the lehner 1930 and bk9918 esc

[captain harlock]

I also have the associated rc10l3 touring so do you think that I can make som insane speed with it with just 8 cells and a high end motor like the 1920/4 turn motor for example?

[RC-Monster Mike]

You can get some serious speed in the rc10l3 for sure. Your limit will be the batteries ability to deliver the juice. 70-80 should be within grasp.

[captain harlock]

Hey, Monster Mike, what motor/controller did you use in your T2 to make it clock at 65mph? I think I was able to make such speed with my B4 when it was equipped with a Kontronik fun480-42 motor@12volts the buggy even lift the front end when it reached its peak because of excessive pace. Now I'm using the Lehner 1920/8 motor on the B4 with a Kontronik 55-10-32 controller, but strangely enough the car doesn't accelerate as fast as when it was with fun 480, although the 1920 is "torqueier" than the 480. I think the problem is in the esc itself because the motor might be draining more amps from the esc than the 480. the 480 drains 40 amps continuous and 60 amps surge, but the 1920/8 might be draining much higher amps than that whether continuous or surge, but either way I would like to hear from you people.

[RC-Monster Mike]

The Kontronic controllers are also notorious for only working well with the Kontronic motors. The fun series motors are nice (the one you mentioned is about the same as the 4200 basic). I was using a Shulze 58ce controller and a 6s motor when I did the speed run.

[captain harlock]

Well..dont you know whats the surge amp rate and the cont. amp rate for the 1920/8 motor? I looked at some info when I visited the LMT website, no info at all. Maybe you can tell. And which controller will suit the b4 in terms of size and the 1920 in terms of power?

[RC-Monster Mike]

The posted information about the motors (max amps, etc.) really is not indicitive of the actual numbers when driving the car. The 480 fun motor will out accelerate a larger motor in a small truck because it has a smaller rotor and can spool up faster. the 1920 can certainly supply more power for longer, though. How many cells are you planning on running in your b4? Mounting the controller will take a little creativity, but should't be too difficult. If you are running 8 or more cells, the 9918 will handle the job with ease. For less cells, the same controller will do, but would need a receiver pack for the best performance. The MGM 80 amp controller could handle the job as well, and is easier to mount (smaller size).

[captain harlock]

How many cells have you used to make the 65mph speed run? and by the way? haven't you checked the post of my DREAM E-MAXX? guess its a stupid one huh?:o

[RC-Monster Mike]

I just saw your dream e-maxx post. I wouldn't call it stupid, though. A rather nice dream, if you ask me.

[RCcarnut]

How many cells have you used to make the 65mph speed run?

I have been 62.5 mph on 9.6 volts(8 nimh cells) in my traxxas bandit with a 9918 and lehner 5300. When I order my 6s motor this week I think I can get near 70 on 9.6 volts, the 6s has a 5900 kv rating. We will see:)

These are short runs and at very high gearing. You would not be able to run this gearing all the time only just for a few passes or it will fry the motor or controller. Although you could just add a couple cells and probably get 60+ mph on normal gearing. I just don't have a ten cell charger so it's a pain for me to run more than 8 right now. I would not run more than 10 on the lehner 5300, 12 volts puts it right under its 65k rpm limit.

With the 5300 and normal gearing my bandit does about 50-55mph on 8 cells right now. Really fun to drive.

[captain harlock]

I just received the 1930/5 motor, but now I have a problem. When I use 7 cells with the motor it runs nice and cool, but at 12 or 13,2 volts the motor makes a very strange sound and it coggs to the point that it sometimes feel like the speed cont.(9918) cant deliver enough power, it seems as if the controller is about to shutt down. I really have no Idea what's going on. The 9918 works with the help of a 4cell receiver pack and I have took out the black jumper near the red one to disable the BEC system, May be it could be the problem, but may be not. If you say that I'm using too much cells then I dont really think so because there are som people who used 12 cells with such motor without having such problem. Monster Mike, I seek your help.:W:

[RC-Monster Mike]

The 1930/5 will be spinning at over 80000 rpms on that voltage (so yes, it is too high voltage if you want to have the motor for a while!). The controller should still handle it, though. Perhaps you could describe the sound a little better to me. Also, did you change the gearing when you added all those cells? Lower gearing woiuld definately be necessary. Another thing to try is a real receiver pack (5 cell nimh or nicad). the aa batteries are considerably less than ideal.

[captain harlock]

Well, I really didn't connect the motor to the spur gear yet, but you know, the motor for some reason stopped that wierd sound and its working fine now( after reprogramming the damn ESC) and about the 80,000 rpms, how did you know that the motor will be making such a high rpm rate? when I calculated the whole thing myself the motor was supposed to run at 55000 or more rpms, since the 1930/5 turn is rated at 4180 RPMs per volt so this rpm rate multiplied by 12-13.2 volts will give the 55000 rpms I guess and the receiver pack...Lehner said that I should be using 4 cells if the transmitter, servo and receiver are made by FUTABA.

[RC-Monster Mike]

I actually misread your post and thought it was a 1920/5 motor, which spins over 6000rpm/volt. Even your 1930 will spin that fast with no load, though. Interesting on the Futaba receiver pack thing. I am glad it seems to be working. It is not a good idea to run a brushless motor with no load (FYI), so please don't rev it up without putting a load on it. LMK kow you like it when you have it on your vehicle.

[Serum]

I just saw this thread.

You are safe, running this motor till 85000 rpms.. (it is a highamp version) That 50000 is for the non highamps.. (2240 highamp version permits 'only' 50000 rpm)

Sooooo

85000 rpm's.... Buckle up..

[RC-Monster Mike]

Safe is one thing. Ideal is another. either way, he should be fine, as his motor is a 1930, not the 1920 size I thought it was.