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LabTech
11-02-2005, 02:53 PM
What would you use to replace a power pod norvel .061 nitro 25%. You would have to keep the weight issues close to the same. Im helping to set up a program that has already taught 400 7th grade girls how to build and fly thier own rc power gliders (see profile pic). Its a national program called STEPS. The planes are dow blue foam wings and poster board fuse about the size of a Gental Lady. Im guessing an outrunner with a 8 amp controler and 2 650 lipos. I need your input real fast! Thanks this is a wonderful program!

fdix
11-02-2005, 03:53 PM
What is max total weight for the power system?

LabTech
11-02-2005, 03:57 PM
I would be replacing the tank mount w/nitro the standard 4 cell receiver batt and the norvell .061. Ill try to get some measurements up.

LabTech
11-02-2005, 04:13 PM
Norvel engine and APC 6x2 prop-92 grams
25% Nitro load 9 grams
4 cell 600 mah flight batts 89 grams

190 grams or 6.7 Oz

Dr Kiwi
11-02-2005, 05:09 PM
Custom CDR 20mm billet motor ('hot wind') = 26g
2s TP 730 Prolite = 34g
6x5 Aeronaut prop and adapter = ~10g
Total = 70g

6.9v, 7.45A, 51W, 10710rpm, 50.7mph, 229g, 8.06oz, 4.49g/W

This removes 120g from the AUW - I reckon this should be a great improvement?

Cheers, Phil

watt_the?!
11-02-2005, 06:44 PM
yeah but the norvel puts out 240W.

so we need to know the AUW of your plane please.

LabTech
11-02-2005, 06:46 PM
Doc that does sound very nice:D I have to build up at least 5 units.I am conserned if one of them were to get wacked by a novice not much repair parts available on a cd moter. I was hopeing for some sort of electrefly type of outrunner. Something off the shelf, stuff that would be a fair replacement for a norvell .061. Something I can tell my bosses its 52.99 or (watt ever) lol The Norvel engines run about 3 min. and the planes are mostly specked by then. The Girls then glide them in hopefully.

LabTech
11-02-2005, 06:49 PM
Can you do a conversion like that? What formula did you use for the 240 watt 1/3 hp?

watt_the?!
11-02-2005, 06:58 PM
Can you do a conversion like that? What formula did you use for the 240 watt 1/3 hp?

YEP.

either way you are replacing this, which dynos at up to 1/3hp with a 50W system.

at 50W you are looking at, of course, 1/15th hp.

LabTech
11-02-2005, 07:02 PM
Ok then it should be easy to get an outrunner system running the same 240 watts for say 3 min right?

LabTech
11-02-2005, 07:04 PM
That is if a norvell is outputting 240 watts w/25% nitro with a 6-2 prop....

watt_the?!
11-02-2005, 07:05 PM
That is if a norvell is outputting 240 watts w/25% nitro with a 6-2 prop....

and there's no reason why it wouldnt be..what rpm have you got? that'll tell us. (0.3hp is about 25000rpm...i.e. fast)

edit: ok i just checked it and at 22500 you should have 0.31hp...so since your prop needs 25500rpm for 0.31 hp, then the two curves line up somewhere between 22500 and 25500....assuming thety dont intersect before that...

that's where my money is.

LabTech
11-02-2005, 07:26 PM
Ok that fits the Norvell specs:

Displacement.061 cu in (1.0 cc)2Weight1.83 oz (52 g) incl. muffler3MufflerIncluded, Rotating Exhaust Outlet, Pressure Tap4Glow PlugFreedom XL Included5Cylinder Piston SetRevlite AAO (Aluminum piston, Aluminum cylinder ceramic-coated)6Voltage1.5 V7Fuel Consumption8.45 fl. oz./hour (250 g/hour)8Fuel0-35% nitro9Bore.44 in (11.25 mm)10Stroke.39 in (10 mm)11Compression Ratio9.5-11.012Horsepower0.31 at 22,500 rpm

LabTech
11-02-2005, 07:32 PM
Can you all recommend something meet or beat the .31 HP available off the shelf. We typically have 60 some flights in 2 1/2 hours. How fast can I recharge a lipo set? Will 6 tritons do that or is something better?

watt_the?!
11-02-2005, 07:51 PM
just let us know the AUW of your plane as it is...i.e. including the engine and stuff...then we can do the assessment.

oh, and to answer your question..yes..something delivering 10V and 20A or so should do the trick...but that is a big assumption without knowing AUW.

LabTech
11-02-2005, 07:54 PM
The AUW is about 666 grams. Gosh I hope thats not an Omen:) that is just the fuse, wing , servos wireing. Total rough flight weight is 855 grams some 30 oz......

watt_the?!
11-02-2005, 08:07 PM
The AUW is about 666 grams. Gosh I hope thats not an Omen:) that is just the fuse, wing , servos wireing. Total rough flight weight is 855 grams some 30 oz......

as long as your name isnt Damien then we should be ok.

my guess is you'll need at least 20oz thrust..we can work backwards from there.

