https://www.digikey.com/en/products/detail/adafruit-industries-llc/4245/10287035
I was wondering when youāre driving what controls do you use to pivot the shooter up to pass? Is it a fixed position or manual angle control?
We use two fixed angles for passing, one over the stage and the other is flat on the ground. The driver has to press the pass button, and the robot decides which angle to use based on its position on the field
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This is related to the question about using gears for holding pulley to shaft above.
The Shooter Roller tube OD is 44mm. Was this diameter chosen because the performance and packaging requirement. I remember you guys mentioned vulcanized rubber with it, what was the rubber thickness?
Looks like your Upduction is 60:36 on your Shooter Roller drive. Did you try higher/lower ratio?
Lastly, is this jig saw puzzle feature is there to enable to install/uninstall the shooter assy to pivot? pretty slick!
Thanks
Yes
3 mm
Tried higher, saw no performance improvement, so moved back to this.
Lower was too slowā¦
The āpuzzleā in the base of the shooter is, as you wrote, for easy removal
The source - Trust me bro
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I want to ask about the Swerve Module, why doesnāt there have its own assembly alone or a complete assembly for the Swerve Module? Also, what are the specific functions of the parts you sent in the robot?
Iām curious about how you guys decided on the geometry for this part on the pivot:
Seems like a really neat way to both clamp the bearing and allow for serviceability, but Iām kinda confused about all the squiggly bits and the asymmetry?
Also, what ratio did you guys use for the pivot?
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The original CAD of the robot was done in SolidWorks, we uploaded it to OneShape to make it more accessible to teams.
However, mostly due to our lack of experience with OneShape, we decided to upload a top-level X_t file as-is and hope for the best.
The other X_t files which we posted do contain separate assemblies for each subsystem.
The part in the second picture is a mechanical barrier that holds our shooter while in travel mode, there are two of these right below both edges of the shooter (highlighted in blue).
And the part in the third picture is a Hall Effect sensor (and print) which detects when the arm reaches the bottom of its range of motion.
This part was designed for quick and easy removal of the shooter from the pivot. The challenge with a removable piece like this is ensuring it is very rigid. These squiggly bits function like a āLegoā and create a much more rigid connection to the other plate compared to using just screws.
As to the asymmetry, itās just a product of the shape of this area of the plate, we tried to maximize the amount of contact surface between the two plates because more contact surface results in a tighter grip on the arm.
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But why use Hall Effect sensor in robot? What is the way to use this sensor?
The TalonFX encoders, that we use for control, is relative. Meaning, that at the start of the code we donāt know the position of the arm. The hall sensor tells us if the arm is closed or not. We check it at the start of the code, and if the arm is not closed, we get a fault and need to reset the arm.
We usually prefer to use an absolute encoder for subsystems of this sort, but because Doppler is so compact, there isnāt enough space to insert one on the pivot, so we opted to use a hall sensor instead.
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totally not me about to build this in LEGO
also 231 likes on this, good golly gee willakers
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Hey, your robot is awesome,
I have to learn the intake mechanism so I go through this cad. I have a small doubt.
in the photo, the minimum distance between Roller 1 and the ground/carpet is around 75 mm but generally, the team makes this distance less then game piece height which is 50 mm. I need to understand how your intake takes the note like touch it own it way.
Thank you for your support.
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The reason that teams usually make that distance lower than the gamepiece is to make the top roller touch first, and to give some compression with the ground. This is beneficial for balls, or essentially any gamepiece that can ārollā into the robot. The notes donāt roll into the robot, they slide into it, and when we we tested ground compression we saw that they āstickā to the carpet quite a bit. This did manage to intake, but it pulled a lot of current and sometimes had trouble with centering. Instead, the bottom roller encounteres the note first and ākicksā it up to be sucked right in.
I was skeptic at first, and thought the notes would just be kicked forward as we drive but something about the bottom roller speed / grip really seemed to work well with the notes. They go in at the slightest touch and the current draw was much lower than with the top roller compression.
23 Likes
Have you guys thought to remake it with sds mk4in? Would it fit in this robot as is?
I donāt know about āas isā, but with some modifications to the climb winches and the front of the chassis - sure, you could make it work.
We donāt really see the added value(for us) in remaking the robot, and weāre happy with our current swerve modules, so we probably arenāt switching to SDS anytime soon.
To remove the entire Shooter assy, you would need to remove the main shaft also, correct? If so, what is the purpose of having the clamshell piece?
Thanks
Removing the shooter assy does require us to remove the main shaft, but only because itās connected through a belt to one of the shafts on the shooter. besides from that, the shooter is completely supported by custom made blocks around the main shaft through the clamshell pieces. Thatās why they are still needed to separate the shooter from these blocks.
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