scudrunner77

I hang my head in shame and admit that I have converted what was a 1/2a screaming, streamer cutting, beast of a combat wing know as the "bulldog" into a E-powered park flyer. I did this primarily to have a plane to take on the road and not have to deal with all the glow stuff. I flew it at the cost on a bluff and also let a friend fly it for his first ever RC airplane experience. He did very well despite the wind. It actually weighs an ounce less now, so thats 11.75oz with 360 square inches. It's a real floater and easy to fly. I used a GWS brushless motor on 7.4v with 8x4 prop. It maintains level flight at 1/2 throttle and will climb in a thermal. I'm pretty surprised at how well this wing flies at both ends of the spectrum.

flyswatter

It looks like a good flyer and fun, sr. The wing looks great in the air and that is a beautiful place to fly. Makes me envious!

combatpigg

My Feedback: (3)

SR, I didn't know you gave your PitBull a sex change operation! How does "it" [no longer a "he"] compare with the Norvel? Is it still combat-capable?

scudrunner77

It's definitely been neutered... It's probably lacking a 1/3 the power from where it was with the Norvel. Maybe even worst then that, but if you want a relaxing/training wing it's not a bad setup. I'm sure you could do combat with it. It would probably be similar to the larger SSC wings you have as far as speed and action go, but flight times would not be very long unless I got a bigger battery. Here is a pict of the motor install. I consider this a down and dirty temp setup (cause I still want to do more 1/2a combat[>:]) so I just electrical tape a 900mah battery behind motor to the sticks. I think it would take all of about 10min to convert it back and forth....

BMatthews

The big question should be how many watts are you running. You need to compare apples to apples insead of apples to cucumbers. Without matching the apparent Norvel watts with the electric there's no way to really say that it's better or worse.

Any idea what power you're running with the setup as shown? Or just amp draw?

rainedave

My Feedback: (1)

According to the GWS site, the 8x4 on a 7.4v battery draws 10.4 amps, 13.4oz of thrust and 76.96 watts. That's assuming he's using the GWBLM001 motor which is what it looks like in his photo.

http://www.gws.com.tw/english/produc...r/gwblm001.htm

Just jumping to 8.4v would give 105.84 watts. That worth the extra battery weight.

combatpigg

My Feedback: (3)

I think the comparison that means the most is how well the power plant can make a plane like this climb. The other comparison that matters to me is how much it costs to get that level of performance.

rainedave

My Feedback: (1)

I'm with you on the cost of electric factor. The brushless/lipo route can hit $150 to $200 very fast. But, the GWS stuff is very affordable. Their brushless motors start around $14. You can get a GWS motor, ESC and NiMH battery for under $60.

scudrunner77

The motor raineday posted a link to is the one, so those specs should be close.

Bruce do you know how may watts a nice running Big Mig 061 on a 6x3 puts out?

If you want to rate in on the climb-o-meter it climbs well but does not have the vertical it did with the Norvel.

scudrunner77

My set up could be done for $53

GWS Brushless $14
900 mah 7.4 lipo $13
Castle Creation Thunderbird 9 ESC $26

combatpigg

My Feedback: (3)

There isn't much difference in price between the brushless set up and the J250 racing idea, then. Right now it is getting harder to put the words "racing" and "J250" in the same sentence, with the performance I've been getting.

rainedave

My Feedback: (1)

Another option is the GWS direct drive brushed system spinning a 6x3 prop:

http://www.gws.com.tw/english/produc...tem/edp400.htm

The performance is very similar to sd's brushless setup.

KidEpoxy

boy, sure would be nice to have a stickied thread with the Watts of some common 1/2A engines.

Or at least get the electricts to turn the props used on the nitros & post the rpms.
It doesnt really help knowing the rpm of a big orange 5x3 since we cant compare it to the little apc/mas 5x3. Even the E-Only apc would give different numbers than the nitro one. Sure we cant directly read the efficiency of a geared slowflyer prop to a 20k 5x3, but some basic Apples to Apples rpm would be nice

Somebody bolt a non-electric prop on them cans and check the rpms.

Raymond LeFlyr

My Feedback: (2)

I finally received my Hong Kong J250 motors. Hooked one up to a 910 mah, 2-cell pack with the prop that Bipe recommended and the results were - lotsa air! I have cut out a Blue Albacorde to test a pusher configuration and plan to try a tractor 24-inch delta too. But I have a passle (or is that, passel) of family arriving this afternoon so I will have to hold up further "work" til next week. But initial results with the J250 are encouraging.

