mkranitz

My Feedback: (60)

Hey Guys,

I have a Vario Bell 230 kit that I bought from a friend. It is large (73" long) and uses Futaba S-136G retract servos (non-proportional). I purchased a "Go-Slo" from SonicTronics (the McDaniel RC one), but forgot that it only works on proportional servos.

I am thinking about replacing the retract servos with high-torque proportional ones. Is there any downside here (e.g. in terms of holding loads in the up or down position)? Also, I'm assuming they draw less current. Mechanically, I would also like the ability to adjust the endpoints, which cannot be done on a retract gear (the 180 degree rotation is not needed mechanically and actually strains the pushrod setup).

Michael

TLH101

My Feedback: (90)

I may be off on this, but I beleive that a retract servo has no elctrical load (or very minimal) draw at the end points of its travel, where as a proportional has a load at either end and none at center.

mkranitz

My Feedback: (60)

I may have just borne you out on this. I put in a JR 8611 digital high-torque servo. On the end where the gear hang down, there is no load or buzzing. But, when the servo has to keep the gear tucked in the heli there is a constant load on the servo and it buzzes like crazy, telling me that it's drawing way too much current. This stinks because I'd like realistic retraction of gear.....

Bayou Talker

My Feedback: (1)

I assume that you have the retracts on a 2 way switch. How about putting them on a variable knob such as the flap control? That way you should have more control on the limits and the speed of deployment.

Dr1Driver

Your retract gear should have positive locks on either end point. That will stop the load on the servo. Adjust the servo arm length until you get a positive lock with no buzzing. It IS possible. The servo should NOT hold the gear in either up or down position, the locks should. Instead of using a servo arm, try an undrilled wheel. That way, you get the exact travel you need. Proportional servos will work, provided they have the torque required to cycle the gear. The advantage would be, as you mention, the ability to adjust the endpoints with your TX.

Dr.1

mkranitz

My Feedback: (60)

The knob would still result in a load on the servo. I've decided to put a lever switch in the wheel well and connect it to ONLY the "retract" wire coming out of the servo lead. When the lever gets depressed by the wheel retracting, it cuts power to the "up" direction of the servo. When the gear is extended, power is restored.

JimTrainor

What provides the power to extend the gear after it is up?

MustangFan

Consider >>>>>

Hitec's 5645 servo is a digital high torque servo. Using their programmer you can slow it down ( but still have high torque ) ... plus set end points.
The servos are $50.00, the programmer is $150.00. I have tested the servo with the programmer ... it can be programmed to go 180 degrees ( +/- 90+ degrees from center.

If you can borrow a programmer ... then $50.00 is all you will need !

lrb75

My Feedback: (12)

Airtronics made a proportional retract servo. I'm not sure if they still do or if the go slow or transmitter settings would slow it down.