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e-Miniature Aircraft Furion - Razor - Ion-X > New outrunner for Ion
 
 
DrScoles
Veteran
Location: Redmond WA

I got an LRK outrunner motor for my Ion...pretty big difference over the hacker. Motor doesn't get hot, but if you fly it too long, the batts will get too hot. And you save 6oz by losing the middle gear, however I have not weighed the new motor and it is heavier than the hacker...

It seems like we keep going back and forth between improvements and a new weakest link. I guess the ideal would be a bullet proof speed controller and then we could run higher cell count packs and increase the voltage....thereby lowering the current...then everything would be happy.... we need over 50 volt ESC's!!!!!!!!!!!!!!!!!!!!!!

With the 5s4p, I can run 5 minutes full bore, come down let it take breather, then go off for 5 full minutes again, not getting anywhere near the full capacity on the packs...

Exciting times for this electric stuff!!! Still hasn't got me to sell the glow stuff, My Tempest with a YS91 still kills the electric, but it seems like the gap is closing every day... what a great time to be in this hobby!




Mike
09-20-2004 Over year old.
 
 
AirWolfRC
rrProfessor
Location: 42½ N, 83½ W

A point of interest or two;

The Ion weighs about 10 lbs. To get "spirited" performance, you will want up to 3 HP from the motor. That's 2238 Watts. A 2P (2100) pack can deliver about 40 Amps without too much trouble. This, of course, will need 10ga or even 8ga wires to keep wire losses down. Voltage needed will be 2238W / 40A = 56Volts = 15S pack.

Anybody have a 15S2P 2100 pack with a 50 amp controller that can handle 60 volts?

Wolfgang
09-20-2004 Over year old.
HOMEPAGE  
 
 
SteveH
rrProfessor
Location: Texas

Great if you can afford it! I witnessed an Ion blow a speed controller this last weekend at a funfly and by the time it was over, it also took out all the batteries; $800 worth I was told.

SteveH
Magnum Fuel
AMA76186
09-20-2004 Over year old.
 
 
reckless loony
Senior Heliman
Location: MIA

Quote 
I guess the ideal would be a bullet proof speed controller and then we could run higher cell count packs and increase the voltage....thereby lowering the current...then everything would be happy.... we need over 50 volt ESC's!!!!!!!!!!!!!!!!!!!!!!


Sure you can run higher voltages and thus drop the current draw except at those voltages you would find aeromodellers getting themselves electrocuted hence why the higher voltages are NOT used.
09-20-2004 Over year old.
 
 
AirWolfRC
rrProfessor
Location: 42½ N, 83½ W

If you want to go down that road, then you have to ask about those rotor blade tips at 350 MPH and those 12 inch props at 12000 RPM waiting to take a bite out of someone.

Like anything else, proper caution is required.

Wolfgang
09-20-2004 Over year old.
HOMEPAGE  
 
 
alawel
Veteran
Location: Springfield Oregon

ION with Outrunner

I was at a fun fly with DrScoles this last weekend. The performance of his Ion was pretty amazing. I suspect that as limits are pushed on this stuff the week links will keep popping up until the biggest problem will be the operator. Safeguards should be able to be built into systems that will require the type of voltages that the Ion seems to be heading towards.

I agree wholeheartedly with Doc, it's a great time to be flying helis, and a very fluid time if your playing with the cutting edge electric stuff.

Mike, as always, I enjoyed watching you fly this weekend, it gives me all sorts of new and exciting ways to crash my heli.

Alan
09-20-2004 Over year old.
 
 
AirWolfRC
rrProfessor
Location: 42½ N, 83½ W

Soooo, why not run 2 motors, each with their own controller paralleled off a 7s4p 2100 pack ? Now you can use 45 amp controllers off the shelf and be within rated limits. Just have to work in the second motor on the back side of the main gear.

Wolfgang
09-20-2004 Over year old.
HOMEPAGE  
 
 
JonMann
Senior Heliman
Location: Clayton, CA

Mike,

"With the 5s4p, I can run 5 minutes full bore, come down let it take breather, then go off for 5 full minutes again, not getting anywhere near the full capacity on the packs... "

Which packs do you have the original yellow label ones or the new blue labels? (Mil spec versions). How hot were the packs getting?? How much did it take to re-charge them after the two 5 minute flights?