20 oz thrust is an 8 x 4 prop at 1000rpm or a 9 x 5 prop at 8000 or a 10 x 6 prop at 6500.

himax 2025-4200 and 5.33:1 gearbox draws 14A on 10 x 6 prop and delivers 7000rpm for 24 oz thrust...thats the ticket right there,.

or anything similar.

LabTech
11-02-2005, 08:14 PM
The engines are swapped on each plane with a sig power pod. I would have to adapt the motor and batts to the power pod. I was thinking an outrunner might work better than a gearbox. Im not sure how big a prop I can swing on top of the wings. 8" prop is pushing it....

watt_the?!
11-02-2005, 08:20 PM
urrrghhh..thought we had it sorted...

typhoon micro 15/10 with 8 x 5 prop.
3s lipo.

LabTech
11-02-2005, 08:28 PM
ok heh then who makes a controller for that puppy. And do you have a web site for typhoon? Also again (I know I'm dense) how fast can I charge the 3s pack and who do you recommend that can handle say 15 flights (3 min run time long) in 2 1/2 hours?

watt_the?!
11-02-2005, 08:31 PM
you could get 2 flights, maybe 3 out of each pack..so youll need to get hold of about 5 packs and have a couple on charge...2000-2400mah 3s lipo.

www.rbckits.com (http://www.rbckits.com) make the typhoon..its a good motor.

you could also have a look at something from justgofly.com

tim

LabTech
11-02-2005, 08:34 PM
Thanks Tim hope you have a nice flight soon. You have been very helpfull!

JustGoFly.com
11-03-2005, 12:51 AM
Hi - I need more information on the weight of the plane but seems you are looking for something that is not an amp hog and since your flyers are newbies they are likely not looking for 25,000 RPM on a bullet of a plane.

Check the JustGoFly 450XT. It's capable of driving a large prop direct drive and will provide enough power for a 2 lb plane at less than 100 watts per lb. If you'd like to compare conversions with one of my customers drop a note to the gentleman at the bottom of the 450XT page and ask of his experiences with this motor and watch his video:
JustGoFly 450XT VIDEO of 49" 29 oz gas Conversion .25 (http://www.rchobbyhub.com/modules/g...10/FWTA152a.asf)

Many other options are available - but I need to know:
1) Plane Weight - specify if it's flying weight.
2) Battery capability (mah, C rating)
3) Desired flying experience - 40-50mph, 50-70mph, 70-100mph, 100 + mph
4) Thrust desired

Take a look at our motors - they are extremely popular:
http://www.JustGoFly.com

Vinnie
JustGoFly

Dr Kiwi
11-03-2005, 02:18 AM
Sorry Guys,

I realize that I misunderstood the size of this aircraft - in the initial post there was mention of an 8A ESC and 2s 650 Lipos, and I understood a limitation to 6" prop size - how one gets 240W @ 22,500rpm out of THAT I don't know????????

Cheers, Phil

LabTech
11-03-2005, 12:50 PM
I would guess the plane with a Norvel .061 tuned correct is capable of a 10 to 15 degree climb in low winds. At 15 MPH headwind those planes just about stop. Based on that I'm guessing they run out about 20 mph under power. If the girls have built the airframe well straight and true they are up around 400'(AMA rules :) ) when the Norvel runs out of gas. An expert pilot takes the plane to the best of thier ability to the highest they can obtain. Then they give the radio over to the girl to attempt to land back at the field. Currently the planes weight is around 2 LBS AUW. I am trying to get the program to switch to electric power. I belive they can get the girls more flight time, get up in the air faster, and stay close or less than the the original AUW. We swap in a "radio pod" in every plane and put a "engine pod" on every plane. We take them out after they fly and the girls then have a glider to take home and show the family and friends what they have made in a few days.

LabTech
11-03-2005, 12:54 PM
Here is the originator of the STEPS program.

http://www.uwstout.edu/ctem/steps/

We are just one of many universitys reaching out to the young ladys. I am one of the persons responsible to give them "expert help" HA -thanks for all your help I am out there a bit on this.

savydad
11-19-2005, 07:36 AM
One thing I might add, which is beyond me why noone else has mentioned it...You are working with young students, first time r/c fliers, and talking about using lipos????????? From my understanding, lipos are not something to be taken lightly when crashed/shocked. If there is no "budget" for this program that is awesome, but if there is, then there should be concern on replacement packs when they do get crashed, as well as the safety concerns of storing these crashed packs. Well, I read through the thread thinking this, and saw one of the last posts that an experienced pilot flew them up and the girls land them, but that still leaves an opportunity for them to be crashed. Maybe I'm off my marbles, maybe not.

Todd

LabTech
11-23-2005, 07:16 PM
There is consern for budgets and saftey is also an issue. These planes in general are gliding in at a slow rate. Thats not to say a few have had more trouble; but in general they are real floaters. I realize that you dont just throw a damaged pack in the back of a bus:)