Lehner 2240

[Promod]

Here is a short, low quality vid of my one E-maxx. The power system was a Lehner 2240 motor and Schulze 32.80 speed control with 24 worn out cells. The truck has a 1/8th buggy center differential.
This was the first run with the diff. I see that the truck needs new cells and much heavier oil in the center diff(40,000 now).
My Eagle tree system recorded watts over 2600!

Sorry for the poot quality of the vid.

http://www.rcpics.net/img/49861

Here is a picture of the center diff.

http://www.rcpics.net/img/49862

Thank you,
Promod

[RC-Monster Mike]

What kind of speed did your eagle tree record with that setup (if it records speed)? Definately cool. We are working on a center diff/slipper setup currently. What diff is that (kyosho mp5?)? The plastic gear is a nice feature to be easy on pinion gears.

[Promod]

Mike,
I don't have the Eagle tree set up to record MPH. It is the same motor and speed control that went 70 mph. But this truck with the center diff and G-maxx chassis is close to one pound lighter than the 70 mph truck.
It is an ofna diff but I'm not sure which one. The spur gear is the same one used on the strobe slippers.

Thank you,
Promod

[RC-Monster Mike]

So a 51 tooth spur? Cool. Do you or have you done any rough off roading with that setup (racing on a track, for instance)? I am curious how well the diff holds up without a slipper.

[lipomax]

That's a great idea! What tooth pinion gear are you using? In addition, is that a 2240 12 turn? With a "center diff", if you held the rear tires, do the front spin x2 as fast? I'm no familiar with 1/8th scale. Thanks!

[lipomax]

Oh, one more question - I notice you only use 4 shocks too - which shocks are those? I'm using the stock ones and even with 100 weight oil, the plastic bodies expand too much and don't dampen very well.

[rc4x4nut]

:eek: What does your truck weigh? I think I am going to have my gmaxx go on a diet.

[Serum]

Those are Ofna 9.5 shocks. cheapest way to get them;

directly from UE, 67 dollars /4 pieces.

I use 4 of them on my heavy weight savage.

[Serum]

FANTASTIC bytheway..

SUPERB centerdiff..!!!! Are you willing to share what particular parts you used?

Do you think a plettenberg bigmaxx is able to pull this with this lower gearing ratio?

What 2240 do you use? How does it drives on 16 or 18 cells? does it stay below the 100A on a cellcount like that? (perhaps i can use the 18.97 controller on it..?)

[Promod]

Mike,
Yes it is a 51T spur. I've never ran it on a track just in the yard. Wouldn't the center differential act as the slipper clutch?

lipomax,
I'm using a 15T pinion gear. Final drive ratio is 11.25:1. It would be the same as a stock E-maxx geared 30/69 in 2nd gear. The motor is a Lehner 2240/12. With the center diff the rear tires don't spin any faster. There is no gear reduction in the center diff. The center diff can be "tuned" with different weight oil. This is suppose to help the truck handle better for racing. But the reason I installed the center diff was to save weight and have a much higher gear ratio for future speed runs. The shocks are UE Supershocks.

rc4x4nut,
The truck RTR but no cells weighs less than 7 1/2 pounds. The center diff saved almost one half pound over the ultramaxx tranny I was using. The 2240 motor alone weighs 1 1/2 pounds.

Thank you,
Promod

[Serum]

Do you know how much current it draws on 16 or 18 cells?

[Promod]

Serum,
Here is the center diff used.

http://cgi.ebay.com/ws/eBayISAPI.dll...957238305&rd=1

Here is where I got the custom rear drive shaft.

http://www.rcalloys.com/

The rest was just fabrication. It really was not that hard.

Never tested a Plettenberg so I really can't say. I've got a 2240/10 running 18 cells in another E-maxx. It spikes to 107 amps but pulls 60 to 80 amps normal. So the 18.97 should work fine.

Thank you,
Promod

[Serum]

Thank you! here is one upcoming 2240/10 driver then!!!!!

How fast does it goes on 18 cells?

What gearing ratio are you using with this setup?

Perhaps i could also drop in a 9918 for this 2240/10 then

I really love that eagletree system..

[RC-Monster Mike]

The diff would act as a slipper, unless the front and rear wheels happened to land at the same time (which could happen a bit on a track). The reduction is also tricky with just a center diff (tall ratio requiring slow motors), and the mod1 pitch is not run of the mill. My design uses the top shaft of the e-maxx tranny (and therefore the stock slipper clutch/spur gear) with a center diff. The reduction is similar to the stock tranny (actually a little more reduction), but lighter and the tuning abilities of the center diff.

Lipo- - Yes, if you hold the front, the rears will spin faster, just like any diff. The only reduction is the pinion/spur as promod suggested, but the diff works like any other diff otherwise.

[Serum]

Fill up that sucker with 300K.. It still would not wheelie..