Savage Going Brushless

[glypo]

Hi All,

I'm going to get a Savage SS and convert it to brushless.

The problem is I'm fairly new to all this brushless stuff and have no idea what I'm after.

I've had a look through previous threads and people mention the Novak HV for the E-Maxx a lot. However I would like some extreme power, and can't seem to find anything in previous posts.

I'd like to run about 12 cells, so I suppose around 100A ESC? However I don't know what ESC and Motor to use. Any suggestions and I'd be very grateful for them!

Thanks

Jason

[kufman]

Feigao 10L motor

schulze 18.97 controller?

Give Jaime at www.staluckrc.com a call and I am sure he can help you figure it out.

[bomb-proof]

Jamie at starluck is familiar with that same project and he can tell ya what to run.

[rhylsadar]

hi
i have a converted savage. what is your intention with the gear box? fix it in 1st or 2nd gear?
i run it in 1st gear with a plettenberg maxximum and schulze 18.97kw. 12-16cells.
many run the bigmaxximum or lehner 1940/7 (2nd gear), 1930/8 (1st gear).
have you modded your diffs already?
bye
rhylsadar

[starluckrc]

Feigao 540-9L on a budget. Plettenberg Maxximum with Fan not on a budget. Plettenberg BigMaxximum for the insane and not on a budget. You can get by with the Warrior 9918 on the Feigao. You'll need the 18.97kw at a minumum to run the Pletties. I've helped set up a couple, so just drop me a line if you need more info.

[glypo]

Wow thanks for the replies!

To be honest I hadn’t even thought about what gear to lock in. I think I like the sound of the ‘insane’ option.

I’m looking to pay around £200 for the motor and esc ($377) but could push that too £300 max ($565.814).

So if my budget covers the good system I’d be happy. If you couldn’t tell from the currency I’m from the UK, starluck do you ship internationally?

As for the diff mod, I don’t actually have the Savage yet. I will be getting the kit in a couple of weeks and intend to do the diff mod.

I’ll then get my brushless set-up in just over a month. I was hoping this would give me time to figure out how to do this.

Rhylsadar and startluck – is there a simple way to mount the motors? Or will I need a custom mount made. I’m clueless to what I need as of yet so any help would be excellent.

Thank you all so much for your help :)

[glypo]

Sorry for the double post, but done some searching on the internet and found that the 'maxximum' is 1.3HP as is.

This sounds insane. I want a nitro killer really at the end of the day, I've got a point to prove - Electric is powerful!

Is the 'bigmaxximum' over the top? It sounds just mental. Ideally I wanted to run 12 cells too.

[OptimaMan]

With "only" 12 cells, you will only have about 1200 watts. You really want to go to like 16 or more cells to really have decent power and run times. Especially if you want to make a statement and show the gas guys.

I think a 10L or 7XL with 18 cells is a great bargain.

[starluckrc]

On 12 cells, you would want to stick with the Maxximum. The BigMaxximum likes higher voltage than that (16-18 cells). The Maxximum will have no problem running with the nitros. Get the version with fan since mod 1 pinions are easier to fine for its 5mm shaft. You will need to make a motor mount. That shouldn't be too hard. BTW, I do ship internationally.

[Chase023]

One of the first Savages I seen go brushless was using the Plettenberg Maxximum. It is pretty fast with it.
I was very impressed when I saw vids of it.
Jamie's/Starluckrc's advice will steer you in the direction you want to go.

It all depends on how much you can or want to spend.

[glypo]

Once again thank you so much for the replies, appreciate them very much! I was thinking this project was going to be tricky but you have all made it a lot easier!

Glad to hear you ship internationally, even though Germany isn’t very far away, it’s tricky to get hold of the good brushless stuff here in the UK.

I think 18 cells would be the next logical set-up for me in cells, anything in divisions of 6’s.

Got yet another question, roughly how long would a bigmaxximum run for with 3,700mAh cells?

Ideally I need run times of 5 minutes, if not quite something near to 5 anyway. I can only imagine the power of that with 18 cells through it!

Starluck – one final question for you (sorry for all the hassle, I’ll be buying from you when the time comes though :) ) Do you sell the 18.97? Also what sort of price would a 18.97 and a bigmaxximum be?

Once again thank you all!.

