The Best Passive Intake?

  1. 10 months ago

    I’m bored and I decided to look into an iffy topic, passive intakes for ITZ. I’ve been looking and I’ve seen a handful. What do you think is the best passive intake? Just wondering. It’ll be fun to see the concepts, prototypes, and actually builds.

  2. Easton

    12 Nov 2017 GA, USA 1958A

    I think the best passive intake I've seen is actually for mobile goals. It is this:

    I think it is good because it can actually be faster than a real mobile goal lift at getting into the 10 point zone (due to no time used up in lifting the goal off the ground)

  3. tabor473

    12 Nov 2017 V5 Beta Tester OYES, WPI

    @Easton I think the best passive intake I've seen is actually for mobile goals. It is this:

    I think it is good because it can actually be faster than a real mobile goal lift at getting into the 10 point zone (due to no time used up in lifting the goal off the ground)

    The chassis speed noticeably drops when they hit the goal.

  4. Easton

    12 Nov 2017 GA, USA 1958A

    @tabor473 The chassis speed noticeably drops when they hit the goal.

    True, but maybe it wouldn't if they had a stronger base (At our competition yesterday, one robot on the winning alliance was a mogo only robot with an 8 speed motor drive). I bet that robot from our competition could handle it without losing much speed.

  5. roboticblackbelt

    12 Nov 2017 Framingham, MA 9421X

    @tabor473 The chassis speed noticeably drops when they hit the goal.

    It seems as though that is partially because of a lack of traction, as you can see the wheels continue to spin once the robot hits the pipe. Although it would probably slow down the robot anyway.

  6. Aponthis

    12 Nov 2017 Tempe, Arizona Formerly 127A, 127C, 127X

    @Easton I think the best passive intake I've seen is actually for mobile goals. It is this:

    I think it is good because it can actually be faster than a real mobile goal lift at getting into the 10 point zone (due to no time used up in lifting the goal off the ground)

    There are a couple of reasons why I don't see this being practical. First, it gets in the way. It is constantly down, and very annoying for the driver, I am sure. It's hard to maneuver between the game objects and stationary goals this year, sometimes. Second, it is incapable of scoring in the 20-point zone. The 20-point zone is critical. Third, as others have stated, it is much slower to push the mobile goal around the field than to pick it up and drive it. This is obviously from the friction between the heavy mobile goal and the field tiles.

    If we are talking about the best passive intake, there are a few passive cone intakes out there right now that are outstanding. The one on my recently-revealed robot works pretty well, but I am probably going to mostly rebuild it (which should only take about an hour), so that it works perfectly. This design is also useful for internal stackers. I would say that it will be better than active designs, even without factoring in the extra motor that is freed up.

  7. spartanshl

    13 Nov 2017 Cumming, Ga 109A

    @Easton True, but maybe it wouldn't if they had a stronger base (At our competition yesterday, one robot on the winning alliance was a mogo only robot with an 8 speed motor drive). I bet that robot from our competition could handle it without losing much speed.

    Correction. The only robot with an 8 motor drive was mine and that was because we only had 2 days to build so we decided to do it for fun. We were pushing around 20lbs bots, so I bet that mogo would be no problem ;)

    p.s. 109z, on the winning alliance, was a 6 motor hs bot.

  8. @Easton True, but maybe it wouldn't if they had a stronger base (At our competition yesterday, one robot on the winning alliance was a mogo only robot with an 8 speed motor drive).

    We actually had a 6 motor hs bot, it's extremely easy to push around robots with all omni-wheel drivetrains if you know what you're doing ;)

  9. 1961Uranium

    13 Nov 2017 Georgia, United States Blitz Alliance 1961U

    @Aponthis There are a couple of reasons why I don't see this being practical. First, it gets in the way. It is constantly down, and very annoying for the driver, I am sure. It's hard to maneuver between the game objects and stationary goals this year, sometimes. Second, it is incapable of scoring in the 20-point zone. The 20-point zone is critical. Third, as others have stated, it is much slower to push the mobile goal around the field than to pick it up and drive it. This is obviously from the friction between the heavy mobile goal and the field tiles.

    If we are talking about the best passive intake, there are a few passive cone intakes out there right now that are outstanding. The one on my recently-revealed robot works pretty well, but I am probably going to mostly rebuild it (which should only take about an hour), so that it works perfectly. This design is also useful for internal stackers. I would say that it will be better than active designs, even without factoring in the extra motor that is freed up.

    That, and also considering the risk of possession

  10. Edited 10 months ago by _Colossus_

    @Easton

    I think it is good because it can actually be faster than a real mobile goal lift at getting into the 10 point zone (due to no time used up in lifting the goal off the ground)

    Well... I’m tempted to share a video of our robot scoring MOGOs to show how fast a motorized mogo lift can be, but my team would kill me. ;)

    The trick to speeding things up is have a high level of automation. Take our mogo lift for example: it works the same as other motorized mogo lifts; 2 motors with a 1:3 ratio. We use a potentiometer to check the angle of the mogo lift. The driver just needs to press one button and the mogo goes to the preset max or press another button and it goes to the preset min height. The mogo lift itself can also detect the presence of a mogo and automatically lifts when the mogo is inserted fully into the intake. When we combine these two features, the driver really only needs to focus on driving the 6m turbo base while the rest is automated. This allows us to start from the starting bar, pick up a mogo from the middle of the field, align with the 20pt zone, cross the starting bar, dump the mogo into the 20pt zone, and exit within 6 seconds. (Obviously for driver skills)

    @Inventor Inventor
    If you want to try passive, stick to cones only.

