Taranis Gimbal Replacement

I love my Taranis. I really do. Its flexibilty to allow me to do whatever I can dream of has set the bar high for computer radios. Unfortunately, to bring this mavel of comuting technology to the masses some compromises had to be made. The most offensive, in my opinion, is the quality of the gimbals.

The Why

Back about 20 years or so ago there were not a good many of transmitters to select from like we do today. If you were interested in the hobby you were interested in making an investment in a transmitter to do so. The debates back then were as much focused on capability as they were on ergonomics. JR touted "Feel the difference." Having a solid sensitive feel to get in touch with the aircraft you were flying was as much of a part of the experience as assigning a channel and expo. 

With more people just wanting to get in the air these days, the overall cost has come down... due to lack of quality hardware. Sure it could have quad bearings but what quality? Brass bushing or ball bearing? Steel or ceramic balls? ABS, PVC, or machined aluminum structure? All of these factors, and more, play into the feel.

For the past 6 years I have been flying with a JR X-388S radio. Articles on this radio date back to the early 1990s! This is, no doubt, one of the radios that was an instant hit with many pilots for its feel and functionality. I loved it and ached for the day when I would be able to leave it behind. 

Four months ago I recieved my Taranis. After flying with it many times, enough was enough and change needed to happen. The center of the sticks felt "boxy" and centering was not precise. the weight of the tension was not enough, even with the tension all the way up!, The smoothness was gone and I felt as if I was playing with a child's toy, not a sophisticated piece of engeneering. I fly big models that I painstakingly detail. This was not the experience that I wanted. 

Further still, I had my wife who does not fly RC at all, test out the old JR radio and the Taranis and just asked her for prefrence and to describe the feel. She, not surprisingly, instantly identified the JR as far superior for the exact same reasons that I've mentioned... without any information from me beforehand.

Change

I decided to sacrifice my old JR radio and extract the gimbals to get back what I had lost. After consulting with CraftyDan Crews on the forums I took the plunge... and it only took one hour.

I test-fit the gimbals first to make sure the alignment and sizing would work.

Taranis on the left and JR on the right. Holes lined up fine but I needed to trim some plastic off the JR's housing to get it to fit under the circuit boards for the trim levers. I had to do this for both gimbals and the dremel cutoff wheel did the trick swiftly. I also noted that the sliders would need clearance as well so I had to trim plastic from the gimbal there as well. Nothing functionally was lost. Only additional plastic from the molding process was removed. 

In this image you can see where, on the left side, I removed plastic (and cut the screw shorter) to make way for the slider pots.

Having taped the switches to hold them in place, I fitted the left stick first. Please note how the pivot point of the gimbal now sits lower into the transmitter. Its only by a few millimeters (5mm at most) but it does make a difference in the feel.

So, which wire is what? There are three pins on a potentometer (pot) that senses the stick movement. The three pins are as follows: a wiper (pin that changes resistance), a high side, and a low side. Using my volt meter, I determined the wiper by connecting two wires and measuring the resistance. If there was no change in the resistance when the stick was moved, then I had both of the high and low sides and not the wiper. I noted this in my head and soldered the wire connections. After this, and before setting my shrink tube, I turned on the transmitter, navigated to the calibration menu, and confirmed that my stick movement was the correct direction. I knew that I would have to re-calibrate later so I was not concerned if it was off-center, only that the direction was correct. I set my shrink tubes. Then, I repeated this three more times.

Here you can see both sticks installed and fully-wired up. I re-assembled the transmitter and re-calibrated my sticks, sliders, and knobs, and OH BABY!!! The feel is back. 

My completed Taranis with JR Propo gimbals that are the better part of 20 years old. If I ever want to upgrade this I can replace the bearings for better ones. While, I still feel the balance of the radio is not quite right, even with a 2.65Ah battery in the base, the flight experience is much much better. 

Other gimbal swaps out there include Hitec's Aurora 9 for about $42 (instructional article linked below) or you can find older radios at swap meets and classifieds for around the same price. If you happen to just have an old radio that you prefer the feel of, then I highly recommend you give this a try. 

Now, I love my Taranis even more.