For all you folks who aren’t subscribed to our YouTube channel, here are a couple videos of what Triple Helix has been up to with our prototyping this year.
We started with this crude intake prototype.
This was refined to work on the path of the cargo to the shooter.
You might consider having a bottom kicker bar to assist in getting the balls off the ground. An easy way to test if a kicker bar helps is taping a piece of churro or hex to the bumper. In our testing this really did help!
Can you upload a video of that intake actuating? I want to see that linkage in action.
Will do. Keep an eye on our YouTube channel.
Arm testing video is up.
Nice linkage.
How do you go about designing a linkage like this in Solidworks?
I tried just starting from scratch in Solidworks and think I could recreate it but it would be a slow guess and check process. Is there a proper way? Maybe if I can define the 2 end points - where I want the rollers relative to the chassis and where I want them when folded in?
@cadandcookies has a great video about linkages: Linkages: Basic Linkages In Onshape - YouTube
The triple helix one is a bit more complicated in that there’s another rotational point in that top linkage.
That linkage is something we have been looking for as a solution to how tight our robot is this year. We have a similar linkage but your solution is so much more elegant and compact!
I have an idea for a way to describe the process we used. Will noodle around and publish it when I can.
Very interesting that the flexible “fingers” are able to intake the ball. Are those fingers just polycarb strips that are screwed onto a hex bar axle?
The flaps are constructed from vinyl strip door material-- i.e. the kind of door you’d find at the back of a supermarket.
Interesting. We tried using some of that same material on a roller over the intake to knock down bouncing balls to make intaking easier. We were not impressed by the results. We didn’t try using it for the intake itself though.
Just when our team was wondering how we were going to package a swing-down intake with two rollers… Thank you for sharing!
What are people finding to be a good intake speed?
Most of the videos I’ve seen so far looks to have been 80-100% motor speed.
A rule of thumb that I’ve seen is having the surface speed of your intake roller be about 2x your robot speed. The thought being that even at the robot moving full speed forward, the roller is still bringing the game piece in.
We posted a slide deck which details the process we followed to design this 4-bar intake deployment mechanism:
Thanks for the valuable and rapid feedback @ahartnet @ndp @ferrari77 @ToddF
this video is also something we use a lot! 973 RAMP - Designing linkages with sketches - YouTube
I appreciate any tutorial that ends with the phrase “ship it!”; I say that to our students all the time.
Good old kinematic 2-position synthesis. So satisfying.