Advice on govenor/rev limiter for T-Rex 600 Nitro

[Farmer Giles]

Revlock 10 here on my Raptor 30.

Still fine tuning the engine a bit but so far so good and I am probably at the same kind of flying level as you, hovering, lazy 8 etc..

I've just set it up mechanically for now but I will get is set up remotely at some point but it's fine for what I'm doing just now.

I got mine second hand with a spare sensor for £20.

HTH

Edit, if the engine is reving away then it sounds like your throttle curve needs some work. I would recommend having a decent throttle curve set up in the TX underneath the governor so your not totally reliant on it to fly just in case it packs up mid flight.

[Andy from Sandy]

My YS is tuned perfectly and have found 2000 rpm to give the best hold but I wont be in a rush to get another revlock.

I started out with a Revlock 10 and an OS 50. The two worked together perfectly. I then got a YS50 and this engine used to hunt with the Revlock. I changed it out for a TJ Pro and all was well again.

I now use the MultiGov. The only thing I don't like is I can't fine tune the headspeed whilst in flight, like I could with the Revlock or TJ Pro.

[wildc4rd]

Thanks all for the advice, the Revlock 10 arrived from Fast Lad today, looks pretty simple, but anything I should know before dropping the motor out and fitting it?

[SteveH39]

on a trex 600 the mounting can be a bit fiddly for the sensor, i mounted mine inside the frame and secured it firstly with heatshrink, then a small dab of CA to hold with a tie wrap for security. not failed on me (touch wood) in over 2 years.

[wildc4rd]

OK, its on, everything is back together and the mode on the governor switches from a, to b flashing, then to b solid in normal/idle up 1/idle up 2 on the Tx. I have enabled the governor feature in my Tx (DSX9) but am now unsure how to set the rev limits. I am aware of the 8.5 to 1 gear ratio, and for now will probably just use 15000 RPM in the 3 modes, for about 1800 RPM headspeed.

Any advice on this apreciated.

[jamiem]

The only bit of advice with the physical setup is to make sure that everything on the throttle linkage is at 90 degrees at 50% throttle, throttle end points are even and no more than around 115-120 each way (you might need to play with the throttle servo horn to get this right), then go through the full setup.

Also, its not a limiter as such, you still need to set your throttle curves (which should be ok already if you've been flying it), then enable to gov at your desired rpm.

[wildc4rd]

The physical setup is pretty good, as I have been flying it without the governor for about 5 weeks. The problem I have now is in the final stages of the setup.

Its in remote mode, hooked into the Aux4 channel of the RD921 receiver. I have gone through the first parts of the setup with it, setting idle/full throttle and the servo type. The unit switches correctly in Normal,Idleup1 and Idleup2, what I don't quite get is the setting of the target RPM, specifically setting the rpm offset using the 'ATV of the Mode/Speed channel'. Is this anything to do with the % figures in the governor menu on the DSX9?

While on the subject of those % figures, what should they be used for, as currently all 4 (Norm, ST1, ST2 and Hold) are all at 0%.

Hope that clarifies a little, and thanks for the help thus far.

[wildc4rd]

Got it sorted early today, my estimate of 1800 headspeed was close (its actually about 1845 average). Bit slower than it used to be, but about an extra 2 minutes flight time. Seems much more stable in wind as well, without the head speed going up and down from transitional lift in the gusts.

All in all, well impressed, thanks to all posters for the help/advice.

[wildc4rd]

OK, a few more flights on it, I notice it is 'hunting' a little, I have a JR DS801 on the throttle at the moment, is it that this servo is too slow? or is another part of my setup causing trouble?

Thanks (again) in advance.

[moyesboy]

There is a gain to the governor just like the gain on the gyro. too much gain and the speed goes up and down. The gain is set with the pot on the governor.
however before you fiddle with that - the problem is the thorttle/rev response is nothing like smooth. The tuned exhaust means the power comes in and out at particular rpm, the load on the rotor due to rpm changes with revs x revs, plus the fuel mixture is never quiote right and has a sweet spot.
If you find it is hunting at 1845, try tweaking it to 1800 or 1900 and it might be smooth there.

I have a revlock 20 on my 600n sport, and an align gov on my 600pro. both driving DS8231 digitals. The revlock is slightly better with the align over reving just a little when provoked. However on my knight 50 the revlock was unstable and hunted at lower head speeds. So I guess the extra performance on the revlock is at the expense of being oversensitive in some situations.

[wildc4rd]

Makes sence, am I going to be OK heading up towards 1900 headspeed (16000 ish motor RPM) on the standard dampers?

[moyesboy]

I don't think there is a problem going fast head speed with soft dampers unless you are flinging it about when you might just get a boom stike.
Hard dampers make the heli more responsive but it then wobbles unless the head speed is high.
for 3D on the 600n folks fly with 2050 or 2100 sometimes 2200. The max power of the motor (OS50 hyper) is 17000 which is about 2000. the idea is to run a little higher than max power so when the motor slows it comes on to its maximum power revs. if you set he head speed to the max power revs then when it slows it loses power and so it bogs more easily.
...but that is for when you start aerobatics.
the nice thing about a governor is when you start flying fast circuitas and practising coming into the hover without balooning up. yuo get an auto rotoation effect that would normall ymake the motor over rev but the governor prevents it.
Its also interesting to hover really low inverted. Close to the ground the rotor gets less drag due to ground effect and without a governor you can hear it speed up. with a governor you can hear it throttling the motor back which can be quite disconcerting!

[wildc4rd]

I don't think there is a problem going fast head speed with soft dampers unless you are flinging it about when you might just get a boom stike... ...but that is for when you start aerobatics... ...flying fast circuits... ...hover really low inverted.

As I'm 6 weeks or so in, though working on it harder than anyone else at the club at the moment, lol, I don't see these things as a problem just yet.

I'll bung it up to 16000 on the governor tomorrow (afternoon, working in the morning worst luck), and see how it goes.

Thanks again for the help.

[wildc4rd]

Yep, 1900 seems to be fine, got 7 or 8 flights in this afternoon after work. Cheers all for the advice yet again.