This is all so clear in my head what I need now.

[starluckrc]

The BigMaxximum and 18.97kw will be back in stock in a few days. Runtime should easily be over 5 minutes. I haven't ran a setup yet that didn't get at least 7 minutes on my old 2600's. Just drop me an email for a combo deal on motor, controller, and pinions for your setup.

[rhylsadar]

hi
i bought a conversion kit (should be available at nitro-mods.de or d-1-1.de). includes a motor mount, battery holders and a gear shaft to fix the gearbox in one gear. all this is relatively easy to produce by yourself except the gear shaft.
12 cells is nice but to get real power you need more cells.
the 4poler pletties are hard with the controller. heat reduction with a fan on the controller is needed. otherwise you will get thermal shut downs. very important are good plugs. 4mm gold plugs of good quality or the like. battery wires should be as short as possible.
very good batteries to get good performance. i.e. pushed and matched cells.
the bigmaxximum in 2nd gear with 16cells and a gearing like 16-18/49 should be nice.
runtime with gp3300 cells is around 10min.
bye
rhylsadar

motor plate (http://62.2.107.106/~beat/images/08-02-04/pletti1_(8).jpg)
fan on controller (http://62.2.107.106/~beat/images/16-11-04/schulze2.jpg)
gear shaft (http://62.2.107.106/~beat/images/8-04-04/welle.jpg)
fixed in 1st gear (http://62.2.107.106/~beat/images/09-04-04/blwelle4.jpg)
modified gear shaft with 4 pins (http://62.2.107.106/~beat/images/18-12-04/fourpins2.jpg)
whole BL savage (http://62.2.107.106/~beat/images/21-07-04/titans2.jpg)

and here an old movie from last year. rightclick and save as (30mb) (http://62.2.107.106/~beat/Dateien/SavyJumping2.mpg)

[glypo]

Thanks for the reply :)

However I can't find the kit on any of those sites :( I don't know German, but clicked on every link but couldn't find it on either :(

[rhylsadar]

hi
yes possible they do not have it online yet. there was another shop you sold those kits before. but now you can get it there. just send an email. they will understand you. :-)
rhylsadar

[BL_Force]

I looked at that kit, but I couldn't justify the cost versus how it looked, so I figured out a better solution.

[glypo]

Hello again everyone, hope you are all well.

I've got just a quick question if I may.

Basically I've been told a Lehner 2230 with a Schulze 18.129 will be more powerful then the bigmaxximum by some people, and that the Bigmaxximum will be more powerful by others.

Ideally I'm looking to run 18 cells with the Savage. Info on the net that I've found also seems to be inconsistent.

So any help will be much appreciated,

Thank you.

[starluckrc]

By the numbers, the Pletty has a longer rotor. I'm sure Lehner packs more copper in the can. Should be pretty close. Either is more than you can use. I'll take the 4-pole Pletty myself for that application.

[rhylsadar]

hi
yes the 2230 is pretty powerful. if you use a lehner you can also go with BK controllers. for the pletty you need the schulze.
whatever you choose that beast will be very powerful.

I looked at that kit, but I couldn't justify the cost versus how it looked, so I figured out a better solution.

well what cost is justified depends on what abilities and opportunity costs you have to produce things by yourself.
i like your solution for sure. if it is "better" is difficult to say yet. it is different. i now have run over 500km with my bl savage only bashing it in the gravelpits. holds up pretty good.

rhylsadar

[glypo]

Thanks for the replies everyone, much appreciated as usual.

I'm going to have to do this project, just they dont really seem that powerful in photos.

Seen my mates Picco .27 with 3 speed, and that goes like a rocket. I'm not sure if an 18 cell brushless set-up will keep up :(

[Reinhard]

hmm..
if the 18cell setup doesn´´t keep up:

well:
take a 2230 Lehner..
give it 8s Kokm 3200 ( 720g light, so comparable to 12cells Sanyo 2400 in weight)
or 8s2p 4200mAh ThunderPower Prolites.. ( 650g light, comparalbe to 10cells GP3300 in weight !!)

BUT: the batts will have 27Volt under load !!
they can put out 2200Watt in peaks easyly
or 1300Watt continously !
(18cells GP3300 can put out around 800Watt continously)

so:
you will get a truck that weights less because lighter batteries..
drives longer because of higher voltage and higher capacity
has a lot more power
and runs at higher efficience because of much lower currents and higher voltage

the only downside: the batts are not the cheapest..
but if you want REAL power (and reasonable runtime), the only way...

