RE: Turbine or EDF
 

The problem if I rememebr right is pablo was using batteries that had a different shape they were custom from thunderpower not the BVM sabble cells. I saw them they where nothing like my batteries but they where 6500mah thunderpowers but they where shaped like bricks.

Here is the weight right from BVM. But Jack's scale is the true weight.



The new chemistry inside these cells also promises to deliver 2-3 times the cycle life which is very desirable as this affects your cost per flight.
Dimensions: 3 1/2" Wide
5 5/8" Long
1 1/4" Thick

Dimensions: 1 3/4" Wide
5 5/8" Long
1 1/4" Thick
4.75 lbs Weight

RE: Turbine or EDF
 

Why would anyone measure custom packs and use them for a comparison? Leave it to Jim to muddy the waters when making a statement about a simple battery comparison. I would have expected him to state "custom" packs or something to denote we weren't talking about the standard TP/BVM setup but in this case I'm sure it worked in his favor. I'm sure he'll also say I didn't say they were "standard TP/BVM packs" but then he also didn't say they were "non standard custom packs" either. Full disclosure makes a vendor look honest, this type of misleading comparison meant to illustrate their batteries are lighter makes the vendor look, well, each person can decide for themselves...

Jack

RE: Turbine or EDF
 

Thanks.

RE: Turbine or EDF
 

I just ordered the BVM F-80 electric power :) So.. I will gladly VOLUNTEER to test battery packs in the plane if anyone wants to offer :)

RE: Turbine or EDF
 

Way to go Bob. She'll be a beauty I'm sure. I've watched BV fly his and it is very impressive!

RE: Turbine or EDF
 

Good going Bob. I agree with Bob B. I saw BV fly the F-80 at EJets '09 and it flew very well and it's not a plane you often see at the field.

RE: Turbine or EDF
 

Awesome! I was hoping you'd go electric but didn't want to tell you having no turbine experience myself. I can tell you I've converted the Bandit to electric (we've flown it on the 5612 VioFan on 12 cells so far but tomorrow we will fly it on the 6215 VioFan with 15 cells) and I can tell you it cooks! We have yet to fly it on 15S but it did 156 MPH on 12S with the 5612 fan system @ 20.6 lbs. Once we get the speed numbers for 15S along with a video to go with it, I'll post some pictures for all...

Jack

RE: Turbine or EDF
 

6215..........6200 watts? E-Power is over the top.

RE: Turbine or EDF
 

Thank you guys. :) FYI I saw the Electra with the 6215 the other weekend in Hamburg.. boy o boy did it cook!. I'm talking IMPRESSIVE speed.. close to the 200mph variety.

I almost got lazy and got the Fury arf kit, I was l_l close but the F-80 is just cool.

RE: Turbine or EDF
 

Cool Jack. Can't wait to see video. When I get to the East Coast I'm going pull out my Skymaster 1/8th F-16 and rework the intake. It hasn't flown since I removed the TJ-100. I was not very happy with the performance of that fan. The F-16's top speed was 130 mph after struggling to get in the air and needing a dive to gain speed. If a F-16 can't raise its nose and go verticle, it is under powered. I've been kicking around which fan I want to use, either the EVF or the DS-77 HST or the new SM110-HP (once Stu gets it tested).

RE: Turbine or EDF
 

I hope someone made a vid of it? But BobV should have a vid of his 6215 in something. ?

RE: Turbine or EDF
 

I can give you a quick video fix, please note this is the 5612 VioFan running on 12S in the new Bandit (to be referred to as eBandit from this point forward), it was shot last week on the second flight. The AUW is 20.5 lbs and we did this test just to see what kiind of performance the 5612 would offer, not too shabby either! If all goes well, we'll fly the Bandit with the 6215 VioFan tomorrow and post video in the evening.

BTW, this isn't my best video work, I had the camera set to backlight and was a bit shaky too, no need to point it out ;-)

[link=http://www.flylowandfast.com/Files/Video/Bandit/eBandit 5612 (HD 720p).wmv]eBandit ARF 5612[/link], Windows Media, High Definition, 152 MB
[link=http://www.flylowandfast.com/Files/Video/Bandit/eBandit 5612 (High).wmv]eBandit ARF 5612[/link], Windows Media, Standard Definition, 25 MB

Jack

RE: Turbine or EDF
 

Correct, these were the packs that Pablo was using. We also measured and weighed EVO saddle packs (that have the tilt in the middle) and we are using those for templates for our JetPacks(tm).

RE: Turbine or EDF
 

Nice looking video! I didn't even notice the shaking :) Plenty of performance for a 20# plane that's for sure.
Thank you for posting!

