Lehner Basic XL 2800 on 24 volts?
 

I know the Lehner Basic XL motors are limited to 65,000 rpm. The rpm/volt quoted for the Basic XL 2800 is 2800 on the Lehner website. With 24 volts this works out to be 67,200 rpm. If this is the unloaded speed, would the loaded speed in a dual brushless powered e-maxx with this motor on 24 volts be less than 65,000 rpm? I was thinking about BK Electronics 12020 Warrior Controllers, 2 Lehner basic XL 2800 motors, and 20 cells. I would parallel wire the 2 speed controllers to get the full 24 volts with out having to use a total of 40 cells. Would this work, geared 20 or 21 tooth pinions and 66 tooth spur?

Speed chart for idea of speed

http://qcda.com/emaxx/speedchart.asp

Why do you want to do it that way? 20 cells to a single Wanderer XL motor like a 10XL would be a very powerful setup, and would be well within the specs of even a 9920. 20 cells total would not be enough to supply dual Lehner 2800s, unless you did 10 cells to each motor. You could run 28 cells total, 14 to each motor, though.

Overrevving motors is not a good practice, and in the case of the Lehner 2800XL, 2800 is the loaded kv. You can assume that the unloaded kv would be about 200 higher, so unloaded with the full battery voltage would yield a RPM of about 72,000, which is much too high. At that point you risk damaging the motor by way of the magnet coming loose. It's also possible that the bearings would seize, causing a huge current to be pulled by the motor(s), which could kill a controller (potentially).

There's no way you could reliably run 24v through the 2800XL. I run 21.6v on the 2000XL and the motor is already pretty toasty at the end of a run, wouldn't consider putting 24v through it. I agree with what metalman said, dual brushless in an emaxx is a waste of time (and money :D). A wanderer 10XL on 20cells is a lot more than fast enough in an emaxx

I fried a xl2000 on 18 cells for heat build up. If you going all out for that may i suggest a bigger motor on the 40 cells you planning on putting on the truck with one esc. You could drop back the cells size to a gp2200. It would be a crazy ride.

I run a Lehner 2800xl in my Ofna 9.5 buggy and it's hot after a run, gonna get a heatsink in addition to the fan it already has because of the heat it makes. I've got it geared 12/51, but think I might go to 14/65 instead which would be a little lower and drop the heat down a little. Problem with the Lehner Basics is the 1/8" shaft, limits the mod1 pinion selection and sometimes makes them fly off.

Thanks guys.

What about dual lehner Basic XL 2400 motors, geared 23 pinion, 64 spur, with 20 cells? And do the cells really put out a full 1.2 volts? I thought they put out a little less, making 20 cells on a Lehner Basic XL 2800 possible. If each cell only puts out a max of 1.16 volts under load, the rpm would be only 64960 rpm. I am running new GP 3300 cells, in a side by side racing configuration, not stick packs. I want the lehner because I insist on a screwed, not a pressed on motor endbell, and my friends all say Lehner makes the best motors for the price, $150 per motor is the most I want to spend, and I insist on the awesome look of dual brushless, I refuse to run single brushless. I just want to know if my set up is safe. I though if the batteries never put out more than 1.16 volts, the rpm would be safe. And I would not run the motors without a load. What other websites sell brushless motors?

Thanks guys.

What about dual lehner Basic XL 2400 motors, geared 23 pinion, 64 spur, with 20 cells? And do the cells really put out a full 1.2 volts? I thought they put out a little less, making 20 cells on a Lehner Basic XL 2800 possible. If each cell only puts out a max of 1.16 volts under load, the rpm would be only 64960 rpm. I am running new GP 3300 cells, in a side by side racing configuration, not stick packs. I want the lehner because I insist on a screwed, not a pressed on motor endbell, and my friends all say Lehner makes the best motors for the price, $150 per motor is the most I want to spend, and I insist on the awesome look of dual brushless, I refuse to run single brushless. I just want to know if my set up is safe. I though if the batteries never put out more than 1.16 volts, the rpm would be safe. I should have said 20 cells, not 24 volts, because I know the cells would put out less than 1.2 volts each. And I would not run the motors without a load. What other websites sell brushless motors?

