ElectroStreak Ready for Covering

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Entropist
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ElectroStreak Ready for Covering

Unread post by Entropist » Sat Jul 10, 2010 2:20 pm

I think I started this kit in the last century, when electric planes were not so popular. Since finding this group, I've continued the project. I'm about ready to cover (pending servos somewhere between Hong Kong and Canada, or Switzerland, or Singapore or somewhere), and will use the original brushed motor, at least for a start. You can see from the yardstick in the back that the wingspan is about 44 inches. The ElectroStreak was discontinued by Great Planes, although a few seem to still be around on the web.

John
IMG_3776.JPG
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Re: ElectroStreak Ready for Covering

Unread post by steve » Sat Jul 10, 2010 4:02 pm

Nice build there...

I would guess that you wont have great success with that Brushed motor....

It looks like a speed 500 or 600 motor and with the weight of your plane, you may want to consider the Brushless type from the get go. With a 8" prop, she'll draw anywhwere from 18-22 amps. I have had several speed 600 brushed motors and I used an 7 cell 1050mah nimhs with great success but poor performance with anything made from balsa due to weight. I would guess, to have any power at all with that motor, your plane should weigh no more than 8-11 oz's and definitely go with lipos to reduce the weight of a nimh pack. A 2 cell would let the motor last longer but on 3s, you may get airborne with a bit more authority until it burns up. I have had "0" luck with running these motors with a 3 cell so others may have a different opinion.

Also, I could be absolutely wrong on this as it is just my opinion

Keep us posted on the covering.

It does look like a fast plane.

Steve
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Re: ElectroStreak Ready for Covering

Unread post by astroflyer » Sat Jul 10, 2010 4:59 pm

I built and flew one of those somewhere around 1990. It was my first electric plane. Wish I had it today with a brushless outrunner and lipos!!!

matter of fact my smaller stinger design is based on the electrostreak.

My streak was powered with an astro 15 direct drive, 8/6 prop and ten 1800mah nicads. It weighed 44 ounces, just over the 42 ounce weight suggested for this plane at the time. It was a rocket ship for six minutes. Very hard to land due to the weight and high landing speed. I regularly overran the groomed part of our runway to slam into the wall of tall grass at the end, often with some damage. far to heavy for this plane.

If I had it today it'd be at least a pound lighter with an outrunner and three cell lipo of about 2200mah.

I agree with steve's comments, brushed is not the way to go with this bird. The brushed astro 15 I used was miles ahead of a canned speed 600 or whatever in power, but even that motor cannot hold up to a smaller and lighter outrunner.
Last edited by astroflyer on Sat Jul 10, 2010 8:55 pm, edited 1 time in total.

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Re: ElectroStreak Ready for Covering

Unread post by Entropist » Sat Jul 10, 2010 8:05 pm

You guys are right, I'm sure, but here's what I'm thinking over:
1 - I've got all the parts for the stock build, the motor is fitted, assembling the power side would be short work in an evening;
2 - I can always convert later - who knows, maybe I'll have repairs, anyway;
3 - I'm not looking for maximum performance, still in learning mode;
4 - A brushless outrunner is going to require major chop and rebuild on a very nicely assembled nose;
5 - The weight of a brushless is going to be so much lighter the balance will be way off; and
6 - This is my first real build, I don't have the experience to mess too much- like picking a brushless and prop etc.
So, I might start covering from the rear and defer the power side until at least next weekend and get some in person expertise to talk it over. (Brian told me he thinks I bought the kit in 1999, so I guess a little delay would not be unusual, especially since there's a package from HK at the post office to divert me this week).
Thanks for you input, your continuing ideas are welcome.

John
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Re: ElectroStreak Ready for Covering

Unread post by retiredVTT » Sat Jul 10, 2010 9:10 pm

Hi John,

Next time we are out (looks like it might not be this Sunday) bring the fuselage. I'm thinking of all those outrunners that can be mounted internally WITHOUT the "X" mount. I may have something that would slip up into the fuselage from the bottom and bolt directly to the front former (firewall). For cooling purposes the front bottom should be left open for the first few inches, so we could have a look at how much room you have. An AXI 2814 motor comes to mind, maybe even a smaller 2804. Also you will want a rear vent in the fuselage bottom to release warm air from the motor and battery compartments.

