I just got a Carona about a month ago and i am just starting to fly. When I was at the hobby store the guy said that it was not necessary for me to get a fusion moror and /or fusion esc so I got what I got. When getting my batery I was woried that if I got a NiCd i would forget to cycle them properly :stupid: thus giving them a bad memory; I was also woried that a NiCd would not give me a long enough run time, so I got a 3000mAh 8-cell NiMH and it works great [concidering I asked for a 7-cell and he only charged me for 7 cells, and the pack almost doesn't fit on the cruch]. I am now beginning to loath the guy because he convinced me to only get 1 pack, and also only to get a ac/dc wall adapter as a charger. I was getting sick of waiting 6 hours for my pach to charge [and worying about overcharging it] so i went to another hobby store and got the pirana digipeak charger so I wouldn't have to wory about overcharging them or having to wait so long. I think I fryed my $75 [canadian] batery pack with the digipeak charger. I programed the charger corectly and i put the bat on to charge after a flight [after which the bat was quite cool] and went on my computer. I went to check it after it was done and it was a little bit hot [i have been told that this is extreamly bad for NiMH packs] so I threw it in my freezer for 10 minutes so it would cool. Then when the pack became room temperature again, I put it on my helli and it didn't go [my esc has a low voltage cut system].
Can you guy's [darthdark or others] please help me, i need to find out all I can about my NiMH pack because I am getting another soon and I waant to take good care of it.
Here is what I know so far: never charge above rated capacity[eg 3000 pack charge at 3A max]
do not allow NiMH to heat up [this confuses me]
to condition the pack, charge the first time at 1/10th the rated capacity [this i didn't do]
Sorry, but this is all I know, please help me!

Hi colstonman:

This is going to take someone with more experience than I to answer, but it would help to have some more info:

How many flights/sessions with the NiMh pack charged with the "wall wart" charger?

How did it behave during those sessions, and how long were flight times?

Did the heli do anything different in the last session BEFORE using the Piranah charger?

Have you crashed and how bad and when?

How long did it take to charge the pack on the Piranah?

What exactly are you running for a motor and ESC?

What kind of battery pack?

What kind of battery connectors?

Did the pack OR the ESC get too hot to touch?

Send some of this data along to help analize the situation. Keep in mind that the NiMh packs WILL get warm, but shouln't get so hot that you would burn the back of your hand, for example, unless you have a bad pack or bad charger.

Chat later,

Russ

about 16sessions, from charged till the helli wouldn't lift anymore

during those sessions, i got a lot of power consistantly untill the voltage dropped below a certain point then i got a 1/2 second power loss but it continued to hover. If the voltage drops a lot then my ESC shuts off power to the motor and that's my signal to go back inside and charge. I get about 9-10 mins consistantly.

in the last session before i used the piranah i noticed a smell like melting plastic and i found that my ESC and motor were verry hot [i mean scalding] other than that it flew normally.

I have chashed from about a 3' hover and all I suffered was a tailboom strike and i was back in hover in less than a minute. I have also tipped it over [greening my m/r blades] when on my front lawn because my training wheeles caught the ground.

For a motor I am using a Peak Racing Jaguar [$33 canadian] and for a ESC I am using a Robbe RSC 830 uP BEC

I have 1 8-cell 9.6V 3000mAh pack that was assembled by my hobby guy.

I am using [verry poor] taymina cnectors.

Usually my pack never got that warm but only on that last flight before using the Piranah charger did my ESC get too hot to touch.

Hope that helps, thanks for all the help!

Colstonman, I sent you a PM as to where to get help

Hi again colstonman!

O.K. ... Good feedback on the questions. Keep in mind I am fairly new to this electric stuff, so you may want to wait for some additional comments from some more experienced Corona folks. I did a couple of months of resaerch on these forums before buying my Corona, and got great advice from many other flyers to come up with the best combination of equipment.

I am not familiar with the Peak Racing Jaguar motor or the Robbe RSC 830 uP BEC ESC. However, the "30" in the Robbe "RSC 838" leads me to think that it is a 30 amp ESC, which I think is too small considering the 8 cell pack. Most everyone is running 7 cell packs in their Coronas and 35 to 40 amp ESC's. Not knowing what voltage your motor likes, I'm suspicious that the motor is drawing excessive current through the ESC (electronic pulse SWITCH) because of over voltage from the 8 cell pack and possibly cooked the ESC. And, if the ESC IS only 30 amps, I think it's probably melted.

OR, the motor became too hot as a result of excessive current flow (due to too much voltage from the 8 cell pack), may have damaged the motor (like a short in the windings) which caused excessive current to be drawn through the ESC and perhaps damaged the ESC.

