E-LST2 Project

[riceman]

Hi all – I haven’t posted much but have been lurking here since my first purchase from Mike back in July of this year. Since then I’ve put together a couple of trucks – G2R and an MGT. but nothing I thought really worth posting since most of what I did wasn’t too radical and has been done and posted here already. I guess that can be said of my latest project too but here it is anyway. It’s still a work in progress but it’s finally up and running. There are a few things left to work out (battery trays, location of mounting esc, clean up wiring) but I thought I would post what I have done to get to this point. Here is a short list of what has gone into it so far starting with a completely stock LST2 roller. I pulled out the OS30 which is now sitting in a parts bin (anyone need a nearly new OS 30?) and fabricated a motor mount using 2” 1/8” thick aluminum angle. The mount will eventually be beefed up to 1/4 “ thick angle to deal with any flexing issues but for now it’s doing the job for the initial test runs. Thanks to all who have braved the risks of testing the Mamba Max and posting their results or otherwise I may not have attempted this project.

Motor = Neu 1515 1Y 2200kv
ESC = Mamba Max with external UBEC
Batteries = Maxamps 4S 8000 mah (2 2s2p packs in series) and I have also run 5S 4000 mah (3s and 2 s in series)
Single speed conversion running stock 63t spur and 25t brass pinion

So far so good. Even with the wheelie bar attached this thing will flip on it’s lid even while rolling at about 10mph (5S lipos). There is so much torque even with the 2nd gear only single speed. I have not stressed it out yet due to the fact that I haven’t figured out a way to secure the battery packs yet – so no major jumps just yet. Right now I fabricated a temporary tray out of polycarbonate and taped the batteries down. I’ll have to go to something a little less brittle. The electronics seem to be happy. After several speed runs nothing is over 110 degrees. Looks like there is room to go up on gearing. According to Brian G.'s speed calculator (thanks Brian) it's currently geared at around 32mph. The MM is set up for forward only. Motor braking is turned off. Braking is handled mechanically via third channel mixing.



The roller


Single speed conversion using Robinson Racing slipper parts


Bolt pattern of the stock spur and RRP slipped is a match


Mamba Max with UBEC wired


3" servo extension with red wire clipped to bypass MM internal BEC




Roll bar is getting a workout during initial testing!


Here is a short video of the truck bashing about. Please cut my cameraman some slack. It was either give my 7 year old son the video camera or the controls to the e-lst. Apologies for the music drowning out the sweet whine of the Neu, but I felt I need to spare everyone my son’s and his 5 year old sister’s commentary.
http://www.youtube.com/watch?v=rpkbuyXOg6Q

As I mentioned earlier, this is very much a work in progress. I welcome everyone’s comments and suggestions. Thanks everyone for a great forum.

[Nick]

Cool, that's one BIG pinion.

[coolhandcountry]

Do you have a weight on that beast?
I like it. It is pretty bad Arse. :)

[Serum]

Looking good..!

[jhautz]

Looks SWEET!!

What gearing are you running in that thing? Hows the mamba handleing the weight of that beast? No heat issues on the Mamba?

[Serum]

?

'Single speed conversion running stock 63t spur and 25t brass pinion'
'even with the 2nd gear only single speed'

you can do the rest with the calculator of Brian.

[MetalMan]

How's the motor mount holding up? It looks rather thin. In my experience using 1/8" thick aluminum as a motor mount, it bent very easily from minor things.

[riceman]

Originally Posted by coolhandcountry

Do you have a weight on that beast?
I like it. It is pretty bad Arse. :)

I just put it on a scale with 5S 4000mah batteries. 12 pounds 14 oz. Mind you this includes roll bar and wheelie bar. Wheels and tires are Losi 420's with Bowties. I can shed a pound or more by getting rid of the roll and wheelie bar but not unitl I learn to control it.:026:


Serum - thanks for addressing the question about gearing. The nice thing about the RR Slipper mod is that I can bolt up different size Robinson Racing spurs. I would have to go with 32 pitch pinions but they are much easier to get in the very tall tooth count than mod 1 pinions.

As for heat/temp issues that was addressed in the original post as well. Adn if you could bear to watch the whole video I can be shown taking the temp readings.

MetalMan - As I said in the original post, the 1/8 inch mount is holding up for initial testing and will eventually be beefed up once I'm happy with a gearing choice.

[aqwut]

Yeah.. using the bow ties saves over 776 grams..... stock tires/wheels are 1776.... bow ties are 1000.... :) looks good dude.... I used a flat aluminum tray (2 1/4") highter than the main chassis.... and I place the batteries up there and old it down with battery straps.. I do not have pictures of this yet.. but I made it for both of the lsts....

[riceman]

I was finally able to get it out to the track but unfortunately the day was cut short after two pretty ugly laps. I had 5S 4000mah in at the time. There is definitely enough power to easily clear the quad but it helps if everything is lined up. I have to work on some suspension tuning as it definitely handles differently from my nitro version. Here's a short vid of the truck at the track ending in a not so pretty collision with the rail.:035: Battery tray, electronics and such all survived the impact. The only thing broken was the right front spindle where the turnbuckle attaches. The truck looks slow at the track only because I was driving very poorly...err...cautiously.:dft001: It never got past half throttle. Maybe 3/4 for the approach on the quad. Again, please pardon the poor driving - once it's dialed in a little better I'll post another (hopefully better) video.

[coolhandcountry]

It looks like the power will get away from you. That is always a good thing some times.

[riceman]

Some holiday practice time at the track. I went with 4S 4400mah batteries this time and it appears to be just right for this track. My lap times are comparable to what I do with my nitro LST2 and the only limitation at this point is my lack of driving skills:005: Here is short video of the best string of laps that day. The first couple laps are pretty brutal but fortunately it got better before I broke anything. A few more adjustments to dial it in and I think I'm good to go.

[Serum]

Either it is undergeared or something slipping like crazy.. but your slipper looks fixed to me, correct?

Can it be it was in high gearing?

[riceman]

Hmm - does it really sound like it's winding too high? Everything is running cool but now I'll have to check things out. The RR slipper is just a means to mount the stock spur. I'm still using the stock LST2 slipper setup but it is pretty tight - or at least I thought it was. It may very well be undergeared. I'm waiting on another pinion at the moment which will add another 2t to the setup. I'll see what happens.

[coolhandcountry]

I agree with rene.
It don't seem like it is doing all it could.