About Me:

the serious guy

Please tell us a bit about your UAV interest

jet engines

Activity Feed

John Rambo commented on tom hobart's blog post How it Works!
"From the website "The vehicle’s yaw is controlled by adjusting the speeds of the two motors. I.e. speeding up the clockwise motor while slowing down the counter-clockwise"Didn't you guys forget the 2nd motor?"
Sep 5, 2017
John Rambo commented on Nicolai Valenti's blog post 50 MINUTE flight with my cargo drone video (with only a 3s 5200 mah) AND WITHOUT THE CARGO BOX
"I smell hoax 
With somewhat similar setup (3.2ah, I'm not crazy enough to parallel it with 2ah)  I get 15 minutes (quad w/o battery weights 1kg). 18 minutes with 4ah. By going seriously efficient I could hope for 30 minutes, but 50(!) - that's a…"
Aug 19, 2017
John Rambo commented on Patrick Hanley's blog post Hanley Innovations Upgrades Stallion 3D to Version 5.0
"Guys, how about NAFEMS compliance? Flow over the standard sphere, flat plate etc.? Or, let me put it other way around - how accurate it is?"
Jul 28, 2017
John Rambo commented on Chris Anderson's blog post How do modern open source autopilots compare to aerospace-grade IMUs?
"The device itself must contain aerospace graded IC components inside. The components graded for aerospace are -55C to 125C (with a standard being -40C and military grade being -65C). Price difference is 20-40%.
Another thing is tripple a redundancy…"
Jun 23, 2017
John Rambo replied to Anton Vanhoucke's discussion 433 Mhz dipole vs. GPS: total decimation
"Had problem similar to yours. Came up with a two solutions:
1) reduce the power output of the 433MHz transceiver. That's a poor man's fix.
2) replace dipole with ground-plane antenna (nose-down, ground-facing). That virtualy doubles 433MHz TX power…"
Jun 28, 2016
John Rambo posted a discussion
Having played with the MP settings for the entire day I don't seem to be able to enable gimbal control from MP. Its greyed-out by default (see TYPE field in the picture), while it should show "SERVO".Ports A10 & A11 do not show any signals…
Jun 23, 2016
John Rambo commented on Tersus GNSS's blog post Precis-BX305 Static RTK Results Released
"I might sound noobish, but how on earth do you determine N & E error. I mean, how do you know the coordinates of a fixed point(i.e. base-station) you're measuring error against, with such level of accuracy?"
Jun 17, 2016
John Rambo commented on Martin Hill's blog post Long Endurance Drone RC Airship
"Martin, is that the same airship from your previous post?
Would be interesting to see how it swims in the air. And because you've stabilized the video, its even more difficult to understand its true orientation.
Was there any wind during the flight?"
Jun 14, 2016
John Rambo commented on Jacek Szostak's blog post Do you need a nice LRS 433MHz antenna? Do it yourself!
"@Jacek, where did you get that "Flex Wire" from? Tried googling on that keyword with no luck."
Apr 25, 2016
John Rambo commented on Jacek Szostak's blog post Do you need a nice LRS 433MHz antenna? Do it yourself!
"I ran a similar test last year. 
Hand-made Inverted-Vee gave me the best performance."
Apr 25, 2016
John Rambo commented on Martin Hill's blog post RC Airship as Drone
"@Marthin H.,

the problem with blimps is -  they can't be small and efficient, just like quad's can't. 
it seems your L/D ratio is 6:1? That's not a shape which gives you a smallest drag possible. I've done a study and, surprisingly, 3:1 is a way to…"
Apr 1, 2016
John Rambo commented on CSG's blog post 433MHz Super Long Distance FHSS LoRa Wireless data modem with USB UART 5+ km range
"I've made it 73km with a simple dipole antenna attached to RF1276 (SX1276), and would have gone more, if I were higher, as I've reached a horizon limit. -148dB RX sensitivity. Not willing to promote anything, but 168dB link margin is quite…"
Mar 22, 2016
John Rambo commented on Kieran Schmidt-Das's blog post Weight vs Battery life..... Thank you for making this possible
"I was always wondering why it is recommended to hover at ~50% max. throttle? Also, I was always wondering why people are checking max. thrust for evaluating max. lift capability? Propeller/motor has a max. efficiency at ~20% of its max. thrust. So,…"
Mar 14, 2016
John Rambo commented on Andrew Ocejo's blog post DIY HDMI video Downlink for under $300
"thanks Andrew, now I'm back to my experiments of replacing IP comms with FCOE on RbPi-based video streaming."
Mar 8, 2016
John Rambo commented on Andrew Ocejo's blog post DIY HDMI video Downlink for under $300
"Andrew, can you please confirm this is not a typo error and you were really able to achieve 250 microseconds delay? That's some 700x better than the current setup drones community has been using (RbPi + RbPi camera gives some 170ms)"
Mar 7, 2016
John Rambo commented on Simon Howroyd's blog post Efficient Powerpath Balancing for Fuel Cell Battery Hybrid Powertrains
"@Martin - here's the URLto schematics and firmware
I must also apologize Simon for hijacking his original thread.
Your problems seems rather obvious - your battery can't handle high currents or has relatively high internal resistance (likely both).…"
Feb 22, 2016