Hey everyone, so I don't have the APM tuned very well but at least its hitting waypoints and holding altitude and airspeed. I decided to get it flying and see just how long it would go. Here it the result:

here are the Tlogs

this is the equipment list:

Techpod Kit

Foxtech 370kv motor

APC 12*8 prop

Castle ice2HV 40 ESC

2x Zippycompact 6s 5000 mah lipo

APM 2.5 + telemetry + airspeed sensor

AttoPilot 45A current sensor

6x Hitech 65-hb servos

So whats next for the techpod? well, I will refining the gains. After I have it flying smoothly, I have a setup in the works that will be pushing flight times over 5 hours. Stay updated on the lated techpod news @ hobbyuav.com

 

Views: 7921

Tags: flight, techpod, time, uav

Comment by Gisela & Joe Noci on September 10, 2013 at 12:09am

@ Reto,

Just a follow on on the large prop/small prop debate - look at the aerovel flexrotor - aerovelco.com - 40 hours endurance - albeit with a gas engine - but the prop...not wingspan scale but any prop of wingspan scale may just swing the plane instead of the prop...and the idea is not new - they  started that one 3 years ago or more. It is not variable pitch either.

Joe


100KM
Comment by Reto Buettner on September 10, 2013 at 1:18am

@ Joe: Thanks for the indication. I am well aware of the Flexrotor. See my post on July 30. I like the approach, but it seems to be quite difficult, they havn't published any progress since two years. I am more than happy to hear if this technology makes it to market.

The Quadshot of TransitionRobotics is another interesting VTOL design.

Cheers, Reto


100KM
Comment by Reto Buettner on September 10, 2013 at 4:22am

@ Joe: I just found that the newest progress of aerovel is on Youtube, not on their website. Why they don't update their website is not clear to me. They seem to be making some progress, which is nice.


Moderator
Comment by Gary Mortimer on September 10, 2013 at 4:47am

Yes if you look on the sUAS News feed on the right of the front page at the moment you will see they have been flying it this week.


100KM
Comment by Reto Buettner on September 11, 2013 at 1:13am

That is exactely how I noticed :-)


100KM
Comment by moglos on October 3, 2013 at 4:17am

Gruezi Reto

I've been trying your advice above in ecalc and I'm having trouble getting good results based on your rules of thumb (on page 4 of this thread).

I'm flying a Bormatec Maja 2.2m wingspan with AUW of about 2.5kg, 3 cell, cruise speed of about 40 km/hr at 75 watts using a 10 x 5 or 11 x 6 prop. I blew up my Turnigy SK3 3530 1150kva motor today (overloaded it with the 11 x 6 prop on takeoff) so I'm looking for a new motor.

My problem with ecalc is that if I use a prop with a pitch ratio of 1 I can't get the maximum power and pitch speed at 100W/kg and at a bit less than double my cruise speed like you recommended

Is there something I'm missing?


100KM
Comment by Reto Buettner on October 6, 2013 at 11:18am

The Maja is aerodynamically not efficient. Therefore I suggest to adjust the rules of thumb:

1. Prop pitch ratio at 0.75 (lower)

2. Pitch speed a bit under double the cruise speed (unchanged)

3. Propulsion power around 150W/kg (higher)

You are looking for 350W and a pitch speed of about 80km/h. The following setup might work well:

Prop: 14x9

Motor: 680kV

In your case this would be a larger prop. This is special, as your starting point is a very small prop for the given weight. A standard motorglider like an Easyglider equipped with a 10x5 prop weighs only 1kg.

And: Consider replacing your Maja. There are a lot more efficient and better mannered airframes around.


100KM
Comment by moglos on October 6, 2013 at 2:26pm

Merci vielmal

Thank you for your input, I'll give that a try.

You're right about the aerodynamics of the Maja.

Can you recommend a more efficient and better mannered airframe? I do like the payload/lift capacity of the Maja, but I don't really need that much. I like the Techpod but it doesn't seem to have much space at all.


100KM
Comment by Reto Buettner on October 7, 2013 at 1:52am

Concerning the airframe you must first define your requirements:

- Weight and size of payload?

- Forward view required?

- Endurance in time and distance?

One of the following will probably meet your requirements: If you don't need forward view, then I would go for a motorglider, like the Solius, Cularis or Hobby King ASK21 EP Glider 2600mm Fiberglass. They are efficient and well mannered. If you need forward view, you might choose the Techpod, the Skywalker X8 or the RVJET.


100KM
Comment by moglos on October 7, 2013 at 3:26pm

Hi Reto

Thanks for those tips. Forward view isn't required. Payload would be one (or two) compact cameras pointed straight down, roll stabilised. 60-90 minutes endurance would be good, 120 minutes would be great. At around 40-50 km hr. 

I fly my Maja with a roll stabilised NEX5 (or Canon S100) mounted sideways (landscape) under one wing. It makes my aerodynamics even worse, but the fuselage just isn't big enough.

I expect I'll have to keep it under the wing because I don't think any of those airframes would have the room.

I like the look of the ASK21 fuselage space, but the wing is quite low so I couldn't mount a camera under the wing. I probably could create a bracket to mount it in front of the wing, or within the wing even. 

I like the Techpod too. There is a new one called the Cyclops which is available in fibreglass and has much more payload room. (It sounds like the original Techpod team had a disagreement and now they are now both making their own planes based on the same design.)

http://www.rcgroups.com/forums/showthread.php?t=1833786

Comment

You need to be a member of DIY Drones to add comments!

Join DIY Drones

© 2014   Created by Chris Anderson.   Powered by

Badges  |  Report an Issue  |  Terms of Service