Going to take the plunge and convert my XB8EC
 

Hi Guys,

Been reading this forum for a while now and have finally decided to convert my nitro. Pls keep in mind that Im a complete newbie :oops:

A few questions that Im still not clear on:

1) Whats the best setup that I have now? I will be using the buggy mostly for bashing and the occasional race againsts the nitros.
2) Temps and humidity is very high where I live in (90F and 90%) so cooling is very important so Im guessing I have to run a larger motor to keep the temps down and cooling fans?
3) Whats the complete list of equipment/material that I have to purchase to make the complete conversion?

Thanks guys! :mdr:

Tentative list of Equipment needed:

MGM Compro 160 amp, 18 cell brushless car controller
Electric Motor Mount - RC-Monster
Flight Power EVO25 5000mah 5s 18.5V Lipoly

Which would be better for a buggy if used for primarily bashing and occasional races?

Neu 1512 1.5D/F Sensorless Brushless Motor or Neu 1515 1.5d/F Sensorless Brushless Motor? Any other more appropriate motor?

Thanks!

The first 3 items look good, and choosing a neu motor is also good, but the 1.5D's are a bit too high kv to use on 5s, especially if you live in a hot area.
I only have a truggy so I don't know exactly what would be better between the 1512 and 1515 for a buggy. Usually people with buggys use 1512's and people with truggys use 1515's, but that's not a set rule or anything.
The motor I have in my truggy is a 1515 2.5D (1700kv) on 5s, it works well and stay pretty cool. If you choose a 1515 for 5s I think the 2.5D is the best wind to choose.
Usually aim for 30 000 - 35 000rpm for racing to have a good balance of power and reliability. Neu's should still stay cool even if they're doing around 40 000rpm as long as it's geared right, but I'd still try and stay in the mid 30's. kv x volatage = rpm
eg 1700kv x 18.5v = 31450rpm That's only an estimate. Voltage drop of the batteries and how loaded up the motor is will affect what rpm it reaches, but it gives you an idea.
So if you choose a 1512 I'd look at the 3D (1700kv). The 1.5y (1900kv) or maybe the 2.5D (2000kv).

Oh, and welcome to the forum. I don't know why your post didn't get answer a bit sooner, that doesn't happen very often. Hopefully one of the buggy guys will be able to help you decide between the 1512 and 1515.

Thanks for the welcome Patrick. Guess the guys are out partying and celebrating the New Year!.

Btw, Happy New Year to you! Hope it will be filled with happiness and joy. Cheers! :smile:

Ok, after researching summore:

Tentative list of Equipment needed:

MGM Compro 160 amp, 18 cell brushless car controller
Electric Motor Mount - RC-Monster
Flight Power EVO25 5000mah 5s 18.5V Lipoly
Neu 1512/1.5y/F finned motor
Neu Rear endbell cover

Guys, will need some input on gearing for the buggy. Which would fit and be 'safe' for such a setup pls?

Thanks once again!:whistle:

Use this site made by BrianG http://www.scriptasylum.com/rc_speed/_top_speed.html
For racing 35-40mph is a good speed, depending on the size of the track, and the length of the races.

I ran my buggy on the exact setup you listed with the exception of the motor. I was useing a Neu 1515/2.5/D finned or a 1512/2.5/D smooth motor and it ran fine on both. FOr the 1515/25.D I was able to run 18 pinion gears with no issue in the heat of summer, and with the 1512/2.5D I ran 15-16 pinions. That gave around 45mph for either setup. Giong down on the pinion size wasnt a problem on either setup if you wanted to slow it down a little for the track. Both setups ran fine heat wise and performace wise, but if you are truly worried about heat go for the 1515 it will run just a tad cooler but you will be able to make up the speed with the taller gearing.

The Neus are great motors, they run great unless you put them way outside their comfort zone. They arent like the feigaos that run ok if you get the gearing and load just right but if you move off of that perfect setup they just heat up like crazy.

The 160/18 runs cool and you shouldnt have any problems and 5s also helps keep the temps down. You should be very happy with that setup.

Thats my opinion anyway.

Since heat issues are very high in priority for me.

Fine-tuned selection of stuff needed:

MGM Compro 160 amp, 18 cell brushless car controller with Active cooling
MGM usbCom+
Electric Motor Mount - RC-Monster
Flight Power EVO25 5000mah 5s 18.5V Lipoly
Neu 1515/2.5D/F finned motor
Neu Rear endbell cover
18T pinion gear

Any other opinions on the selection? or suggestions pls?