Should be flying my LRK motor by the weekend, just curious what to expect. Have two sets of the yellow label packs and a little worried about what these bigger motors will do to these.

Thanks - jon
09-20-2004 Over year old.
 
 
K-Lo
Senior Heliman
Location: Monterrey Mexico

Higher voltage electrecution is safer than higher current electrecution...


Just a thought.

Do what you can with what you have. Often is more than enough.
09-27-2004 Over year old.
HOMEPAGE  
 
 
AirWolfRC
rrProfessor
Location: 42½ N, 83½ W

Will someone please tell me why there is so much paranoia out there, especially from those that don't know what they are talking about ???

You're not going to get electrocuted by 28 volts, I don't care what the boogy man told you.

Wolfgang
09-27-2004 Over year old.
HOMEPAGE  
 
 
DaveThomasPilot
Heliman
Location: Apex, NC

QUOTE]Sure you can run higher voltages and thus drop the current draw except at those voltages you would find aeromodellers getting themselves electrocuted hence why the higher voltages are NOT used.[/QUOTE]

Actually, 60V is safe. I used to design DC/DC converters and 60V was the SELV voltage. As long as the average voltage was below 60V, it did not have to be covered. Touched 60V all the time in the lab--can't feel it.

Telephone lines are 48V when on hook. You can definitely feel the ring voltage (may be an extra 90 VRMS or higher), but not the on hook voltage.

Getting burned is another story. See what happens if your wedding ring bridges the terminals on a 40 amp supply...

Dave Thomas
09-27-2004 Over year old.
 
 
Bushy
Veteran
Location: Tucson, AZ

Saw the results from an airmans' wedding ring across the 28 volt battery system on a jet fighter.
Guaranteed amputation. That was 35 years ago and I haven't worn ANY jewelry around electrical or electronic equipment since then.

Your 8000 ma 42 volt lipo will do the same job if you give it the chance.

Those 6 little sub c's in my race car may be only 7.4 volts BUT, they'll deliver over 100 amps if you present them the opportunity to do so.

Scary stuff if you think about it.

Be velly velly careful.

Dave
09-28-2004 Over year old.
 
 
Qrrambero
Veteran
Location: San Francisco / Bay Area

Will someone please tell me why there is so much paranoia out there, especially from those that don't know what they are talking about ???

This conversation is taking me when my mother gave me a battery watch in Christmas (Around 1,970). Well one of my wise friends told me to watch out because if it was raining and the watch got wet I could get Electrocuted.
I was like some of you so naive that I used this watch just when it was a sunny day. I am glad that it was a bad watch and in few months did not work any more.
09-28-2004 Over year old.
 
 
reckless loony
Senior Heliman
Location: MIA

Quote 
Actually, 60V is safe. I used to design DC/DC converters and 60V was the SELV voltage. As long as the average voltage was below 60V, it did not have to be covered. Touched 60V all the time in the lab--can't feel it.


It really depends on the current that flows through one’s chest. 1ma is generally considered the threshold of sensation, 15ma and more is considered hazardous due to muscle control loss and thus possibility of involuntary injury, ventricular fibrillation occurs at about 50ma with 100ma is generally considered as highly likely to be dead.

Now the human body internal resistance is about 400ohms while the skin resistance varies significantly based on how much sweat the person is producing. This can vary from about 1000ohms to over a 1Mohm.

From Ohm’s law V=I x R where V is voltage, I is current and R is resistance

Looking at worse case situation where it’s a hot day and you are really sweating thus skin resistance at 1000ohms.

At 15ma require a voltage of 15v
At 50ma require a voltage of 50v
At 100ma require a voltage of 100v

I myself have even experienced a mild shock from a 12v car battery so don’t think it can’t happen.
10-01-2004 Over year old.
 
 
AirWolfRC
rrProfessor
Location: 42½ N, 83½ W

I have to suspect your numbers. It is easy to coroborate, or disprove, any set of numbers.