However, I could be talked into the brushless GWS route too. Jeeze youse guys are tough to please.

boberos

Raymond,
You are gonna like that Albacorde. Awesome flier with no bad habits. Just don't trust it to a park flyer receiver like I did. This plane gets real far, real fast. (read out of range)
Bob G

rainedave

My Feedback: (1)

KE, I will put an APC 5.7x3 on my GWS direct drive S400 and tach it. I will try it with both an 8.4v NiMH and a 9.6v NiMH, both are 650mah. Wouldn't it be great if it topped 16,000! But I really doubt it will.

rainedave

My Feedback: (1)

Ok. The 8.4v 650mah NiMH battery pack turns the APC 5.7x3 at 14,900. It turns the Cox gray 6x3 at 12,600. It turns the orange GWS 6x3 at about 14,750.

I have an old Ace analogue Tachmaster II, it's not digital, so I'm reading the needle as best I can. My readings are within 100rpm or so.

As soon as my 9.6v battery finished charging I will re-test. I think it's safe to predict that the APC 5.7x3 will top 15,000 on this battery.

This actually out turns some of my old Babe Bees on 25% nitro, which did around 14,500 the last time I tached them.

Should I try a Cox gray 4.5x2? The problem is, this motor system is a lot heavier than an .020, so that's not a practical prop to use.

BMatthews

There's another factor to consider as well. The thrust of the GWS setup looks good until you realize that there's not much pitch speed to work with due to the prop and limited RPM's

I have to suck it back and say that the climb measure is probably the best way to compare performances. Either that or a direct drive motor running the same prop as the engine. If it can turn it to the same RPM then you have the same performance.

rainedave

My Feedback: (1)

My 9.6v battery finally finished charging. I got between 15,500 and 16,000 with the APC 5.7x3 prop. The little markings on my Ace Tachmaster are in 500 rpm increments and the needle sat right between those two readings. So I'm going to say it turns the APC at a steady 15,750. That's not too bad for a $9.29 motor. I am confident that it will fly my Randolph Bee-Tween very well.

http://www2.towerhobbies.com/cgi-bin...?&I=LXHHN1&P=0

I just wanted to add that the APC 5.7x3 that I used is a GLOW prop, not an electric one. I'm trying to remember what people were getting with the AP Wasp .061 throttled engine. I seem to remember it being around 16,000. The ESC provides very smooth reliable throttling of this little GWS motor. The drawback, of course, is that performance starts to drop as soon as you start draining current from a battery.

scudrunner77

raineday- Thanks for all those numbers. I think it's a fair way to compair glow to electric... by checking the RPM of the same prop on both types of power.

KidEpoxy

"raineday- Thanks for all those numbers. I think it's a fair way to compair glow to electric... by checking the RPM of the same prop on both types of power. "

Ditto here, Thanx for the research & report.

I'll just put SR77 & Bruce's posts together, and say
It is a fair way to compare glow to electric, if the electric will be run direct (ungeared)

rainedave

My Feedback: (1)

First, SR77, I didn't mean to hijack your thread![X(] I get carries away so easily with this hobby sometimes.

Somewhere I have a few Cox gray 5x3s but I put them somewhere for safe keeping; know what I mean? I really want to see what that prop will turn at. This motor is brand new and not broken in yet. Plus, I'm going to assume that electric motors unload in the air, too, so an airborn, boken-in motor should top 16,000; that's only about 300 more rpm. A real test would be to put this setup on a DNU and directly compare its flight performance to one with a Babe Bee.

combatpigg

My Feedback: (3)

I'm still not buying the comparison, if you are adapting a glow prop to an electric motor. Reason being, you are handicapping the electric motor if it will turn a thinner E prop with better results. I still believe the best comparison would be with the thrust-o-meter or in the air with a plane that weighs close to the thrust output of the combos being tested.

rainedave

My Feedback: (1)

CP. I agree that thrust and actual flight are the best tests.

What surprised me is that the APC 5.7x3 glow prop actually spun faster than the orange GWS electric prop that came with the motor. I also believe that the APC produces more thrust than the thin, flimsy orange prop. For one thing it does not flex and twist like the orange one does.

I just read an article where someone bought a cheap digital Walmart fish scale and attached it to the tail of his plane to test different props. I don't go into that store, but maybe I can find another place that sells them. It would be a good tool to own, even though I haven't renewed my fishing license in twenty years.[X(]

rainedave

My Feedback: (1)

I think this is one he used:

http://www.walmart.com/catalog/produ...32573917502498