I'm getting closer to gathering all the components for the 140C, but am hitting a budget wall. If you'd like to support the show/USA trip, I've put some of the remaining items I need for "sale" on my website, or really a way to donate/support the trip.

I have to emphasize, I'm offering it as an opportunity if you'd like to help. We're still friends if you can't or don't want to : )

Direct link to Help Raptor 140C: http://store.mygeekshow.com/category-s/1819.htm
Learn more about the Raptor 140C: https://www.youtube.com/watch?v=lRGbDmPCoeQ
Watch the most recent USA Trip Update: https://www.youtube.com/watch?v=DIF1J4VfY9s

If you don't want to pick something specific, you can go to: http://mygeekshow.com/donate/

Thank you for your 2+ years of support! We're getting closer...

Views: 1463

Comment by Jeff Taylor on January 27, 2014 at 6:03pm

Hey Trent, we've definitely got extra T9Xs sitting around and might even have that exact ESC as well, if not probably something similar. PM me your address we can send them out tomorrow. Good luck!

Comment by Trent at MyGeekShow on January 27, 2014 at 6:13pm

Awesome Jeff! Sending now. I'll take it off the store as well. What name/logo/business would you like on it?

Comment by Rob_Lefebvre on January 27, 2014 at 6:25pm

Hey Trent, so what exactly have you purchased already?  It's a little unclear.

The battery chargers, are you really going to leave the cells loose and charge them individually?  I'm not sure that's a great idea.  I assumed people weld these into packs when they use them.

And those servos, you have those?  I've used Corona servos in the past and was NOT impressed at all.

And the motor is not listed, do you have that yet?  Turnigy?  NTM or SK3 or what?

I'd potentially be in to get you some better servos and/or motor.  They're going to take a lot of wear and tear on this trip.

I'm also curious, if you're having trouble pulling this together, how are you funding the rest of the trip?

Comment by Trent at MyGeekShow on January 27, 2014 at 6:40pm

R_Lefebvre: Good Q's!

-I've got everything taken care of except what is on the store.

-Those battery chargers are to get me started while I test their flight performance and simultaneously learn about welding and charging in series/parallel. They are in a way, different challenges. As I need to make progress, I'm treating them separately.

-The servos had good reviews, and was in the weight, speed, strength area I was looking for. I've not had a bad experience with any servos actually, just lucky I guess. Or maybe I've never had an airplane survive that long : )

-The motor is listed now, was missing a checkbox : ) Its a turnigy. I realize not the highest quality on earth, but for the price you're getting a solid performer. Been using them for 2 years now and have had good experiences. If funding is there, I'd consider a higher quality/more efficient motor.

-Thank you! You're awesome. I would love to get better equipment too, but I'm having to balance all the components of the trip, including food, airfare, fuel, wiring, antennas, batteries, etc, etc. I had to draw a line somewhere and say, this is sufficient. 

-I'm not having too much trouble, things are progressing very well. I'm confident I'll have the resources needed to make it successfully. How quickly or efficiently, or even comfortably, now that remains to be seen! : )

Comment by Rob_Lefebvre on January 27, 2014 at 7:19pm

My concern with the servos is... I have a bunch of Corona DS929HV servos with the mounting ears snapped off.  The plastic they use is crap.  So, I'm not impressed with them.  I really like the Magnetic Induction servos made by Iltair.  I wonder if these would work, but I've never used this size, only the full size:


And this motor might be better:


Comment by Justin Stiltner on January 27, 2014 at 10:02pm


You may want to take one of the motors and servos etc. and set up a static endurance test, estimate how long your motor is going to run for on the trip  then have a bench power supply run the test motor for at least that long.  This will tell you hopefully how many extra motors you should take with you, similarly you could put a load on a servo and have it continuously move back and forth to find out the replacement interval for those servos.  I would also consider building multiple aircraft and taking them with you just in case.

Comment by Marius van Rijnsoever on January 27, 2014 at 11:39pm
hi Trent.

I can sponsor you a motor, but you can almost double your range with a more efficient motor. Turnigy does not publish it efficiency for your current motor, but when other people have tested similat models they get 5 gram/watt at best. Tiger motors can easily do 10 gram/watt and can go as high as 20 gram/watt depending on load.

If you can calculate his many grams of thrust you need I can recommend/sponsor you a high efficiency motor.

Keep up the good work. Marius
Comment by Andrew Rabbitt on January 28, 2014 at 12:40am

Marius,  Are you really saying your Tiger motors are four times as efficient as a Turnigy?  If so, I wonder why the Turnigy's are not melting during use, because that's a lot of power going nowhere!

(apart from the fact that g/W isn't a very scientific measure of efficiency...)

Comment by Marius van Rijnsoever on January 28, 2014 at 1:09am

Efficiency in layman's term is "bang for bucks". There is no more scientific way express efficiency as grams (bang) per watt (buck) in this situation in my opinion.

Efficiency in any motor is a bell curve with an optimum performance range for each motor. Turnigy does not publish its efficiency range (wonder why :), but when people test it they find it to be around 5 gr/W


If you compare that with a more expensive motor (not really specific to tiger) you will see that efficiency is much better (especially in the lower rpm range). The reason why I need to know how much thrust he needs in cruising speed, is because this will affect which motor runs more efficient.

4x more efficient is outside the practical range (as this is for very slow rpm), but 2x more efficient is doable.

Comment by Marius van Rijnsoever on January 28, 2014 at 2:12am

Of course airplane efficiency is different from the individual motor efficiency. But since most characteristics of the raptors flight are locked in (design, weight, and cruising speed). There are 2 mayor things left to increase efficiency. One is centre of gravity, but Trent has already optimised this. And secondly the motor/prop combination.

A tiger motor can be less efficient than a Turnigy motor depending on the setup of both. Most efficiency curves are bell curved shaped, meaning you need to "hit the sweet spot". If all motors would be designed the same there would not be such a price and weight and Kv range.

Andrew, what would you consider to be a scientific measure of efficiency?


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