Just a Few Questions

[maxair45]

Its -15 by me and the gas in my car is still frozen so I decided to get some wrenching done. I've got almost everything set for my bl buggy but I have a few questions.

-I've seen some people run the motor diectalyy to the diff instead of going through a trans. What are the benefits?

-I'm planning on running a Medusa Afterburner motor with a MMM esc but I am unsure on how many cells to run. Any reccomendations?

-I'd figure it'd be a lot cheaper to run 2 2s or 3s packs but how do I connect them to run together(ie 2 2s 5000 MaH batterys how do I connect them to run 1 4s 5000 maH).

Any other things that i should know about these systems will appreciated greatly.

Thanks

[suicideneil]

1. Depends really on whether the vehcile has a trans or diff to start with. With a center diff, you can tune the car more so that it doesnt wheelie like crazy- better cornering too. Beyond that, there is the obvious weight saving, lower CoG usually, and you have fewer gears to worry about grinding compared to with a tranny.

2. Depends on how much room you have for cells to start with. Typically, you will see a 4s lipo setup using a ~2000kv motor, and a 6s lipo setup using a ~1600kv motor (assuming this is for racing rather than bashing really). The castle 2650kv motor is great for 4s lipo, but with a kv that high you wouldnt run higher voltage, but would run lower gearing perhaps (Im not the greatest expert on buggies and truggies).

3. Series harness- see BrianG's website for diagrams: Clicky

[_paralyzed_]

gas can't freeze

-direct to diff conversions have no flexibility in gearing and shouldn't be considered unless you understand all of brushless r/c's parameters

- we can't say until we know you're spur/pinion and diff gearing, kv of your motor, tire size and desired top speed

-BrianG's website http://www.scriptasylum.com/rc_speed/_wiring.html located in sticky in the brushless section titled, "speed calculator"

you should read the stickies in the brushless section and any faq's and you will be well on your way

[Tempted]

Hmm... What of one was to make an adjustable motor mount directly above the diff and then wallow out a 5mm pinion to mount on the pinion gear of the diff. Then use something like a flywheel cover to protect said pinion gear. Possible? Probably. Practical? Just use a tranny and foget about it....

[jayjay283]

Gas freezes, or at least turns into a slushy so you cant drive, you have to have a 1/2 tank of gas up here or it will slushy and you cant get home from work lol

[lincpimp]

He is getting a medusa 1600 v2 60mm motor from me. 5-6 lipo will be fine with that motor. If you plan to race 4s lipo with s larger pinion will work too.

Stick with the center diff or the tranny. Direct to diff outrunner setups require more experience to do right. Good to get a few std style conversions under your belt before trying!

As far as lipos... I prefer a single pack if possible, but you can run a pair of packs if it fits the vehicle better.

anything can freeze at the right temp...but Gasoline is a collection of hydrocarbons that have different freezing temps...depending on the percentages of the materials it could be anywhere from -50F to -250F....its go to be above absolute 0 ( which is -459F)

[maxair45]

The kv of the motor is 1600. I am looking for 45-50 MPH speed wise. I'll give the speed calculator a go.

As far as the gas i think it just gelled up. Its been happening to a lot of my neighbors who don't have enough room to park their cars indoors.

Thanks for all the help.

[_paralyzed_]

its the water in cheap gas thats freezing. I should have said gas can't freeze at naturally occuring temperatures, but it can freeze. I just need to shut up sometimes.

[Tempted]

Paralyzed is correct, gasoline will not freeze at any natural tempurature. The water in the fuel freezes and causes the slushy effect. Keep a full tank and you should be fine.

[maxair45]

Update:

Medusa is on its way(thanks linc) and I'm going to the lhs to get the MMM tommorw. I just finished up taking off the nitro components of my buggy and I've ran into one more question.

-All the breaking will be through the esc(correct?). My buggy's breaking system goes through the diff(a loop at the top of the diff connects to the servo). Can I just remove this servo and the breaking assembly? Just want to be sure before I screw something up.

Thanks

[maxair45]

I just remembered I saw some esc's at my lhs and they were like $40 and resembled a quark. I asked why they were so cheap and it was because they were for airplanes and they didn't have breaks. Well If the esc dosen't have breaks my car can't the breaks that are already on there do it? I don't see why not. The only problem is where the breaks is also where the throttle goes too(gas and break servo as I said before) so either I need a another channel or ???
Could making a y harness for the servo and the esc do the trick? How many channels can the M8 run?

Thanks for all your help guys.

[maxair45]

anyone have any input?

[BrianG]

Yes, an air ESC can be used if:

1) You are using mechanical brakes and don't want reverse. The mechanical brake servo can either be paralleled with the ESC via a Y cable, or use channel mixing and run the ESC off ch2 and the brake servo off ch3.

2) The ESC can recognize a pistol radio throttle signal. The min/max setting in an air tx and a car tx are different and some air ESCs won't work with a car tx. In those cases, a Pistix adaptor is what you need, but are hard to find.

3) Keep in mind burst current. Aircraft doesn't demand the current surges that cars do so be careful not to overload it.

[maxair45]

So if I run a Y harness connecting the break servo and the esc they will both pick up their signals. I'll ask my lhs to see if i'll overload the esc.

Thanks for all the help. next i'll be ordering the RCM lx series mount for it. Thanks guys.