RE: Brushed Electric Motor Break-In Guide (Not Just For Heli's)
[quote]ORIGINAL: Karter01 Alright thanks for the reply. Why would you go with dry break in? Isn't there more friction? Or am I getting things confused? Thanks again [/quote] Sure, no prob. A wet break in takes all of the oil out of the motor. Most people think that it's carbon dust coming off the commutator. Basically with the small motors that we are talking about, they are not made to take apart, so it's going to be difficult to oil them with just enough oil and not get too much on there. If oil gets on the comm from excess oil being spun around fast and flinging off, it's not going to perform as well. Also I've never seen an mfg recommend a wet break in, although I have seen a couple recommend dry. If the motors aren't too pricey (and most rc ones are not), give it a try either way and see which one works better for you =)
Posted on: 10/13/2008 3:55 PM by Author "mrasmm" in the forum "Electric RC Helis"
http://www.rcuniverse.com/forum/fb.asp?m=8045378

RE: Brushed Electric Motor Break-In Guide (Not Just For Heli's)
[quote]ORIGINAL: Karter01 Sorry for bringing up an old thread. So, based on the above info, the rubbing alcohol is the best break in procedure? Or is the water? Thanks [/quote] Hey, no prob =) If it applies then it's not old to me. If you want to do a wet break in then alcohol would be a better choice than water because it evaporates more completely than water (so less corrosion). Of course be careful because it is flammable. Make sure to oil everything back up with just enough to coat the rubbing parts. I still would recommend the dry break in method though, but whatever way you want to do it =)
Posted on: 10/13/2008 4:04 AM by Author "mrasmm" in the forum "Electric RC Helis"
http://www.rcuniverse.com/forum/fb.asp?m=8044043

RE: Brushed Electric Motor Break-In Guide (Not Just For Heli's)
10 min is pretty short to seat the brushes, although it's probably better than not doing one. So with no load these motors draw 27A each? That's quite a bit. My guess is that it probably draws that much when you run them in your truck, but if you run the motors no load, they should draw significantly less power. What I would probably do is if you have a computer PSU (you can convert them for RC use), then hook the motors up on the 5v rail, probably one at a time unless they draw a lot less than what you're thinking, and let them run for a bit. I've found it takes longer than you think to actually seat the brushes. I think the pic I have on this post is somewhere around 90min, and that motor had some ridges on the brushes that let it break in faster, and I'm not sure that you could call those brushes seated. If you just have the battery pack, hook up a volt meter to the leads and just measure it every few minutes, and when it hits 6.0v then take the pack off and throw it on the charger.
Posted on: 8/11/2008 1:51 AM by Author "mrasmm" in the forum "Electric RC Helis"
http://www.rcuniverse.com/forum/fb.asp?m=7832130

RE: Lipo C Rating...variable ratings???
There are variances in mfg process that account for some variability. Ask any engineer about it and you'll probably get an ear full =P When they say C rating they are talking about max discharge rate while holding a specific voltage without causing the pack to heat up excessively or otherwise be damaged. For C just thing of capacity, so if it's a 25C pack on a 3500mAh or 3.5Ah pack, you can continuously discharge at 25 times 3.5A or 87.5A Most likely on the first one it is 20C cont discharge with a 30C burst (which is what they can put out for a short amount of time, mfg's have various burst time ratings too and so they should specify for how long), so that's the same as a 20C pack, or at least that is my guess. Higher C is generally better, but as far as the C rating goes, you can really only compare that number to the same brand of packs. There is no standard for testing C ratings, so mfg's sometimes pump up results with different methods to get better ratings so they can sell more packs. There are some guys that have done their own discharge curve graphs of various packs and C ratings. If you can find one of those for the packs you are looking at they are going to be the be your best way to compare packs side by side. Generally speaking with electronics you want a good safety margin, this is true with lipo's. They will run cooler and probably last longer and perform better. Find out what the max dishage rate is with a watt meter (or get the info online or something if someone else has the same setup as you) divide that # by .8 for about a 20% margin, round up to the nearest C rating on battery packs and go with that C rating or better. So for example say your truck has a max discharge of 67A, 67 / .8 = 83.75, say you want a 3500mAh pack, 83.75 / 3.5 = 23.92, so the closest C rating you can get rounding up would be a 25C pack, so you would need to get at least a 25C 3500mAh pack.
Posted on: 8/10/2008 5:16 AM by Author "mrasmm" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7829047

