View Full Version : COR Robotics and Subzero T-Shirt Cannon!
Ginger Power
01-08-2016, 13:39
I had the awesome opportunity to work with Subzero Robotics (5690) this weekend on a T-Shirt Launching Robot. Subzero, located out of Esko, Minnesota (near Duluth) is an upcoming team in Minnesota, and incredibly fun to work with.
I CADed the robot on Creo Parametric and created a Bill of Materials which 5690 then ordered. The final robot includes multiple improvements and changes to the CAD model based on what materials were available.
Here is a short video (https://youtu.be/EkxMvktDRTc) I threw together that shows the robot in action with a few pictures as well.
Robot Specs:
- 4 cim drive with 4 toughbox micro gearboxes
- WCD using a hex output shaft from the toughbox micro
- Toughbox Micro has a gear ratio of 8.45:1
- The air tank (http://www.walmart.com/ip/48086455?wmlspartner=wlpa&adid=22222222227035473737&wl0=&wl1=g&wl2=c&wl3=75973224394&wl4=&wl5=pla&wl6=176367840994&veh=sem) was purchased from Walmart (believe it or not) and is designed for use on a semi truck
- The barrel has a fairly restricted range of motion from nearly vertical to about 30 degrees for safety reasons
- The system is rated for up to 125 PSI, and includes a vent plug valve set to release air at 110 PSI
- The Solenoid Valve (http://www.electricsolenoidvalves.com/3-4-12v-dc-electric-brass-solenoid-valve/) that is used is a quick release 3/4" NPT valve
- At max pressure, the robot can launch T-shirts around 100 feet and can fire 4 times before needing to refill the air
We built the robot in 2 days with 10 people, and it was a bunch of fun! IF you have any questions or suggestions I'd love to hear them.
I wish I had seen that tank when we built our cannon. Instead we spent a painful amount of money for this (http://www.mcmaster.com/#9888k9/=13jdrry) because we wanted the 1" port.
Ginger Power
01-08-2016, 13:48
I wish I had seen that tank when we built our cannon. Instead we spent a painful amount of money for this (http://www.mcmaster.com/#9888k9/=13jdrry) because we wanted the 1" port.
I wanted to go with 1" NPT, but it wasn't worth it to me for the cost.
And your solenoid was like $150 cheaper than ours. You really should publish your BOM because you found some good components.
Ginger Power
01-08-2016, 14:06
And your solenoid was like $150 cheaper than ours. You really should publish your BOM because you found some good components.
Will do! I'll be back home tonight and I'll make sure to post my BoM!
Thank you Ryan for all your help building this robot! It was a great learning opportunity that I'm sure will help our team in the future!
Great job guys! How many shots per tank estimated?
Great job guys! How many shots per tank estimated?
- At max pressure, the robot can launch T-shirts around 100 feet and can fire 4 times before needing to refill the air
..
Ginger Power
02-08-2016, 12:37
Here is the link (https://docs.google.com/spreadsheets/d/1lS0wGw4HQ1LxkJnmVtCwWOjIfSePFbVuvA3e05hOneM/edit?usp=sharing) to the Bill of Materials. It doesn't include a couple of components including the components necessary to articulate the barrel. Some additional brass fittings may also be useful for configuring the air system as desired. The logic behind not including some items is that it forces whatever team I'm working with to get creative, and engineer a solution based on the items available to them.
Great job guys! How many shots per tank estimated?
Thanks! When we fill the tank to 110 PSI we get around 4 solid shots. The tank drops by around 20 PSI after every shot. That would put the 4th shot at around 50 PSI which is more than enough to hit the bottom row of the stands at a high school football game!
For the valve here is a cheaper option that is rated for a much higher pressure. http://www.airbagit.com/Brass-Air-Valves-p/airvalve-02.htm they also offer mounting brackets for them as well as rebuild kits. That is the one we used on a t-shirt cannon on my former team and I can verify its response time is very quick because we were able to control the distance of the shot by how long the valve opening pulse was.
