Search results

There have been a number of changes along the way, but it's finally airborne!! Doing regular 3 minute test flights to get some time it.

Some updates on the rotor balance monitoring system. I’ve tidied up the software and sorted out the conversion to ips. Ips values are between 10 and 15% higher than a PB3, at some stage I might do some accurate bench calibrations to see where the discrepancy lies. What I’ve also found is that...

After changing some parts on the rotor head I need to balance again and this time got readings from a PB3 as well. I used the phone screen recording function to record the PB3 results, and manually typed them into excel. It’s a bit more time consuming than downloading a CSV file from the data...

You must have had collective friction, I don't have any so cannot let go my left hand. And the right hand is busy with other things... But have just found out that Android 11 and newer phones have a built-in screen recorder which works great!! Set up the PB screen, press record, go flying, and...

Thanks Mike, I’ve got a PB3 as well, next time I’ll compare readings and calibrate my numbers that way. Just find it rather challenging managing a phone while flying a helicopter. The biggest problem I have is that I can no longer physically do the required lead/lag adjustment because it’s too...

Here's a plot of RRPM for the period corresponding to the first graph in post 20. There was an engine failure in hover practice at ~385, the other times where the RRPM changed were mostly quick stops. Each time there was a noticeable change in RRPM the vibration measurement had a spike. The...

The plan was never to sell in NZ, the market is much too small for that. The world market for under 254lbs EVTOLs, however, is huge. Jetson One has sold more than 400, and at this rate I’ll be delivering before they do.

I've had it airborne, just sorting out the last few niggles now. The emphasis has changed though, it will be ultralight (including batteries) with a flight time of 15 minutes. Won't be ultralight for longer flight times.

The previous measurements were done on a tethered helicopter, to see how the balancer works in real life I installed it in my first electric heli (which is a Mosquito Air converted to electric) and balanced the MR. It was a bit of a roundabout journey, first going the wrong direction (point 1...

I’m curious to hear what you envisage the power requirements of your flying machine would be. You talk about carrying one person, does your person weigh 40, 80 or 100kg? In many parts of the world 80kg would be considered a minimum requirement. Having measured power requirements of EVTOLs my...

Mike, Your graph of phase angle is correct, nice job extracting that from a jpg picture. I was moving the cyclic by hand so the phases wouldn’t be exactly 90 degrees apart, but the effect is clearly visible. The balancer has two inputs. The position sensor output is digital and consists of a...

Vertical vibration is proving to a bit more of a challenge than horizontal. Firstly the symptoms: With rotors up to speed and zero collective there is minimal vertical vibration. Pulling collective with the cyclic centred everything stays good. A cyclic input with up collective, however...

Mike, I think I now understand the question about filtering. Correct me if I'm wrong, I suspect the PB4 takes the accelerometer signal and sends it through a band pass filter with the centre frequency at the rotor frequency. I don't do that, I do a fourier transform so no filters involved. I...

Here are the results for horizontal balancing of the rotor. For some this will be over the top, but Mike G and a few others will appreciate the numbers. From post #1 I already knew that blade B was the heavy blade and that I needed to add weight to blade A. The question is how much weight? I...

Doug, If the accelerometer signal is reasonably sinusoidal a 2 channel scope is a really good way of measuring. The latest digital scopes will do most of the measuring for you. If there is an easy way to attach a small magnet to the moving bits I would recommend using a hall effect sensor for...

Doug, I might have made it look easy, but that definitely wasn’t the case. About 5 years ago I tried to develop a rotor balancer. I got it to the point where it worked really well on the bench, but as soon as I installed it in a gyro or heli it turned into a random number generator. I spent...

This is what it looks like from the seat.

Doug, The position sensor is a hall effect sensor which picks up a magnet attached to the MR pulley. The accelerometer is an old school +-6g, 2 axis, linear accelerometer. Sampling needs to be synchronised with the position sensor which is very difficult to do with the new digital...