RE: How to convert an ATX power supply to rc use
[quote]ORIGINAL: AquarianGuy78 so simply connecting the charger (i have an apache 2500 on the way) to a 12v and ground wire from one of the dongles (molex plugs for drives) isn't possible? [/quote] if you mean while your computer is running? I'm sure you could, some of the risks would include, overloading the 12v rail with instant power off (most PSU's will do this when they get an undervolt to avoid frying anything), causing a power spike on the 12v rail and possibly damaging what is connected to it, if it's a cheap PSU which most of them people have in computers they haven't custom built it could cause the PSU to fail prematurely, and sometimes when they fail they take out something like a mobo or cpu. If you're just talking about hooking them straight up to a PSU that is not hooked to anything, nope that wont work. The PSU's have failsafe circuitry to better handle power events inside a computer and power down when they sense something like that to avoid frying something inside the computer.
Posted on: 8/10/2008 5:01 AM by Author "mrasmm" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7829037

RE: Brushed Electric Motor Break-In Guide (Not Just For Heli's)
looks like choppers beat me to it =P you can run the motors singly, or you can run them in parallel, or you can run them in series. For the motors I've done, I find that somewhere around 1/4th to 1/3rd of the rated voltage you will run them works well for seating the brushes, while not over heating the motors. Even without a load on them many of these motors get quite hot because the windings are basically a pure resistance load. To do that the best option for you would be to run the motors in series. Which is one lead from the battery to one pole on the motor, connecting one pole of each motor together, and connecting the remaining pole to the other lead of the battery. Of course the polarity of the motors during break in can make enough of a difference that I think it's worth checking, like choppers already suggested. Also with your pack since it is rechargeable the LVC (low voltage cut off) is going to be a big deal for the life of your pack. 1.0v/cell under load for NiCD and MiMH, and 3.0v/cell under load with lithium packs except a123's, and with those LVC truly is not that big of a deal. If you are just hardwiring to a pack, this could be very easy to let slip by, and it could damage or reduce the capacity of your pack, especially in the case of lithium packs. If you have something like an exquinox (or the hyperion or a bunch of others that are the same thing), it will work great for this purpose with lipo's.. Set it to the same mode you charge in and use those leads to hook to the motors. It will only allow it to go to 3.0v per cell if I remember right (it's either that or 2.7v per cell, which is a little low), and then it will shut off. Good luck =)
Posted on: 8/10/2008 4:54 AM by Author "mrasmm" in the forum "Electric RC Helis"
http://www.rcuniverse.com/forum/fb.asp?m=7829030

RE: Li-Po for Newbs
As far as how to treat it, yes it's a good idea to run a "form" charge on lipo's, 0.5C charge 2C discharge for 3 cycles, and allow the pack to cool down between cycles to something like 80F You can run it down about 80%. I shoot for a resting nominal voltage, so that means on a 4s pack, I would shoot for an 14.8v reading after the battery has rested for a min or two after your flight. Max discharge is like 3.0v/cell under load (so 12v in your case), there are all sorts of meters that make sounds or blink or throttle your ESC ect. Recharge at a max of 1C or 3.2A for your battery. Watch the temps and keep the pack below 90F while charging =) A slower charge on the pack may make it last longer (but then again it may not really make a difference), something like 0.5C to 0.7C. If you put more than about 2.7Ah in your pack, then you've likely drained it too far. Make sure to balance the pack atleast every 4 or 5 flights. I prefer to just do it every time. Some go 30 or 40 flights before they balance, I see that as being more risk than I want to take, especially with how easy balancing is. try rcbatteryclinic.com welcome to RCU =)
Posted on: 7/24/2008 4:43 PM by Author "mrasmm" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7768032

RE: Help on Charging two packs Lipo
sure, no prob. Yeah things can get complicated quick. A good investment might be a couple of those cellpro chargers. They don't run too much, and they do a great job charging packs. good luck =)
Posted on: 7/14/2008 4:54 PM by Author "mrasmm" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7730401