Bill
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Re: ElectroStreak Ready for Covering

Unread post by Entropist » Sun Jul 11, 2010 2:32 pm

Bill,
Your expertise is showing, this might be a perfect alternative.
I Googled the 2814 and found a HobbyKing page with detailed dimensions on their equivalent. The diameter of the motor is exactly the same as the Goldfire. The motor is shorter, but might be exactly long enough to reach the second frame. If I understand their package on the web, I may be able to mount it with very little woodwork, possibly all internally.
The 2814 replacement is quoted at 106 grams, and I weighed the one that came with the kit at 214 g. I can probably get the COG in the right place with the batteries.
Ventilation is provided by a kidney bean shaped slot below the motor and behind the prop, and by an open tail about 5/8 by 5/8, and it would be easy to add more later, if required.
I can scan and send you the appropriate part of the plan in a private email if you'd like to have a look, but I will bring it next week with the fuselage. Given the power of this motor, I will not be flying it until I get more experience, but given the other comments about weight and landing, this might all make for an easier plane to fly.

Really appreciating the input from you all.

John
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Re: ElectroStreak Ready for Covering

Unread post by retiredVTT » Sun Jul 11, 2010 8:12 pm

Sounds good John...definitely bring it along! I'll bring an AXI 2814 motor as well.

The secret to most electric flight is to shed the ounces! Even though this one was designed for electric, it will likely fly that much better with a lighter wind loading, especially while your getting to know it's characteristics.

Many planes that were shelved are being revived with todays motors and lipo packs. I missed out on getting an ES when they were a stock item so I'm interested in seeing it airborne.

Bill
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Re: ElectroStreak Ready for Covering

Unread post by RocketManRC » Mon Jul 12, 2010 8:28 am

Hey John, you might consider an inrunner like this one which I have used before in my Funjet and Tom is using in his Easystar:

http://www.hobbycity.com/hobbycity/stor ... oduct=4201

It is the same diameter and hole pattern as a speed 480 brushed motor so it should be no problem to install. I think I have one in my collection so I'll put it in my toolbox so you could try it.

With a Turnigy Plush 40A ESC, a 6x4 APC prop and 3S-2200 battery it should go like stink.

Rick
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Re: ElectroStreak Ready for Covering

Unread post by Entropist » Mon Jul 12, 2010 9:55 pm

Rick, looks great.
Here's a shot of the plan. The motor is exactly 35 mm diameter, and the inrunner would fit comfortably. As I looked at the mounting options, I think it would be better as it would mount on the front noseblock and clear F-2. I haven't quite figured out the size code for these motors. I did find that the 2814 referred to the stator size, but I don't know how to jump to Speed 380 or so on. Anyway, that looks like a very viable option, and I'll bring the plane on the weekend (is this the field out the Beaverbank Road?), which now has covered wings, ailerons, elevator, rudder, maybe more.
IMG_3778.JPG

By the way, have to note that the plan for the ES shows that it was designed by Tom Stryker in 1987 - that can't just be coincidence, can it?

John
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Re: ElectroStreak Ready for Covering

Unread post by retiredVTT » Mon Jul 12, 2010 11:14 pm

There is another option...a Phaser 15/4 motor. Hobby Lobby used to sell them. They are a brushless motor and were the forerunner to the outrunner motor. 5mm shaft, built like an inrunner, the bolt holes up front are 28mm center to center, which I think makes it the size of the brushed 600. I have one you can have if it works.

There were made in the Czech Republic perhaps by the Mega people. This would drive a 9/4 prop on 3S and provide around 250 Watts using a 30 amp esc. This motor weighs 139 grams, is 40mm long and 36mm in diameter.

I checked the AXI 2814/12 that I have and it is heavier than the newer model that I find at the HL site. This one has a 5mm shaft, the newer one is quoted as 4mm. This one weighs around 150gms.

I don't have the weight of your ES but if I recall they were not exceptionally light. Perhaps around 32 oz maybe.

LATER EDIT...Well, look at this review of the ES arf...43 ounces..! And look what the motor UPGRADE was in 2002, none other than a Phaser 15/4 motor ....they were using an 8/5 folding prop..

http://www.rcgroups.com/forums/showthread.php?t=183050


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