Hi guys,

Hoping that someone may be able to help me with this one. I am currently using an Axi 5325/24 and Jeti Spin Pro 99 Opto in a Gaudius F3a model.

The setup has work faultlessly for around 50 flights, I have simply set up the controller with the Jeti Box and flown.

However over the last three weeks, whilst on take off, on a number of occasions when the motor hits full power and the aeroplane is just about airborne, the motor makes a terrible screetching sound and has a severe loss in power. The result is that I've had to abort the take off, sucessfully on most occasions until yesterday when I snapped the U/C legs.

The motor will not do this everytime I fly, only sometimes. Yesterday for example I had three flights without problem, but on the fourth and fifth flights the problem occured despite opening up to full power before take off to check all was ok.

The only thing I have changed on the model is the batteries. For the first 50ish flights I have used 2x Turnigy Nano Tech flight packs and 1x Zippy pack (2x5s 5000mah 25-50c)and never had this problem.

I recently bought another 2x Turnigy Nano Techs (2x5s 5000mah) and the problem started to occur. In fact as far as I can tell it will only happen with these two new flght packs.

I am not currently using the Jeti Anti Spark device.

Can anyone help?

Many thanks

Stephen

Hi Stephen,

this issue is timing related. Try to reduce timing and the problem may go away. 22° would be something to start with
Your drive set-up is close to the maximum power. Your newer batteries have less internal resistance (better hold voltage) and cross the maximum power your set-up can deliver.

I had the same issue with a Hacker Motor once. Reducing timing from 30° to 22° did the trick. You can also try to reduce acceleration a bit. If nothing else works a smaller prop may be required. This is however the last option I'd try.

Best
M

Hi Malte,

Thank you for this very useful information, much appreciated. I will reduce both timing and acceleration and see if it solves the problem. Just waiting for a new Undercarraige to arrive first!

Best wishes

Stephen