(oh: if that is not enough, you can go to 10s or 12s... power of 3000Watt should bow away the diffs like nothing *lol* ... (the Plettenberg BIGMaxximum is rated with 1800Watt, the Plettenberg Maxximum with 1000Watt))






and that will result in

[glypo]

Thanks for the reply Reinhard.

I was always under the impression that LiPo packs didn't have a very high current output? However I think I must be wrong now.

I've been in contact with someone for a long time now, and he's answered many of my questions, and I cant say too much (I don't think) but he's sorting me out with a good conversion kit. It was going to be for 18 cells, but I think I might need to contact him and say I will be going LiPo.

I have also been told that they have the tendency to explode and can ruin the ESC. As for the ESC, if I use a Lehner 2230, I wouldn't be able to use a 18.129 with these LiPo’s would I? I suppose a 24.149 would be happy though?

However I take it I would be able to take on the Picco 27 speed savage with this set-up?

Once more, thank you all so much for your help, I’m so glad you are all so generous with your help. Saves me wasting a lot of money!

[Reinhard]

ave also been told that they have the tendency to explode and can ruin the ESC. As for the ESC, if I use a Lehner 2230, I wouldn't be able to use a 18.129 with these LiPo?s would I? I suppose a 24.149 would be happy though?

well:
if you use 18cells with 18.129

let say: 17Volt * 129A = 2200WAtt theoretically Power (NICd/Nimh will deliver 17Volt at there best with 18cells at 129A)

so: now let say you go lipoly and 10s (5s on each side of the truck)

to reach the same 2200Watt power:

2300 / 33Volt = 65A --> only 65A are needed...

so: you don´´t need necessarely a 149A controller !!!

a 90A controller which can handle 10s should be enough and there should be still enough safety left..

(10s - 90A ---> comparable to 18cells and 175A !!)

===================================

a bk-electronics 3670 micro car costs $308,20US$
10s * 70A = 2300Watt

the controller can handle that continously..
you will only see it at short peaks...
so: controller is safe
lipos (kokam 3200) can handle peaks up to 90A.. so batts are safe

compared to NiCd:
for that power on 18cells you need a controller that can handle
150A
batts: well: 150A IS a lot of stress for batts!

a bk-electronics 20120 which can handle 120A (so still weaker on power than the 3670 on 10s) costs already $467,66

[Reinhard]

Lehner 2230/13 with 10S lipos
http://www.lehner-motoren.de/diagram/2230/2230-13.33s/liste.txt

Plettenberg BigMaxximum with 18cells
http://www.plettenberg-motoren.com/Daten/PDF/Daten/MAXXimum/HP220BIGMAXXimum.pdf

we can see:
BigMaxximum 18cells: at 70A current 1140W POweroutput at 90% efficience
at 30A 530WAtt at 91%

2230-13 10s Lipos: at 39A current 1200W Poweroutput at 93% efficience
at 17A 530Watt at 92,4%
at 56A 1851Watt at 90,4% (still higher efficience than the BigMaxx at 1140Watt)

you can see:
2230 is less stress for controller (at 40A more power than bigmaxx at 70A)
2230 has higher efficience than bigmaxx
2230: batts see lot less stress: 56A enough for 1800Watt.. lipos can handle that for minutes where as: 70A on 18cell-setup are only 1150Watt and already hard for NiMh !

2230: 380g
BigMaxx: 355g

BUT: 18cells GP 3300 --> 1150g and: 71Wh energie on board
10s Kokam3200 --> 900g and: 118Wh energie on board

more power, better efficience, cooler components, 200g less weight, 40% more runtime
longer lifetime of the lipos (because see less stress than the NiMh on weaker 18cell-setup)

if you have the money: go for the lipos !

[glypo]

Wow, you clearly are very clued up on this.

Thanks a lot.

