GV-1 problem

[Jonty]

Hi all

I have posted this question on a number of sites and have had no luck so far. I have a Raptor 50 running an OS 50 hyper with a GV-1. I am having a few problems with the GV-1 that I cannot solve.

First, from the first day I purchased it, whenever I flick into idle up 1 and idle up 2, the head speeds up dramtically for about 5 seconds then slows down again to the preset speed. At this point there are no more problems for the rest of the flight as the headspeed holds. Also, when I switch it out of idle up the head also speeds up then settles back down. This happens no mattter what mixture the heli is running on, whether too rich, too lean or just right. I have read that someone else has had the same problem so it is not isolated.

Further, just recenlty I have noticed that mid way throuh a flight, the head speeds up dramatically for about 5 seconds then slows back down for no apparent reason.

If anyone has any ideas I would apprciate it. I have gone over throttle geometry and it appears fine (I am running a JR811 on throttle).

[WayneBrown]

I've seen this with a motor out-of-tune repeatedly.
A few questions first, and then some suggestions and things to check.
Do you have the ability to manually override the GV-1 from the TX?
Do you have throttle curves that were appropriately setup to fly?
Are you using both magnets, one reversed from the other (polarity)
Are you achieving 95% or higher on the gain?
is your machine vibration free, or nearly so?

IF you answered negative to ANY of the above, you need to rectify that issue first, then look at the following.

Tap test or wiggle test the lead to the sensor, ie: rotate the engine to the highest gain position, and yank, twist, and tap on the lead from the control unit to the sensor, including the sensor.
Wiggle test the leads from the RX to the control unit.
tune/adjust mixture with GV-1 in the OFF position, then once satisfied enable the GV-1 and see if issue persists.

I've seen many sensors either bad NIB, or fail if you did not keep the case together with heat shrink or thread and CA glue.
Check over a few things, and post your findings

[Jonty]

Thanks Wayne

The only issue from your questions is the throttle curves (also I cannot overide governor from the TX I don't think - I am using a JR9X old version). My normal curves are fine, but for idle 1 and idle 2 I have just guessed a V curve just so the governor remains engaged and doesn't drop below 25%.

My understanding was that is makes no difference what the throttle curves are for the Governor (provided the cuves don't overide the governor), it is only important to have curves that are close enough to running without the governor in case the governer fails.

You are right in that it may be the governor is shutting off for some reason and it is running on a throttle curves which are a bit higher than the preset governor speed. I will also check the sensor tonight.

Other than that, I always tune with the governor off and it seems to make no difference to my problems what tuning state the engine is in.

I have CA'ed the sensor but it may have virbated free. I did notice that my engine died completely in idle up 2 the other day!