RE: Turbine or EDF
 

That goes very well, Jack, of course with Rob at the sticks it's always gonna look super. The guys from esrpitmodel.com put my new 4 bladed fan in their Bandit and won something at Georgia jets with it, it performs about the same, but I think they were getting less than 5kW, closer to 4kW as they were using smaller cells, I guess. they had a 90mm exhaust dia by mistake, now down to 83mm and it really cooks. What this all shows us is that with a well designed, efficient model, with proper ducting, we don't need as much power as we used to think as long as we're looking to fly good aerobatics rather than break the sound barrier.



What was the music, BTW? Sounded like Sammy Hagar?

RE: Turbine or EDF
 

Stu I think it's Audio Slave but not sure. tt's Chris Cornell voice though.

Jack, nice job on the convesion.

Rob, as usual, nice flying.

Kirk

RE: Turbine or EDF
 

It was Soundgarden, "Superunknown" and yes, Rob can fly a 4' x 8' sheet of plywood and make you want to buy it ;-)

We installed the 6215 in it on Sunday and took the day to measure and record numbers from 12S through 15S, we used a combination of Eagle Tree, Spin data, Eflite meter and a Dillon digital force guage to measure Thrust, Efflux, Volts, Amps, Watts, Temp, RPM's and efficiency and came away with some impressive numbers. The debate to share or not is on though because of the fact installed data is hard to interpret. Everyone wants to put their fan on a bench with a bell the size of an Olive Garden salad bowl and talk about high thrust numbers but those can drop dramatically once installed yet yield great performance. Needless to say tomorrows flight will add 3+ lbs of thrust and another 25 MPH Efflux (again, installed numbers) over what you see in the video, should prove interesting.

BTW, we're @ 3.5" exhaust to mimick the Electra...

Jack

RE: Turbine or EDF
 

I agree about not needing to break the sound barrier. I know that for some guys speed is the Holy Grail but not for me. Sufficient power for a reasonable flight time, large maneuvers and scale like speeds. All good stuff!

RE: Turbine or EDF
 

Jack nice install! The inlets look like the handy work of Ralf?

RE: Turbine or EDF
 

Yes they are, RD inlets all the way! There's debate about loss by their length and sweep but they look too sweet not to use 'em. I saw them installed in Ralf's SBB a few months before E-Jets and worked out a deal with him to fabricate a set for me...

Jack

RE: Turbine or EDF
 

Jack,

Where are you placing the batteries? In the same location as the Electra?

Kirk

RE: Turbine or EDF
 

That's great news Bob! Good choice. I almost missed this amongst the rest of the back and forth on here.

Kirk, have a good trip across country. Can't wait for you to be in the same time zone! :D

RE: Turbine or EDF
 

Actually, longer inlets/shorter exhaust is a more efficient way to go for a number of reasons:

1. The boundary layer in the inlets is likely to be laminar (and therefore have much less drag) whereas the boundary layer in the exhaust will always be turbulent.
2. The inlets are usually larger in cross section than the exhaust, which means the velocity in them is lower. Lower velocity means less drag.
3. The inlets usually have to make bends to come from the side of the aircraft to the centre to meet the fan. Longer inlets usually have more gradual bends, which means lower losses. Longer inlets also change cross sectional shape more gradually, meaning less chance of flow separation occurring.
4. Longer inlets place the fan back so you can have space to put the battery closer to the CG without having to resort to custom (=expensive) saddle type packs.

The only downside of longer inlets is the slight weight penalty, as they are heavier than 0.010" Mylar.

The reason all the BVM EDF's are short is because they are carry ons from the ICDF days, where the fan unit was mounted forward for CG reasons. All newly designed EDF kits of any note have the fan placed aft with the batts close to the CG.

RE: Turbine or EDF
 

Stu,

Maybe you can reaffirm they are the best choice by helping me out with a static thrust question. We know on an Electra we see 14.25 lbs installed thrust using the stock BVM inlets (granted, they are huge and the inlet-to-FSA ratio is 106%) and the 5612 fan on 12S. When you take the same power plant and put it in the Bandit with the longer inlets (and 96% inlet-to-FSA ratio as calculated by RD), we see only 11.65 lbs. The Efflux also drops from 212 to 191, now is that solely to be blamed on the smaller inlets and lower inlet-to-FSA ratio or do the swept inlets get part of the blame? Likewise do they perform any differently in the air once you start shoving air into them?

Thanks,

Jack

RE: Turbine or EDF
 

At first I had them in between the inlets but Rob wanted the CG back 3/4" behind the stock mark, so I had to change to a saddle configuration. Because the inlets are so large and come back so far, I had to cut notches in the engine hatch area, you can see in the first picture I posted above the cutout area on each side of the engine hatch area, this is for two of the 6500 5S saddle packs. The third pack goes in between the inlets, one of the reasons I kept the electronics install so clean and over the front wheel was to have this area free to push batteries back in between the inlets easier...

Jack