I think I like the sound of 10s 3200mAh Kokam. I take it the power from the Kokam and Thunder Power is about the same? The Kokam seem a lot cheaper so the slightly shorter battery life wont matter a great deal, as long as I can’t get 6 minutes I’ll be happy :)

I take it I could expect at least 6 minutes? If not I might have to get the ThunderPower ones which seem to cost more :(

Once again, thank you so much, you really know your stuff :D

[Reinhard]

well..
with 10s kokam 3200

i think you get around
2.5 to 3times the drivetime you would get with 12 GP3300 at same powerlevel

and
1.5 to 2times the drivetime you would get out of 18 GP3300 at same powerlevel

so i think: with 18 GP3300 you will see 6-10min drivetime..
so with 10s kokam 3200 i would expect 10-15min

remember: double power in the truck does not mean, that your batts are empty at halfe time, because:
you won´´t drive all the time full throttle..

this peak-power will be only in some short burst...
when you accelerate the current will be the first few seconds maybe double as high as when you go with full throttle at full speed...

(have seen some graphs out of an hpi super RS4 with 4s3p lipos: at accelerating it saw around 70A peaks for first second.. but after 2 second when it reached full-speed (around 50-60mph) the current was only 30A....

what i wana say: on driving around in curves or on shorter tracks the power of 12cells vs. 18cells vs. 10s lipo setup will be the very same..
so about same energie used out of the batts..

the high power is only used for few seconds when accelerating..
(remember: a truck at 50mph is very fast very far away, so you have to brake, turn, ....)

[glypo]

Reinhard, you're the best!

Thanks for the help. I'll get into contact with my brushless guy and see what speed controllers he can offer me for 10s LiPoly, should be crazy speed!

Thanks again!

[Chase023]

The Lehner 2230 clearly is a more powerful set-up, but the BigMaxximum is not too shabby either.

Here are 4 videos I have of my Stock E-Maxx and my modified E-Maxx on 18 cells with a BigMaxximum.
(Remember the truck in the vids weigh about 14-14.5 lbs)

This should give some idea on the power of some of these brushless set-ups.

Super G-Maxx Test Run Part 1 (4.7 Megs) (www.juggernaut23.com/Rc%20Vids/Super%20G-Maxx%20Test%20Part%201.wmv)
Super G-Maxx Test Run Part 2 (8.3 Megs) (www.juggernaut23.com/Rc%20Vids/Super%20G-Maxx%20Test%20Part%202.wmv)
Super G-Maxx Test Run Part 3 (8.0 Megs) (www.juggernaut23.com/Rc%20Vids/Super%20G-Maxx%20Test%20Part%203.wmv)
Super G-Maxx Test Run Part 4 (10.8 Megs) (www.juggernaut23.com/Rc%20Vids/Super%20G-Maxx%20Test%20Part%204.wmv)

I need some guidance on which exactly LiPo set-up I need to run my current set-up to equal the 18 cell set-up I have now. I can't have the batteries be longer than an standard sub C 8 cell length side x side. :D

[glypo]

Thanks for the reply, the truck looks pretty nippy with that set-up, however doesn't look like nitro speed?

This question is mainly for Reinhard, or any other people who are clued up on brushless stuff. I've been speaking to a mate who is very clever, he said he hasn't been keeping up with the lipo or brushless scene, so he thinks that he's "probably" wrong.

However these are his comments (edited down):


Take kokam 3200 cells, 20C - that means peak current output 20x3.2A = 64A. Enough? but 10s2p pack of them is 20 cells, 6400mAh and 128A max draw.
I just don't know if 10s1p will cut it. The hope is that you can gear low enough so that you don't pull the huge current I guess - that way you don't need the crazy 100A+ controllers either. Get your power from high voltage and back off on the current.

Maybe I am slightly rooted in the past, when nobody would consider running anything 1p in a car. But you would also have twice the batt weight and cost and weight = poor handling in a race truck, no amount of power can overcome that


So do I need to run 10s2p?

This person is VERY clever, but admits himself he's been away from the lipo/brushless thing for a little while.

Thank you all, don’t know where I’d be without this forum!

