LST2 Conversion

hi,

i think about a lst2 conversion.
i want use 6s2p a123 batteries, a mmm v3 and a 10xl motor.

here a pic of the motor, i dont know who is the manufacturer:



what is recommended, shall i use the 2speed adapter or the smaller pinion only?
do i have any advantages if i use 2speed?

is there a chance to use the original 2speed clutch bell with an adapter?

[lincpimp]

Sounds like a good setup, Should work fine.

If you keep the 2 speed you will have to keep the mech brakes and reverse. I recently completed a conversion on an aftershock. I used a tdr single speed hub which removes the 2 speed spur gears and allow the use of the bolt on 2nd speed gears. The aftershock has the forward only trans, so I can use the motor brakes and reverse. It works fine, and the MMM has plenty of power for brake and reverse. All of the tdr products are available on the lst forum, not sure if you are a member there, but it is the best place for lst info. If you want to keep the 2 speed, RCM makes an adapter that allows the use of the stock lst clutchbell gears with a 5mm shaft motor. You will need to make a motor mount, or buy the recently released tdr mount.

i would like to keep the mech brake.
i think this will give me more runtime at a racetrack?
can you send me a link for the tdr motor mount?

[brushlessboy16]

Since the MMM uses regenerative braking, I think using the esc brakes would actually increase runtime. just my 2 cents

Here is a link to the custom/conversion page on LST Forums. There are threads for both the motor mount and the TD-Racing web sight, neither of which are ready and or running quite yet; but soon.

http://lstforums.com/forums/viewforum.php?f=42

I'm in aggreement with Linc on using motor braking for racing. The MMM brakes are more than adequate @ 40 or 50% and although I'm not an engineer I don't think running mechanical would give you any extra run time. I have also found that positioning the battery forward of the tranny to work perfectly. My truck runs equal or better lap times with the quicker nitro Revo's as long as the driver is'nt choking. Check it out here:

http://www.rc-monster.com/forum/showthread.php?t=14092

Originally Posted by brushlessboy16

Since the MMM uses regenerative braking, I think using the esc brakes would actually increase runtime. just my 2 cents

can anybody confirm this?
this would do my conversion alot easier because i have more space for the 12 a123 cells.

is anywhere a pic from a lst2 with 6s2p a123 cells?

can i use the mmm bec or shall i buy a ubec? i dont wanna kill the mmm :)

[lincpimp]

Yes, forward battery mount is a requirement for better weight distribution and steering. If you take the brake and reverse servo out most packs will fit well between the radio box and tranny. And the esc can then be mounted where the fuel tank normally sits.

cool, then i will use the esc brake.
and the brake will not coast runtime?

[othello]

While braking energy is stored back to the battery.

Take a look at this graph for example


While decelerating Amps do rise as do voltage (comparable to recharging your batteries). As long as you do not apply throttle and your motor is still revving energy is stored back. The amount of energy depends on how hard you brake and seems to be "proportional" to motor RPM when you let off your brakes.

So yes, if you use ESC brakes runtime will increase somewhat.

[lincpimp]

Originally Posted by Burnsi

cool, then i will use the esc brake.
and the brake will not coast runtime?

Just remember to use the esc brake you need to run the forward only kit from losi and a tdr single speed hub. Those 2 parts eliminate the weak factory reverse setup and the one way bearing in the 2 speed setup.

hi othello, nett dich hier zu sehen :)
deine grafik geht nicht, kommt eine hotlinking warnung.



ok, i will take out the mech brake and use the esc brake.
its good, because i have more space for my a123 cells then.

thanks

[othello]

Ok ... i uploaded the graph again. It should be displayed now.



Take a look at those two amp spikes while decelerating. I must have hit the brakes 2 times. You would normaly expect voltage to drop but it is not ... it is rising which indicates that the current flow is reversed and energy is stored back to the batteries.