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Hi, someone has done a servo motor with vertical speed, I have one but I can not assign negative values, but works well up when making only goes down to 0.

thanks

Hello rodrigo

This should be no Problem.

I do not have a gauge like this in my 737, but i think you mean a Display like in the standard cessna. So a needle is in Middle Position when holding level and go Up and Down when you climp or descent.

For this you need an Offset.... Maby 02c8 sounds good. You need to transform it like suscribe in Offsetmapping to show feet or meters per sec or min as you want. (Or you transform it like it´s best for youre gauge dimensions)

After that you need to set youre Servo as you normal do.... Starting Value maby 0 Endvalue 180 for example.

Then you use interpolation to define the Offsetvalue to youre servo.
Start with the negative Part.... Use the biggest negativ value that can be shown (lowest scale on youre gauge) For example -2000 in my function and set this for servo piont ( Whatever if you use a right or leftturn servo this must be 0 or 180)
then define the middle point.... If Offset is 0 then Servo need to be in the middle.... also on 90° (Middle between 0-180)
At last set the upper limit for positive values. In my case +2000 and set servo to opposit of lower setting. ( 0 or180... the opposit of the first entry)

Attention: If the Value raises over the limit the servo turns against the endstob an can be damaged.... Maby you set a puffer in interpolation to protect.


Finaly i recommend you to use a Stepper Motor and not a Servo... it´s smoother and the gauge in a cessna for example needs more then a 180° Turning... It´s nearly 360°. A Stepper is much better here in most situations i think.

Good luck !

You should be able to assign negative values. Just set the range for your servo from -3500 to 3500 (min value, max value)

You would need a set of cogs to let the needle turn the 270 degrees and as suggested a stepper would be an easier way to go to realize that.