[Reinhard]

glypo: your friend says nothing wrong..
(hope i have understood everything with my poor English-knowlege)

here some discharge-Graphs from heli-use of the Kokam3200:

the currents:
http://toedtli.ch/div/diag-01.jpg

the corresponding voltage:
http://toedtli.ch/div/diag-02.jpg

hmm...
some posts ago you were happy with the step from your 12cell to a 18cell-setup (around 1800-2000Watt maximum Power)

and now you are wondinger if the 10s1p which can peak you with 90A at 3,2Volt per cell = 32Volt*90A = 2900Watt

the 18cell-system can give you 1800-2000Watt very short..
the 10s1p Lipo will give you this 1800Watt for minutes !

and for weight:
the 10s1p Lipo are around 850-900g
the 18cells 3700 are around 1150-1200g

believe me: a 10s1p kokam3200 will blow a way a 18cell-system like nothing !!!

(infect: i for myself see no need of more than 600-800Watt power in an emaxx.. its also up to 40mph fast, but not that stressfull to the parts...)

[Chase023]

I really need to do some research on the Li-Poly packs so I can use them instead of my GP3300 on my other projects.

So I am assuming the to make a 10s, I would buy say 5 of 2s cells where it is attached using some type of module or some series connector??
Are the Kokams the best in discharge and capacity??
Using Lipoly cells might help me out alot on my project. I might have to really think about it due to weight savings.

Not too familiar with the LI-poly batteries other than my small Thunder power 3s1p for my Xray M18 touring car.

Isn't a 10s kinda equal to like a 29-30 cell GP3300??

[glypo]

Reinhard I can't thank you enough.

So basically 10s1p will be very fast indeed, much so over 18 cells. I'll get 10sp1 then, no point in adding all that weight to an already very fast car!

Thanks again!

[Reinhard]

@Chase023: what is your projekt ?

the kokam3200 are the strongest lipos (for C-rating) in the moment..
glypo wants lot power .. so Kokam3200

if you want a very good capacity/weight-rating, the Kokam3200 are not good at all..

82g weight for 3200mah..

compared with Thunderpower Prolites: 2p weight only 74g but have 4000mAh

depends in what you want and need...

normal persons (sorry glypo ;) ) don´t need over 2000Watt in an E-Maxx
but still:
also the Prolites can deliver over 2500Watt in peaks as 10s2p and are even 100g lighter than 10s1p Kokam3200 at 25% more capacity...

what is your project ?

[glypo]

normal persons (sorry glypo ;) ) don´t need over 2000Watt in an E-Maxx
but still:

I know I'm crazy :) :)

This is my other project car:

http://www.glypo.co.uk/image/menace1.jpg

http://www.glypo.co.uk/image/menace2.jpg

It's a Schumacher Menace, with the stock rather poor Thunder Tiger .21 engine and it's 3 speed transmission it went 70mph. It's now got a Picco .26 which pulls the 3 speed with high gearing, and it is FAST!

I know the Brushless Savage wont be as fast as the Menace, but hopefully it'll be fast enough to keep me happy :)

[Chase023]

First, I am deciding on using a Plettenberg Bolido for my 5th scale FG McLaren F1.
I am waiting on their 4WD conversion to go ahead with the brushless conversion. I am thinking a 10s would suffice being it that it is =~ to 30 GP3300 cells.

Also I have a Custom Monster Truck that I might think of using Two Plettenberg Bolidos. (No its not my nor an E-Maxx, hehe) At the moment I have two BigMaxximums mounted using 36 cells. This is in no way of trying to get a specific performance or anything like that, I am just going for all out brute power for fun. About the weight thing, I am not too worried but I think having less than 7 lbs of batteries would help it out a little. Anyhow I might not even use the Bolidos on this but just a thought and just foreplanning just incase I decide on trying the pair out. Also using Li-Poly cells might help me with battery spacing and using 60+ GP sub C cells would be outrageous so maybe 20+ lipoly cell might be a better go at it.

Glypo, that is a nice Truck you got there.
I not too sure if you can really compare that with a monster truck, but I have seen a 70mph E-Maxx by some guy which is crazy fast for a MT.
I hope you post some pics of your savage once it gets it's brushless conversion done.

[glypo]

Ok, maybe this 10s1p was a bad idea!

I have been into contact with the person I'd be getting the gear from and his comments have made me change my mind:


10S 1 p System is dangerous, the Voltage exceeds the Human killing Voltage (wich is defined by 42 Volt at 1 A) by a few Volts and even a much more Amps, this System could be really a Killer.

I don't want to die!

