Nimbus Tricopter VTOL

Hey Greg i forgot to ask if you also use a Power Module going to the Pix Thanks B.K


In the APM Wiki, there is a section called, Powering the Pixhawk. Going down that page is a sub-section called, " Powering/backup off the servo rail". I use 5.6v zener diodes since I had a bunch of them. Any unused MAIN or AUX slot can be used for the 5v BEC and zener diode.

On my better APM aircraft, I use the MAUCH Power Monitor (a.k.a. Power Module) distributed from Craft & Theory in the U.S. They have many new products now for commercial use and the R/C hobbyist. I used the choices below on my Nimbus and Freeman VTOLs on Pixhawk 1s. (a.k.a. Pixhawk v2.4.8) The Mauch unit comes calibrated with numbers to enter into Mission Planner and use a hall-effect current sensor for accurate readings.

Product Total
Mauch 073: HS-100-LV × 1 $25.30
Mauch 082: 2-6S BEC / 5.35V / DF13-4P × 1 $17.40
Subtotal: $42.70

Hello dear forum users! I studied your topic with great interest. Thanks to you, I was able to collect, configure and fly around the Nimbus. I managed to complete several automatic missions. Nimbus flies great! Thank you all so much! There is one very important point that can significantly increase flight performance. How to make the rear rotor stop longitudinally in the tail boom during a mission? There is a suggestion to use a servo drive and mechanically stop the rotor from self-unwinding when the minimum airspeed is reached. I tried to engage the flap channel, but to no avail. What do you think about it?
And sorry for my French))

Hi Greg: Thank You Sir for the suggestions and i just finished ordering thru Craft and Theory these 2 systems i’ve never used these before so it should be interesting setting them up and since ,My Fly Dream will not answer my emails to get the motors they didn’t send because they sent me a VTOL Plane Kit and not the ARF Nimbus Plane, I ordered 2 sunny sky 520kv motors and also the V2 tilting system from fox tech everything should be here next week. Thanks again.B.K

Hi Aleksandr,

Congratulations on your Nimbus success! Your English is great so don’t worry.

Why do you think that stopping the rear prop in line with the tail boom results in “significantly increase flight performance”? Do you have numbers to support this claim?


Hi Greg. Most likely there was a wrong translation. I mean, that creates airflow resistance in horizontal flight during the rotation of the tail rotor.

Nice video! You have snow like us in winter.

For your statement above, I have not heard of anyone trying to stop the rear prop from turning. It may depend upon the ESC chosen for the motor. You could simply enable the brake function, if available. My point from the previous post was more about the ending position of the rear prop; either in-line or across the tail boom. I have not seen any flight duration numbers for various prop positions.

In any event, I do not feel that there is significant loss of flight duration from the rear prop. On my Nimbus VTOL, I do not recall the rear prop turning during forward flight. Perhaps someone else will comment.


Hello Greg and anyone that reads this: Can anyone recommend and where to get the Motors for the Nimbus Vtol. Thanks B.K


I got my Sunnysky motors in the U.S. at BuddyRC. Keep in mind that these X3520 motors have the long shaft to deal with as shown in my assembly photos. I have no idea what FoxTech is using for the Nimbus VTOL motors these days. E-mailing MFD or FoxTech directly may offer you the “3 Motors and props” as a sub-package. Others may have some different solutions.

Sunnysky X Series X3520 520kv Brushless Front Motor - BuddyRC $45 (Long Shaft)
SunnySky X4112S-11 KV400 Multicopter Brushless Rear Motor - BuddyRC $54 (Newer Version)

Other Places:
SunnySky X3520 Brushless Motor - SunnySky USA $52.50 (Long Shaft)
SunnySky X4110S Motor - SunnySky USA $45.

Foxtech Motor S3520 400kv - $60 (Short Shaft)

MFD Support (English only):
MFD Sales(English only):

Hi Greg: Thanks for the info i contacted MFD both sales and support Again i had also received those X3520 520 kv from buddy rc on sat then i saw how long the shaft was and panicked called them but i guess they aren’t opened on Sat or Sun so i left a message with info then i texted them and asked them if they had short shafts for these motors and i haven’t been contacted as of yet and no one hasn’t called me either. I haven’t went back to see how you dealt with the long shaft so did you just cut them to length?I also checked several times on Foxtech web site and didn’t see any info on the motors they put on the Nim VTOL now just the KV they recommend i texted them for info on this but once again no one answers me i even asked them where on their web site are the motors so i could purchase a replacement set and as of yet no answers(Only You and i thank you for that) IDK i guess i just frustrated and anxious, OH those X3520 520 kv motors are HUGE compared to the nimbus X2814 510 kv motors so if i have to cut those shafts off will those tilt servo’s be able to handle the weight? or should i get one’s that will ? Ok Thank You Greg. B.K

No, you can’t cut them since they are hardened steel shafts. You might find shorter replacement shafts at either BuddyRC or Sunnysky USA but I didn’t want to get into that type of replacement.

I don’t know what tilt servos you are using. Don’t you have the motors from your first build? Are they all destroyed from the crash?

Hi Greg: When i had that Crash it destroyed the motor and the tilt servo, i ordered another pair of the Foxtech Nimbus VTOL V2-Tilting System i tried finding the motors on their site = but no luck, 3 weeks ago i had ordered a pair of LD Power motors from BG 2814- 510kv they came in to day they had the long shaft to so i cut the shafts off with my dremmel tool everything works great except after further it was brought to my that they’re for 4 cell not 6 cell (Crap) well now i’m thinking of using or trying a 20,000 Mah 4 cell batt to see how that works on the VTOL? ,So what Motors are you using, and do you have original motors and tilt servo’s on your Nimbus.Thanks B.K

Greg: so i finally figured out how to look up stuff at foxtech i found the motors that was shown in the picture of the tilting system X3520-8 KV:520 but when i clicked on them it showed a long shaft on the motor i texted them to see if it comes with a short shaft for the tilting system. B.K

I use these engines and the 6S battery

Those are for the normal Nimbus plane, not the VTOL version.

Yeah, I’m not sure what is going on there. They removed the motor numbers from their VTOL offerings and only show the long-shaft motor. Both the SunnySky X3520-8 520Kv Motor and the Foxtech X3520-8 520kv Motor are rated for 1750w so I suspect they are the same, just rebranded from OEM.

Using Aleksandr’s link to AliExpress, I changed it to English and found this offering. His motor was a 650w rating but the one below is for 890w. I can’t attest to the quality of the motor but the price is nice for the hobbyist. However, they are rated for only half the power of the Sunnysky motor. I’m not sure if this is sufficient, especially in your Florida heat.

QA4220(3520) 580KV 890w Motor - $33. (short shaft)

Hi Greg: Thanks should the 450kv 580w be better than the 580kv 890w ?? well i tried again to contact Buddy Rc again i just keep getting voice mail well if i get stuck with these sunnysky long shaft and can’t return them for a refund then i’ll cut the shafts off and see if the tilt servo’s can take the weight of these motors and depending on which motor’s KV you suggest i’ll send for them.Thanks Greg again.B.K


You still haven’t posted your tilt servo number.

Hi Greg: Sorry the Tilt servos that came with the Foxtech V2 tillting system is AO7, B53 CHL premum digital servo HV 4.8-8.4v cordless motor. And you think the 580kv motors would work ok i’ll order them thanks B.K