RE: ESM FW D-9
 

Well...I now have one of these D9's enroute from VQ

RE: ESM FW D-9
 

Unless someone keeps it! lol I am going to hold it hostage until you bend to the forced installation of a gas engine! The only REAL way to power this butcher Bird! :)

RE: ESM FW D-9
 

I have a 50cc gas motor...so there. Now gimmie!!! lol

RE: ESM FW D-9
 

Yah but will it be installed in the D9? I will even set your needles for you. Then you wont have to send it to the factory and ask them to do it, like our other club members! Also, with the right sized tank, you can fly a very long time.

RE: ESM FW D-9
 

Ill consider it.

RE: ESM FW D-9
 

Hey Tim,

Thanks for the kind words and it was great to meet you.

The Dora sure does slow down nicely and for a 26-27 lbs model, it's quite impressive what it can do. The two mate's that came along with me were both saying it almost sounded like a chopper at a set of lights. I just can't get over how well and low the engine idles. Steve Thomas forgot to bring the 3 blade solo prop hub so I'm going to email him and see if he can mail it out to me, and finally try the Fw-190 shaped blades I've got sitting here.

Thanks

dave

RE: ESM FW D-9
 

Friends,

I was finally able to test fly my ESM Dora EP project and and can report complete success!   The 50cc Rimfire motor is much more powerful than it needs to be.  The model at nearly 26lbs. has unlimited vertical performance.   Half throttle is sufficient for most situations.   The plane is very forgiving and pleasant to fly.   The flaps allow the ship to slow to a crawl for landing.   Ground handling is superb with no tendency to tip up on the nose.  The 155mm CG is indeed satisfactory.  Pictures will be posted later.

Regards,

Doug Andre

RE: ESM FW D-9
 

Nice! Looking forward to the pics!

Casey

RE: ESM FW D-9
 

Doug,

What batteries and mah capacity were you using and how long of a flight can you reasonably get?

RE: ESM FW D-9
 

Kahlog,

I am flying on two 5000mah 45c Thunder Power LiPos. Twelve cells generating 4700 watts.  Prop is APC 22x10 E .  Fight time is about eight minutes at medium throttle.  Six minutes at high speeds.  I will run a smaller prop next time out and may extend flight time.    The 230 KV Rimfire motor is far too much for this application but is a show stopper especially those full power passes when the prop tips go supersonic.  A lower KV would have been the better choice.
Our club has 125 members with lots of planes and this ship is the most unique and commented on by far. 

Regards,

Doug Andre<br type="_moz"/>

RE: ESM FW D-9
 

Mine should be here tomorrow. Im planning on using the 65cc rimfire 160kv motor on 12s 40c 6000mah. Prop will be a 22x14.

Your setup shows a static full throttle speed of 96.7mph
My setup shows a static full throttle speed of 94.2

I also have some 21x14's so will try to use them and see about slightly less amp draw for longer flights, but with 6000mah, should get roughly 9 mins at medium throttle.
Even so, the lower kv of the 65cc should end up using less amps then the 50cc so should in theory allow for a tad longer flight time. But to see that, I may need to drop to a 21x13 or even a 20x12. Dont really want to go down that far since im using 20x10's on my 8s eflite 110 setups

Im choosing the 65cc rimfire for the ability to swing a really nice n large 3 blade prop if I decide to do so...such as that Biela 20x14

Vertical still wants me to use the 50cc gas motor I have lying around. Still considering it I suppose.

RE: ESM FW D-9
 

Guys, here is the link to ecalc http://www.ecalc.ch/motorcalc_e.htm?ecalc and from my experience I can say that it is very reliable. The APC-E props are a good benchmark in terms of power consumption and performance.</p>

Setting up a 233kV motor on 12S for this bird is not easy because with pitch 10 prop it is OK but not ideal, while on pitch 12 it might get too fast. So my choice in this case would be a 2 blade 19x10 or 20x10 but it is too power hungry with the later one.</p>

And I think that I have already mentioned that on Rimfire 65cc 3 blade 20x14 3 is really OK while a 2 blade 21x14 can be considered as ideal. I am considering this combo also for my self.</p>


</p>

Velco</p>


</p>


</p>

RE: ESM FW D-9
 

Guys,
I want to stress what a great EP conversion subject this plane makes.  Never in my 30 years of R/C warbird flying have I ever managed to get away with no lead in the nose!  Also, the proportions of the fuselage and the positions of the formers are ready made for containing big batteries. 
Using 6000 Mah batteries should pose no problem with space or weight.
Regards,

Doug<br type="_moz"/>

RE: ESM FW D-9
 

Hi Doug,
Any chance of some pictures?
Powered my ESM Ki84 with eflite 160, flies better than a trainer, plenty power.

Regards John....

RE: ESM FW D-9
 

John,

The same 160   set up would have flown this Focke-Wulf !     I will post pictures as soon as we get some good ones. 