The Lipos will weight around 2 kg then and eat up the room of around 6-7
Sub C 6 cell packs !!!!
THAT is WAY too much in such a small car, the weight to power ratio will
be very bad.

Heavy = bad handling, something I don't want also

The ONLY fitting esc will be the 40.160 K from Schulze (but the size will be the problem: 120x71x20 mm at around 250 gramm of weight, it has NO BEC, so you need a extra Pack, more( you might need a giant scale servo for the heavy weight)

The power requires BEC packs, and generally more weight all around, something I'm trying to save.

you might come to a electric system of around 3 kg and then a
car of not under 6 kg making a total not under 9 kg, (in general i calculate over 5,300 USD for the whole System !!!!!)

That's one heavy truck, the money is a lot as well, I'd rather spend less then that :eek: However, I'll spend a lot, just 5,300USD is a LOT, a lot more then I had originally planned. Maybe 8s1p will be better?

Oh dear!!

[Reinhard]

sorry, but nearly everything you rfriend said is nonsence..

1.) killing-voltage is defined at 60Volt...
here in europe for that there is the "small-voltage-law" that allows only to use ub to 42volt in rc-models..
thats perfectly true for 10s fresh from charger..

32cells-models (= 45Volt fresh from charger) are used for around 15-20years now in RC-planes, boats and some big-scale rc-cars..
nearly every motor-manufactor offers controller for up to 32cells..
(Kontronik, Schulze, Plettenberg (Brushed and brushless),bk-electronics, Jeti, .....)
so: this is prooven to be save for over 15years...
in my rc-plane-club 5 people have planes with 27, 30 or 32cells..
no one has died so far ;)

for the weight:
wrong...

18cells GP3300 - as said = around 1200g --> possible continouse Poweroutput: around 800Watt
short for seconds: around 1800Watt

Lipo:
for example 10s KOkam3200: around 900g (SO LIGHTER !!!)
--> possible continouse Poweroutput: 1600Watt
short for seconds: around 2700Watt

or: 10s2p Thunderpower Prolites 4000mAh:
around 840g weight (SO MUCH LIGHTER THAN 1200g GP3300)
--> possible continouse Poweroutput: 1500Watt
--> 10 seconds long: 2600Watt
--> short peaks: 2800Watt

--------------------
so: heavier ? NO.. your friend is wrong (or you have posted out of concens)
not powerfull enough at light weight: no... stronger than heavier GP..

no controllers for 10s lipos ? wrong...
many controllers.. and in some way even cheaper than a low-voltage controller with higher current-rating !

oh: this Lipo-facts are not invented by me...
so many Helis fly now with lipos.. (nearly all) because power is absolut amazing..

for example:
AcrobatSE: before:
12 GP3300 with 780g weight.. Power: up to 800-900Watt
Flyingtime: 6min

AcrobatSE: now:
5s Kokam3200 with only 450g weight... Power: up to 1450Watt
Flyingtime: 6-7min (but with much more power and less weight)

you don´´t believe it:
look here:
Video from AcrobatSE but only with 4s !!! (with 5s much more power)
http://www.eheli-tuning.de/acrobat_se_samuelis.avi

or this here:
http://www.eheli-tuning.de/acrobat_se_ploechinger.avi

or: this with 10s Lipo:
http://www.eheli-tuning.de/acrobat_shark_ploechinger.avi

---------------------------------

what i still thing:

instead of plettenberg BigMaxximum
(with 18 cells)

a Powersystem of
10s (under 1kg batt-weight)
with much less currents, less heat and more runtime
on a Motor from - for example - Lehner 1940

would greatly outperforme the Bigmaxximum combo..
lighter... less heat...
more power...
more runtime..

[Reinhard]

oh: for BEC:

you safe 400g weight at the batts, and can not afford 80g weight for a RC-battery ?? :eek:

or:
you can also use a Lipo for RX with electronic unit:
2s Lipo with 1000mAh weights only 32g... to bring voltage from 7,4Volt to 5Volt will weight only 2-5g

or: you can use a extern BEC which works very fine..

many RC-Heli-pilots use them in there helis with 10s lipos... (or even 12s helis...)

besides: on a classic 18cell-setups with Plettenberg bix-Maxximum you will also need a extern RC-battery, or a extern BEC...
so thats absolut no argument at all!

[glypo]

Thanks for the replies again.

