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Old Apr 14, 2001, 12:29 AM
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Canton, Ga. USA
Joined Apr 2001
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Ultra Sport 40 conversion to electric

I've been flying this plane a while with a IC Fox 50. I'm new to electrics. Any Suggestions on an Electric motor/battery for conversion. Anyone done this?
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Old Apr 14, 2001, 08:59 AM
Lipoly Killer
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Gulfport/Biloxi Biloxi Reg, Mississippi, United States
Joined Dec 2000
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Johnny, there's a number of motors available that would be suitable. I imagine with the Fox 50 that you are wanting good performance in your electic conversion. I have experience with two good combos-Astro 40G and the MaxCim 13Y with 24 and 20 cells, respectively.If I had to make a choice, I'd go with the MaxCim, 3/1 ratio(or higher), 20 Panasonic 2000 Nimh Cells and an APC 14/10E prop. Yes, it's expensive, however, it has the capability to be used in a number of applications. I would also think seriously about getting the MaxCim and using the Astro gearbox for the MaxCim.You can't change ratios at the field, however, the Astro is pretty much bulletproof.
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Old Apr 14, 2001, 03:32 PM
Our Daddy and Heli Junkie
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Johnny, welcome to the Zone

A good place to start with any conversion if you are new is to post the specs for the plane. Some of us may know them, most won't.

You will want at least 50 watts a pound for good power. That will be the AUW including batteries.

For lots of basic information, go to the FAQ link above. It will explain watts-amps-gearing-chargers and such.

Good Luck and lets see the specs!
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Old Apr 14, 2001, 03:36 PM
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Oh, and my idea for the setup, if it is an 40 sized IC plane.

Astro Flight 15 with a superbox. 12-8 prop and 14x2400 nicad cells with a Castle Creations Pegasus 35 ESC.
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Old Apr 14, 2001, 05:37 PM
gwh
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Fort Worth, Texas
Joined Dec 1996
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Frank is right on the target. I would recommend the Maxcim on 20 cells. For the type of performance you are used to with the fox you will want a system propped for about 100 watts per pound.

For an example of what the Maxcim is capable of take a look at the AVI on this web page: http://home.texoma.net/%7Ehubbard/ss40.htm

The plane is a World Models Super Stunts 40. It has a 66 inch wing span. I am running a Maxcim Y wind on 20 cells, 3.53 gearing and a 16*10 prop.
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Old Apr 14, 2001, 08:19 PM
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Canton, Ga. USA
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Thanks for the Help. The Plane is a Great Planes Ultra-Sport Tricycle config. Wingspan: 55". Box says finished weight is 6 lbs, but I still need to weigh it. 566 sq in wing area. At 6 lbs, I'm calculating wing loading at 24.4 oz/sq ft. The Maxcim motor sounds good to me. I'm using a 11x6 APC prop now. I'm afraid a 14-16" prop may be too big(It may be smacking the ground :0 )
Any suggestions on a AC/DC charger?
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Old Apr 15, 2001, 03:47 AM
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Not putting the Maxcim down, but the AF setup is about 1/2 the price. I fly a similar size plane on an AF05G and get very good perfomance.

You could also go Aveox, like a 1409/3 with a superbox or an F12 or F16.
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Old Apr 17, 2001, 12:29 PM
Lipoly Killer
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Gulfport/Biloxi Biloxi Reg, Mississippi, United States
Joined Dec 2000
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Johnny, here's what I'm doing with my GP Giles 202: I'm replacing the hard 3/32" wing ribs and spars with contest balsa. I'm also substituting contest 1/16" balsa for the sheeting. I'm replacing all of the lite ply in the fuse with 1/8" contest balsa. You don't need the ply for an electric.I also suggest that you forget the trike gear and go with a Dubro plastic gear mounted in the fuse just ahead of the wing.You could even go lighter and make a carbon fibre gear ala the new FM article.When you use the Dubro gear, you automatically gain prop clearance and they are tough!
I guess that all of this sounds extreme, however, it's really simple.You have made an expensive investment in the motor and batteries so why not take full advantage of it? These mods should about equal the power of the Fox 50.
I put the Dubro gear on my TaiJi, after removing the retracts, and with wheel pants, it looks really sharp. If one of you guys would instruct me how to send a digital picture to the ezone, I'll share!
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Old Apr 21, 2001, 12:17 PM
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Canton, Ga. USA
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The plane is already built. I'm not sure I'm up for all thoses modifications. I'm currently building a 60 size Royal Zero. I'll take your advice on replacing some wood with contest balsa on that one. Any idea where I can get those Panasonic 2000 Nimh cells? Can I use a smaller prop, say a 12/10, and go with a lower gear ratio 2.5/1?
I'll try to post a picture
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Old Apr 21, 2001, 08:32 PM
Lipoly Killer
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Gulfport/Biloxi Biloxi Reg, Mississippi, United States
Joined Dec 2000
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Johnny, I got my Panasonics from SMS. Check the EZONE links for web address. Greg gives great service so you won't be disappointed.

