Yardstick

Great, yet another service life extension coming up for my Cougar throttle

If you have changed one thing and something unrelated immediately goes wrong, then odds are it is the change that is responsible. The Midori sensors appear pretty robust - test the sensor outside the gimbal i.e. rotate the shaft with your fingers. My suspicion would be that it will track just fine. If that's the case, it comes back to an issue with re-installation. BTW forget about sourcing Midori sensors - $100 each and only available in pairs.

See this thread: In the end I stuck with the first set linked in the final post. They are not an exact match but the forces are close enough that I have Ian's originals fitted on the Y-axis and these replacements on the X-axis and there is no noticeable transition in forces between axes. Anyway you could always get 4 springs to be on the safe side.

WarBRD with Cougar and F/A-18 grips and 75mm extension, centre mounted. All good here. Currently use the heavy springs which are a very precise but a little on the light side although strong enough to centre the stick correctly. Have tried the extra heavy WarBRD springs but they were too much of a step up in terms of stiffness.

That’s what I also hoped was the issue but have checked and the bolt is tight. I even used a marker pen to draw a line on the arm to see if I could see any movement but can’t detect any. I’m going to try some loctite to see if that makes a difference. Update: I went down the Loctite route and tightened the screw as much as I dared. 3 days on, the centre point drift seems to have been largely eliminated. I've also switched to manual calibration, which seems to help with any extreme readings causing the calibration centre to drift.

After some further investigation, I’ve established that the sensor is good and the issue appears to be mechanical. However, after stripping down the gimbal and insuring that all the bolts are secure, I’m at a loss to work out what is causing the drift. There is a little play in the main bearings (lateral twist of about 1mm) but I can’t induce any significant movement in the controller output by twisting the stick. Anyway I first noticed the play a number of years ago and up until a few days ago, everything was performing as it should. Now, over time I get seemingly random drift in the min / max for the Y-axis (up to 15%) with a corresponding drift in the centre.

Well with some experimentation, I answered my own question. Even after removing the new springs, the sensor is still behaving erratically. I've flashed the firmware (usually the go to solution for calibration issues), re-installed the drivers and tried it on another PC. However, I am now I'm having to conclude that it could be a bad sensor or maybe a damaged wire. If it is the later at least I have a chance of fixing it. The Midori Halls Effect sensors are a drop in replacement and are still available but at c. $100 + shipping each and only available in pairs, not a realistic replacement. one minute

I have recently had to replace the X-axis springs in my U2:NXT modded Cougar. Having done this the Y-axis calibration is playing up. It calibrates OK, then quickly loses the centre and range of travel drifts over time. If I move the Y-axis up and down starting with a min of 0% and max of 100%, the min will first move to say 6% and a max of 100%. Then then the max will move to 94% and min 0% and so on. I immediately though that the sensor had come loose and was rotating independently. However, having stripped the base down, I can't find anything that needs tightening or any damaged wires. The build quality of Ian Johnson's gimbal is amazing BTW - still looks like new after c. 15 years of heavy use, no wear or play anywhere. So I'm left scratching my head trying to work out why the Y-axis is playing up. Since the only thing that has changed is a new set of springs and these are adjacent to the Halls sensor. My only remaining theory is that the new springs are spring steel and Ian's originals were stainless steel. If the new spring was inadvertently magnetised could this be screwing with the sensor, even from 60mm away? I understand stainless steel is difficult to magnetise (maybe one of the reasons Ian chose it in the first place). I have some stainless steel replacement springs on a slow boat from China, so should be able to test the theory in a few weeks but would be interested in others thoughts.

These are the replacement springs I currently have fitted on the X axis - maybe a little stronger than stock but only really noticable at the extremes of deflection (Spring steel, L:40 x W:8.5 x D:1.6) https://www.ebay.co.uk/itm/Expansion-Extension-Entended-Tension-springs-DIY-metal-Die-stand-mechanic-Motor/183492465366?ssPageName=STRK%3AMEBIDX%3AIT&var=690824744766&_trksid=p2057872.m2749.l2649 I have these on order (slow boat from China) and in theory they should be a better match for the originals (Stainless steel, L:40 x W:10 x D:1.5) https://www.ebay.co.uk/itm/Expansion-Tension-Spring-0-3-2mm-304-Stainless-Extension-Expanding-All-Sizes-DIY/283388107286?ssPageName=STRK%3AMEBIDX%3AIT&var=584365142309&_trksid=p2057872.m2749.l2649

Fair point - it had crossed my mind that it might be an option.

Well some of the springs I ordered arrived yesterday and the first set I fitted seem to be a reasonable match. The X axis is now a little heavier than before but really not that noticeable and it will do for now. I should have a set springs that are potentially a better match to Ian's originals in the next few weeks. BTW is there any trick to fitting the springs? I was lucky that the ones I used had hook ends but I would have really struggled had they been loops.

Ian didn't have any springs left but he gave me the name of the company that originally made them - they were custom parts. However, I suspect they are going to only do custom orders in numbers greater than the 2 springs I need. I will see if I can source something elsewhere of equivalent dimensions / resistance but if that fails, I will give Ian's supplier a try.

I've found some stainless steel springs of the correct dimensions and gauge steel but I suspect that this does not mean they will necessarily have similar properties. However, they are in China and current shipping is about 8 weeks! I'll see how I get on with Ian, at the very least hopefully he can give me the specs of the originals so I can try and source them.

Thanks - I did wonder if Ian was still active. I've sent him an email, fingers crossed.

After about 15 years of use one of the X-axis springs on my Cougar U2 NXT gimbal has failed. Measuring these up they appear to be stainless steel L:42mm, D:9mm with a gauge of 1.5mm. After a quick ebay search, it looks like finding an exact match might be tricky. Does anyone have good source for the correct type of springs or had to replace the U2 NXT springs in the past?