I have to say that heli looks impressive.

I have to say, I'm confused again. I've got one person telling me one thing, and another person telling me something else!

As for lipos, the general saying: "when using lipo the less weight
results in less amp draw"
Isn´t that correct at all, the Lipos do have higher voltages (single
cell: Nimh: 1,2 V Lipo: 3,7 V) so if ya use more lipos (maybe 3 instead
of 6 nimh cells) you´ll have other voltages to use (7,2 to around 12 V
in this comparison) so the amp draw for the SAME Motor will go down (if
the Motor could hold the Voltage without getting damaged)

But the comparison is a bit like comparing bananas and apples:
The used motors aren´t the same, the lower voltage Motor has to have
higher RPM/V to reach the requested RPM and the higher Voltage Motor
will use less RPM / V as the higher Voltage will push the RPM up, so 2
different Motors are used.

In General: Lipos are the way of the future, if ya really want the
lightest system in comparison to the nimh system (SAME Motor and rest
electrics) then lipo is really the way.
If ya like the more mAh of lipos (thus coming to more running time) you
are OK too.
If ya really wanna use the lipos to get the same mAh but much higher
voltages (as 4 cells equals around 14-16 nimh cells) in a car that
normally would use 12 cells, they could run 22 V (normally around 14V)
then you´ll have a differend system at all.

The overall saying that higher voltage will result in less amps is not
that correct at all, if ya need 600 W and 12 V you´ll have around 50 A
draw, if ya get 600 W with 20 V you´ll have 30A that is way lower, but
another motor is needed to get the same RPM than in the 12V exsample !!

[Reinhard]

OF COURSE you need another motor (or at least other winding)...

thats the whole thing about it..

yes: you can gear it very high, so you can use the same motor with higher volts... but that will not neccessaryly bring down the amps, because on heavy loads, the motor will produce MUCH more power and the amps will be as high (or even higher) as before..

so:
the whole thing is:

instead of 18cells GP3300 ( around 1150g heavy) and 20A average current (durring 10minutes, about 430Watt average Power)

use a different motor with less rpm/volt
and 10s Lipo with 4000mAh (only 850g weight) and 12A average current (durring 20minutes, about 430WAtt average Power)

THATS what i wanted to say...

(take a paper and pencil and calculate it to verify...)


----------------------

oh: besides: in another forum somebody equided a F5B-Plane with Lipos:

F5B-Plane normally: 18cells 3300GP, currents around 160A for 3-6seconds !!!!

he now uses 9s Kokam3200 --> much less weight... results in faster acceleration, easier landings because of lighter weight..
currents are only around 85A --> cheaper controller, less heat..
and nearly the same power:

18 cells NiMh: 17Volt * 160A = 2700Watt
9s Kokam3200: 29.7volt * 85A = 2500Watt

with lighter weight of the plane about the same power, but much less weight and double runtime..

[Reinhard]

just found a direct comparison between
GP NiMh 3300 and Thunderpower Lipos (the old generation from 2004):


Video 1: with 12 cells GP 3300 (http://www262.www2.nefserver.info/Videos4/acrobatse.avi)
--> battery-weight: 760g
--> flighttime: 6-7min
--> battery-lifetime: around 50-70flights (= 300minutes - 500minutes)

and here the same model, but with lipo:
Video 2: with 4s3p 6000mAh Lipos (http://www.eheli-tuning.de/acrobat_se_samuelis.avi)
--> battery-weight: 490g
--> flighttime: 10min like on the video (15min with the power shown on video 1)
--> battery-lifetime: around 100-150flights (= 1000minutes - 2200min)


with the newer generation of Lipos things are even better for lipos..

at least you can see (again):
MORE POWER
MORE LIFETIME
LESS WEIGHT
MORE AGILITY of the modell
MORE RUNTIME

[glypo]

Thank you so much Reinhard,

As you can tell I'm very new to the whole brushless thing, and you are making me really understand it now.

So if I get these Lipo cells, it'll be alright as long as a I use a motor with more turns? (hence lower rpm/volt). You have really helped with this, thank you so much, it's all so much clearer in my head :)

[harley1874666]

5-7 minutes? is that it on a brushless savvy? i was considering going this route with a third savvy but it hardly seems worth it with that kind of runtime.

