Question about shifting gearbox?
 

Hi, we are thinking about buying a shifting gearbox (ball shifter or super shifter) since we saw how effective they are but first i want to know how they work(the shifting). Is it related to programming and if yes how to we do it. Or it's only mechanical and do we need some extra gear or pieces.

Re: Question about shifting gearbox?
 

It's a mechanical gearbox, that is shifted via the control system, usually either using pneumatics, or a servo.

It is therefore programmed like you would program either a pneumatic actuator, or a servo.

Re: Question about shifting gearbox?
 

Gear shifting is done with either pneumatics or servos. If you have a pneumatic system on your robot, plumbing in two small cylinders will not be difficult. I have found pneumatic shifters to be quicker and more reliable than servo powered ones.

To add shifting you will have to replace your gearbox and potentially much of your drive-train of you are modifying an existing robot. Adjusting and readjusting chains or belts with idlers is no simple task, especially if you haven't designed the robot in CAD.

Re: Question about shifting gearbox?
 

Thank you for helping shed light on the issue. Do you have any recommendation for a gearbox that can shift with pneumatic. It's for our list to buy things for next year so we won't be changing the robot.

Re: Question about shifting gearbox?
 

If you do a search here on Chief Delphi you'll find a lot of the answers you are looking for.

Re: Question about shifting gearbox?
 

The gearbox is mechanical but is shifted pneumatically via programming. We have used it this year. I highly recommend that you use 2 cims per gearbox for the speed and torque. 2 cims is okay but will draw a lot of current. Our gear ratio that we had was High speed was 24:1 and low speed was 6:1. It was easy to program them in java for my team. I also do encourage you to have a button that kills robot driving when you are shifting then drive or else you are throwing a piece of metal into spinning gears with a lot of power. It is not needed but recommended because of it leading to possible shifting problems in the future of its usage.

Re: Question about shifting gearbox?
 

Figure out your desired speeds/how exactly you wanna design your drivetrain(ie. direct drive or do a reduction with belts or sprockets) and from there, determine whether the VEXPro BallShifter, WCP Shifter, or Super Shifter would be better suited for you. Also of note, the Super Shifter can shift with a servo if you don't plan on using pneumatics next year.

Also, AndyMark are releasing a new shifter soon, so who knows what that will bring to the table.

Re: Question about shifting gearbox?
 

The Ball Shifter from VEXPro is pretty good from what I've experienced.

http://www.vexrobotics.com/vexpro/ge...l-shifter.html

Re: Question about shifting gearbox?
 

If you do go with the pneumatic shifter you are going to want to use chains. It will come handy when you are going against a robot that is pushing you. These shifters worked amazing for us during our events in MAR.

Re: Question about shifting gearbox?
 

Why?

Re: Question about shifting gearbox?
 

During our MAR competition at Hatsboro Horsham we had the belt drive and we had amazing torque. We started pushing 2 robots and when the third came there was so much power from the 3 robots that our belts started skipping or something along those lines. At night we had about an hour before pits closed and we switched to chains. Did amazing and pushed better than ever.

Re: Question about shifting gearbox?
 

Use a double solenoid to shift gears. Program it like you would a normal pneumatic, except that you'll probably want some sort of toggle between the different gears.

Re: Question about shifting gearbox?
 

We used a double solenoid for ours but we didn't use a toggle because we did more high gear for the speed instead of low for the torque.

Re: Question about shifting gearbox?
 

We plan to use pneumatic next year also. Thank you for the help.

Re: Question about shifting gearbox?
 

I 100% agree with you, we have been using pneumatic shifters every time we decide to have a two speed gearbox and never have any trouble with them at all.