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Old Mar 02, 2013, 10:04 PM
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Fast forward nearly a year and there is more to the story! I've finally gotten around to assembling my Espadita and found some new information that can explain the lighter figure quoted by SMM. Cody states the best CG is not at 74mm as recommended, but at 87, which is over 1/2" farther aft than recommended. This requires moving the ballast case back so the tow hook comes out about 85. 1/2" is a long way back. I'll know in a couple of days what the flying weight will be at 85-87mm. I have to finish installing the left wing servos and then I can balance the plane. I'll keep everyone posted.

I'm using the 809 servos and they are pressing on the skins. There is a notable outline on the skin. I even sanded the servo sides as much as possible but the aluminum cooling band doesn't sand well and I don't know how thick it is. It's frustrating to get a $1400 airplane with bumps in the skin. I doubt anyone would have noticed if the airfoil was .5mm thicker to allow the servos to fit without a shoe horn or having stress marks in the skin. This is too nice of a plane for stuff like that! YMMV

Finally (for now anyway), why didn't he just make the nose 1" longer? This would have brought the plane into a much more acceptable weight, the 35 ounces quoted by SMM. I doubt any competitor would have even thought of a Sprite if they knew they could get the Espadita at 35 ounces w/o any form of magic. I know plane design is a series of compromises. When you pick up the individual parts of the Espadita, they are very light and strong. Would it have hurt to extend the nose a bit to get the overall weight down? I don't think so. So it's back to the drawing board to come up with a nice, mid-30's molded 2M for US TD pilots.

I hope to get my hands on a Sprite to do some comparison. I know assembly takes longer and more thought and skill is needed to do a nice job, and you get a bagged tail set which isn't as dent resistant as a molded stab and that for me is a turn off. For an $1150 finished plane, I'd like to have molded parts please. Also, I'd be concerned about the stab halves at slope and DS speeds. You have to buy the "Hot" if you want slope speeds at higher ballast weights. It's too bad you need 2 sets of wings for the Sprite to do both thermal and slope. Surely a compromise of dihedral and extra carbon for the "regular" version to make it as strong as the "Hot". Choices, choices!

George
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Old Mar 03, 2013, 08:25 AM
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Quote:
Originally Posted by gavoss View Post
Fast forward nearly a year and there is more to the story! I've finally gotten around to assembling my Espadita and found some new information that can explain the lighter figure quoted by SMM. Cody states the best CG is not at 74mm as recommended, but at 87, which is over 1/2" farther aft than recommended. This requires moving the ballast case back so the tow hook comes out about 85. 1/2" is a long way back. I'll know in a couple of days what the flying weight will be at 85-87mm. I have to finish installing the left wing servos and then I can balance the plane. I'll keep everyone posted.

I'm using the 809 servos and they are pressing on the skins. There is a notable outline on the skin. I even sanded the servo sides as much as possible but the aluminum cooling band doesn't sand well and I don't know how thick it is. It's frustrating to get a $1400 airplane with bumps in the skin. I doubt anyone would have noticed if the airfoil was .5mm thicker to allow the servos to fit without a shoe horn or having stress marks in the skin. This is too nice of a plane for stuff like that! YMMV

Finally (for now anyway), why didn't he just make the nose 1" longer? This would have brought the plane into a much more acceptable weight, the 35 ounces quoted by SMM. I doubt any competitor would have even thought of a Sprite if they knew they could get the Espadita at 35 ounces w/o any form of magic. I know plane design is a series of compromises. When you pick up the individual parts of the Espadita, they are very light and strong. Would it have hurt to extend the nose a bit to get the overall weight down? I don't think so. So it's back to the drawing board to come up with a nice, mid-30's molded 2M for US TD pilots.

I hope to get my hands on a Sprite to do some comparison. I know assembly takes longer and more thought and skill is needed to do a nice job, and you get a bagged tail set which isn't as dent resistant as a molded stab and that for me is a turn off. For an $1150 finished plane, I'd like to have molded parts please. Also, I'd be concerned about the stab halves at slope and DS speeds. You have to buy the "Hot" if you want slope speeds at higher ballast weights. It's too bad you need 2 sets of wings for the Sprite to do both thermal and slope. Surely a compromise of dihedral and extra carbon for the "regular" version to make it as strong as the "Hot". Choices, choices!

George
Why didn't you use the 3150 servos which the plane is buildt around???
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Old Mar 03, 2013, 09:41 AM
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Servo check! Ok, I looked at the differences between the Airtronics servo and the Futaba. You can see the #'s below. The Airtronics is .5mm thicker, weighs less than 1/2 of the Futaba, has 11 ounces less torque at 6V and is over 2x as fast as the Futaba. The Futaba can't be run at 6V.

I based my choice on SMM recommendation so I guess it's my fault for not looking at the servo thickness. Still, I am really hoping that I can get close to the 35 ounce weight called out by SMM. I hope that explains it.