Actually a full pack put's out more volt's than it's rated. Like 18 cell's would be 18 x 1,2 volt = 21,6 volt's. Wrong. Matched pack's when fully charged put's out more volt's. Like a 6 cell pack is around 8,4 volt's fully charged, instead of the 7,2 volt's it's rated at.

Do not forget this, it could blow up the controller.

The controller states for 4-20 cells, wouldn't the manufacturer consider this?
if the cells put out 1.2 volts, then 19 cells on the Lehner Basic XL 2800 would be 63,840 rpm and 18 would be 60,480 rpm. Is this safe?

I am not sure why you want so many rpms and such a small motor. It is your money though. What are your plans? You just going for a all out speed record. I wouldn't want to try and bash a xl2400 around on 20 cells. I am not sure i would want to bash a truck with 40 cells on it at all.

Would 2 motors heat up less because they could share the load?

yea, kinda. but the fact of the matter is that you shouldnt put that much power through a hot motor like that. i had a xl3100 on 12 cells and i fried it probably because it got really hot...and your setup will do exactly that. have you ever even owned a brushless setup? 2 is not only overkill, for less money you can have a better setup... i run a 10xl on 16 cells and soon 6s lipo and its plenty for me. actually, its to much for a race track. my point is, if you really want to run dual brushless, go with a wanderer with a rcm heatsink/clamp. the can wont pop, L would run alot cooler, and i personally think there better. the lehner basics arent all that. your friend is right and wrong, lehner does make the best brushless motor but not all of them are the best. the basics are made in china and the others are hand made in germany. the german ones are the best, but the feigao/ wanderers are just as good if not better than the basics. probably better since there larger and disappate heat better. keep in mind that the basic xl is only about the size of a feigao or wanderer S...

20 cells is way to much on such a small motor. if i was you i would go with a good single setup instead of 2. Its your money though.

I think the can would pop open 5 mins into the run!! :P

its just way to much for such a small motor

Who sells the 6 wind wanderer XL motors or the 8 wind L? Not available here. Are they available with a 5 mm shaft? Can they take 20 cells?

i wouldnt use either wit h20 cells and mike can get them if you really want them

The minimum XL motor that should be used with 20 cells would be a 8XL, but that would definitely be pushing the 8XL. For practical use, the 9XL would be a much better choice as the minimum, with the 10XL being possibly an even better choice.

extrememods; aim to keep the motor spinning at no more than 50,000rpm, ideally 35,000 - 40,000rpm is best though. For 20cells, the BASIC 1600XL would be perfect, or wanderer 13L / 10XL. For dual setup I would say the 10XL is absolute overkill. Personally I would not spend $300 on 2 motors, but spend the same on a single lehner 1940/1950. Dual brushless is pointless, and will be very hard on batteries.

If, for whatever reason, you do decide you want dual BL, I would say go for dual warrior 7020/BASIC 1600XL. I disagree with squee; my experience with the BASIC XL motors has been nothing but good.

What is your plans for this motors? Are you going for a speed record?

Yes, I want to beat promod. Can I do this with a Feigao, Wanderer, or Nemesis?

Oh! Well you can go with a bigger motor and more cells and you will be faster. The smaller motors are not as good to do it with.

extrememods, you'll need in the region of 3000Watts to reach 70mph. A single big motor would do the job (2250 minimum, ideally 2280 or 3060)

wow i didnt think anybody would really challenge promod but this is going to be interesting.

Well promod got 72 mph with a 2240. I think the 2250 on more cells would go faster. I couldn't get my setup to do right. I was going to shoot for about 80. Oh well. Back in the slow lane.

For a single run, I reckon a 2250 could push 75mph if geared high and with loads of cells. If promod made his record with a 2240, then the logical way to beat it is with a 2250 and even more cells. :D

Can I run a lehner 1950 4 winding (not the high amp version) on a BK Electronics 12020 Warrior Controller with 17 cells. If the motor puts out 1800 watts, the batteries supply 20.4 volts, that means the motor would only pull 88.235 amps, right? What pinion size should I use on a 66 tooth spur gear? Would this be a better setup than 20 cells on a dual wanderer or fegaio/nemesis L or XL setup, with the BK Electronics 12020 Warrior Controller?