You could try the 12/10. Do you have a Whattmeter? Motocalc?
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Old Apr 22, 2001, 12:17 PM
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Oak Harbor, Washington, United States
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Johnny, if you want it to fly like an Ultra Sports should, you'll want 100 watts/lb. You have a couple of parameters that you need to allow for, the small prop clearance, and the fixed, (already built), weight.

A Maxcim system with its nearly unlimited gear ratio gearbox would be a good choice, but I'm not sure you can fit it in the sleek nose of an Ultra Sports because of the offset of the gearbox. Because of the nose shape, you might want to find a direct drive system for your plane. This would also fit your need for running a smaller prop.

We use gearboxes because they add versatility and effeciency, but if I were converting a .40 size Ultra Sport I'd be more concerned with speed and power even if it meant short 4 or 5 minute flights.

Of course, being an electric motor, you can add a gearbox to it for a later project that was built with electric power in mind.

Just my thoughts on the subject,

Norm
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Old Apr 22, 2001, 12:48 PM
Lipoly Killer
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Gulfport/Biloxi Biloxi Reg, Mississippi, United States
Joined Dec 2000
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Johnny, Norm's got some good points.Instead of converting your UltraSport 40 that's already built and limiting your choices a little, why not build a new plane and incorporate all of the suggestions that you find on EZONE? The chances are that you will have less frustration and probably take less time to build a new one instead of tinkering with a previous gas plane. Your choices for power systems automatically increases. Dereck advocates 10 cell systems as the most bang for the buck and I agree. He also flies the "big iron" set-ups and he was the inspiration for me going that way. A Astro 035, 05,15,25,& 40 are great. The MaxCim and Aveox motors are good. Castle Creations make some great combo's with Aveox motors.MEC makes a great combo. The car motors make a good inexpensive system that has only the drawback of less longevity(they cost less!).

There are a number of aircraft that you can build, some with less wood substitution than others. SMS sells a great 10 cell airplane, the FunFly 700 that was designed for electric, thus no wood substitutions are required.

I strongely urge you to consider all of your options before flopping down your money.Getting a good charger, a Whattmeter and access to a program such as Motocalc, will lessen the entry learning curve.

Sorry to preach, but I and the others on EZONE sincerely want for you to succeed and not have to go through the all of trials of trying something new.

Good luck!
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Old Apr 22, 2001, 03:40 PM
Visitor from Reality
United States, VA, Arlington
Joined Dec 1996
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Hi Johny
You could try a halfway house trick. Keep the wing, just build a new lighter fuselage to the same moments but alter the nose to take a geared motor. While you're whittlin', you just make a big top hatch to get at the nicad pack - taking wings off for recharge/pack swapping is a real PITA in a sports model and needs to hit the history books.

As the model is such a good flier, you'll have pretty much the same when you fly your electric, maybe a little faster to land. Lose the trike gear and fit a taildragger onto your new fuselage - that'll cover your prop clearance and lighten your model in one go. While you can make a custom gear easily enough, TnT just quoted me $27 shipped for a custom gear to my sizes - close enough in cost for me to let them do it.

GP fuselages are always on the 'adequate' side of structure weight, so you can add a lot of lightness with a new fus - I took eight ounces out of my GP CAP fuselage alone, and the one I started with was a stripped out version of the kit. All you need is the plan, a little building experience and less wood. 1/4" ply firewalls are only needed for folk whose powerplants vibrate and need whacking over to start, for one.

To make this baby move is going to run into 16 cells at a minimum, maybe that wing will haul 18 (great!) or 20 (WOW!). At 566 squares, it would be a good 16 cell if built down light enough.

When you start tinkering with these powers, its good economics to get the next up power rating - something rated at 500 watts while running at 499watts is liable to get all smokey, while 500 watts from something that can live at 700 will barely get warm.

Why do you think Frank, myself and many others run MaxCims? This kind of power does not come cheap though.

You're on the right track though, with a little work you won't lose performance when you lose the noise

Regards

Dereck
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Old Apr 23, 2001, 01:15 AM
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Oak Harbor, Washington, United States
Joined Jan 2001
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Johnny, I did a little research on this. What I came up with was a direct drive Astro 40 on 18 or 20 cells. Turning a 10 to 12 inch prop should get close to 700 watts. If you go with 2000 NimH cells you should be able to keep your weight to around 7 lbs., (strickly a guess here), to get about 100 watts/lb.

Now, having said that, I'm not experienced with flying an Astro 40 direct, nor using NimH cells, so I hope someone more familiar with this set up might step in and confirm all of this

As Frank said, you'd probably be happier just building a new project for electric and then have more options. Another probable problem with the Ultra Sport, will you have to remove the wing each time to replace battery packs??? That can be a real PITA.

Norm
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