- Thottle Jockey Pro
begin, I have to say that the support Paul of Model
Avionics gives to his products is top notch! I have seen
many times on forums where he quickly responds to
questions about the Throttle Jockey. You do not see that
very often at all were the designer is actively helping
in the public forums. He is also very quick to respond to
questions emailed to him. I think that says a lot about
him and his products.
What is a governor? No, in this case it does not refer to a politician :) hahaha In our r/c hobby this refers to a device that monitors the engine speed and controls the throttle servo to maintain a set speed. So why is this important? In helicopters a constant head speed gives consistancy in performance. Also it is critical to peak tail performance. For every hundred rpm you loose on the head the tail will drop over twice that! So how does a governor work? In the case of the TJ Pro it uses a magnetic sensor that is placed under the engine fan. In the fan you mount a magnet that is included with the governor. As the fan turns the TJ Pro counts the number of times it passes the sensor per minute. This gives the rpm of the engine which is used to calculate the rpm of the rotor blades. The governor actively controls the throttle servo telling it to increase or decrease the throttle to maintain a constant head speed.
Okay, now we have got some of the basic questions out of the way so lets look at what you get and what you need. In the picture on the left you can see several items are included. The primary item is the governor itself (no that is not a CSM 560 Micro gyro, yes that is the same case). Also you get some extension servo wires to run from the TJ Pro to the receiver. The previous version had these cables soldered directly to the governor. I like the use of standard extension cables so if you damage a cable you can easily replace it. In with the roll of cables is the magnetic sensor. The kit also includes two magnetics, two zip ties, foam mounting tape, heat shrink tubing, 30 size mounting bracket, 60 size mounting bracket, and the instruction sheet. The only item you will need during installation is some CA glue. Optional items are a high point balancer, counter weight, and an extra channel on the radio.
thing you do for installation is install the magnet(s).
If you do have the stock plastic Raptor 30/50 fan then
you will notice two places on the underside of the fan
specifically made for the magnets. For other fans you
will have to drill your own holes. Before you glue the
magnet(s) in place you have a couple of questions to
answer. Do you have a high point balancer to check the
fan? And if you do then do you want to use one magnet or
If you have a six channel radio and channel 5 is used to
control the gain of a gyro then there is another option.
This is only for people that are good at building
electronic projects. You can make a manual adjustment
circuit for the gain plug on the gyro. <HERE>
is one such circuit. Most of the time once you have the
gain set for the gyro you do not need to adjust it
anymore so a manual setting is not much of an
inconvenience. You can then use the gyro function in the
radio to set seperate head speeds for different flight
Tip #2: For convenience you can change the length of the sensor wire to a couple of inches then use an extension cable to connect it to the TJ Pro. This will allow easy removal of the engine without having to undo the cable routing to get the engine out.
Throttle Jockey Pro by Model
First I do have to let you know my position on the use of governors in general. I think a governor is great on a well setup helicopter, however I too often see people use them to mask a poor setup. As an example in a non-governor setup if after flying two to three minutes you see the head speed is higher then you know the engine was set a little lean. With a governor you would not see this because it would lower the throttle to keep the head speed the same. Eventually the engine would get so hot that it dies in flight. A governor does not remove the need to have a properly tuned engine, you still need to do that yourself for now (there is an accessory jack for optional future devices). There are still signs you can watch for to know when you have a hot engine such as hearing pre-ignition (kinda like a metal pinging sound). Also when you do an auto the engine should drop to an idle quickly as well as when you land the engine should also drop to an idle quickly. If it takes more then five seconds or even stays high then the engine is hot.
Okay, so what were the results? Very good! I was impressed at how well it worked. Over a few weekends I would have my flying buddys tach my head speed while I performed a range of set maneuvers with the governor on versus governor off. It compared very well with my throttle curve/cyclic mix. Things like continuous flips my own mix would vary by only 10 rpm while the governor varied by 30. With continuous tic-tocs both my mix and the governor varied by 30. Then there were some combination maneuvers the governor would do a little better then my throttle curve/cyclic mix. One thing that was really nice is in a high dive or tail slide I did not have to manage the collective to keep the head speed from sky rocketing. It did much better then I could. Even with good management my head speed usually goes up a hundred or more rpm. With the TJ Pro it kept it locked in which I liked a lot. Also I have setup a lot of GV-1's for other people and the TJ Pro had better dynamic performance (more constant rpm during tricks). Also the setup was extremely easy. The GV-1 is not difficult but there are several steps you need to make sure you do.When I was setting up my TJ Pro I had everything hook up and ready for what I thought was going to take a few minutes for the calibration. Instead as I read the instruction is was basically just raise the throttle stick up then back down and you are done! How much easier could it have been! Another advantage the TJ Pro has is an accessory plug for future add-on's. It also has a high frame rate mode for Super servos like the 9253/9254/94757/8700. The GV-1 does have the advantage of a display unit to set the target rpm's and a voltage monitor, however I do not see this as a big feature. I would rather use a Gem2000 for the battery monitor and as for setting the head speed you can get an optical tachometer. You can use the optical tach to check other pilots head speed that way. Actually you do not even need a tach. Just adjust it higher or lower to make the helicopter feel the way you want for the type flying you do. The feel is what it is all about anyway, not if you are running exacty the same head speed as someone else.