Hello everyone. My name is Brendan from Missouri team 9445(D). I’ve been using a plunger system similar to cam’s system, but I have a question. I’ve been quite inspired by team 8059A’s launcher, but I’m not sure I would be able to make one as efficient. So, my question is, has anyone used a single flywheel with more than six motors? If so, can you please post pictures? Or, if you have made any complex gearboxes or drive systems, could you also post pictures please? I’ve got some interesting ideas, but I’m looking for some inspiration. Thanks guys!
To start with, I don’t think it is necessary to use more than 6 motors. The reason 8059A has a really efficient launcher is because they have a single wheel launcher rather than a double flywheel. A double flywheel could be efficient if you have encoders, but if you don’t, one side will go faster than the other. What seems to be difficult about building this design? The flywheel, intake, drive. I built a similar design in about a week and I thought it would take a month. Give it a try. You can try a 25:1 powered b 4 motors. That shoots over the field but you can decrease motor power.
Four motors seems to be sort of a sweet spot for flywheels. 8059a has a great design and a good benchmark to base your design off. Quite a few teams have had great success with similar designs to 8059a, so I can definitely recommend you start there. A simple compound gearing setup like the one shown above should be all you need for some high speed flywheel action.
In terms of inspiration heres a few interesting ideas.
- Build a quick, full field, 2 motor catapult.
- Instead of using code, build a gearbox that changes the gear ratio as you flywheel is spinning up
- Build multiple catapults and fire them individually to achieve 4+ balls per second.
- Build a sweet auto aiming turret like 323Z
- Strap 10 motors to a ridiculous flywheel
Remember to build your flywheel well, a few extra moments to make sure everything is tight and straight can mean a flywheel free of excess friction that will perform much better than otherwise.
I disagree with this, through my own experiences with double flywheels I can say a well built one can shoot reasonably straight even with out a program controlling its velocity. The only situation what you speak of could apply is a flywheel with excess friction or damaged/dying motors. Something you should try to avoid as much as possible anyway.
I was thinking of a system to divert the drive train power to the flywheel for shooting match loads, then shifting it to the wheels. I’ve not had experience with flywheels, is this something that could be useful? I think I can do it, the question is just whether it would be beneficial. I would think you could shoot faster since there would be so much torque to keep the flywheel spinning at your desired speed, that the time between shots would be next to zero. This is just a theory though.
Its interesting I was considering a very similar idea earlier this year in a thread dedicated to catapults. I guess yes, it would increase the fire rate but the tradeoff is the added weight, complexity and and loss of two motors (to pneumatics). I think it might be more useful in a multiple flywheel/catapult setup. But Im not sure.
At any rate it would be awesome if you did build something like that, even as a proof of concept!
5237C, Gael Force, actually built a transmission between their flywheel and their chassis. And I have to admit, it sure was impressive. However, while it does allow for your 6 motors to be used for two tasks, it adds a lot of friction and complexity to your robot (inherent to a transmission). This makes problems a lot harder to diagnose and fix. And as EvolvingJohn said previously, you would then have to use pneumatics, losing two motors.
Personally, I think that you are better off having separate motors for your chassis and launcher. Try testing other launching mechanisms and see if they are more efficient!
Actually, you wouldn’t have to use pneumatics at all. I don’t really want to give away how you could do it, but it is my belief that you could do it, and still utilize 12 motors on your robot.
I will say this about 6 motor single flywheels, the potential for better acceleration and recovery times is there if you can manage the battery power correctly.
Well I could assume you are referring to passive transmissions? Like the one shown in this video:
Which is fine unless you want to drive backwards, or intake backwards etc. I think a transmission like that is more practical transferring the motor power off of the flywheel for a lift or something.
I have considered some sort of power transfer to allow more power for the flywheel (ex. 2 motors dedicated to drive and 8 on flywheel that can transfer to drive), but it does not seem practical since there is a certain point where increasing fire rate doesn’t matter because taking 1 second to launch 4 balls from the center of the field and taking 0.5 seconds doesn’t really affect the outcome of the match. To add to this, any fire rate greater than 1 ball per second from the loading zone is excessive once we get to a point where the field is cleared in one and a half minutes.
I think I should say something about this - the reason why 8059 has/have efficient launcher(s) is not because we are using single flywheel.
I mean… there are truckloads of teams using single flywheel as well, but that does not mean all the teams are enjoying the same efficiency.
You don’t get a recovery time of about 0.4 second between shots and about 90% accuracy simply by just using single flywheel.
Think it is misleading to other teams who are deciding on what’s best for their robots… especially those new teams reading this.
I would rather put 8059’s efficiency due to good quality of build + good mastery of most of the variables involved during fine-tuning process
I don’t quite agree to this.
Rate of firing (and assuming good accuracy and as quick intake) will definitely makes a difference.
eg. you can achieve more during autonomous if your rate of firing is faster than your opponent, or if your rate of firing is close to twice of your opposing alliance, then you will not need to be worried about having an alliance that is not so ideal
But I do agree that nbn is not a all-about-rate-of-firing game. It is about how much resources we should dedicate to the launching mechanism and for the rest of the impt aspects.
That is very true, I was thinking about driver control during elimination rounds, not auton or qualification rounds.
I second this. I built a flywheel similar to 8059’s in about 3 days. It took about 2.5 hours to get each gearbox right, and then another hour to install it properly. We got it to run off of a charged battery for 5 minutes without stalling before we gave up, and before the battery voltage dropped to 4.5V. It takes time to perfect these flywheels, but the pay off is incredible. Make sure all of the bearings and holes are lined up and square, and that’s a good place to start.
We also managed to grind a support bearing down while testing, so be careful.
Same thing happened to us once. We all smelled something burning, but didn’t realize what it was until we saw the bearing.
We had the experience of the horrible cracking sound as three low strength gears sacrificed themselves to the flywheel monster because of an error in programming