[nitro_freak1]

id say if u want power and stay in a budget get a warrior 9920 and a feigao 7XL... u will get AMAZING power out of it and can run 14-16 cells i beleive. to be honest i think the others are WAY over priced.. for this setup it will run u about 280-290.... get up with MIKE at http://www.rc-monster.com he will hook u up. cuz i dont see a point in spending 400 on a esc when u can spend 200 and get the same or VERY VERY close amount of power. just my .02 ;)

[harley1874666]

sounds good, i'll hit him up with some questions.

[badboy2]

man these brushless set ups are too much $$ is there anything i can find for around 200bux?i just wanna go like on a basic brushless set up...maybe starluck can recommend some

[nitro_freak1]

well if u want a CHEAP burshless u can get the novak one.. there goin for around 200-220... but they run hot. and ur n ot gonna get the power like u will with the warrior combo. i would just spend the extra 60 and get it... just stop being cheap BB2 and get it... u know ur made of money LOL

[badboy2]

kev show me the links of motors and esc's i can match

[nitro_freak1]

here is the ESC.
http://rc-monster.com/proddetail.php?prod=9920warrior&cat=21

7XL
http://www.rc-monster.com/proddetail.php?prod=feigao5407xl&cat=36

10L
http://www.rc-monster.com/proddetail.php?prod=feigao10l&cat=36

9L
http://www.rc-monster.com/proddetail.php?prod=feigao9Lmotor&cat=36

8L
http://www.rc-monster.com/proddetail.php?prod=feigao5408L&cat=36

there ya go bud ;)

[badboy2]

can i use 540?i thot i need 550?

[nitro_freak1]

u can use every motor i just posted.. u can run a 540 or a 550 in the emaxx..... the titans (stock motors) are 540's and the JOHNSON's are 550's ( i beleive) buyes u can run either one.....

[harley1874666]

can you get the motor mount from rc monster also?

[nitro_freak1]

i beleive so, just PM mike there if u dont see it posted he may have one

[badboy2]

harley for which truck are u lookin for?i might find some on my search ..

[harley1874666]

the hpi savage.

[nitro_freak1]

no there is a place ( http://home.comcast.net/~milemarkers/Products.htm ) that sells a conversoin for it. its 100 bux for it and it comes with almost everything u need besides esc (its not a BL motor tho :( )

[badboy2]

man if i only knew about this i could have done it long time ago
..there u go harley thats a good deal

[nitro_freak1]

yea that is the CHEAPEST conversion out for the savage.... comes with everything besides esc. its a BARGIN!

[harley1874666]

so 100 for the conversion, and 200 for two evx controllers. i don't really think that's much of a bargain.

[badboy2]

so 100 for the conversion, and 200 for two evx controllers. i don't really think that's much of a bargain.

just get the 99bux it will come with everything except esc ...evx esc is cheap..better than getting the 169 conversion only from rcboyz which doesnt have motor or anything,when the dewalt conversion u get motor and mounts but no esc only

[nitro_freak1]

y do u need 2 evx????? thats what im wondering. u need 1 yup thats right 1 u can pick one up for around 50-70 bux. so 170 tops and u have the whole converiosn and she is ready y to go.......

[badboy2]

i think if he goes dual set up he needs2 escs..

[harley1874666]

yes, dual requires 2 esc's to run properly using two batt packs.

[danhfvcsd]

That fella also does custom work too - although there's a 3month waiting list -lmao- Not a problem waiting for me tho - so i got him doing up two custom mounts for me and a mate like "joeling's" mount design :)

[mothman]

Hey danhfvcsd, Im planning to ask him to fabricate the "joeling's" mount too. How much do you have to pay for the motor mount to be fabricated? Is that mean you have to wait for 3 months??

[danhfvcsd]

yeah - that's 3 months before he can get round to starting it -lol- But since i am gonna be doing this slowly, i am in no hurry ;) I got a BL-LST on it's way -lol-

We're thinking of getting it done using 7075 alum, and maybe a lil thicker - cost was roughly quoted around USD$80 for TWO of them - and shipping - so yeah - pretty cheap if you ask me and don't mind the wait -lol-

Here's his email if ya like - he was a real nice fella too ;)....not to mention he has one of the best names ever :rolleyes:
dan@kershawdesigns.com