Vex Pro: Ball Shifter with a servo?

[Cash4587]

Is there a way to shift the vex ball shifters with a servo? If not is Vex Pro going to come out with one next year? It would be a great addition to their product line and I think it would get it's use out of it. Especially from the teams that don't use pneumatic systems. Anyways thanks for the help.

[AdamHeard]

Anyone know what 67 did this year to shift?

[Aren_Hill]

Originally Posted by AdamHeard

Anyone know what 67 did this year to shift?

Zip tied it in high gear

[Cash4587]

Originally Posted by Aren_Hill

Zip tied it in high gear

LOL. Nice.

[jman4747]

Personally I think it could be a good excuse to learn pneumatic systems and a good practical goal for teams who haven't used them before. If weight is your issue one or two plastic tanks and the smaller compressor should be no problem. That said making a bracket for a servo to replace the mount for the cylinder doesn't seem hard at all as I look at the CAD. One thing I haven't seen however is the potential use of solenoid actuators for shifting and that might be something to look in to as a pneumatic alternative.

[Cash4587]

Originally Posted by jman4747

Personally I think it could be a good excuse to learn pneumatic systems and a good practical goal for teams who haven't used them before. If weight is your issue one or two plastic tanks and the smaller compressor should be no problem. That said making a bracket for a servo to replace the mount for the cylinder doesn't seem hard at all as I look at the CAD. One thing I haven't seen however is the potential use of solenoid actuators for shifting and that might be something to look in to as a pneumatic alternative.

Interesting thoughts. My team has all the pneumatic parts needed for a whole system but didn't see the need because we would have only needed it to push a disk into our shooter wheels. We opted out of that and used a vex motor instead. It works much better in my opinion and is far simpler. We also thought about it and we really didn't need to do a pneumatic system to do well in this years game despite the many things we could have used it for. Even thought the weight is not an issue it's the fact that we have to add a whole system to our bot to do things we can do without it. Are all solenoids legal? That might be something I will have to look into doing to shift since I don't see my team using pneumatics anytime soon even with it's possible gain. Unless they make sense in next years game.

[MichaelBick]

Originally Posted by Cash4587

Interesting thoughts. My team has all the pneumatic parts needed for a whole system but didn't see the need because we would have only needed it to push a disk into our shooter wheels. We opted out of that and used a vex motor instead. It works much better in my opinion and is far simpler. We also thought about it and we really didn't need to do a pneumatic system to do well in this years game despite the many things we could have used it for. Even thought the weight is not an issue it's the fact that we have to add a whole system to our bot to do things we can do without it. Are all solenoids legal? That might be something I will have to look into doing to shift since I don't see my team using pneumatics anytime soon even with it's possible gain. Unless they make sense in next years game.

Pneumatics has a tons of uses. While you can do things in other ways, I find that pneumatics makes a lot of mechanisms simpler. Basically anything that is 2 position(and some 3 and 4 position stuff) is usually easier to do with pneumatics. It's one of the easiest ways to make complex mechanism with very little resources.

[jman4747]

I would say always leave yourself as many options as possible. The vary nature of the challenges we face each year constitute being able to use every tool at you're allowed. Even if you have no intention of using them the learning experiences and extra team building alone could be worth it.

As for solenoid actuator rules, "Electrical solenoid actuators, no greater than 1 in. stroke and rated electrical input power no greater than 10 watts (W) continuous duty at 12 volts (VDC) Unlimited" FRC Game Manual 2013

[magnets]

Electric solenoids probably aren't a great idea for shifting, as they will burn out if they are held in the same position for a long time. Also, I don't think that a 10W electric solenoid will have enough power to activate the shifting mechanism.

[Adam Freeman]

Originally Posted by AdamHeard

Anyone know what 67 did this year to shift?

Aren is correct. We were unable to package our typical window motor shifter with the smaller chassis size. We then designed a VEX-393 motor shiter setup that ended up stalling out and frying a digital side car (or two...). After that, we tried to design a typical servo shifting system. We ran out of time before the season started to install the servo shifter, but after looking at it more closely I don't think it would have worked very well. We were trying to emulate the AM-Super-shifter servo setup, but had a hard time getting the rotation of the shift arm transferred into axial movement of the shaft that shifts the gear box. There seemed to be a lot of play in that shaft. Probably just needed some additional constraints that we didn't have time to design in.

I also looked into trying to find a suitable electric solenoid to shift with, but was unable to find one that seemed like it met all the rules and had enough power to shift.

In the end, we just zip tied the ball shifters in high gear and attempted to avoid pushing matches.

Maybe the guys at VEXpro can design one for us teams that can't seem to make room for a pneumatic system.

-Adam

[AllenGregoryIV]

We also looked at the possibility of electronic solenoids to shift or be brakes and couldn't find any that had enough power or worked in a way that we though would be reliable or adaptable for that application.

I also wouldn't count out pneumatics, infact we are planning to assume we will need pneumatics from the start and than remove them if we can get away with it.

[Cash4587]

Depending on the game pneumatics are always an option. It is just this year I didnt see the true need for them. Next year may be different . But I would just like to have the option to shift without a whole system of pneumatics.