Brushless Vs Cox and Norvel  
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All Forums >> RC Airplanes >> "1/2 A" & "1/8 A" airplanes >> Brushless Vs Cox and Norvel
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Brushless Vs Cox and Norvel - 6/28/2008 9:28:11 PM   
Cashpoboy


 

Posts: 64
Joined: 8/8/2005
From: Bedford, TX, USA
Status: offline 		I have some Tee Dee 051 and a Norvel 061 and would like to know if brushless motor power to weight compares to these piston screamers.

I have a couple of 1/2A racers and would like to go brushless unless I can really go faster with the Cox or Norvell motors. Will the brushless setups compete with these little screamers or are Norvel and Cox quickly becoming dinosaurs?

I really like the no fuss motor setups and cleanness of it all but hey they are racers and speed is the name of the game.

       Post #: 1

RE: Brushless Vs Cox and Norvel - 6/28/2008 9:56:08 PM   
combatpigg



Posts: 9826
Joined: 11/22/2003
From: arlington, WA, USA
Status: online 		If you want to go really fast with 1/2A glow power, you'll need to run $150 combat or free flight engines. That is a better comparison to brushless performance than comparing with a Cox or Norvel. If the plane is small enough, clean enough to take advantage of a 4.2x4 APC, figure on an engine like a Fora or Cyclon able to turn it 32,000 on the ground.

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RE: Brushless Vs Cox and Norvel - 6/28/2008 10:09:45 PM   
Cashpoboy


 

Posts: 64
Joined: 8/8/2005
From: Bedford, TX, USA
Status: offline 		Thanks combatpigg for the info.

So if I follow you correctly you are saying that the brushless stuff would outperform the TD and the Norvel?

I want to switch to brushless but not if it is going to be a step down in speed from what I already have.

I don't need to go faster just don't want to go slower.

What do you think?

(in reply to combatpigg)
       Post #: 3

RE: Brushless Vs Cox and Norvel - 6/28/2008 10:20:40 PM   
combatpigg



Posts: 9826
Joined: 11/22/2003
From: arlington, WA, USA
Status: online 		From what I've seen, if you have the money you can blow the doors off a 1/2A glow plane with electricity [with stuff that can be at your doorstep in 3 days].
I don't know what you have for planes to work with and would have no idea how to equip them for E power.
I base my decision on what I enjoy mostly. We all have our preferences and individual situations. A lot of club fields will not allow the noise that screaming glow puts out, so E power is your natural choice anyway.

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Led Zeppelin is NOT "old fogie" music.

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RE: Brushless Vs Cox and Norvel - 6/28/2008 11:04:24 PM   
DeviousDave


 

Posts: 434
Joined: 2/25/2007
From: , MI, USA
Status: offline 		It's true, if you are looking for ultimate performance in a 1/2A sized plane, electric is a better way to go. Weights aren't too different, and you can roughly double the power to the prop. Electric props work a lot better than conventional glow props and there are 10 times the choices to match your airframe.

The good ol' days were pretty darn good, but today's pretty good too!

(in reply to combatpigg)
       Post #: 5

RE: Brushless Vs Cox and Norvel - 6/28/2008 11:41:47 PM   
BMatthews



Posts: 8951
Joined: 10/4/2002
From: Burnaby, BC, CANADA
Status: offline 		They are getting better and better every day. Just look at the pitch speeds on this one for an example....

http://www.graysonhobby.com/catalog/product_info.php?cPath=9_57&products_id=585

If you can load up the battery pack to handle the current then it sure looks like it'll deliver the goods. Im not sure how this relates to CP's Fora performance but I think we are looking at better than TeeDee levels from what I'm seeing.

As for weight you need to remember that with modern ESC's you don't need a radio battery. So you need to fudge that into the weight calculations. Still I think you'll be looking at a small 1 to 2 oz penalty overall.


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Bruce-
Proudly wasting balsa since 1965.

Free Flighters go that extra mile........

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RE: Brushless Vs Cox and Norvel - 6/29/2008 12:13:40 AM   
hogflyer



Posts: 1450
Joined: 3/23/2005
From: Wichita, KS, USA
Status: offline 		We recently had a discussion on pylon racers and their speeds at the field. When EP was brought up, it was remarked that they can get incredible speeds, but after that 1-1/2 to 2 minute flight, you have to get the battery out very fast to prevent it from melting or catching fire in the plane due the incredible head build-up. These batteries need to be high-discharge capacity, and they won't last that long due to the heat damage they'll sustain.

Hogflyer

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RE: Brushless Vs Cox and Norvel - 6/29/2008 3:04:02 AM   
vicman



Posts: 6212
Joined: 12/8/2002
From: Valdese, NC, USA
Status: offline 		In answer to your questions by my experience in a single model, my Rivets flew pretty respectably with an .049 Black Widow. With a park 400 on 3S1500 it was very similar in speed but weighed more. I went back to a TD .049 and had to add wt to get the CG right again but its a decent bit faster. If I went with a direct drive and spendy battery set-up I would say lekky would spank the TD pretty bad in speed but not weight.