Regards,

Doug Andre<br type="_moz"/>

RE: ESM FW D-9
 

APC-e props are not that efficient at producing thrust. In my experience, they consume more amps then a same size turnigy cherry type e prop and the apc produce less thrust. The problem lies in the blade structure on the apc. Way too thin and acts more like a knife through the air then a prop blade.

Additonally, a 19x10 or 20x10 is too small for a 50cc rimfire. Doug used a 22x10 which is more appropriate, however a 21x10 would allow a tad less power drain while still loading the motor enough. As ive stated before, I run 20x10's on an e-flite power 110 in 8s.

In the case of the 50cc rimfire, if Doug wanted to prop down some, then a 21x10 or 20x12 is what id recommend and NOT an APC-e prop. The 50 and 65cc rimfire notes specifically state do not use an electric only prop such as the apc-e line due to the massive torque of the motors.
20x12 turnigy cherry wood type e:
http://www.hobbyking.com/hobbyking/s...propeller.html

RE: ESM FW D-9
 

Kahlog,

Thanks for the information. I will begin experimenting with the props you noted.      The APC props have served me well over the last fifteen years or so.   My experience has been that all of the wooden props make great thrust but also draw more amps.  I know that wooden props must be safer under those massive loads.   Well, at least the full size FW had wooden prop blades!

Regards,

Doug Andre<br type="_moz"/>

RE: ESM FW D-9
 

Here is another idea for you Doug. So currently your running a 22x10. Well, a 20x12 3 blade would effectively be a 21x11 2 blade. A nice sweet spot for a 50cc electric motor.
http://www.troybuiltmodels.com/items/BP2012-3BY.html

For me, using the 65cc motor, Id have to use a 20x14 3blade otherwise the pitch is too low. 22x12 3blade would only fly the plane max of 80mph.
The problem is, a 20x14 is rather hard to get as not many carry it. I could still use a 22x12, but would have to increase the cell count to 14 and with that id get 94mph. Id be better of just ordering the 20x14 directly from Germany and staying with 12s

RE: ESM FW D-9
 

Found two places that sell the 20x14 3 blade prop. One is Aircraft international.
http://www.aircraftinternational.com...rbonProps.aspx
They request you submit an order giving CC number, but with no confirmation they even have the item in stock or what the shipping would be. Prop price alone was $80

The other is in germany and this place had the prop in stock and didnt require a backorder request. It was also cheaper. price was 79USD which included shipping to me. They accept paypal as well. I had to translate everything from german on the register page, but not that hard with an online translator. This place auto removed the VAT from the original price since shipping address was Vereinigte Staaten von Amerika

http://www.der-schweighofer.at/

RE: ESM FW D-9
 

I have never said that APC E props are the best, I just said that they are good as a benchmark. There are props with better performance but also more power hungry, like TGS, and there are props with slightly lower performance but some 10% less power hungry like Turnigy Light Electric and as kahlog said, there are Turnigy cherry wood better performing and probably some 5% less power demanding from APC E.</p>

I really have a lot of experience with the electrics and I never got it wrong. It would be really hard even to try to remember how many different types of electric planes I have had so far and especially with how many different combos, and I have always had the desired effect. And how did I manage that, well first spending countless hours in Motocalc understanding the problem and second trying different props at the field.</p>

I had promised to explain some time ago how prop choice differs from gas to electric. One thing is extremely important to understand, the measurements we make while the plane is static can be completely deceiving, for the very simple reason because the plane is static, and that can be significant only if you like to 3d and hover a lot, otherwise not that much! What is the point of having static 2:1 thrust:weight ratio on on a warbird? It really doesn't not make much sense, I hope we can agree on this one.</p>

Note: some numbers I will be using are just there for easier explanations, not from real life measurements!</p>

Now I will explain the importance of pitch. We should look at the prop as screw which is trying to "screw in" itself into the air. The faster the plane is moving this "screwing in" becomes less and less until the prop doesn't screw in more at all. Why is this, because the plane is moving faster than the prop can grab some additional air. So higher pitch gives a better max speed, but slower response.</p>

Practically THE MOST important figure you can have a from a certain combo is the Reserve of thrust from a cruising speed. And what is the Reserve of thrust? Lets say that a certain plane needs certain amount of power to fly level. For any maneuvre, like KE, loop, etc. Reserve of thrust is needed in order to keep the constant speed. We can consider pitch as the gear on a car. For e.g. it will be much easier to accelerate in the 2nd from 50mph (pitch 6), rather than in the 5th gear (pitch 12). Unfortunately we do not have a gear box on our model planes (variable pitch) to be able to continue accelerating so we need a compromise between a pitch and max revs. BUT guess what, electric motors have such torque that we do not need a gear box and we can stay all the time in the 5th gear, hence we can turn highly pitched props!</p>

I will try to summarize now otherwise it will become too complex to follow. Gas engines unload in the air and max revs, with the right prop and tuned exhaust, can be much higher in the air than on the ground, therefore compensating for the relatively low pitch. On the contrary, electric motors do not unload that much in the air but can spin much higher pitched props thanks to an incredible torque they have.</p>