RE: Help on Charging two packs Lipo
oh, a couple of other things I forgot. This balance adapter 1 x 6s to 2 x 3s is iMax compatible, which is the same as align esky eflite csrc and a slew of other ones. If you want to charge TP compatible packs with this adapter, you're gonna need a bunch of adapters to convert the wider spacing on the balance tap to the more narrow that TP uses (one for each battery pack and one for the balancing charger), either that, or add align compatible balance taps to your balancer and battery packs. If that is the case, I would see if you can find something similar that has TP compatible connectors. Also I'm not familiar with that charger, so I don't know what kind of balance taps it uses, but if you are balance charging TP packs with it, then it's probably TP here is the link to the product (edit the spaces out, the site wouldn't let me link directly to it, musta had some problems somewhere along the line) http://www.hobbycity .com/hobbycity/store/uh_viewItem.asp?idProduct=6569&Product_Name=Twin_pack_charge_lead_(2_x_3S)6S_ www.commonsenserc.com would sell all of the stuff to either make your own of one of these, or convert the align compatible taps to TP compatible. good luck =)
Posted on: 7/14/2008 3:53 AM by Author "mrasmm" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7728382

RE: Help on Charging two packs Lipo
I think you've kinda got it. What I would do is just use the one in the first picture. Depending on how it works, you wont need to use the deans connector if you have a balance charger setup. Balance taps are rated for about 3A, and a 1C (which is the max charge rate for standard lipo's) for your packs is only 2.2A, so unless the connectors start heating up that should work. I imagine that this is just a connector, and involves no real circuitry or anything like that. The main thing you want to make sure is that your 2 batteries are the same in things like starting voltage per cell, capacity, cycles put on the packs, ect. If they are not in balance when you start charging them, or at least close, you could run into some real issues. So for the charger you would set 6 cell lipo with a charge rate of 2.2A or less and a total capacity of 2200mAh. If your connectors end up getting hot, or you want to charge fast than 3A, your setup could involve the second picture and be more complicated, depending on the specifics about that charger.
Posted on: 7/14/2008 3:37 AM by Author "mrasmm" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7728371

RE: How to convert an ATX power supply to rc use
[quote]ORIGINAL: Tusken Thank you mrasmm for the help. Does anyone have a recomendation for a good off the shelf psu i could convert to be able to charge 4s. Thanks [/quote] sure thing. FSP group makes a good PSU for about 40 or 50 bucks that would be able to put out what the label says. If not, I'd just look for something that's more along the lines of 16 to 18A or higher on the 12v
Posted on: 3/1/2008 12:52 AM by Author "mrasmm" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7159249

RE: How to convert an ATX power supply to rc use
[quote]ORIGINAL: Tusken Im having a problem with my power supply shutting off when i try to charge 4s packs. The psu is out of a compaq pc and is rated 8 amps at 12v. It works fine charging 3s and im getting about 12.6v under the charge load. Does it take that much more juice to charge 4s packs? or ?? Allso I had the same problem as edwal07 on page2 ""and the 5v sense to the 5v. In this configuration I had voltage but no current. I removed the 5v sense and it latched on perfectly. "" I had 12v+ but it wouldnt power anything until i disconnected the grey and red wire. This is the charger im using if that matters. http://www.allerc.com/etecchargers.htm Thanks Rob [/quote] it all depends on the conversion efficiency of your charger, but yes it will take considerable more power, about 33% more assuming a 100% efficient conversion factor. If it's a compaq PSU, it's likely not very good, infact most cheap PSU's are only good for about 50% sustained draw of what they are rated for. The simplest fix would be to just charge at a slower rate, and see how that works basically the math of it is: max voltage of 4s lipo pack is 16.8v, at 2.5A. I assume an 80% conversion efficiency, so if you do the math you end up with 16.8v x 2.5A / .8 = 52.5w required, and if you figure your PSU, you'll need basically 4.5A sustained current @12v In your case you run into a problem because your PSU probably just puts out 12v, and if you load it up around 4A, then the voltage drops below 12v, as soon as that happens your charger shuts off to prevent an undervolt that would fry it.
Posted on: 2/29/2008 2:35 AM by Author "mrasmm" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7154524

RE: Brushed Electric Motor Break-In Guide (Not Just For Heli's)
[quote]ORIGINAL: Micro RC Racing Owner Shane i would like to do this to the motors on my Honey Bee FP that will be here in a few days, but my dad doesnt want me to becasue he thinks that it will do more harm then good.. what should i do? lol [/quote] well have him read the article if he hasn't, and see if that helps him make more sense of the benefits of doing it. If not, then I guess that's where you are =) The motors are only like $10 bucks depending on where you buy them, so it's not too big of a deal either way, as long as it doesn't cause damage to the 4 in 1 =) GL
Posted on: 2/29/2008 2:27 AM by Author "mrasmm" in the forum "Electric RC Helis"
http://www.rcuniverse.com/forum/fb.asp?m=7154513