OR, maybe the brushes in the motor were in need of replacement after 16 ten minute flights (2 hours flight time) and was the cause if the problem, and just happened to coincide with the change to the Piranah charger.

Without doubt, you have a chicken/egg situation here.

Before I go on to a possible solution, you digest these comments, which will probably trigger a couple of new clues. And maybe someone else will come along with another or similar diagnosis and we'll go from there.

Maybe you could give us a hint as to whether you really like the heli hobby, and if you think you'll stick with it and want to spend some $$ to upgrade to a brushless motor/ESC setup and eliminate all these and other brushed motor problems?

Chat later,

Russ

Mini Boy, thanks for all the help.

I was thinking of going brushless but i was afraid of the cost as i am running out of money. I have to wait till summer before i start working and then the cash flow isn't that great. i want to know what a brushless setup would cost [motor and ESC] and the ideal place to purchase them [as hobby dealers rip u off].

But I don't thing it was my ESC, because it worked fine today, just my bat won't hold a charge. i charged it then put it on my LMH and i think it was suffering from some kind of 'after charge affect' where i think the bat still wanted to recieve charge as oposed to let it out. I need to know how long after I charge my bat should I wait, so it can recover from this after charg affect.

I really need to get another pack so I have one that has been conditioned properly and will last. I am wondering if i have ruined my pack and if i have to get another, i am thinking that if NiMH packs are too much trouble then should I get NiCd's? I was wondering if you used NiMH's or NiCd's, because if it is cheaper for me to get NiCd's then I will [price v.s. run time].

Again, thanks for the help.

Um i am new, what's a PM?

A PM is a private message. At the top of your page when you have a PM it says it in red letters. Click on it and it will take you to your private message board.

Hi again colstonman:

As soon as the pack is charged and still warm, but not HOT, it's ok to fly it. And no, NiMh's are less troublesome than NiCd's, and perform better. And don't go buying any more battery packs yet ... if the charger is bad, you don't want to go wrecking anymore packs.

Well, the way I see it everything was fine, except for slow pack recharging, until the last flight before using the Piranah charger. If this info is correct, what went wrong on that flight when the motor and ESC got too touch?
Had the motor and ESC been heting up excessively prior to that flight?

Can't blame the charger, you hadn't used it yet.

Neither the ESC nor the battery would have made the motor get any hotter than usual, so I am suspicious of something going wrong with the motor during that flight. The motor drawing excessive current from the battery THROUGH the ESC would also make the ESC get hot. That could be caused by the brushes being worn to the end of their usefulness and/or the springs being heated up and detempered. Can you see a lot of sparking in the motor? Sloppy or binding or noisy bearings? I don't want to confuse this any more, but those Tamiya connectors may not be helping either ... do they look discolored or burned or melted?

It's also possible that everything was going fine till you charged the pack on the Piranah charger, but you need to be the judge of that.

Before you start changing parts, it may be time to take some measurements ... do you have a volt-ohm meter?

Does the Piranah give you an indication of the pack voltage at the BEGINNING and the END of the charge cycle, the final current put into the pack and the elapsed time it charged? This is pretty important Info. Let me know.

Chat later,

Russ

I would like to thank you Mini Boy for all your help, i have learned a lot for my first thread, but i found out that it was infact my Tx that was not charged [hitting head on wall]. I was so afraid of giving a memory to the NiCd in my transmitter that i left it uncharged for days trying to deplete that Tx. sry for the inconvienience, and thanx for all the help.

Also, if u have some info for a brushless system then would you give me a heads up, i checked my motor and i think i am needing new brushes, please tell me all you know.

The kid with hope in his LMH engulfed heart.

HOLY COW Colstonman!

I did the same thing when I got my new charger ... worrying so much about the NiMh packs ($160.00 worth) that I completely forgot to payzin attention to the TX pack! Oh well, that's what they call "chalking it up to experience".

O.K. then. I presume the dead TX was not telling your RX that you wanted throttle making it appear that your motor pack was sick. That certainly makes sense. Then I would have to surmise that the previously hot motor and ESC situation were more than likely a result of the motor brushes wearing down, causing sparking at the commutator, causing voltage drop at the brushes, excessive current, heat, reduced motor power etc., etc. I think you get my drift.

I'm glad you solved the mystery, as it can be pretty complicated at times.

