Re: Andy Mark Supershifter with Pneumatic shifters
 

This solenoid is one-directional, push only. The spring return is only minimal to return the armature to the retracted position when de-energized. It is also intermitant duty, which means it can be energized no more than 50% of the time without overheating. A shifting actuator must maintain force in either direction at all times. This is one reason an air cylinder is well suited to the job. A continuous duty solenoid of this same wattage would have about 1/3 the force.

Re: Andy Mark Supershifter with Pneumatic shifters
 

3/32.

As I mentioned this is the first year solenoid actuators have even been permitted on a FRC robot, so there is no history of them being used for shifting that I know of. If someone successfully did this in 2012 I would be curious to hear about it.

Re: Andy Mark Supershifter with Pneumatic shifters
 

Yes i agree with jspatz1 about this conversaion, but im also wondering about this solenoid shifter, if anyone has use this setup,please feel free to add to this conversation, i see the pros and cons about using pneumatic shifters......what are the pros and cons using solenoid shifters

Re: Andy Mark Supershifter with Pneumatic shifters
 

pros: less weight(no compressor and tanks)

cons: slower

Re: Andy Mark Supershifter with Pneumatic shifters
 

Why should it be 60 PSI? Shouldn't it be closer to the actual force required?

Our own shifters we had, we've always run at 20 PSI for the solenoid valves sake. I was under the assumption that it took less force than the 12 lbs to shift but I could be wrong about this as I have no experience with the super shifters.

Re: Andy Mark Supershifter with Pneumatic shifters
 

We run our SuperShifters at 20 psi as well without issue. 60psi shifts with 27 lbs of force (force = pressure*area, where the Bimba 040.5-DP has a 3/4" bore).

Another setup that I've heard of is using a window motor coupled to both transmissions with a spring setup to engage the gear if it is not lined up during the initial gear change request. I do not know what team had this setup, but it is definitely worth researching some more as it could offset the weight of a pneumatics system, even those with pvc air reservoirs.

Re: Andy Mark Supershifter with Pneumatic shifters
 

Force = Pressure * Area. Much smaller force there.

Re: Andy Mark Supershifter with Pneumatic shifters
 

That would be Team 67...

Re: Andy Mark Supershifter with Pneumatic shifters
 

That's a clue that I should go to bed.::rtm::

Fixed for posterity, thanks.

Re: Andy Mark Supershifter with Pneumatic shifters
 

Pneumatic solenoid valves of the type used in FRC are internally piloted valves, which means the pressurized supply air is used to actuate the valve spool, not the solenoid. The solenoid is very small and only opens a tiny port to trigger the pilot air. Such valves have a minimum pressure that will allow it to operate, usually around 30-40 psi. So they actually prefer a high pressure and only function reliably when it is sufficient. So a note to teams: If you have a valve that is not responding when you are certain it is getting a proper electrical input, and you are using low pressure, chances are the pressure too low for the valve to operate.

Re: Andy Mark Supershifter with Pneumatic shifters
 

Right, and the minimum pressure for the valve we were using was at 20PSI. For me, that's not a good reason to say that you need to generate the same force as a 60psi 1/2" piston with a push/pull solenoid to make the thing work.