I took 2 different kinds of ohm meters (digitsal & analog) and held the probes 1/2" apart and measured a wet portion of the body (toung). The lowest reading found was 15K. That's a long way from the 1K that you cited. 1ma x 15K = 15V, and you will feel that.

Now, a 9V battery on the toung will announce it's presence (an easy way to tell if it's good or dead) but 30 volts on the fingers, I doubt you will notice it unless your hands are dirty and wet.

Wolfgang
10-01-2004 Over year old.
HOMEPAGE  
 
 
reckless loony
Senior Heliman
Location: MIA

The problem with using a multimeter is that you will NOT get a correct reading. I myself have just taken readings with two digital multimeters. One gives 120K and the other 36K for my tongue. You yourself found that the lowest reading you got was 15K thus with a 9v battery the current through your tongue based on a resistance of 15K would be 0.6ma it is generally considered that a current of 1ma is required as the threshold of sensation. Anyway here is some info that you may wish to read which I just found, there is of coarse more available.

From the University of British Columbia (Canada) safety manual.
Take note of what is written on top of page 7.

http://www.ece.ubc.ca/~safety/priv/man.pdf


From the NSW government Australia

http://www.minerals.nsw.gov.au/safe...ctric_Shock.pdf

This gives a couple of tables that you may find of interest

http://www.electrical-contractor.ne...ES&H_Manual.htm

Also take note:
“Nonelectrical Workers. The Occupational Safety and Health Administration requires training for nonelectrical workers whose job assignments require them to be close to exposed parts of electrical circuits operating at 50 V or more.”
10-04-2004 Over year old.
 
 
AirWolfRC
rrProfessor
Location: 42½ N, 83½ W

I notice that you stopped at taking resistance readings and continue to avoid following through to completion any kind of testing yourself. Instead, you defer to published material. Is this going to be another case of talking it to death ? . . . well, not if you properly control the testing :-)

Wolfgang
10-04-2004 Over year old.
HOMEPAGE  
 
 
reckless loony
Senior Heliman
Location: MIA

Quote 
I notice that you stopped at taking resistance readings and continue to avoid following through to completion any kind of testing yourself.


Well considering I have a difference of 84K between the two multimeters at the same location what is the point of getting more incorrect meaningless resistance readings? A multimeter will not give you correct actual resistance readings of a human body it is inappropriate for that application.

Quote 
Instead, you defer to published material. Is this going to be another case of talking it to death ?


Not at all I presented the information from what I believe is to be from appropriate sources how people wish to interpret that information is purely up to them they may even want to go to their nearest university, state reference library or even to search the internet to find other data. If people desire to run higher voltages above 50v in their electric aircraft then by all means do so just be aware of the consequences. There are certainly benefits of running high voltages due to

P = V x I

Where P = power in Watts also known as Joules per second
V = voltage
I = current

With a suitable electric motor by increasing the V you reduce the amount of I required thus longer run times for the same power developed. Or by keeping I the same getting even more power. You also reduce energy loss due to resistance in wiring, connectors, etc since

P = (I)^2 x R

Thus dropping I results in less energy being lost due to resistance.
10-05-2004 Over year old.
 
 
AirWolfRC
rrProfessor
Location: 42½ N, 83½ W

reckless loony, you are doing exactly what I was talking about.

You talk instead of do. You discuss instead of demonstrate and by pointing a finger at what others have said, you hope to rationalize what you believe.

You would do well to follow through. Then you might find the falacy of statements like;
Quote 
by increasing the V you reduce the amount of I required thus longer run times for the same power developed
Longer run times for the same power ??

Wolfgang
10-05-2004 Over year old.
HOMEPAGE  
 
 
dylwad
Heliman
Location: Phoenix, AZ

Brushless motors, speed controls and connectors are INSULATED.

Whats the big deal about getting electrocuted? Id imagine the rotor blades would chew your arm off long before youd have a chance to strip some of the insulation off of wiring and touch it.

Besides the terminals on some brushed motors, where could you possibly touch an electric setup to get shocked?


Higher voltage can give longer run times, more power, lighter weight, cooler temps and longer battery life, as long as the system is designed for high voltage.
Dylan
10-19-2004 Over year old.
 
 
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e-Miniature Aircraft Furion - Razor - Ion-X > New outrunner for Ion
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