All of that aside, if the $$ supply is limited 'till summer, I would forget about a brushless motor/ESC for now, clean up the commutator on the present motor and change the brushes if you can find some. After you do that it would be really great to see if you can "seat" the brushes with a commutator stone. This should get the motor into "like new" condition. I would suggest getting some spare brushes too. The helis aren't like cars that coast some of the time, or planes that glide some of the time ... they are developing horsepower every second of the time you are off the ground. Consequently the motors work harder than most folks think. Hence the total joy of brush-LESS!

Then spend a few bucks on another battery pack or two. Depending on how quickly your Piranah charges them, you probably would be needing three or so packs to be able to to keep rotating packs and keep flying. Incidentally, a brushed motor is probably not going to like being run constantly without some cool-down time, so you may only need two packs. You can figure that one out. I am also not too sure of 8 cell packs, but maybe someone more knowlegeable than I can help with that question. You want to buy packs that will work with the brushless motor also. It's also nice to have them all similar so you don't have to be remembering how much flight time you will get out of dis-similar packs.

When you are able to spring for a brushless, do a lot of searches (as in "Corona brushless" or "best brushless for Corona") and reading on these forums ... hunrdreds of guys like you (and I) have gone this same route. For instance, after I ordered my Corona and continued to read all these daily posts and asked a zillion questions, I wound up ordering a Hacker brushless and ESC, and the original motor/ESC that came with the Corona are STILL in an in opened bag (with the kind of cheesy gyro)! You want to be VERY careful what you buy as I've heard some horror stories with some brushless motors and ESC's too!! The idea is to make this more fun, NOT more exasperating!

Hope this helps a bit,

Happy coptering,

Russ

An afterthought: Don't worry too much about the so called "memory effect" with the NiMh's ... they don't operate the same as NiCd's. I'm told and have read from very reliable sources that all you do is be SURE not to store them for more than a few hours in a fully charged state. When they are run down, leave them that way and charge them just before use (a couple or three hours). Like NiCd's, however, the first charge won't give you much flight time, they have to go through 3 or so charge/discharge/recharge cycles before they get acclimated to full capacity.

ENOUGH!

Russ

Thankx russ, lotsa help.

Could you direct me towards the best brushless setup there is out there as a lot of people seem to be using the hacker motor and i have heard of a lot of people using a different ESC tho. would anyone help me out here? I want to take my chopper to hamilton this weekend and if i can get enough info before then then I may spend the weekend there testing my brushless setup as oposed to flying for spectators and crashing [ooh, i got a really good one for that thread].

So any help or recomendations on the brushless setup would be great [purchasing aswell] so I can stay in the air longer

Hi Again Colstonman!

Well, I am partial to the Hacker setup as I did get some real good advice from Hoverup and others while in the process of researching. It's made in Germany, and I am quite partial to German products for their design and quality. As a result they are a tad pricey, but I'm a firm believer in that old proverb that you get what you pay for. AND, were I to build another heli, I wouldn't think twice about buying another Hacker.

Brushless motors (at least the hobby type) are really just coming into mass popularity, thus more brands, more competition and therefor declining prices. As that trend goes on, there probably won't be many folks using brushed motors 5 years from now!

There are lots of heli fliers using less expensive (but not by a whole lot) Mega and Jeti and probably other brand brushless motors, but I can't attest to their track records. Incidentally, my Hacker ESC is a Jeti! ... it says right on it. THIS is where the RESEARCH and the reading, reading, reading comes in! Don't rush it, if you do it right, you won't have to fiddle around anymore. you'll be in the air, not on the bench.

Nuff said.

Happy Choptering,

Russ

Oh, damn ... Fitz at www.fxaeromodels.com is where I got my Hacker combo.

Mini Boy, you gave me that link and i am interested in getting the hacker brushledd motor/ESC but I need to know f those prices are in US $$? And also how I would get them from wherever they are to where I am [if they use a curior then fine]. Also, which Hacker should I get/which hacker are you running? there are a lot or numbers and I am not wanting to get the wrong motor.

Thanx 4 all the help

Hi Again Colstonman!

I went to the FXA website to check the Hacker #'s, and the motors are NOT in stock!! Aarrgghhhhhhh!!

At any rate, numbers are:
Hacker Motor C40-12T
(or C40-12S, they ARE the same)
Hacker/Jeti ESC 40-3P-Heli

I would e-mail Fitz and ask when he expects them in REALISTICALLY. You may have to do a "Hacker brushless" search on the internet to find another dealer.

Yes, the prices ($275.00 for the pair) is US Dollars.

I'll check with Roffee's to se if they carry Hacker.

Get back to you later today,

Russ

OMG! that's all the money i have left, and i just broke a tailfin.

Thanks for all the help Mini Boy, i thank you for your time.