Ginger Power
03-08-2016, 11:38
For the valve here is a cheaper option that is rated for a much higher pressure. http://www.airbagit.com/Brass-Air-Valves-p/airvalve-02.htm they also offer mounting brackets for them as well as rebuild kits. That is the one we used on a t-shirt cannon on my former team and I can verify its response time is very quick because we were able to control the distance of the shot by how long the valve opening pulse was.
Does a 1/2" NPT valve allow for enough air flow for a good shot? All the research I've done has told me to go no less than 3/4" NPT as the narrowest point.
Does a 1/2" NPT valve allow for enough air flow for a good shot? All the research I've done has told me to go no less than 3/4" NPT as the narrowest point.
Sorry I meant to post the one with the same 3/4" npt port and same 20 mm orifice as the one you used. http://www.airbagit.com/Brass-Air-Valves-p/airvalve-06.htm
Ginger Power
03-08-2016, 11:45
Sorry I meant to post the one with the same 3/4" npt port and same 20 mm orifice as the one you used. http://www.airbagit.com/Brass-Air-Valves-p/airvalve-06.htm
Dang, that's a sweet find! I'm going to update my BoM to use this thing!
The robot got its first real test today. We filled the barrel up with candy (with a foam plug put in first) and let it fly. The kids loved it! We haven't had any problems with the shooter so far, the only thing is that we still need to make sure it's completely air tight. I do believe we have a problem with some of our gearboxes, but hey that's what happens when you have the programmers build them. :rolleyes: So far we are very pleased with the robot and its performance. The crowd of children and parents were very excited and impressed.
Looks great! That range is nothing to scoff at for sure. It could use some decorations though.
4 shots isn't much... you should think about stocking extra tanks or using a larger air tank or something.
Looks great! That range is nothing to scoff at for sure. It could use some decorations though.
4 shots isn't much... you should think about stocking extra tanks or using a larger air tank or something.
It actually gets more than 4 shots. If the tank is filled up to around 110 psi we get 4 long shots. After this the psi is still around 60 which allows for around 5 more mid range shots. For the parade we recently had it in we only need to pressurize the tank a couple of times during the mile long parade.
It actually gets more than 4 shots. If the tank is filled up to around 110 psi we get 4 long shots. After this the psi is still around 60 which allows for around 5 more mid range shots. For the parade we recently had it in we only need to pressurize the tank a couple of times during the mile long parade.
You can also probably get a lot more shots by lowering the time the solenoid is open for when you don't need 100 feet. We had a 5 gal tank @ ~120 psi that fed through a regulator into a 1 gal tank @ ~60 psi and we were able to get 8-10 shots at >50 ft (not even completely optimized) before dropping below 60 psi in the main tank. By my calculations, your tank is ~ 9 gal, so you easily have the energy to get well over 10 good shots, it's just about how efficiently you use it.
You can also probably get a lot more shots by lowering the time the solenoid is open for when you don't need 100 feet. We had a 5 gal tank @ ~120 psi that fed through a regulator into a 1 gal tank @ ~60 psi and we were able to get 8-10 shots at >50 ft (not even completely optimized) before dropping below 60 psi in the main tank. By my calculations, your tank is ~ 9 gal, so you easily have the energy to get well over 10 good shots, it's just about how efficiently you use it.
Right now we haven't done anything with controlling the solenoid. its controlled with how long you hold the button. A really quick tap is all we use to fire at the moment. Later on we will hopefully be adding a way to control the amount of time the solenoid is open. This robot will be going through many changes as we learn and experiment with it!
Chief Hedgehog
11-08-2016, 03:46
@Ginger Power
Do you have a website for COR? This would be a great place to post it:p Just saying!
Ginger Power
11-08-2016, 10:51
@Ginger Power
Do you have a website for COR? This would be a great place to post it:p Just saying!
Technically there's a website, but it's such a work in progress that there's almost no reason to post a link. Here it (http://corrobotics.weebly.com) is anyways.
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