cathurga

Well people, here are some 'real world' figures, I got her out onto the test strip and hooked up the wattmeter. I must say that the figures are not too far off what ecalc says, so I have vindicated myself a little (I feel better now, but know that I am still in the wrong for the most part, read on).

Full throttle figures:
1350Watts at 55A, peaking at 60A (ecalc figures, assuming single motor multiplied by two = 1380 Watts at 70A)

3/4 throttle:
1000Watts at 32A

1/2 Throttle
600Watts at 16A

Unfortunately I am unable to see the revs at these settings, but there was very little strain on the motors and very little heat build up on them or battery, and I did a check on one motor to compare with both. For this test I got:

Full throttle
650Watts at 30A

I was also unable to measure the thrust at the moment, but she wanted to scoot for sure. I realise the I shouldnt rely on the ecalc but I am hoping the thrust measurements that it spits out are within a reasonable accuracy level. For the setup that I have, one motor, at half the weight of the plane gives a thrust ratio of just under 1.2:1 and anything over 1:1 is ok in my books. I have assumed the planes weight to be around 14lbs (6.5Kg) but I cannot measure that until it is all built and CG is set. I have a little building to do yet, so will concentrate on getting that done. I might maiden her on this setup even though it is only offering 100W/lb which might be ok, and if she survives, put on the 13x10x3's (that I am still nervous about cutting) and that would get me closer to 120W/lb and a bit more pitch speed.

Anyways, all this calculating is doing my head in.....as soon as she is flying I will be happier.

Asl always, thanks for the help guys....

kahloq

Your using the turnigy 400kv motors for those test numbers? If so, is it by chance the turnigy easymatch g60 400kv? If so...you've got plenty of headroom. Ive mentioned before ive got several of those motors.......2 in an esm 95" me-110 spinning 16x10x3s and a couple single engine planes with same prop.
Obviously amp draw is higher then yor 13x8x3s, but then again....bigger plane....more room for batteries. The esm me-110 runs 2x 6s 6000s in parallel.

Anyway.....sounds like your right on the bubble power wise. 100watts per pound should be ok and rather scale. 120 would be better

cathurga

Kahloq,

They seem like very similar motors and the G60 was very high on my shopping list. There were a couple of things that I couldnt get my head around before I made my choice...

The G60 doesnt appear to have a bolt on prop mount, I dont have anything against collet type ones apart from some club members who have battled to get vibrations out of theirs, the collets didnt seem to fit well. Although I haven't seen one 'in the flesh', I just didnt want to buy from HK, get them shipped to me and then see I dont have an option.
When I put the numbers into ecalc, the G60, for the same Kv rating seemed to rev a lot lower. I did check the ACTUAL specs that ecalc have in their settings, and it was more or less very similar, there was quite a difference in output though. I know ecalc is not the elec 'bible' so to speak, but given I live far from any decent options if wrong, I chose the others. The G60 seems like a carbon copy of the Power 60, which I have, and as per my tests above, they didnt cut the mustard on a 13x8x3. I flew my P60 on a Corsair, and it is fantastic on a 15x 2 blader, best motor ever for that application.
The G60 500Kv I found interesting too, and on the 13x8x3 maybe would have been a better buy....
Lets not mince words, the ones I got were US$15 cheaper per motor, and from a testing standpoint, I liked that LOL

Thanks for all your input, you have given me some confidence to maiden it on the current setup, and although I like scale flying, I will be aiming for the 120W/lb just for a little more 'oomph'. You are obviously a very experienced pilot, I have seen many of your threads on this and other forums, and take heed of your advice.

I have not seen any of your videos of the ME-110. I have always liked that aircraft, and would love to see it in the air....

cathurga

Dave, are you sure CMP are still making them? I see they have been removed from the catalogs on CMPairplane website, and I can find no trace of them. I sent them a mail months ago asking, and never got a reply. Shame really, especially if it has been a good seller for them. Some of the usual suppliers are all out of stock, including Ak-Models.

There was a thread started on a lesser used forum, where a lot of people fly ESM models, and there was a rumour that they were going to produce a Mosquito....that should be a decent model....hopefully it transpires...

kahloq

I dont have a video of the me-110 flying. While i have a digital videocamera, there usuaaly wasnt someone available that was good with keeping planes in the camera's viewfinder.

I did just recently get a Drift HD action cam that I can mount on my head or whatever and film stuff myself. Similar to what a GoPro is.

cathurga

That is impressive for sure. When you get some video, I would love to see it. What is that 'box under the wing, it looks like it is near a join in the outer section or something? Has it counter rotating props?

kahloq

The "box" is a turnigy bomb drop system. I made the outer wing panels removable for better tranportation ability. The bomb drop sits on a ply base that has holes through for bolts to go into hidden blind nuts to hold the outer panels on. The bomb drop make it seem like the ply plates belong there. 1 bomb per side of plane
They are functional of course...I had already dropped them when that photo was taken.