  11. 1961Uranium

    13 Nov 2017 Georgia, United States Blitz Alliance 1961U

    @_Colossus_ @Easton

    Well... I’m tempted to share a video of our robot scoring MOGOs to show how fast a motorized mogo lift can be, but my team would kill me. ;)

    The trick to speeding things up is have a high level of automation. Take our mogo lift for example: it works the same as other motorized mogo lifts; 2 motors with a 1:3 ratio. We use a potentiometer to check the angle of the mogo lift. The driver just needs to press one button and the mogo goes to the preset max or press another button and it goes to the preset min height. The mogo lift itself can also detect the presence of a mogo and automatically lifts when the mogo is inserted fully into the intake. When we combine these two features, the driver really only needs to focus on driving the 6m turbo base while the rest is automated. This allows us to start from the starting bar, pick up a mogo from the middle of the field, align with the 20pt zone, cross the starting bar, dump the mogo into the 20pt zone, and exit within 6 seconds. (Obviously for driver skills)

    @Inventor Inventor
    If you want to try passive, stick to cones only.

    You have 3:1? How many cones can you pick up along with the MOGO?

  12. @eagles1961U
    Without any rubber bands, I would say 6-8 cones. We have not really tried any higher because we are focusing on skills. However, we get most of our power from some clever mechanical advantage ;).
    Look out for our first official skills run on Nov. 18.

  13. Aponthis

    13 Nov 2017 Tempe, Arizona Formerly 127A, 127C, 127X

    @eagles1961U You have 3:1? How many cones can you pick up along with the MOGO?

    I have the same ratio and number of motors. Literally two rubber bands cancelled the mass of the mobile goal. Ours can lift at least 14 cones on a mobile goal, but as of right now it doesn't really drop them cleanly (because it is programmed to go down at full speed, I just need to have a button to lower stacks slower for larger stacks. No big issue). The biggest problem is that the robot tips forward while picking up mobile goals with that many cones stacked, unless I drive forward while doing it. Yeah, that's kind of sketchy. I guess it's just because we don't have enough mass in the back of the robot, and because our batteries are not currently mounted as far back as they will be.

  14. 1961Uranium

    13 Nov 2017 Georgia, United States Blitz Alliance 1961U
    Edited 10 months ago by 1961Uranium

    @Aponthis I have the same ratio and number of motors. Literally two rubber bands cancelled the mass of the mobile goal. Ours can lift at least 14 cones on a mobile goal, but as of right now it doesn't really drop them cleanly (because it is programmed to go down at full speed, I just need to have a button to lower stacks slower for larger stacks. No big issue). The biggest problem is that the robot tips forward while picking up mobile goals with that many cones stacked, unless I drive forward while doing it. Yeah, that's kind of sketchy. I guess it's just because we don't have enough mass in the back of the robot, and because our batteries are not currently mounted as far back as they will be.

    We have 5:1 with one motor right now, it can pick up around 9-11 cones max depending on the battery power. I actually have never seen a team with 3:1 on their mogo intake, so thats why I was surprised. @_Colossus_ Does it burn out if you do a skills run without rubber bands?

  15. Aponthis

    13 Nov 2017 Tempe, Arizona Formerly 127A, 127C, 127X
    Edited 10 months ago by Aponthis

    @eagles1961U We have 5:1 with one motor right now, it can pick up around 9-11 cones max depending on the battery power. I actually have never seen a team with 3:1 on their mogo intake, so thats why I was surprised. @_Colossus_ Does it burn out if you do a skills run without rubber bands?

    It should have more torque, since it has two motors and the speed isn't twice as great.

  16. 1961Uranium

    13 Nov 2017 Georgia, United States Blitz Alliance 1961U

    @Aponthis It should have more torque, since it has two motors and the speed isn't twice as great.

    Yea, I actually have no idea why I was surprised...

  17. Aponthis

    13 Nov 2017 Tempe, Arizona Formerly 127A, 127C, 127X

    @eagles1961U Yea, I actually have no idea why I was surprised...

    It happens to all of us. Our brains get stuck in a weird way of thinking about things.

  18. @eagles1961U I actually have never seen a team with 3:1 on their mogo intake, so thats why I was surprised.

    109A had a 1:3 mogo intake at the competition on Saturday.

  19. @eagles1961U
    I don't think that I was clear in my last post, but we never use rubber bands in skills because we are only holding one mogo and maybe one cone. I don't know what speed it is running at any given position since its being controlled by a PI loop, and my constants are 0.0001 and 0.000005. On its way up, it still overshoots by a few degrees while holding a mogo. If we position the mogo lift to come down on any of the bars separating hte zones, it is strong enough to lift our robot (14lbs). If you are considering switching, to a 1:3 ratio, please be aware we don't power the 4 bar traditionally, so you may get varied results. Also, once the mogo is in place, it does not require any power, pneumatics to hold the lift up.

    Going back to the topic of passive intakes, I too have seen some very good ones. From my testing, the biggest problem is making sure that the cones position perfectly each time. Also, from the passive intakes that I have seen, I worry that they might fail once they exceed 10ish cones.

  20. callen

    13 Nov 2017 Braintree, MA, USA

    I designed a passive intake/passive release so that I'd thought through various things over the summer in case my students decided to try something like that. They went a totally different route. If I get the chance to draw things clearly, I'll post some sketches. The passive intake wasn't as tough as the passive release and coupling the passive release with the intake. Hopefully I'll find that kind of time soon...

 

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