With a suction intake it is possible to have one mechanism for both the cargo and the hatches, what are the downsides to using a vacuum intake? I’m pretty new to this and was just doing some research and wanted to get ur guys’ thoughts.
One issue you may discover is that suction requires a fair bit of air pressure to generate. The compressors we use on the field are designed for a 10% duty cycle, so running the compressor continuously for the duration of the match is not only unsafe but also loads and drains your battery quickly.
It probably could be done, but there’s a good reason that most FIRST students have never seen one on the field.
Not too bad to test for yourselves. We prototyped with a small shop vac and found comparable results to the armabot that we purchased later. This was last year with the power cube. The impeller was similar size to the shop vac but we couldn’t determine the rpm of the shop vac. The armabot uses the 775pro so it’s around 20,000 rpm. We used the vacuum on the power cube with pretty good results during the season. The only downside for this is that there is only about 5 inches of diameter for a vacuum to attach to on the hatch. That is small, we had around 9 inches diameter for the power cube. When we used something smaller, we dropped cubes fairly frequently in a match.
I think it’s a pretty good idea (and have been encouraging my old team to try it).
For FRC, it’s a lot more practical to use a motor than pneumatics to generate suction, since more power is available and there are no potential conflicts with pneumatics rules. For example, see this or this or this.
i believe someone on our team was considering a venturi generator, though i’m not sure about the pros and cons.
We’ve been looking into it. Prototyped using a CIM to control a shop vac. Worked on the hatches and the cargo.
Awesome thanks! Does it look like it will be efficient?
as for the prototype; easy to make and one intake worked for both game pieces so I’d call it efficient
Our team thought of that but we decided not because the game pieces will get scratched throughout the competition and the deal will not be as good as the start of the competition
I was apart of a team that tried this a couple years ago.
It’s easier than you think.
Grab a mattress air pump that works on low voltage. (We weren’t sure if the included motor was legal at the time so we swapped it out for a bag motor.)
I see people talking about needing a lot of air pressure which is incorrect. You just need good air flow (which the mattress pump is more than adequate for) The pressure is just the outside air pressure pushing the ball into the funnel.
Experiment with a couple different size funnels. We started with a 6" funnel that occasionally dropped the stronghold ball. We upgraded to a 10" and one of the students almost broke the bot when he went to rip the ball out.
Don’t expect to suck up a ball even 1" away though. You’re not gonna get anything to do that, but once you bump it that ball will stick. (even the texture on the ball won’t slow you down)
The hatch will be a bit tricky since it has that giant hole in the middle that the vacuum won’t keep up with.
Redline motors are your best choice for making your own turbine vacuum. We tested ours from last year today and it works with the cargo 10x better than it did with power cubes.
Also, the person above me that mentioned air flow. Is correct.
The armavac you linked was sold out, are there any good alternatives you know of?
I personally think that people wanting to use vacuums to pick up balls are massively underestimating howuch the balls will be bouncing around.
Consider studying team 3824’s 2014 robot. A regional winning vacuum bot in a game that had ball game pieces.
As they did you might consider using wheels to bring the ball into your robot and then use the vacuum to hold it on your elevator. If the vacuum cup was lighter weight than a gripper could be.
If 1102 does a vacuum system in any way this year, I imagine it would be doing so utilizing a method like this.
Have you tested on Hatch Panels? If so, how well does the vacuum work considering you’ve got less area to suck onto?
We did not test hatch panels yet. We do not have a good method to do so yet. If we do decide to come up with a method to do so, I will report back.
By the way, what are some good cheap Shop Vacs I could buy to prototype with? And do you guys think that vacuum would be strong enough to hold the hatches?
I do not want to speculate on how well hatches may work. I have no idea honestly.
My team bought this vacuum turbine assembly and stripped the AC motor out of it. Created a shaft adapter and placed a redline motor into it. This created a vacuum turbine that generated around 30+ Lbs of pull. We staged 2 in series and got things up to 60+ Lbs of vacuum force. This is on power cubes. I do not have numbers for cargo…based on what I have see so far…the numbers should be better on Cargo.
Would you be willing to share your ideas with me for the vacuum unit? We have been testing ideas and have not yet had a breakthrough.
Many teams are using a pump like this https://www.amazon.com/dp/B00DYA21PU/ref=cm_sw_r_cp_apa_i_rP1xCbJYXEC5G and are switching the motor out for a approved 550 series motor as that is what comes with the pump, here is a vid of the team I mentor using this vaccum with the pump listed on a hatch, we are using it for a dedicated floor pickup for hatches, we have a different faster and more secure method for the loading station, but that system can’t grab off the floor, so we are using the two in conjunction https://www.chiefdelphi.com/uploads/default/original/3X/2/0/205632b498b0744ca53098cc03aab5665ca12bd4.mov