Regarding the g60's and collet prop adapter. I didnt use them. Instead, I got a set of prop shaft adapters for the e-flite power 90(same shaft diameter as the g60 and power 60). In the set, there's a bolt on and a dual set screw version. Additonally, they are already pre-tapped for a bolt through the middle type spinner. So on the g60,s....file a flat spot in two places on the motor shaft and put the prop shaft adapter in place and tighten down the set screws. Put spinner backplate, then prop, then shaft nut to hold prop. Bolt thru spinner and tighten that down and viola. I dont have to use a dave brown or tru-turn spinner adapter doing it this way.

cathurga

Mossie-lovers,

There is a poll going on to determine options for ESM to consider as a production range. It might help to have your votes if you havent already. They are talking of a 100" Mossie.

Get down there and vote... http://www.rcuniverse.com/forum/m_11362870/tm.htm

badazzgti03

My Feedback: (4)

So my set up for the Rimfire .60s and hobbywing 60As wont work??? Cause that's what i bought and what I have on hand and i'm pretty much outta cash

kahloq

Badazz....yes it will work, but you have to be carefull not to go full throttle for too long and make sure the esc's get PLENTY of airflow.
One way to reduce the amp draw a tad would be use 12x8x3's instead of 13x8x3's. If you've already got the props, then just be carefull of high throttle.

I highly doubt you'll be at full throttle when flying the plane. Seriously, you wont need it once it the air. Do NOT run the plane up to full throttle with the plane standing stillfor more then a breif second(to test amp draw) since there'd be no airflow over the esc's.

I would advise some time in the future when you can get a bit more cash, to replace the esc to 80's, but as long as you're mindfull of the throttle, you'll be ok.

cathurga

Badazz, you dont have batteries and props yet right? If not you could always opt for less volts and that could provide you with a decent setup.....also if you are not fussed about props being 2-blade, you could get a very economical setup.

Best not to go an buy new stuff, make the best of what you got.

badazzgti03

My Feedback: (4)

Cathurga,
ok cool, yeah the only time i would even go full throttle would be on take off. but I have not gotten batteries yet and really don't know what to get 4s or 5s? as for props I have on order 12X6 2 blade. For now i will be using and economical set up. Later on down the road ill upgrade to the 80A and 3 blade props.

kahloq

If your only running 5s, your not going to get even close to max ampsor watts for that rimfire motor. Hell, I thought you were still considering using 6s on the rimfire .60s.

Definitely do NOT go 4s as the plane will be sluggish at best if it even gets off the ground.

With the 5s, you need the biggest props that will fit....so 13x8 props. 2 blades will use less amps and perform slightly better then 3 blade, but the 3 blade on 5s on those rimfires isnt going to pull massive amps either.

You dont have to run 45c rated batteries either. 30c batts will fuffice just fine and will also help keep amp draw in check. The higher the C rating, the more amps the battery can push.

cathurga

Agree with Kahloq......even a 12x7 2-blade would be ok at that prop speed, 12x6 would be ok but maybe a little low on the forward speed.....scale for sure, but not ripping. If you do go 13x8 it will be strong for sure, but you will still need to avoid prolonged full throttle, and static running for long periods...

Good luck. I am hopefully doing some taxi tests this weekend...

kahloq

Here's a rundown on the speed you'll see on the different batteries and prop pitches. Note this is static max speed. Drag of the airframe in the air and motor load will lower these numbers by about 8%

4s lipo:
12x6 prop: 54.6mph - Dont even try this...the plane wont get off the ground
12x7 prop: 63.7mph - Probably would fly, but you'd be at close to full throttle the entire time
13x8 prop: 72.8mph - Flyable...but amp draw would be pretty high since you'd still be close to full throttle

5s lipo:
12x6 prop: 68.3mph - Flyable....but as above...rather slow
12x7 prop: 79.7mph - Flyable....a bit of head room
13x8 prop: 91.1mph - Best choice for 5s....good speed and power for reserve. Most available thrust output for 5s

6s lipo:
12x6 prop: 81.9mph - Flyable....just enough for scale speed with a smidgeon of extra
12x7 prop: 95.6mph - Good speed. Not amp hog, but enough for sport flying and a tad more.
13x8 prop: 109.3mph - Excellent speed. Wide envolope range for flying manuevers.

