speed ( low for climbing and high for the rest of the match)

We used cable pulled by a 2 inch stroke pneumatic that we mounted to the belly pan, but we never put it in the cadd

On the drive train we used #25 chain with tooth sprocket

Quote:
Originally Posted by mman1506 View Post
Very cool, any details on the layup of the lifter forks? I was hoping to do something similar but I never got around to it.
The Forks are made out of a peace 0.4 carbon reinforced with Kevlar and had denim layer that our carbon sponsor had left over from a project

Quote:
Originally Posted by Rafi Ahmed View Post
Great robot this year! Always fun to see what you guys come up with.

Did you current limit or slow down your drive gearboxes any? Anything you would change with them?
We used amp limiting that limits each motor to 25 amps

Quote:
Originally Posted by mman1506 View Post
Are those custom omni wheels?
Yes, we had a hard time finding inch omni wheels that fit what we wanted, so we used the andymark roller replacement kits and made our own



05-03-2018 06:42 PM

sanddrag


Unread Re: pic: Mean Machine's 2018 CAD Release

This is a great looking robot that appears to be very well thought out. Thank you for sharing the CAD.



05-03-2018 08:09 PM

EthanHunter


Unread Re: pic: Mean Machine's 2018 CAD Release

If you could post native Inventor files my team and I would really appreciate it. Even if they're a bit broken.



05-04-2018 08:24 AM

PowerCubeLunch


Unread Re: pic: Mean Machine's 2018 CAD Release

Hoo boy, I can't wait to take a look at this!



05-04-2018 10:14 AM

DStew88


Unread Re: pic: Mean Machine's 2018 CAD Release

Quote:
Originally Posted by Trevor View Post
We used amp limiting that limits each motor to 25 amps
Is that the only software you use to help protect the drive motors? Do you have any ramp rates to limit the current draw when starting from 0 velocity? Also how did you come to choose 25 amps as your limit?

I'm impressed you were able to limit 6 motors to 25 amps each and still get such great driving characteristics from them. Most other 775 drive teams (including 88, my team) have used 8 total to further lower the current per motor.



05-04-2018 01:18 PM

AdamHeard


Unread Re: pic: Mean Machine's 2018 CAD Release

Quote:
Originally Posted by Trevor View Post
Yes, we had a hard time finding inch omni wheels that fit what we wanted, so we used the andymark roller replacement kits and made our own
Rotacaster in La has 125mm Omnis with a 1.125 bearing bore and 85A rollers.

1/4" plate worked well as hubs.



05-06-2018 12:17 PM

JacobD


Unread Re: pic: Mean Machine's 2018 CAD Release

Did you do any welding on your bumper supports for the drive train? It looks like there isn't enough gusseting otherwise, or I could just be mistaking.



05-06-2018 05:13 PM

Trevor


Unread Re: pic: Mean Machine's 2018 CAD Release

Quote:
Originally Posted by JacobD View Post
Did you do any welding on your bumper supports for the drive train? It looks like there isn't enough gusseting otherwise, or I could just be mistaking.
There is a 0.125 inch carbon gusset that holds the bumper supports, they also where the plates that held the wings and you can only see them in the whole assembly as they aren't in the drive train sub assembly.



05-07-2018 03:07 AM

Bryce2471


Unread Re: pic: Mean Machine's 2018 CAD Release

Quote:
Originally Posted by DStew88 View Post
Is that the only software you use to help protect the drive motors? Do you have any ramp rates to limit the current draw when starting from 0 velocity? Also how did you come to choose 25 amps as your limit?
The flat 25 amps was the only limit in place to protect the motors. We built an off season robot with a 775pro drive drain, and I believe we decided on 25amps with some (non exaustive) testing on it. We also had voltage limits and ramp rates that would scale based on the height of our elevator, but they were to improve placent control and keep is from falling over.
Quote:
I'm impressed you were able to limit 6 motors to 25 amps each and still get such great driving characteristics from them. Most other 775 drive teams (including 88, my team) have used 8 total to further lower the current per motor.
We used 8 775s on our off season bot, but we didn't really have room for 8 this time, and we felt that the extra motors were somewhat unnecessary based on some other minor testing. (It could do a burn out with two kids standing on it)



05-07-2018 04:02 AM

Bryce2471


Unread Re: pic: Mean Machine's 2018 CAD Release

Delete



05-30-2018 10:28 AM

Tkrzyzanek


Unread Re: pic: Mean Machine's 2018 CAD Release

Quick question, why did you use surgical tubing for your lift?



05-30-2018 01:05 PM

Bryce2471


Unread Re: pic: Mean Machine's 2018 CAD Release

Quote:
Originally Posted by Tkrzyzanek View Post
Quick question, why did you use surgical tubing for your lift?
We used surgical tubing to tension the elevator rope because it is easy to change the resting tension by adding or removing loops and it is relatively light weight. We also have a stock pile of it sitting in our shop, so it was convenient.

We were using a pneumatic cylinder for that application, but it was deemed too heavy.



05-30-2018 01:11 PM

tickspe15


Unread Re: pic: Mean Machine's 2018 CAD Release

Quote:
Originally Posted by Bryce2471 View Post
We used surgical tubing to tension the elevator rope because it is easy to change the resting tension by adding or removing loops and it is relatively light weight. We also have a stock pile of it sitting in our shop, so it was convenient.

We were using a pneumatic cylinder for that application, but it was deemed too heavy.
Does your code account for the variation in force across the travel of the elevator? Were constant force springs also deemed too heavy?



05-30-2018 03:17 PM

Bryce2471


Unread Re: pic: Mean Machine's 2018 CAD Release

Quote:
Originally Posted by tickspe15 View Post
Does your code account for the variation in force across the travel of the elevator? Were constant force springs also deemed too heavy?
The surgical tubing i was referring to does not change tension across the travel of the elevator. So no compensation was made.

In hindsight, my reply to Tkrzyzanek's question may have been off base, because we have surgical tubing on the elevator in three places. What surgical tubing are you referencing? The rope tensioner, middle stage tie-down, or the arm counterbalance?



06-01-2018 09:49 AM

Gary Suter


Unread Re: pic: Mean Machine's 2018 CAD Release

Great Robot! We had fun hitching a ride with you to meet the boss.
What type of motors power the intake wheels?



06-01-2018 11:07 AM

kyle_hamblett


Unread Re: pic: Mean Machine's 2018 CAD Release

I've been looking forward to this CAD release for quite a while. Thanks guys!



view entire thread

Reply
previous
next

Tags

loading ...



All times are GMT -5. The time now is 10:22 AM.

The Chief Delphi Forums are sponsored by Innovation First International, Inc.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi