We have the need to pull a pin to release a ramp to fall to the playing field platform. We were hoping to do this with a electric powered linear actuator keeping within the <10W, <1" rules. However many of the ones we have looked at have poor reviews regarding their power, or ability to deploy with any loads on them. Ideally the actuator would be extended in the unpowered state. Has anyone used an actuator they would recommend for these type of conditions?
Can’t speak for electric solenoids like this as I’ve never used them. I know McMaster has some that would be legal.
Any reason a pneumatic cylinder couldn’t be used? My guess is you don’t have pneumatics on the rest of the robot, correct?
why not use a snow blower motor with a pin pulling set up. or one of the Bosch window motors
We have no Pneumatics on the robot, and would like to not have to implement them just for this.
I don’t think we have a snow blower motor. We are only a 3rd year team. Would this be from an earlier era?
It does seem like a small gear motor or continuous servo could winch out the pin. Also look into door lock actuators from the auto industry (those have been legal in the past but I haven’t checked this year.)
you should have got them in you kick off tote. Small motors some have gears on them some don’t. wrap a cable or cord around the output shaft as it winds up it will pull said “pin”
Got enough weight for the Nidec? Seems like a job it could do just fine…:rolleyes:
That just seems like a waste of weight and space.
Yep. Hence the “:rolleyes:”.
(Also a pretty decent summary of the motor in general–haven’t heard of anybody who’s actually planning to use it yet.)
We got these a couple years ago from Amazon, didn’t actually use but they pull fairly strong and have ~1/2" stroke if I remember correctly. Super cheap, super light weight. Not the smallest package, but could work for you.
+1
Andymark has legal actuators. I’d personally do air though. If all you are using it for you could just have one tank, and do the compressor off the bot.
We’ve had some success in both 2013 and 2016 using the 110lb GlideForce actuators sold by Northern Tool+Equipment, which you can find in the link below. The included motor is not legal, however we were able to easily substitute an AndyMark 9015 motor (with a filed down shaft) in it’s place.
](https://www.northerntool.com/shop/tools/category_lawn-garden+electric-actuators+4294940994)
Do you have any other actuators you could double-purpose to pull the pin? E.g., we have a climbing hook which is not used until it’s time to deploy the ramp. If we get to the ramp, we plan to have the motion of the hook carriage release the ramps, which would deploy with a combination of gravity and springs.
Another possibility to get better leverage would be that, if the actuator you’re planning isn’t beefy enough, put the pin on a spring and use your actuator to pull a smaller pin out of the original pin.
and if it still isn’t beefy enough, you could have an intermediate pin on a spring…
A good analogy is toppling dominoes. dominoes can topple a bigger domino up to a point. you can chain those (by ratio) and knock over a meter tall domino from a tiny one. https://www.youtube.com/watch?v=8yYWILv91YU