Whatever you choose, try to use a 13" diameter prop to get the MOST amount of airflow over the wings. A 13x7 would be a good all around prop for keeping amps down, but keeping decent speed even on 5s. I do not know of a 3 blade 13x7 though. MAS makes a 13x8x3. For best performance, use a 2 blade unless it doesnt load the motor enough. Ive run into that scenario as well where a motor just doesnt perform well if the prop is too small. In the rimfire .60's case, I dont think thatd be an issue.

Up to you whether you want to maintain a scale appearance by using a 3 blade or not. Some people try to say that you can't tell how many blades a prop has when its flying. Well......I think that statement is bogus because I can definitely tell the difference. If appearence matters enough to you, remember, that the plane will spend most of the time on the ground(or hanging up somewhere in your house).

badazzgti03

My Feedback: (4)

Wow all this info and options for electric...can be confusing seem like nitro is the easiest but I do like all these options for electric. Well 6S for the lipos it is!!! if the plane survives , awesome if not, no big lose, ill just throw the electric set up in my top flite Cessna 310 But anyways guys thanks for all the info and would like to see some videos of peoples electric set ups and flights.

cathurga

I would definatlely consider this option to be a good trade off between power/speed/flight time....

13x8 prop: 91.1mph - Best choice for 5s....good speed and power for reserve. Most available thrust output for 5s

If you find you are not getting enough flight time, or if you have an over abundance of power that you are not using (ha ha, as if) you could always prop it down to a 12x7 which still leaves you with some headroom.....

Yep, these would be my options for sure....just depends on how you like your planes to fly.

Edited to add: HK has 5000mah packs for US$36......good price, and you may be able to get them in the US warehouse!

kahloq

Cathurga, Badazz already said he had 12x6 props on order....so thats what he's basically going with....so 6s is the only viable option with that prop. Plus.....its easier to fit a couple 3s packs and series connect them together then one brick size 5s. But....its all up to Badazz on how he wants to do it. A 6s 5000 mah pack should be able to fit right through the nose of the plane as long as you make the bubble removable.

But....it wouldnt cost much to change props. I'd still go with the 6s setup, but would run either a 12x7 or a 13x7 2 blade considering the limit he's imposed by using the 60amp esc's. At least a 6s battery setup could be used in a 60 size plane if he got one somewhere down the road...say like a hangar 9 me-109f that has a battery hatch already in place.

badazzgti03

My Feedback: (4)

I know props are cheap and could easily change to a 13x8...but i am going for the counter rotation set up so i need one pusher prop too..does apc make a 13X8 pusher prop?

Dangaras

Master Airscrew makes 13*8*3 trctor and pusher props.

kahloq

Yes they do and Horizon has them ins stock:
pusher version:
http://www.horizonhobby.com/products...8ep-APC13080EP

normal version:
http://www.horizonhobby.com/products...x-8e-APC13080E

However, if your going to run an 8 pitch on the 6s but only use a 60amp esc, then Id highly suggest using the 12x8 apc tractor and pusher to keep amps down some:
12x8 pusher: http://www.horizonhobby.com/products...-ep-APC12080EP
12x8 normal: http://www.horizonhobby.com/products...x-8e-APC12080E

That would give you the speed you probably want, without as much stress on the motor/esc

badazzgti03

My Feedback: (4)

Thanks Kahloq
ill be ordering up some more props

spitty

Hello all experts,
I'm just before installing all the radio stuff in my Mossi.
After reading the complete Thread I know, that the CG should be around 119 mm inside, means , between fuselage and
nacalle.But please confirm:

That' while the gear is UP !?

Thanks in advance
Andy

cathurga

spitty, I am certainly no expert, but the general consensus is that the CG should be measured between fuse and nacelles, yes.

I am also working on the CG at the moment, and I am currently sitting at 110-112mm at the same place. All measured with the wheels up. I could also do with an experts opinion on how it will fly with the CG as far forward as it is now? I am reluctant to move it right now, but if people think that is too far forward, then I might have to. :-(

Here is the really concerning part....she weighs in at a BEASTLY........wait for it......15lbs or 7Kg's....... I really dont know where she got so fat, but I think I may have to do something about that.....like fly her!

LOL

kahloq

PLEASE read.....CG on this mossie needs to be 108 -112 from LE against the fuse not 110 OUTboard of the nacelles.

The manual is wrong. It showes 110 or so outboard of the nacelles and that would put the cg at roughly 130mm from LE against the fuse...super tail ehavy. Trust me I know...Ive flown this plane. Friend of mine set his to the manual and measured outside the nacelles and lost it cuz it was tail heavy. He built another one and set it where I said and it flew just fine.