Harlow, ESSEX

About Me:

Been out of modelling for some years. Built one of the very first electric mini copters in the UK, and an electric ducted fan, both featured RCM&E at the time.

Please tell us a bit about your UAV interest

Have become hooked!...


Old Harlow

Activity Feed

R J Hamlett replied to Euan Ramsay's discussion Magfield + MuMetal
"Anything that stresses the material destroys it's properties. Hence most types of cutting, and bending. After forming, you have to heat treat it in a hydrogen atmosphere...
Alternatives are to use very thin foils, and be careful, with only gentle…"
Jul 6, 2013
R J Hamlett replied to Euan Ramsay's discussion Magfield + MuMetal
"You do understand, that when you cut or bend mumetal, it has to be annealed again to restore it's properties....

Best Wishes"
Jul 4, 2013
R J Hamlett replied to Wesley Versfeld's discussion Most stable Arducopter version?
"If you have a bit of time, wait and see what 2.9.2 gives.
There are bits of 2.9.1b, that are better than 2.8.1, but currently it has some significant problems is any 'energetic' movements are undertaken by either the pilot, or the auto-pilot. Use a…"
Apr 25, 2013
R J Hamlett replied to Jake Simon's discussion Some Auto Questions/Problems
"If you search the forum, the 'somewhere else' behaviour is well reported...
Apparently there were some significant changes to the handling of the Mediatek GPS with 2.9.1, and it results in spurious readings being accepted. The explanation being…"
Apr 25, 2013
R J Hamlett replied to Nicholas Ee's discussion Need help for approx 35lbs AUW Octocopter X8 props and motors!
"The smallest I could get to even get close to working in this size, was a 9*5" 5 blade prop, which running on Alle KDE500XF-1450 motors, can give enough thrust to hover at about 76% power. However you are then talking about 80amp per motor at hover…"
Apr 17, 2013
R J Hamlett replied to Peter Spero's discussion Turbo Ace X830-d quadcopter Slowly rotates clockwise
"Why did you replace the arms/motors?
If it was because of a 'prang', then start by triple checking the new stuff is square. Then have you recalibrated the IMU?. The rotational control is nothing to do with the GPS. It is compass, and IMU. Does it…"
Apr 17, 2013
R J Hamlett replied to CyberCrash's discussion Need help: I just found out my motor - ESC combination isn't good at all....
"You need to tell us more. Weight of model in particular. But if (for instance), this is about 2.2Kg, reducing your props to 9*5, or 10*3.7, would bring everything inside reasonable limits.
Try some experiments with ecalc, feeding in your current…"
Apr 15, 2013
R J Hamlett replied to Jared Reabow's discussion Close to devistating crash, what went wrong?
Unlike most of the obvious ones, where a motor/prop/ESC fails, yours kept straight, and recovered (ruling out most electrical problems).
Obvious first one, would be a radio control RX set to 'fail' to sticks central with low throttle. That would…"
Apr 7, 2013
R J Hamlett replied to Tono's discussion Is the sonar a must have/use?
"The baro hold is very good in the new software 2.91/9.1b.
It will drift slowly with time, but typically no more than a foot in an entire flight time.
Where sonar wins massively, is doing low altitude terrain following.
Sonar gives faster altitude…"
Apr 6, 2013
R J Hamlett replied to Sean Tierney's discussion Arducopter 2.9.1b HEX troubles
"Is this on the ground?. If so', there was a thread about this in 2.9.1, and a fix given (it was one parameter that needed changing). It didn't affect flight, and I'd suspect the fix has been included in the quad settings.
A search on the forum for…"
Apr 6, 2013
R J Hamlett replied to Jake Simon's discussion Recording Voltage
"On the current release, is is:

enable CUR<enter>

I had it enabled in the bitmask fr my configuration, so hadn't had to turn it on from the command line. At some time in the past, it was 'CURRENT', but it now only wants CUR (though it…"
Apr 5, 2013
R J Hamlett replied to Jake Simon's discussion Recording Voltage
"You can specify what is going to be logged in the onboard memory.
From the cli log menu - where you download the logs, type 'enable current<ent>'. This turns on logging to the onboard memory, the data from the current sensor (including voltage).…"
Apr 3, 2013
R J Hamlett replied to Oxxy Fx's discussion Resolution of in-flight tuning with Ch-6 knob
"The knob should have a resolution of hundreds of points.
You need to step through every stage in the process.
First at your radio. How is the pot configured, what range of output does it generate?.
Then use the radio calibration screen, and look at…"
Mar 30, 2013
R J Hamlett replied to DavooD's discussion I2C sonar: MaxBotix MB1242 with Arducopter 2.9.1
"Have you looked at:

This was a guy working on code for the I2C sonar, and I'd ask him how he was getting on.

Best Wishes"
Mar 29, 2013
R J Hamlett replied to Garrick Merrill's discussion Reloading the APM after X hours of operation?
"The log 'wraps'. Starts overwriting itself from the beginning.
Now all EEPROM/Flash memories have a limited erase/write life. So the more often you write data the faster they will fail. On EEPROM quite low (typically something like 10K cycles).…"
Mar 28, 2013
R J Hamlett replied to Harley Engholm's discussion GPS vibration damping
"Only thing is (of course) that less vibration reduces the risk of failures in electronics in general.
However unlike the IMU, where the acceleration sensors get somewhat swamped by vibration, so good damping improves behaviour, something like a thin…"
Mar 26, 2013