DX8i problems - no electric motor

[alan barnstable]

Yesterday was flying electric Tucano and motor stopped midflight, brought it in OK but motor working OK on ground.

Then tried to set up electric funfighter but wasn't getting the beeps from the motor. Control surfaces all working, but no throttle.

Tried again this morning, same problem. Spectrum receiver, light on.

Rebound receiver to my spare DX6i and it fired up in the sequence with four beeps and the musical tone, and everything working fine.

I had the same problem with a different plane last week, but after numerous attempts at plugging in it was OK.

So the problem appears to be the transmitter, but I haven't found anyone else who's had the same problem, any takers ?

[Denis Watkins]

1st check

Your Monitor, that the throttle arrow is moving up and down with the throttle stick

[alan barnstable]

Have rebound to DX8i, no beeps, but monitor is showing normal throttle movement.

[Frank Skilbeck]

Make sure the trim lever is fully back.if the ESC isn't seeing a low enough throttle setting it won't arm.

[alan barnstable]

I don't ever trim the throttle because all my models are electric or gliders.

One odd thing is that I have to reverse the throttle on all powered models. This has worked fine for the past year, but now I'm having this problem.

Looking at the monitor screen it's showing -85% at closed, and 100% fully open.

Throttle curve is Inh, and is showing 93 at closed, and 0 fully open !

I have tried creating a new model, but the Funfighter will still not work. Also tried changing receiver.

In the meanwhile I have set up on DX6i and it works normally.

[Frank Skilbeck]

Have you managed to reverse the action of the throttle stick? so trim now works with the throttle stick up.Have a look on the servo monitor or plug a servo into the throttle channel.

[Denis Watkins]

It is clear Alan, as Frank is leading you down the right path

The ESC is sensing +ve throttle

And as designed, the ESC is preventing motor up as a safety feature

Set the throttle trim to centre, and reset throttle 0 to 100%, then term down to negative trim

If the motor doesn't run, then reverse the throttle

This is not a DX8 problem, it is just an ESC safety feature to prevent motor start up at switch on with the stick up

[alan barnstable]

Sorry guys, I really appreciate your help, but I'm struggling to understand how to carry out the steps you're suggesting.

The throttle channel is currently reversed (otherwise it gives full power with the stick closed i.e. towards me). On the monitor screen it shows the little block moving from left to right. Although on the throttle curve screen it shows the vertical line tracking down the curve from right to left. This arrangement has worked fine for six different planes for the past year, but has just recently started to play up without me making any changes to anything.

I don't understand the concept of trimming the throttle, obviously I do this for the control surfaces with the trim switches and sub trim adjustment on the servo screen.

How do I trim the throttle ?

Sorry if I'm being a little thick here, it's obviously one of those things which would be easy to explain if we were stood in the same room, but difficult to convey via the written word.

[Dwain Dibley.]

If you had an engine with a carb, with a servo operating the carburettor, you would adjust the servo to open and close the barrel with the throttle trim , just like you would use rudder or elevator trim. Same with the ESC, use the trim to "close" the throttle.

D.D.