Colstonman!

Don't panic! Keep that Robbe motor going ... it's a lot better than the "Electro Fusion" thing that Lite Machines offers (I think most anything is).

Spend a few bucks on more battery packs, get some practice in and have some fun!!

Just keep your eye on the sparking at the brushes and change them as soon as you see excessive sparking and you detect more heat. You don't want to wreck what you've got!!

Good Luck & Happy Choptering,

Russ

Mini Boy,

I checked and my motor isn't arcing at all, but does get warm after a flight [i think this is normal].

I was wondering if more expensive motors [aka mine] last longer [brushes] so I would Know when to change the brushed, i do not notice any wear as I marked the location of the spring when I got it, and it still runs with the same power.

Oh, and my ESC, it is rated for 30A only and I think i am pushing that. It gets pretty warm but i only have 1 pack, thus allowing time for it to cool. When i get more packs, will I need an ice pack to cool my ESC and motor between packs? I was thinking that I would as I put my bat in the freezer after a run or charge to bring it back down to room temp [not sub-zero temps] before I fly again.

Thanks again for all the help

Quickie Questions:

Not being familiar with that motor, I think it's German?? Or Austrian?

It probably has ball bearings?

How much did it cost? .. (More than $11.00 like the world famous "Electro Fusion").

Russ

It has state of california warnings on it so I assume it is American, and it was $33 canadian, it might have a bering but from what i see there is none.

Anything i can do to help. Thanx

Hi again colstonman:

Well ... I did a REAL fast web search for Robbe, motors but I really didn't spend enough time to get any real good info, and on second thought, I only think you said your motor was a Robbe!

SO ... I guess the bottom line is that if you've gotten (I'm GUESSING!) 20 or more flights out of it as this point, and the brushes are still not looking like mercury vapor lamps, the thing has to be reasonably decent. THEREFOR, don't fool around with anything! If it's running well (and yes, it will get warm, and sometimes good and warm), don't worry about it. I think the trick is to be really aware of significant changes in flight duration, noise, unusual heat, smells funny and that sort of thing from flight to flight.

When you get an extra battery pack or two, just make sure to take a break between flights for a bit, and then squeeze the flights together until you are uncomfortable with any excess heat buildup.

Another thing, I don't think you should be putting the packs in the freezer to cool them down. NiMH's are pretty happy with flying hot off the charger. I really don't think they would like the temperature "shock".

Same with the ESC ... cooling it down with an ice pack when it's hot is more likely to cause rapid cooling which could crack a printed circuit board or solder connection or do some other damage.

I think you're all set! It's been rewarding to offer you whatever help I could.

Keep us posted on these forums.

Once again, Happy Choptering,

Russ

Um, actually, my ESC ia a Robbe anf my motor is from Peak Racing.

Sry if i confused you!

Hi again!

Well ... I think it makes no difference if the motor is behaving itself and the ESC is happy with everything. ESPECIALLY if you are using something other than the world renowned "Electro Fusion" motor.

It's coincidental the the forum right below your "poll" deals with yet another motor/ESC situation.

Click this link to get there:

http://www.rcuniverse.com/showthread...33&forumid=192

As you may note from reading between the lines, this problem includes a never ending string of variables which, as time has passed, have been dealt with by many and some conclusions have been made as to what works best with what.

Run what you've got and just keep your eye on it!

Happy Choptering,

Russ )

Thanks for your help, i will keep and eye on it just incase it starts acting up. Tell me if the Hacker prices drop [aka a sale] so i may get some, if i decide to make the jump.

Another thing, is it bad to charge My NiMH at a fast charge [3A] or should i stick to slow charging that will not heat up my bat? I have noticed my run time and bat capacity rising, i thing the wall wart's damaging effects are wearing off and now it peaks at higher voltages aswell.

Have a nice rest of the week, the weekend is in sight.

Hi Colstonman!

I don't think so. My Schulze charger says it'scharging my 7 cell NiMh packs at around 5 amps toward the end of the cycle (automatic cycle). I can tell it to charge at a higher rate, but I trust the logic of the charger and let it be. It packs them out at about 2900 MaH in 30 minutes. Oh, and they are warm, but if you lay one on the side of your face, you won't end up with a Harley Davidson tailpipe burn!!

I've heard many times that the nature of the NiMh packs is to have increased capacity after a few cycles. Those wall wart chargers are not much more than a trickle charger. I got one with my new Minolta camera ... It took 8 hours to charge 4 AA cells for crying out loud! Needless to say, I got a real charger for the camera too.

Off to do some hovering,

Happy choptering,

Russ