Winch?

[zjzak]

So my team is looking in to using a winch this year to power our shooter mechanism. One thing we thought of that has been brought up was using a shifting gearbox so that when the cylinder shifts the motor loses contact with the shaft and it's free to spin, similar to how a ratchet works. Does anybody know if it's as simple as removing a gear in a shifting gearbox to accomplish this or is there more that is involved in it. I have never used shifting gearboxes in the past so I don't know how simple it will be to achieve what we want. Also is there one specific gearbox that would be easy to make this change in? One of andymarks? or one of the vex shifters? Any advice on this is much appreciated!

[Stark4Prez23]

Originally Posted by zjzak

So my team is looking in to using a winch this year to power our shooter mechanism. One thing we thought of that has been brought up was using a shifting gearbox so that when the cylinder shifts the motor loses contact with the shaft and it's free to spin, similar to how a ratchet works. Does anybody know if it's as simple as removing a gear in a shifting gearbox to accomplish this or is there more that is involved in it. I have never used shifting gearboxes in the past so I don't know how simple it will be to achieve what we want. Also is there one specific gearbox that would be easy to make this change in? One of andymarks? or one of the vex shifters? Any advice on this is much appreciated!

So you want to shift into neutral? Well last year, my team was going to do the same thing. We were going to use our drive motors to power our winch system. You mentioned ratchet. I remember us breaking the head off of a gear wrench to make it work. I would look into that. We modified AndyMark SuperShifters for this. We didn't actually use this feature on the bot, but it was part of design. It would be worth looking into. Good luck!

[zjzak]

Originally Posted by Stark4Prez23

So you want to shift into neutral? Well last year, my team was going to do the same thing. We were going to use our drive motors to power our winch system. You mentioned ratchet. I remember us breaking the head off of a gear wrench to make it work. I would look into that. We modified AndyMark SuperShifters for this. We didn't actually use this feature on the bot, but it was part of design. It would be worth looking into. Good luck!

Yes shifting into neutral is exactly what I would like to do. Is that possible with a simple rearranging of gears inside the gear box or is it more complicated than that? I would like to be able to do it by simply shifting to neutral and not necessarily making a ratchet, for the sake of simplicity.

[Bob Steele]

The AM shifters don't really have a 'neutral' per se. You will have to modify them if this is what you are looking for. We used the dog gear in 2010 to release our soccer ball kicker mechanism... you really have "engaged' and 'not engaged' It will take some work on your part. I don't think you want the dog to be holding all of the energy... you will want some type of ratchet to hold it and then the dog/shifter will release the ratchet.

[zjzak]

Originally Posted by Bob Steele

The AM shifters don't really have a 'neutral' per se. You will have to modify them if this is what you are looking for. We used the dog gear in 2010 to release our soccer ball kicker mechanism... you really have "engaged' and 'not engaged' It will take some work on your part. I don't think you want the dog to be holding all of the energy... you will want some type of ratchet to hold it and then the dog/shifter will release the ratchet.

Right, what i was referring to as "neutral" would be "not engaged." But are the dog/shifting gears any weaker than regular gears? I don't think they would be and I would have no problem with a regular gearbox holding the strain we intend to hold for the shooter this year. Did you use a ratchet as well in 2010 for the soccer ball? And in order to convert the shifting gearbox to have a "neutral" stage did you need to buy more gears or was it just rearranging the ones already in the gearbox? Also do you remember what gearbox it was that you used? Thanks again for your input.

[craigboez]

Originally Posted by Bob Steele

I don't think you want the dog to be holding all of the energy... you will want some type of ratchet to hold it and then the dog/shifter will release the ratchet.

Typically the dog does hold all the load, and the ratchet is always engaged. Disengaging a ratchet is difficult, especially when under load. The ratchet serves to prevent the loaded system from backdriving the motor, the dog de-couples the system from the ratchet and allows it to free spool. A typical system:

motor --> first stage gear with ratchet --> second stage gear with dog shifter --> output

[waialua359]

Originally Posted by craigboez

Typically the dog does hold all the load, and the ratchet is always engaged. Disengaging a ratchet is difficult, especially when under load. The ratchet serves to prevent the loaded system from backdriving the motor, the dog de-couples the system from the ratchet and allows it to free spool. A typical system:

motor --> first stage gear with ratchet --> second stage gear with dog shifter --> output

This is what we plan to do with the addition of making it spring loaded in wanting to make it neutral.