Airtronics 809
•Weight: 0.38 oz (10.8 g)
•Dimensions: 0.93x0.45x0.83" (23.5x11.5x21mm)
•Torque: 35 in/oz @ 4.8v, 39 in/oz @ 6.0v
•Speed: 0.12S/60° @ 4.8v, 0.10S/60° @ 6.0v

Futaba 3150
Speed: .24 sec/60° @ 4.8V
Torque: 51.4 oz-in @ 4.8V
Dimensions: 1.2 x 0.4 x 1.1" (30 x 11 x 29mm)
Weight: .81oz (23g)
Power Supply: 4.8V (Futaba does NOT recommend using 6V)
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Old Mar 03, 2013, 10:47 AM
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Greeley, Colorado, USA
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George,
The 809's will fit OK if you sand them enough.
Like you said, they don't sand easily, but can be done if you're patient.

Lenny
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Old Mar 03, 2013, 11:05 AM
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Lenny, can you confirm the 87mm CG?
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Old Mar 03, 2013, 11:17 AM
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Servos are all in place. I only lack soldering up the plugs for the wings and it;s ready for balance.

Like many, I always look back and think of what I would have done differently on the next install. If you use the factory hardware, there isn't much you can do in the fuse. On the other hand, if you make your own servo tray from CG-lined light ply, you can kill 2 birds with one stone by having a lighter tray and strengthening the fuse at the same time. This strengthening is needed ONLY for US contest type landings. The plane is fine as is for non-dork landings.

For the wings, I'd do what Lenny recommends and sand the servos more judiciously. I did sand the servos on the left wing and they went in much easier. I would also look around to see if I could find another servo with similar torque and speed as the Airtronics 809's that is .5mm thinner and could take 6V.

Other than that, there really isn't much else to do as the engineering is there to make install very simple. I'm sure I could do another in a few hours, like 2! There is some pucker factor sliding the servos into the wings as there is no easy way to go back short of pulling on the servo wire but the 2nd wing goes together really easily. I'll have plenty of hints in the full review coming up here on RCG. George
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Old Mar 04, 2013, 05:30 PM
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OK, now for the bad news. I weighed everything today and here is what I came up with:
Wings: 290g each or 580g total
Fuse with servos, wing rod, wires, RX, and ballast box: 338g
Stabs: 31g
Battery pack: 127g
Total ready to balance is 1076g or a hair short of 38 ounces
I expect to have to add at least 3 ounces to get the CG at 84mm which will make the plane fly at 41 ounces.

I don't see any way to get it any lighter. George
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Old Mar 06, 2013, 12:46 PM
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Geez

this Model exits 5 years and people still complain over the weight and discussion GC's and write a review to make a few bucks?
Sure they want a durable, but realy light Allrounder that can win 2m TD competion and excels on the slope.
In addition the Price has to be low as well.


m2c

Thomas
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Old Mar 06, 2013, 01:08 PM
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Ireland, County Kerry, Kerry
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Quote:
Originally Posted by gavoss View Post
(Futaba does NOT recommend using 6V)
No one has taken any notice of that old warning for years now. 3150's work fine on 6v.

Chris
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Old Mar 06, 2013, 01:36 PM
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Originally Posted by Woodstock 1 View Post
No one has taken any notice of that old warning for years now. 3150's work fine on 6v.

Chris
Chris

possibly the misleading servo information about the S3150 is also 5 year old news.

Cheers
Thomas
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Old Mar 06, 2013, 03:25 PM
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Futaba is the one that states the 3150 shouldn't be used at 6V. I guess they don't know their own product, right?

As for the Espadita's weight, there is no way anyone is going to get a production model down to 35 ounces. I'm over that with just the servos and RX installed. Does that make the plane bad? No it doesn't. But it does keep it from being the ultimate 2M tool for US contests. We went through this with SuperV's. A 33-36 ounce SuperV 2M was the perfect 2M at that time. Those with over 40 ounce planes were getting whipped in the early morning rounds. When the wind came up it didn't matter as much, but any contest pilot knows, drop one round and you are just fun flying.

For some, fun flying is fine and that's where the Espadita is. I don't know how Cody got one to 35 ounces. I'm using the same equipment he did and I"m at 38 ounces ready to balance. Figure at least 3 ounces in the nose to get 84-84mm and I'm at 41, not 35 as advertised. If one buys an Espadita he should know up front he's not going to get a finished 35 ounce plane. If the plane is bought for fun flying and slope, this might be the right plane, but for serious US 2M competition, it's too heavy for early morning rounds.

As for the reviews I write, lots of times I buy the plane, like I did with the Espadita and I get infinitely more money with each review I write on RCG...that's zip, nada, ninte, NOTHING. Nothing but the joy I get from helping modelers see a product in its true light. I don't fluff them up, I tell it like it is, but nicely. The point is, if you expect to get an Espadita at a flying weight of 35 ounces, you'll be disappointed. George
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Old Jun 06, 2013, 04:37 PM
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I almost got to fly the espadita at torrey pines untill this happened.
Espadita crash at Torrey Pines (1 min 26 sec)
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Old Jun 10, 2013, 07:29 PM
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Quote:
I almost got to fly the espadita at torrey pines untill this happened.
I found out it fits smaller slope better anyway
2m on a big slope flying fare out...
Triple 20 with Esapadita (4 min 3 sec)


Cheers
Thomas
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