Reversing valvegear?

[ZiderHead]

Phew! Ive been pondering how to program a fully adjusting reverser and don't think it can be done just with on chip programming, besides I doubt you could really see it operating on a moving loco anyway.

A 2 position fwd/rev using a servo looks very doable though so it just moves when you change direction on your controller without hitting a function button.

I haven't tinkered with servos for decades so I'll pass that over to those that have, but there are plenty of micro RC type servos available now for under a tenner.

 

[alcazar]

That sounds like what I'd need, but my local model shop had no suitable servos, and I'm unsure what to look for?

 

[Scale7JB]

Hi Alcazar et al..

It really is so much easier than you think..

Yes, use the Zimo chips, an the live steam function will reverse the servo to opposite stops.

It's easily programmable using a Sprog2.

The servo's you need are the 3.7 gram versions.. About £3 each off of eBay..

The only difficult part is getting the free range of movement of the reach rod through the complete arc of the expansion link..

JB.

 

[alcazar]

As in building it right?

Just looked at those servos, they move a bit quick, less than 1/10th of a second for 60 degrees......
Not quite like the real thing?

 

[Scale7JB]

You can adjust the speed of movement as well as the amount of movement very easily on the chip with the sprog..

JB.

 

[Len Cattley]

Good idea, I'll give them a try.

BTW: whereabouts are you from? Not SE London area?

No Mate Berkshire

Len