TJ RevMax and Cal50

[heli-cuzz]

I installed a revmax on my Caliber 50. I avoided gluing the sensor to the heli. Instead, I glued the two brackets together and drilled two screw holes underneath the fan shroud to mount the sensor. This makes adjusting the sensor very easy. I tried going around the clutch, the Caliber50 ain't havin' it.

[heli-cuzz]

The TJ RevMax was a breeze to set-up and it definitely works very well. No problems with the way I installed the sensor. I was a bit nervous when setting my targeted engine rpm as this is my first governor/rev limiter, so I started at the lowest rpm setting through my radio and raised it slowly to check the rpm limiter. I spooled up the blades a bit and put in idle3. My throttle curve is 100% straight across board. The limiter was set at 9,600rpm for the engine and it kept it there. I knew the system was working. I set it through my radio for 18,000 engine rpm's which calculates my head speed around 1,750 to 1800 rpm's. I spooled it up and switched to idle 3, the beautiful sound of it winding up to speed, I pumped full pitch into the sky and the rest was fun.

I went back to rchelimag issue 5 and read the TJ RevMax article. I'll never throw out any rchelimags.... ever. :D Thanks rchelimag staff guys for a great mag. :cool:

[tdswan]

I'm one of the more cautious guys when it comes to setup, wouldn't it be scary if the governor were to fail and fall back onto the throttle curves set into your radio with them set at 100%? True, you could just hit the throttle hold and auto it down, but I like the idea of having a good throttle curve at the foundation of settting up a governor so you're not faced with autoing it down somewhere instead of getting it back to yourself to land.

I've never heard any horror stories about this happening, but the possibility is always there. Usually it's the throttle servo you hear the stories about and I may just being a little too critical.

[heli-cuzz]

I'm one of the more cautious guys when it comes to setup, wouldn't it be scary if the governor were to fail and fall back onto the throttle curves set into your radio with them set at 100%? True, you could just hit the throttle hold and auto it down, but I like the idea of having a good throttle curve at the foundation of settting up a governor so you're not faced with autoing it down somewhere instead of getting it back to yourself to land.

Yeah td, that has occured to me. I set the rpm limiter through my radio. I use switch C to control the governor. It's a 3 position switch, so I have two different rpm settings, the middle position disables the RevMax, the up position is set for 18,000 rpm, the down position is set for 17,000 rpm. If it fails, I simply switch the governor off and go to normal flite mode. My normal mode is set from 0-100% on the throttle curve. That gives me throttle control, if it does fail somehow.

That tip is from rchelimag TJRevMax article issue#6 Just worded a bit different. :D

It does work. I flew two tanks as trial runs.

[tdswan]

OK....I hope I didn't offend. Good idea with the 3 position switch. I don't toy with governors too much. I have one on my gasser, but don't particularly like it and opt for the quicker response of my throttle curves. I am in need of a little faster throttle servo before I make my final decision on whether I like my gov. or not, though.

It's just nice to have a fail-safe behind any piece of technology. :)

[cbflys]

Guys,

I don't personally use a govener or throttle limiter. But wouldn't it make sense to precisly dial in your throttle curves for a head speed slightly higher than the speed you set your limiter to? This way if it fails (in either switch position), you'll notice a slight increase in RPMs but still have a quite flyable power curve?

Chuck

[heli-cuzz]

My normal mode is very flyable. I can auto in nomal mode without the use of throttle hold as long as the engine cuts out. The revmax also disables itself if your throttle stick goes below 25% on the curve. I really like the limiter, my head speed is far more consistent on the targeted rpm. I've tried a bezillion different idle up throttle curves, and I'd always get the over-revving around zero pitch. This is my first governor/limiter. I'm gonna get one for my Caliber30 too. I'm sold on the revmax.
I like the thought that my engine won't be over-revved, over revving causes damage.

td, no offense taken. :) I have digitals all around on my 50. The TJ RevMax does not require high speed servos. They say, they don't see any performance improvements with the use of a high speed servo.

[AaronS]

the revmax in particular works well with standard servos as compared to most governors.

cbflys- the throttle curve you described for use with the limiter would work, but depending on how aggressive you fly, it may not provide the best setup. For maneuvers that requrie large cyclic deflections at close to 0' collective you may bog the head a little, where as with the curve set to 100% the limiter is doing all the work and the head speed will not fall off. :cool:

[heli-cuzz]

As I previously posted. I used the tips from the TJ RevMax article in the Jun/Jul issue#5. :cool: My head speed is consistent now. The Cal5 flies much better with a governed head speed.

[cbflys]

Aaron,

I agree with your explaination, however - I use aileron -> throttle and elevator -> throttle mixing to compensate for this. This increases the throttle with cyclic inputs. I don't notice any bogging with this setup. Also, I always make sure to use the endpoint adjustments on the collective and throttle channels to make sure the throttle always leads the collective. With the throttle ATVs set around 80% and the collective ATVs set around 140% (assuming identical servo speeds) - you'll see the throttle servo get to its position faster than the collective because it has less distance to travel.

That being said - you guys are convincing me to try out a limiter. No matter how good you setup you throttle/pitch curves - you only have a finite number of points to work with. Everything in between them is interpolated. I can see how the limiter will nail the rotor speed - no matter where you are on the curve.

Chuck

[Fasrc]

I thought exactly as you did. I ran throttle to cyclic mixing for a long time and parised how good it worked, but I totaly changed my mind once I installed my limiter and wondered why I waited so long to do so. Trust me on this one. ;) If you just do sport flying and light 3D than it doesn't matter, but if you do heavy stuff like Tic Tocs, tight funnels and so on...the limiter makes a World of difference.