GSMX250

Hi there members,I’ve not long had a new Spektrum DX8e and have managed to successfully program in three aircraft, at this stage, using up to 5 channels.That is throttle, elevator, aileron, rudder andretract undercarriage.
I am currently trying to set up a P 40 with six channel control, so as above and including flaps.My problem is that I cannot get both undercarriage to deploy, it is a pushrod system, which utilises two servos, one for each side.I am using, the gear channel on the TX and the gear channel on a spec AR 8000 DSMX.So one line out of the receiver to a Y cable and then a cable to each servo.Using a servo tester both undercarriage work properly.
If I change the radio setup and use a spec DX6i and an orange receiver I don’t have a problem and both undercarriage work properly.I have also tried the DX8E with a different spekt receiver, AR 6 210, DSM X and that also failed to deploy both undercarriage legs, but did put up the same leg, as did the other spekt receiver.
I have changed out the “ Y “ lead connection which made no difference.The ailerons on the plane, use a servo in each wing and “Y” lead back to the aileron channel in the receiver, and they work properly.
The two servos that operate the re-tracks are identical servos.
I disconnected the “y” lead from the servos that operate the re-tracks and connected the”y” lead to a matching pair of standard Futaba servos and both of these go full rotation when the undercarriage switch is operated on the DX8e.
So my findings,The DX8E will operate two servos on the undercarriage channel.The DX8e will only operate one of the two servos that are mounted in the wing responsible for retract operation.
The servos that are mounted in the wing will both simultaneously operate properly using a survey tester.
Hmmm… puzzling.
cheers Gary.

rgburrill

Change your receiver. It might be the receiver can't support the current of two servos operating at the same time.

AndyKunz

This is not uncommon with electric retracts. They are often needing a higher input voltage on the signal pin.

Insert a Spektrum SPMCP into the receiver, then the Y into the SPMCP. This will ensure that there is adequate signal level to both retracts.

Andy

GSMX250

Thanks rgburrill I have tried two genuine Spektrum receivers with the same result.

AndyKunz

The SPMCP corre ts the issue.

Andy

GSMX250

Since I had a spare, unused, JR, retract servo, and not an SPMCP I removed the suspect servo from the setup and replaced it with the new JR servo.
Problem solved.
I tested the suspect servo with a servo tester, and it functioned properly on the bench.
Since I had intended to take a smaller foam mustang to the field, the next day, I decided to plug it in and test it.
To my surprise when the Mustang bound to the DXe both ailerons began to jitter “ vigourously”
Fair dinkum!!
Cheers Gary.