Got a project in mind, but need a little help... - RC-Monster Forums

Superbasher · **Got a project in mind, but need a little help... -** 09.01.2008, 05:12 AM

Hi everyone,
I'm looking at converting over a lightning 2 buggy to brushless, but I'm stuck on controller options. Now I've seen the thread on modding a MMM but I'm not too sure on that one. I was thinking of using a boat controller as from the ones I have read up on say they have a brake, now is it proportional? Or not enough for use in a car?

If a boat ESC wouldn't work, what would you reccomend?

Thanks :)

Matt.

DRIFT_BUGGY · 09.01.2008, 05:36 AM

What size lipo battery do you plan on using?

Superbasher · 09.01.2008, 06:33 AM

Most likely 4s because it is cheaper, but if ramping it up to 6s and using a lower Kv motor would keep it running cooler, then I would do that.

09.01.2008, 10:16 AM

Most likely an MGM. I think they are a boat controller but have been redone I guess with car software and the build like heat sinks etc. I have not even held one but if its in the shop here its gotta be good.... the mmm doesn't count yet

. I dont know the product name, its something like r2d2, I know someone else knows though.

suicideneil · 09.01.2008, 12:19 PM

I would have thought a mambamax would be plenty for a 1/8 buggy/truggy really- run an external BEC or Rx pack & a little fan, should be plenty of power with something like an 11L feigao or similar. Heck, even the hvmaxx does brilliantly in something smaller/lighter than an emaxx, and there are loads of those on ebay all the time for about £80-90.
I'd steer clear of the ebay boat/plane escs, as the brake isnt proportional- on/off type only. There is this option though:

http://home.comcast.net/~truerc/esc/escNmotor.htm last one on the page.

Superbasher · 01:18 PM

Neil that ESC sounds good, provided it can do LiPo cut off. Shame it only does to 15 cell NiMH though. Plus the problem with the HV-Maxx is that I am using LiPo cells, and 2 separate LiPo cut offs won't work together.

suicideneil · 09.01.2008, 04:47 PM

You dont have to use 2 separate lvcs- a single 4s lvc, or a single 2s lvc would be fine. Wire the 2s lvc to the side of the hvmaxx that also powers the bec, and that 2s lipo will discharge a little faster than the other, and so the lvc will trip when it reaches 3.2v per cell, protecting both lipos from over discharge in effect. Or you can use the 4s lvc and wire it to the capacitor leads, so that it sees the full 4s voltage, and protects both lipos again- only problem with that is the lipo on the bec side will still drain a little quicker, so buy the time the lvc kicks in you can have one 2s lipo at 6v, and the other at 6.8 = 12.8v; lvc doesnt know this though, since it just wants to see a total voltage of 12.8v, individual cell voltage isnt seen....

Superbasher · 09.01.2008, 04:54 PM

Well thinking about it, its a shame that other ESC doesn't handle 16 cells, as 15 cells is 18v and a 5 cell LiPo is 18.5, although I don't think .5v would really matter? Oh and that way of wiring a LVC to a HV maxx is a little confusing, you mean just plug it into the throttle lead, and to one of the packs?

suicideneil · 09.01.2008, 05:02 PM

Nah, like this:

You're right about the other esc- 0.5v shouldnt be an issue, then again, it might be a pain if something does go pop inside. A mambamaxx would still be my choice- not much work to make it handle 4s lipo, and no separate lvc issues either. Only other options might be something from Quark (80amps model)- but servicing is almost non-existant, or MGM, but their prices are alittle higher. If you see an Mtroniks truck esc, that'll work well.

BrianG · 09.01.2008, 05:07 PM

Neil, you should edit that diagram to point out that the pack with the LVC tap has to be the BEC pack. Otherwise, the ground point of the LVC throttle cable will be at a different reference than the LVC battery input and could cause some major issues.

suicideneil · 09.01.2008, 05:11 PM

So it is written, so it shall be done...

(I do point that out to people, about wiring the lvc to the bec side pack, but since this was for the traxxas forum guys mainly... I see your point

).

Superbasher · 09.01.2008, 05:12 PM

So I'd need a UBEC and LVC? I think I'll give that one a miss then and try and find either one of the Mtroniks ESC's, buy one of those 100A ESC's, or just use my Mamba Max. Now I Just need to find an L can motor...

suicideneil · 09.01.2008, 05:22 PM

I have just the very place (unless you want to get one from the monster):

http://www.bidproduct.com/part/Produ...20MOTOR_1.html

I got one of their hacker clones- same as a feigao basically, only cheaper- quick shipping too, and cheap at that.

Superbasher · 09.02.2008, 04:49 AM

Do you mean the first ones on that page? As I've been looking through their site and they do ESC's for a good price too.

suicideneil · 09.02.2008, 02:30 PM

Depends which kinda motor you want for the buggy- 540 L can sounds about right, which would be the 36/60 motors (2nd page), and choose the kv according to the voltage you will use- aiming for about 30-35,000rpms total.

http://www.bidproduct.com/part/Produ...ESC%20_31.html

Thats about the only one suitable for a car/truck- 80 amps with forwards/brake/reverse. The other boat escs have forwards and reverse, but dont mention brakes...