10cc 3D gasser --- An exercise with a VH Sabre-X 51" and a Evolution 10GX

[Enterprise]

I also just ordered a few more props with a large order for the rest of my fleet. Xoar 13x4 and a WWII 13x6 (who knows till you try). I see from RCG that the APC 14x4W is another prop to try, but I will have to remember to tack into a future order from a place that carries it.

I will hold off on making any attempts at a video until I get it more dialed in.

Also I had a deadstick with it today and landed with no incident. It glides fairly well.

 

[gyro]

I also just ordered a few more props with a large order for the rest of my fleet. Xoar 13x4 and a WWII 13x6 (who knows till you try). I see from RCG that the APC 14x4W is another prop to try, but I will have to remember to tack into a future order from a place that carries it.

I will hold off on making any attempts at a video until I get it more dialed in.

Also I had a deadstick with it today and landed with no incident. It glides fairly well.

Awesome updates today, thanks for keeping us posted! Any determination on the cause for the deadstick?

 

[Steve_B]

I added the weight notes to post #2. I show how I came to the conclusion that the gasser setup adds a pound versus the electric.

Thanks for posting the weight data, all looks ok apart from the battery, a 4s 2200mAh battery will be about 250g, not 312g, that takes the weight (inc 32g for 'miscellaneous stuff') to 1700g (3.79lb).

For the gas conversion one obvious omission is the weight of gas, it wont fly without some! This is going to add say 120g (4oz) to your typical flying weight.

This means that the gas conversion adds 720g (25.7oz or 1.6lb) to the typical flying weight. That's a 42% increase over e-power. I'm not sure that by the time reinforcement and beefing up is done to cope with the vibration induced issues that the weight might not creep up a little more?

I think the one thing this really shows is just how weight efficient modern e-power is on small to medium size models.

 

[3dNater]

This only slightly undermines your point, but to be fair, I am guessing most people are using closer to 4s 3000 in that plane. I know I would.

 

[Steve_B]

I think most use batteries in the 2200-2600 range. I fly my similar sized AJ Slick on 2200's and it's fine. But I think it's best to compare recommended set up. It's always possible to make any plane heavy by adding big batteries.

On the flip side I'm sure on a full tank the gas version will be carrying a lot more than the 4oz of gas I used in my calc. So either way you look at it the comparison your going to be hauling around at least an extra 1.6lb on take off.

 

[Enterprise]

You are correct that I did not include fuel. Having a 51" slick, I fly it on a 4s 2800 and I figured the weight around a 3000 battery which I figured was a more realistic comparison. I am a little surprised it turned out so porky as I had figured a pound to start with. I posted all the weight numbers to show that other than the Hyde mount, I did not really add anything that was not necessary. My initial fear was that going with a 60" model, these numbers would be closer to 6.5 pounds which means it could just barely hover. The gasser weight numbers did include the reinforcements I did as I reweighed the fuse afterwards.

One of the reasons I picked this model was it's huge wing. I realized I was turning a super floatly plane into something with wing loaded more like the 51" slick. I probably should buy another one of these and built it electric to get a better comparison. No one in the area has one that I know of. Maybe I will see NJswede's at FLI.

There is little doubt electric is superior in every manner except flight time in this size class. Also I can put a ton of flights on this plane in short order as it only takes a minute to refuel it.

After the dead stick I leaned out the low end needle as if you run it too rich it will bog down. I have temperature telemetry hooked up to it and it does not seem happy till you get the temp up near 300 as that is a normal operating temp on the low end.

We are going to get some flying in tomorrow in the AM so I will bring it out and try to do some more flying with it. I fixed the elevator servo already. I also moved the ball link to the inside of the servo horn and I have a better geometry.

 

[wedoitall]

epower may be superior in these sizes but IMO gas is WAY Cooler. the sound and the smell of a 2-4 stroke motor gets the ol blood a-pump'n.

I had the Oneill Brothers out of California mod my 27.2 cc 2 stroke into an 8.2 hp beast, without adding one oz. of weight to the motor. Im gonna get in touch with them about one of these, im sure they would be interested. They are very well known in the Hpi/Losi 1/5 scale engine builders/modders circles.

 

[gyro]

epower may be superior in these sizes but IMO gas is WAY Cooler. the sound and the smell of a 2-4 stroke motor gets the ol blood a-pump'n.

I had the Oneill Brothers out of California mod my 27.2 cc 2 stroke into an 8.2 hp beast, without adding one oz. of weight to the motor. Im gonna get in touch with them about one of these, im sure they would be interested. They are very well known in the Hpi/Losi 1/5 scale engine builders/modders circles.

I agree! Gas sounds way better!

 

[Steve_B]

I agree, nothing beats the excitement of a real engine. having got into RC over 40 years ago before e-power was ever imagined I wholeheartedly agree. However e power scores massively on ease of use and accessibility. if not for e power I'd probably not be flying today as the trail to the nearest club field is too much of a pain to make on a regular basis.

Wedoisall, Interesting on the tune up of your motor. In my youth I used to tune 2 stroke motorbikes for the local boy racers. 2 stroke tuning generally concentrates the power in a narrow 'power band' at high revs (you need an expansion chamber to make it work well) while this can give very impressive peak HP figures the inevitable downside (on an engine that doesn't have fancy variable exhaust port timing, which no RC aero engine does) is that you lose low RPM torque. I'd be a bit worried that if they did a standard RC car type tune on a aero motor motor you would end up with a motor that wouldn't have low down torque enough to pull a large prop up to speed. It's ok on cars and motorbikes because they have gears so the engine can be kept in it's power band, not so on a plane they need a flat torque curve, not a 'peaky' one.

 

[Enterprise]

Quick flight video with a newly rigged up hat cam that needs some tweaking. This is with a APC 13x6 and not that exciting, until the end. Not the greatest weather we are having here in the Shire.

[video=youtube;0p1_SZ7VamI]http://www.youtube.com/watch?v=0p1_SZ7VamI[/video]