So for e.g., in the air while moving at 50mph, on an adequate combo a 19x15 has a MUCH higher Reserve of thrust from a 20X12 for all the a.m. reasons while on the ground they give the same static. So for typical warbird type of flying 19x15 is a much better choice, while for freestyle a 20x12 might be a better solution. Or again going back to car analogy, warbirds are Nascars while 3d planes are rally cars :).</p>

Going back to the real life numbers, Rimfire 50CC on 12S and 19x10 will give roughly 14.5kg of static, which is more than enough for an 11kg warbird, and having a 20x10 or even 21x10 will not help at all once in the air at 50mph because the Reserve of thrust will be in the best case the same. On the contrary the power consumption will be much higher.</p>

I hope it is clear what I have tried to explain, if not please do not hesitate to ask because I see to many people having wrong combos and wasting precious energy from the batteries.

BTW Schweighoffer is in Austria and they do deal internationally, I have purchased most of my stuff from them. Here is the direct link to the 3 blade prop http://www.der-schweighofer.at/en/pr...fk_biela_props VAT in Austria is 18% which is deducted for outside of EU export.

Velco</p>

RE: ESM FW D-9
 

Hello Kahloq, I just found Sweighofer myself.:)

Bought these;
http://www.der-schweighofer.at/en/pr...erung_4_stueck

They have a language selection upper right area. Yes, not everything is translated, but the important things are okay.

(Somehow I understand what a gabelkopf is, hehe. Gabel is fork, and kopf is head, so....)

I bet when when the german webshops look at the rest of the world as an increased marked, more and more will include english as language.

Their sales will increase dramatically.

RE: ESM FW D-9
 

I was not stating you said APC-e props are best. I only stated they are not as efficient and why(blade design). I was not arguing with you at all.

You stated that on a 50cc rimfire a 19x10 is optimal in your opinion and stated that a 20x10 or 21x10 would not see any benefit. That isnt accurate. While i agree on top speed would not increase(pitch being the same)....the 21x10 has much more blade area and therefore pushes more air. This means someone could fly at a lower throttle setting if they desired. More thrust is produced for less rpm's. The plane could fly safely at a lower throttle positon.

Like you, Ive been flying electrics for years(close to 10) of all different shapes and sizes. While motorcalc is a nice baseline and is useful to some degree, there are a lot more variables involved so I dont rely on it.

That 19x15 will not have a significantly higher reserve of thrust compared to the 20x12. The 19x15 will load the motor up a LOT more then the 20x12 specifically because of the higher pitch. Static thrust SHOULD show the 19x15 to be effectively higher, but it wont be because of the load it presents to the motor. The 20x12 can reach a higher rpm on the same electric motor since its less load. Since we all know static load is only what the theortical max rpm would be given the pitch and cell count etc, but does not factor in load. Higher load, means the motor has to work harder therefore the end rpm isnt as good. Additionally, with the higher diameter of the 20x12, it will push more air as the blade area is larger...ie larger prop disc...and sicne it will be sping faster for the same power consumption, the thrust output will be higher.

We dont have to agree. It doesnt matter to me. We just see a few things from different angles and thats fine.

RE: ESM FW D-9
 

Yep....they do have a language selection, but it does NOT carry over to the customer registration page or the checkout to place an order. Believe me, I tried a couple times. In the end, I just used bingtranslator to know exactly what was being said or asked of me. :)

RE: ESM FW D-9
 

As you said we do not have to agree, we just have a different opinions, which is also good. The only way to know for real is to brings different props at the field and try, and belive me this is what I have been doing. Unfortunately most of the people stick just to one combo and thats it.

There is no magical combo that works for any plane, as different types of planes are supposed to be flown differently, therefore they require a different approach. Thats why I have used cars for analogy as they are much easier to comprehand. What would Ken Block look like in his rally car on an oval, and what would Tony Stewart look like in his Nascar on a rally course?


But as I have already said, one should set a safe range of props that can be used on a certain bird for a specific combo and try, thats the only way. My approach is that I always start with combos that are "short geared" moving onto "higher geared" ones. Specifically speaking of the Rimfire 50CC on 12S and ESM Dora I would start with 20x8 and once the plane is dialed in and I am happy with my landings I would move on to 19x10 because from my point of view everything else would be just a waste of energy.

Velco

RE: ESM FW D-9
 

I understand your reasoning for the 20x8 as an initial prop choice on the esm d9 with a 50cc rimfire. However, that would make the plane rather slow....which isnt a bad thing for the first few flights. Your in the air speed would max out at about 75mph. Nothing to sneeze at....respectable.

In my case, with the 65cc motor, a 20x8 would not be useable at all(max in flight speed of 53mph)...and i even have some. Even a 20x10 would only provide 67mph.
Anyway...ive got my plane now in hand. Still got to get the motor. Ive got a few 21x14's and 22x14's coming so those will be tested as well as a biela 20x14 3 blade coming from Austria.