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Main => General Discussion Board. => Topic started by: EAL727Capt on July 10, 2010, 12:31:47 PM

Title: Servos vs. Stepping Motors
Post by: EAL727Capt on July 10, 2010, 12:31:47 PM
I've gutted most of my steam instruments for the B727, dumping the synchro mechanisims and am looking for opinions on whether to purchase RC-type servos or stepping motors to drive them.

I'm looking for the smoothest, most realistic operation (who isn't?) am hoping for some advice.

Based upon personal experience, which works better?

Thank you very much,

Jay
KPTA
Title: Re: Servos vs. Stepping Motors
Post by: Bob Reed on July 10, 2010, 12:54:27 PM
727/737Nut needs to jump in here!! He has been down this street.
Title: Re: Servos vs. Stepping Motors
Post by: Boeing Skunk Works on July 10, 2010, 02:21:52 PM
Yep, he's your 727 guage man for sure.

I wanted something faster so I'm using minitors behind my MIP.
Title: Re: Servos vs. Stepping Motors
Post by: 727737Nut on July 10, 2010, 02:45:23 PM
Go with servos, these servos will fit inside a 2" gauge with ease, smooth and programmable to boot!
http://www.servocity.com/html/hs-5045hb_servo.html

servocity.com has the gears you need as well to get more than 180deg movement.   What i did was press a nylon gear on the stock synchro shaft, epoxy a small standoff in the gauge to mount servo to. Takes 30mins to an hour and worrks great using SIOC and oc servo card.
Title: Re: Servos vs. Stepping Motors
Post by: EAL727Capt on July 11, 2010, 07:37:47 AM
Gents, and, in particular, Rob.

Thank you, as always, for the replies.   Based upon what I've researched thus far and on Rob's recommendation, it looks like servos are the way to go.

When would there be an instance when stepping motors should be used?  With very limited knowledge on the subject, I'd say for 360-degree operations (like altimeters, ADF/RMIs, etc.).  Can anyone confirm?

Thank you again,

Jay
KTPA

Title: Re: Servos vs. Stepping Motors
Post by: 727737Nut on July 11, 2010, 10:19:21 AM
No need to then either,  you need to buy an electric altimeter and convert it or use a 5 turn pot and thru gearing it acts a regular altimeter. Every 10K feet = 1 turn on the pot   I have gutted servos, desoldered the motor and pot and just used the electronics with great success!  :)   Servo's are the esiest route or some facsimile of them.