Those power ratings are fairly meaningless,a 1950 is capable of kicking out alot more than that.The low winds only come in hi-amp,meaning you can solder direct to the windings for lower resistance,since the low wind motor will pull so many amps.A motor can only kick out as much power as the batts provide minus ineffciency.That's why you need to run the motor in it's efficiency range and gear for the speed,typically 35000-40000 max rpm,simply more power out for power in.The only way to an efficient high power set up is to go high voltage.
You need to decide how fast you want to go and how much battery power is needed to get there and then let us advise you on a suitable set up and theoretical gearing.It will require center diff or ginormous pinions with a maxx tranny to hit high speeds with 40000 rpm(You'll need a lathe to machine the pinions from gear stock).
Just let us know what vehicle and how fast you want it to go.

Vehicle is an e maxx, could the controller handle the 4 wind motor on 17 cells (3135 rpm/volt *20.4 volts) What other high amp, high voltage controllers are their, and how much do they cost? I want to gear low with high rpm

I don't know if you have read this thread or not. http://www.rc-monster.com/forum/show...=david+goliath

I think it has some interesting points and views in it.

What about a lehner 1950 6 wind sold here, on 20 cells then when I get used to the power, I could get a second controller and motor an have a total of 3600 watts. I want to step up slowly (1800, then 3600) to get used to the power.

Well by the time you buy the two controllers and motors you could have got one 2280 motor and one controller alot cheaper and it will pull alot of speed from a hi gearing. If you run 30 cells on a 2280 it should fly. If it doesn't tear the truck apart.

yeah go with a 2280 with a good controller you will be much more likely to get the speed you want with that setup.

What controller, could I use a 6 wind 2250 on a BK Electronics 12020 Warrior Controller with 20 cells? How many amps would it draw? Why are the 2250 motors rated at 2000 watts and 3000 watts? What would the perforance be with a dual lehner 3080 setup?

thats funny....dual 3080s. That truely is funny as hell. a 3080 is so big there would only be room enough for one. not to mention, you need 10mm pinions, there 700 dollars a piece, and it takes a minimum of about 24 cells to get it moving nicely. ONE 2280 with a center diff and aobut 28 or 30 cells should be plenty to beat promod. i think you should break 80 with that setup.

The drive line would never survive a dual 3060 setup. I had enough problems with one 2250.

What speed controls for dual 3080 motors? What about supermaxx parts? How fast could I go with an oversized motor mount (from my dual 970 sized motor kit) a load of lipos, and some fast gears? I want speed, but what kind of damage would a collision at top speed with this setup do?

did you read my post? it wouldnt be possible really. a 2280 would be more than enough to beat promod...

Well when you squee the trigger to get it to hi speed it would have shafts and gears flying out of the rc. try a dual 2280 first. I think the 36150 should handlethe power. It may even mount up to your 970 motor mount as well. I don't know if you have a brushless experence but you sure what a system that well desroy a driveline.

I've been running this setup for well over 5 years...I originally purchased this motor and controller setup...back in the day when Maximizer products was carrying BK stuff......back then I purchased a 1895 Micro controller with a 1920/8 lehner motor......I'm still running this motor today.....of which has more than enough torque and speed for me ...as for the controller...somehow last spring I managed to send 123 amps...thru the controler and fried it..according to BK....so I sent it in and they replaced it with a 2095 micro controller for about $150.00......Needless to say I was very happy...All I'm saying is while you want all this speed and torque...you might be spending alot of money and will continue to break stuff.....or your emaxx...might be so uncontrollable it isn't any fun at all......listen to some of the recomendations and pick something realitivly reasonable to what you want and have fun.....just my .02 worth....

ps...my emaxx....is geared the following..

13t pinion/66t spur
1920/8 lehner...2095 micro bec
12 cells matched in series....3300 nimh GP cells
8 spyder UE diffs
Gen II Ultramaxxed tranny gears....spare set of Gen III's if needed

If any one has any other Q's about my set up...just ask...