Vic


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RE: Brushless Vs Cox and Norvel - 6/29/2008 4:24:07 AM   
Cashpoboy


 

Posts: 64
Joined: 8/8/2005
From: Bedford, TX, USA
Status: offline 		That is some really good info.

The plane I am converting is a Predator 200.

I forgot I won't need a flight battery so that will save some weight and also with the ESC I can get rid of the throttle servo too.

This won't necessarily be for all out racing but mostly zipping around school yards, so super high performance isn't necessary but I would like to go fairly fast.

What would be a good set up for the predator for E power? I want it to be fast, but easy day in day out use is most important.

Don't need twitchy expensive all out race to the death stuff.

(in reply to vicman)
       Post #: 9

RE: Brushless Vs Cox and Norvel - 6/29/2008 6:24:47 AM   
KidEpoxy



Posts: 3414
Joined: 10/14/2004
From: San Antonio, TX, USA
Status: offline 		The motors are not the limit of the power for the 1/2a conversion,
but how much you want to spend on the battery to feed enough juice to the 2oz motor.

It is not hard to find a 150w-200w brushless in the 1.8-2.8oz weight class
but how many amps the battery can suply is what controls the weight of the battery. Unlike a fuel tank, where 2oz fuel flys twice as long at the same power as 1oz of fuel, the battery size determines how much power it can deliver as well as how long you can fly at that power.

A cheap battery to deliver 15amps would be a 10c 1500mili amp hour, but an expensive batt for the same 15amps of power might be a 20c 750 mha, or even more costly a 30c 500mah. All make the motor turn with the same strength & speed, but the high discharge 30c batt would be much smaller & lighter & cost-a-lot-er.... in addition to running out of steam in mush less time.

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       Post #: 10

RE: Brushless Vs Cox and Norvel - 6/29/2008 6:36:33 AM   
rainedave



Posts: 5190
Joined: 7/21/2005
From: Greensboro, NC, USA
Status: online 		That motor Bruce linked to will draw up to 40 amps with the 5.5x4.5! Getting good lipo packs that can discharge at that rate, yet be small enough for your plane will take the most research. A 3-cell, 4000mah lipo pack rated at 15C would work (you need some head room as a safety margin), but how much does one weigh?

David

< Message edited by rainedave -- 6/29/2008 6:37:10 AM >

(in reply to KidEpoxy)
       Post #: 11

RE: Brushless Vs Cox and Norvel - 6/29/2008 12:31:25 PM   
airraptor


 

Posts: 297
Joined: 1/26/2004
From: fairfield, CA, USA
Status: offline 		I dont know the size of the plane your talking about but i have done gas to electric and electric to gas.

here is what i think would make a great starter electric set up:

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXLWX1&P=0 motor

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXKSY5&P=0 speed control

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXMSG2&P=M prop adapter

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXRVY6&P=0 best batterys you can get you get what you pay for

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXZK90&P=0 APC e prop 6x4 very good prop for most small models

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXKFU7&P=0 APC e prop another good one for cleaner designs notice the wide tips 4.5x4.1


the complete set up is around 8-9 ounces add three HS-65 servos for an additional 1.5 ounces total less than 11 ounces.

this setup you can take up to 180watts for 30-45 sec in a lacking for cooling air setup or 210 in an very well setup cooling design. I suggested the 1500mah evo 25's with a max cont. disch or 37 amps and a speed control of 35 amps. ( 10 volts and 35 amps = 350 watts) way more than you will pull in this set. with all electric setups it is a very wise and money saving tip is to buy a watt meter so you can try different props.

On one of my electric pylon planes that i switched to gas i lost about 20-23mph even though turning close to the same rpm on the prop. this is because of the cyclinder sticking out in the airframe. send me a link to your plane and I will see if I can come up with something better lighter or faster. this set up would push this plane to around 120 or so with a 5x5 prop and turned it around 20,000rpm


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(in reply to rainedave)
       Post #: 12

RE: Brushless Vs Cox and Norvel - 6/29/2008 5:49:21 PM   
KidEpoxy



Posts: 3414
Joined: 10/14/2004
From: San Antonio, TX, USA
Status: offline 		Raptor makes a good point,
with a Glow you are usuallys tuck with the cylinder sticking up in the airstream,
but with a brushless you can reduce the drag... as long as you still have a decent airflow thru the nose & thru the motor & guts.

I think we all agree that a 150-225w setup would do ok for most planes.
but it is a matter of getting the 15-30 amps delivered to the motor for what batery weight cost.

In comparison, I have one DNU that flies ok on 75-80w motor & 800mha battery, but tears it up with a 175w motor (running at 140w) weighing just .6oz more on the same battery.... but shorter flights and more cooldown time for the batts

2-2.5oz can get a good amount of brushless motor, the battery size & weight can make the difference between a screamer and an average plane.

_____________________________

Optional MA is part of AMA history, we can go optional AGAIN if we just say so

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       Post #: 13