how do you convert a servo to move past the 180deg stop

[jaspar]

the title says it all im trying to build or convert some instruments to run with open cockpits servo cards and sioc. most instruments have 270deg arc's on them but servos only turn 180deg. Do I just cut of the little tab on the final o/p gear or do i need to do more?


ta
Jaspar

[737NUT]

the title says it all im trying to build or convert some instruments to run with open cockpits servo cards and sioc. most instruments have 270deg arc's on them but servos only turn 180deg. Do I just cut of the little tab on the final o/p gear or do i need to do more?


ta
Jaspar

Go to Servocity.com, buy a gear for the servo and smaller gear to fix to shaft of instrument you are interfacing, allows 360deg travel of gauge with 180deg travel of servo.

[fsaviator]

Try this link. It's instructions on how to modify an HS-322 servo so you have full rotation.

http://www.simkits.com/downloads/documents/Modify%20a%20servo%20HS-322.pdf

Warren

[737NUT]

That mod doesnt work with the stock internal pot, just an FYI

[jaspar]

thanks waren

I'll try that when I get home as this sounds like the way forwards if i can get continous 360deg rotations to drive an alt etc.

[Matt Olieman]

Just to interject. One of my most frustrating adventure of building a sim is all the wrong advise you can get. But over almost 10 years I've learned to trust a few inexplicably. Rob (737nut) is one of those, he's a servo expert.

[737NUT]

Maybe i need to reiterate here, that mod will make the servo turn CONTINUOUSLY unless you add an external potentiometer like what simkits does when they do that mod. If you notice, you superglue the internal servo pot shaft! You will RUIN your real gauge if you do this mod and hook up your servo. It is very easy using the products from the link i gave you to get 270deg+ movement in a gauge with a standard and unmodified servo. If you do it like i said then apply your slope and intercept math to the software driving the servo, you will get a VERY accurate gauge movement.

That PDF file is VERY misleading as important info is missing. :)

[fsaviator]

thanks waren

I'll try that when I get home as this sounds like the way forwards if i can get continous 360deg rotations to drive an alt etc.

Jasper, not trying to mislead you or anything here... that was a method I used to get 360 degrees rotation as part of my old simkit centered build. If 737NUT advises against it for your build, I'd go with his advise. He's definitely got more experience at this than I do.

Good luck and let us know how it goes.

Warren

[737NUT]

Hey Waren, Wasn't trying to step on your toes there. ;) Just wanted to let them know that when doing that mod you have to add some kind of external feedback pot for that to work. Now another option would be using a DC motor card from OC but you still need a feedback pot.
Happy Simming!
Rob

[fsaviator]

No issues Rob. That's why I'm here... to learn. Thanks for setting me straight.

Warren