RE: How to convert an ATX power supply to rc use
[quote]ORIGINAL: OldRookie I wasn't quite getting the voltage I wanted. I tried the 4 10 ohm 1 watt resistors in series and got pretty good results. The next thing I tried is putting two sets of 10 ohm 1 watt resistors in parallel, and then put the two parallel resistor sets in series. What type of load does this put on the system compared to the 4 10 ohm 1 watt resistors in series? I don't know the formulas for series and parallel circuits. Greg [/quote] hey there, I got your PM, so here it goes. The formula for TDP is voltage squared over resistance, so it's 5.15^2 or 26.5/resistance. For series you add all the resistance together to put it on the bottom, and for parallel, you do two different equations and then add them together so in your case four 10Ω resistors rated at 1w each, will give you a total resistance of 4 x 10Ω or 40Ω then 26.5 / 40Ω = 0.66w TDP between all 4 resistors, so if you divide that 4 ways, then it is 0.165w per resistor, or about a 16.5% load, which is a good range to keep them running cool. In the second case you would really up the amount of power draw. Two 10Ω resistors in series will give you a total of 10Ω + 10Ω = 20Ω then you take 26.5 / 20Ω = 1.33w per two resistors, or 0.66w per resistor, or about 66% of the capacity on a 1w resistor, so that puppy is gona get hot. Then when you add the second set in there, you'll get a total TDP of 2.65w, and 0.66w per 1w resistor. so the first one you'll get 0.66w load on the 5v rail and the second example you'll get 4 times that at 2.65w load on the 5v rail. The temp diff in the resistors between the two is going to be very different. I'll bet in the second example you'll be getting close to 180F or 200F for each resistor, especially without a heat sink. Hopefully that answers your q
Posted on: 2/28/2008 1:11 AM by Author "mrasmm" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7148863

RE: Need HELP controlling the Blade CX2
it's all about setup. Read this and see if it helps you any http://www.heli-wiki.com/mediawiki/index.php/HOWTO_Wiki_Overall_CX_and_CX2_Setup and check out the rest of the cx2 articles on this page http://www.heli-wiki.com/mediawiki/index.php/Index:HOWTO
Posted on: 12/9/2007 2:45 PM by Author "mrasmm" in the forum "RC Helicopter Beginners Forum"
http://www.rcuniverse.com/forum/fb.asp?m=6734724

RE: Which online shop to buy 'ESky Lama V4' from ?
you might want to take a look at www.ushobbysupply.com and talk to michael =)
Posted on: 12/9/2007 2:44 PM by Author "mrasmm" in the forum "RC Helicopter Beginners Forum"
http://www.rcuniverse.com/forum/fb.asp?m=6734715

RE: Li-ion battery charger
what kinsd of packs is it using? ie mAh, and balance tap ends? How much are you looking to spend? What kinds of batteries do you want to charge with it? Any special features you are looking for?
Posted on: 12/9/2007 2:41 PM by Author "mrasmm" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=6734707

RE: what size lipo battery
some people who have setups that are made to run on 6v do run straight a123's without regulators, if any part is 5v though you will definitely want a regulator though. your max voltage with those packs are going to be in the range of 7.2 to 7.4v, the max you'd get with a 4 cell is 6v, and 7.5v with a 5 cell =) GL
Posted on: 12/9/2007 2:40 PM by Author "mrasmm" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=6734703

RE: Hyperion LBA10 NET Kong Power harness?
the list I have says kong power is jst compatible, which is the same as align and great planes.
Posted on: 12/9/2007 2:36 PM by Author "mrasmm" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=6734690

RE: Question about Direct drive tail and G90 gyro?
oh, about the ducted fan units, they work fine if you aren't gona do anything 3D, there are a bunch that will draw as much as the main motor though and not give that much thrust. There is a 3 bladed model that is good and a 5 bladed model that is also good. There are probably 7 or 8 3, 4, or 5 bladed models. You also want to look at overall weight and thrust as well. Something around 70g or higher is where you want to be
Posted on: 12/9/2007 2:34 PM by Author "mrasmm" in the forum "E-Flite Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=6734682

