pic: what do you think?

[CD47-Bot]

loading photo ...

[sburro]

what do you think of this design?

[JVN]

How will you get the pneumatic to go to 3 different positions?

[MrToast]

Looks like a sick mad nasty geared transmission. I think 33 had something like this. 494 also had a really cool CVT. (494's was a demo, though)

[sburro]

Originally Posted by JVN

How will you get the pneumatic to go to 3 different positions?

I do not know as of now. It is a design in the workings.

[Madison]

Presumably, the output is the rightmost shaft? How do the three center gears interface with the output shaft?

[Bill Gold]

Originally Posted by JVN

How will you get the pneumatic to go to 3 different positions?

We used 2 single solenoids with a double solenoid to make the actuator on our arm hold multiple positions firmly. FotoPlasma would probably be able to answer any questions you might have about it.

[patrickrd]

Looks good to me You just need to figure out a way to get the piston to stop mid-stroke... Maybe two pistons in series?? (don't know if anybody's every tried that ). There's probably quite a few clever mechanisms to do the trick.

- Patrick

[Greg Needel]

i think that this might be problematic when it comes to meshing the gears....this is the reason that most teams use shifting "dogs"

it still looks like a sold design but will only be effective if you stop to shift

[Tom Bottiglieri]

Originally Posted by patrickrd

Looks good to me You just need to figure out a way to get the piston to stop mid-stroke... Maybe two pistons in series?? (don't know if anybody's every tried that ). There's probably quite a few clever mechanisms to do the trick.

- Patrick

with this would you have 4 possible positions? Or 3? (While the primary cylinder is in, and the secondary cylinder is in, it is in stage 1. When the primary is in and the secondary is extended it is in stage 2. When the primary is extended and the secondary is in it is also in stage 2. When both are extended it is in stage 3)

[FotoPlasma]

Originally Posted by M. Krass

Presumably, the output is the rightmost shaft? How do the three center gears interface with the output shaft?

The largest gear on the center shaft is always meshed with the long faced gear on the output shaft. When it's in the extreme position, it acts as an idler gear between the input and output gears.

From what our team found out from using a multiposition actuator, this seems like a very plausible design. The problem of a smaller volume of air taking less time to fill a smaller pneumatic piston can be remedied using flow control valves, but that's an implementation problem, rather than design.

[ngreen]

Originally Posted by patrickrd

Looks good to me You just need to figure out a way to get the piston to stop mid-stroke... Maybe two pistons in series?? (don't know if anybody's every tried that ). There's probably quite a few clever mechanisms to do the trick.

- Patrick

I would use a single and double solenoid(multi-positioning pnuematics) with three magnectic reed switches to stop you at the correct positions.

I would presume this would work quite well. I'm not as familiar with the programming side of it but it seems to me that this could be done.

[FotoPlasma]

Originally Posted by ngreen

I would use a single and double solenoid(multi-positioning pnuematics) with three magnectic reed switches to stop you at the correct positions.

If you use hardstops with the actuator, you'd only need one (max 2 for hysteresis) magnetic sensor.

[ngreen]

Yeah you could do it with one, with three I think you could know what position you were in easier (maybe not, I know you can still tell with one but three would easily tell you where you are) to make it into a automatic shifting system.

[JVN]

Seems like after all that hassle, it would just be easier to do a 4-speed similar to 33, or 968. (I'm especially partial to 968, but it is more difficult to manufacture than 33's).

Then again, I've found no need for more than 2 speeds.
You can get along fine with just 2, more is overkill.

John