About

Gender

Male


Location

Morrison, CO


About Me:

UAV builder and FPV entusiast


Please tell us a bit about your UAV interest

Hobby and commercial


Hometown:

Denver


Activity Feed

Jimmy Underhill replied to OBwan's discussion Just basic user instructions for the Tower app
"This is Agribotix' user manual for Tower, it is specifically about using Tower and Solo for orthomosaic "mapping flights," but it may be of use to you.  Starting on page 8 is mission planning.…"
May 31, 2017
Jimmy Underhill commented on Daniel McKinnon's blog post Mobile mapping with Solo, GoPro, Tower, and the Agribotix Field Extractor
"Hi Zohaib,
No the 5.4mm lens does not affect the gimbal performance at all, the lens is pretty much identical in size and weight to the existing lens, but removes the fisheye effect.You may use the standard lens, but overlap should be increased to…"
Oct 24, 2016
Jimmy Underhill replied to SKYBORNE's discussion Compass Variance Auto problem.
"Compass Variance on takeoff is most likely cause by electro magnetic interference from the motor/ESC/batteries during high throttle.  To fix twist up wires for all Pixhawk accessories, and make an effort to run the GPS and Mag wires as far away from…"
Jun 14, 2016
Jimmy Underhill replied to Matt Johnson's discussion Error pos vert variance? What does it mean?
"The horizontal and vertical position variance errors are thrown when the EKF and GPS or other sensors do not agree.
The most common time when this error is thrown is when flying in moderate to strong wind with a pitot tube. Adjust the parameter…"
Jun 14, 2016
Jimmy Underhill commented on Laser Developer's blog post The SF11/C laser altimeter - awesome performance for $249
"LD,The sun came out and I lowered the values some more, I'm -10 from the starting value now.  The lidar is reading better, but still about 10-20% off in the bright sunlight.  Should I lower APD 1 more or is there another setting to adjust?"
May 6, 2016
Jimmy Underhill commented on Laser Developer's blog post The SF11/C laser altimeter - awesome performance for $249
"LD,
Thank you!  I have followed your instructions and lowered the APD value by 4.  After doing this the lidar is reading much more accurately outside.  Of course it's overcast now so I will test in bright sunlight and hopefully my issue is solved!"
May 6, 2016
Jimmy Underhill commented on Laser Developer's blog post The SF11/C laser altimeter - awesome performance for $249
"Hi LD,
Thanks for the instructions, I have found the following results:
Indoors, distance approx 12m horizontal:
Live: 11.92 Filter: 11.59:1 | Signal:17.0 Noise: 0 Limit:No | CPU:23%
Live: 11.83 Filter: 11.60:1 | Signal:17.2 Noise: 0 Limit:No |…"
May 6, 2016
Jimmy Underhill commented on Laser Developer's blog post The SF11/C laser altimeter - awesome performance for $249
"Hi LD,
Not to rush you, but I'm very anxious to get my problem with the SF11/C solved asap.  Can you please post the next step or two?  The company I work for hopes to integrate a LIDAR unit into our production drone and we'd like to use this unit…"
May 6, 2016
Jimmy Underhill commented on Laser Developer's blog post The SF11/C laser altimeter - awesome performance for $249
"Hi LD,
I'm following along and am ready for the next step.  This is pretty cool, thanks for sharing these secrets :)"
May 5, 2016
Jimmy Underhill commented on Laser Developer's blog post The SF11/C laser altimeter - awesome performance for $249
"Hi Laser Developer,
I would most definitely be interested in learning how to troubleshoot my unit, thank you for the offer.  Where shall we start?"
May 4, 2016
Jimmy Underhill commented on Laser Developer's blog post The SF11/C laser altimeter - awesome performance for $249
"I have been doing extensive testing of the SF11/C and a SF10/B that I had previously.  I am finding that the SF10 is much more accurate than the SF11, and in fact, the SF11's accuracy is pretty poor comparatively.
I noticed that inside my shop both…"
May 3, 2016
Jimmy Underhill commented on Laser Developer's blog post The SF11/C laser altimeter - awesome performance for $249
"Hi all,I have got one of these SF11/C units on a quad and it is performing very well.  I am extremely surprised at how accurate it is up to 100m+  very cool!
I do have one issue and I think it's Pixhawk related.  When using RTL or Land, the copter…"
Apr 7, 2016
Jimmy Underhill replied to climr's discussion X8 Motor Output, shoud it be balanced?
"Yes, duh I should have realized.  In forward backward and side to side flight without yaw, the motors do act in pairs.  Just looked at a few logs to confirm.  In yaw they split up."
Apr 5, 2016
Jimmy Underhill replied to climr's discussion X8 Motor Output, shoud it be balanced?
"In addition to the motor direction shown here, the Pixhawk treats the X8 configuration the same as an X4 configuration, and sends identical signals to the motor pairs on each arm if I'm not mistaken.  "
Apr 5, 2016
Jimmy Underhill replied to ori agranat's discussion Motors not spinning properly
"I use this on all my bullet connectors when soldering them solid isn't preferred, works a treat:
http://www.amazon.com/MG-Chemicals-847-25ML-Conductive-Synthetic/dp..."
Apr 1, 2016
Jimmy Underhill replied to Raam Sundar's discussion Which is the Best Auto pilot for beginners..
"Go for a Pixhawk based system instead of APM.  Much better hardware, the APM is known to fail prematurely and isn't as powerful.
The RCTimer Fixhawk is a good clone."
Apr 1, 2016
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