RE: Question about Direct drive tail and G90 gyro?
try this one http://www.eboyztoyz.net/index.php?op=showitem&sku=8605 or this one http://www.eboyztoyz.net/index.php?op=showitem&sku=8549 nope, it wont blow the 3 in 1 unless you crash. They usually draw about 2 amps compared to the stock 0.91A. You'll just want to put a fuse on them. I have an article on how to do that here http://www.heli-wiki.com/mediawiki/index.php/HOWTO_Wiki_Fuse_Mod
Posted on: 12/9/2007 2:30 PM by Author "mrasmm" in the forum "E-Flite Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=6734672

RE: Havok Heli??
yeah, it's gona have yaw (left and right) control and up and down control, and that's it. They are not very controllable, but if you watch on youtube, and if you play around with it for long enough you can get pretty good at them. They aren't alot of money and are quite a bit of fun =) You get them to go forward by adding weight to the front of the heli, and then they always go forward.
Posted on: 12/9/2007 2:27 PM by Author "mrasmm" in the forum "E-Flite Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=6734654

RE: CX2 Battery and Mod questions...
for the charger check out the fmadirect.com cellpro
Posted on: 12/9/2007 2:17 PM by Author "mrasmm" in the forum "E-Flite Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=6734621

RE: Ballancing Chargers
oh, you just said that it takes the voltage from the high cell and puts it into the low cell... so I said... they don't share, the balancer just bleeds off the high cell's charge into a resistive sink usually =)
Posted on: 12/9/2007 10:07 AM by Author "mrasmm" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=6733656

RE: cp questions
if you want to check out the hdx300 build, check out finless bob's tech room on helifreaks as far as all of this, it may make the heli fly really well, and it might not, but the overall opinion is that it's too much money for this heli. If you want to go for it though and you have the money and all of that, then I say do it and let the rest of us know how it worked out =)
Posted on: 12/9/2007 10:05 AM by Author "mrasmm" in the forum "E-Flite Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=6733644

RE: Question about Direct drive tail and G90 gyro?
the direct drive just has more power than the stock tail setup and will last about twice as long =) if you decide to go with it I have a real good link where you can get the setup plus two blades for 10 bucks w/out the tail and 13 bucks with and $3 shipping.
Posted on: 12/9/2007 10:03 AM by Author "mrasmm" in the forum "E-Flite Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=6733635

RE: CX2 Pontons
lol, that was a funny vid =) looks like you got the cg and all of that figured out... it all just might be too close to the walls and stuff..... maybe you could take a big baking pan and fill it with water and put it on the kitchen counter =) I also thought it was a really good idea to only fill the tub up just enough to let the heli float =)
Posted on: 12/9/2007 9:57 AM by Author "mrasmm" in the forum "E-Flite Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=6733616

RE: FMA 4S and LiPO questions with CX2 and Mini-T
oh, that's a lipo LVC =) so that wont take any effect in the charge.... I thought you were referring to some kind of protection circuity in the battery itself =)
Posted on: 12/9/2007 9:48 AM by Author "mrasmm" in the forum "E-Flite Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=6733590

RE: Falcon 40 (Exceed heli) Forum
[quote]ORIGINAL: Agador Sparticus Fellas, Word to the wise - be careful when connecting your lipo charger to the 12v dc. I smoked or rather sparked my esky lipo charger when I accidentally reversed the polarity to my pc power supply charger. I will be sending another order to ushobby supply in the near future. The bird is grounded. Kevin [/quote] it does have reverse polarity protection.... so I wonder what it was that cause the problem with the charger to make it smoke. hehe, yeah like everyone else said, you're pretty lucky nothing worse happened =) [b]TreBo: [/b]welcome to RCU =)
Posted on: 12/9/2007 9:41 AM by Author "mrasmm" in the forum "Electric RC Helis"
http://www.rcuniverse.com/forum/fb.asp?m=6733572

RE: Lipo 10c battery question
that battery max can put out something like 14.4A which is way low for that motor. The other thing to think about is ESC don't run at 75% throttle 100% of the time, they run at 100% throttle 75% of the time. That's why you can't get a smaller battery and just run the motor at a lower speed. The turn over in the motor is controlled by the 3rd wire, so if the motor cannot get going fast enough and the prop slows it down, then the 3rd wire stops sending signal as often because the motor is spinning slower, until it stops and sends no signal, so the ESC will never change polarity =) hence the stuck motor
Posted on: 12/9/2007 9:27 AM by Author "mrasmm" in the forum "E-Flight Power Sources"
http://www.rcuniverse.com/forum/fb.asp?m=6733527