New Products Flash Sale
Thread Tools
Old Nov 22, 2015, 04:21 PM
Lightmare is offline
Find More Posts by Lightmare
Registered User
Joined Feb 2013
35 Posts
Some logs of the same hotliner with different direct drive and geared drives

Hello everyone!

During the last two years I did some comparative experiments to test the performance of different electric drives for a hawk f5b alike hotliner, 1700mm wing span, 1300g weight. Consumed power of all drives is ~2000W on the ground.

Name: a7623345-102-10904627_815525121819736_766547063555238330_o.jpg
Views: 13
Size: 460.5 KB

I tested three different drives, namely:

1. A direct drive Scorpion HK3026 1000kV on a 6s LiPo on a RFM 10x8 prop

2. A HET 2W23 2950kV on a 6s LiPo on a KPG 1:5.2 gearbox on a RFM 14,5x14 and a 15x16 prop

3. A Kontronik Kira 480 2600kV on 6s Lipo on a KPG 1:5.2 on a RFM 14,5x14 prop.

Here are the corresponding logs for a 5-6 seconds vertical climb. Enjoy!

Scorpion on 10x8 direct drive:
Name: ScorpionHK3026-10x8RFM.png
Views: 17
Size: 44.3 KB

HET 2w23 on KPG 1:5.2 on RFM 14,5x14
Name: Het2w23-KPG1-5.2-14.5x14.png
Views: 14
Size: 54.7 KB

HET 2w23 on KPG 1:5.2 on RFM 15x16
Name: Het2w23-KPG1-5.2-15x16.png
Views: 10
Size: 80.1 KB

Kontronik Kira 480-26 on RFM 14,5x14
Name: Kontronik-Kira-480-26-KPG1-5.2-14.5x14.png
Views: 15
Size: 59.0 KB

The current measurment with the Kira was a bit noisy due to a loose contact in my UniLog sensor, but I was able to fit the data sufficiently by hand.

Interestingly with the same plane and the same LiPo and the same motor run time, the performance of all drives looks pretty similar, namely a peak climb rate of ~50m/s vertical and a half maximum acceleration time of ~2,5 seconds.

It seems to me that the efficiency and the acceleration of the RFM 10x8 prop is only a few percent worse compared with the larger RFM 14,5x14 or 15x16 props.

Next steps will be to measure the motor temperature and 'play' a little bit with the pitch of the props.

Best regards,

Lightmare is offline Find More Posts by Lightmare
Last edited by Lightmare; Nov 22, 2015 at 05:08 PM.
Reply With Quote
Sign up now
to remove ads between posts

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Question Direct drive or gear reduction? flying jeep Scale Boats 5 Nov 16, 2015 11:11 AM
Discussion direct drive vs gear assembly? justin.n Scale Boats 3 May 30, 2015 04:56 PM
Discussion Gear drive FC board for direct drive? Edmond Y Mini Multirotors 1 Mar 15, 2015 02:38 PM
Dragonfly with direct drive of geared tail drive? Wilders GWS (Grand Wing Servo) 1 Nov 13, 2004 08:18 PM
Direct Drive 600 with 8x4.5 prop vs. Geared 500 with 11x8 prop on a 2meter glider Ryan Nau Electric Sailplanes 10 Jun 05, 2001 12:37 AM