Thanks in advance.

I should probably be a little more clear about this. The buggy I was running was a Cen Matrix with the cen truggy dif gears in it. Cen uses some very strange gear ratios in the difs so the pinion gear choice does not translate directly to other buggies. The xray buggy(40/12) also uses dif gearing a little off from the standard (43/13).

By my calculations the pinion that will give you the equivilant overall gear ratio to what I ran would be somewhere between 16 and 17. Go wth the 16T pinion if you want to be on the temp safe side.

That should get you approx 40-45mph.

Other than that, I think the setup you have listed will make you very happy. They dont get better than that.

BWT: I just converted a xb8 myself and am really loving it. great buggys!

Since heat issues are very high in priority for me.

Fine-tuned selection of stuff needed:

MGM Compro 160 amp, 18 cell brushless car controller with Active cooling
MGM usbCom+
Electric Motor Mount - RC-Monster
Flight Power EVO25 5000mah 5s 18.5V Lipoly
Neu 1515/2.5D/F finned motor
Neu Rear endbell cover
16T pinion gear

Any other opinions on the selection? or suggestions pls?

Thanks in advance.

OK, Items ordered and on a flight now! w00t!

Will definately need more advice and help once the components are in and its time for the conversion.

Thanks to Mike for all the advice rendered too! :)

Final List of items ordered:

MGM Compro 160 amp, 18 cell brushless car controller with Active cooling
MGM usbCom+
MGM CC cable
Electric Motor Mount - RC-Monster
Flight Power EVO25 5000mah 5s 18.5V Lipoly
RC-Monster Battery Tray
Neu 1515/2.5D/F finned motor
Neu Rear endbell cover
16T pinion gear

gonna be a sweet setup.:yes:

Guys, are these numbers accurate?


Differential Ratio: 3.33 (From X-Ray site: Primary Ratio) Correct figure here?
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 40 (From X-ray site)
Pinion Tooth Count: 16
Total Voltage: 18.5 (5s lipo)
Motor KV: 1700 (Neu 1515 2.5d)
Tire Diameter (inches): 4.5 (Standard 1/8 buggy rim/tyres?)
Tire Ballooning(inches):0
Motor Current Draw: 0
Motor coil Ω: 0.01
Spur/Pinion Ratio: 2.5 : 1
Total Ratio: 8.325 : 1
Tire Circumference (inches): 14.14 inches (359.08mm)
Total Motor Speed: 31450 RPM
Vehicle Speed: 50.57 MPH (81.24km/h)
Effective Speed Rate: 2.73mph/V (4.39kmh/V)
Effective KV Value: 1700
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...

If its fairly accurate, I will be getting about 50mph!!!!!

From X-Ray:

Pinion Spur : 12/40 (will be changed to 16/40 with new pinion)
Primary Ratio : 3.33:1
Internal Ratio : 3.54:1
Final Gear Ratio: 11.79:1

Did I plug in the right values pls?

The stock gearing for any XB8 version is the same. The front and rear ring and pinion gears are 40T/12T for the 3.33:1. The stock spur gear is a 46T. I think the only drivetrain number you would need to adjust is the spur gear to 46T. The 40T gear you are reading about in the description is on the differential, not the main spur. With all other numbers staying the same, the calculator will est. about 44mph. A bit under your first estimate, but certainly not slow! If you want to use the XRAY spur gears, they have several available if you need to adjust your ratio, from 44T-48T.

Thanks dude for your correction. I was wondering how am I gonna control a 50 mph buggy!.. 44 mph is definitely not slow but sounds better than the first reading! Cheers!

LOL! You're going to need a football field to control it. I just got my Neu 1512 2.5d (2000kv) from Mike and installed it in my XB8EC. Geared at 15/48 on the pinion/spur it is wicked fast running on 4S. I'll probably gear up to 16 or 17 on the pinion after I get some Amp readings during the run to make sure things aren't pulling too hard for the lipo.

I plan on getting a 5S pack when the MMM comes out, but this buggy is plenty of fun on 4S with my limited running space right now.

Just received word from my wife that the package has arrived... So now, Should I take urgent leave from work? :lol:

The change in dif gears is a cool option. you can overdrive the front dif with the new combo and it really makes the front pull the car around and out of corners and the back kind of follows. point and shoot driving. I hadn't gotten the chance to drive it that way myself, but a few of my buds got to race with it and gave me their opinions. After my car accident last year I didn't make anymore races except to come play pitman for a bunch of drivers at the nats, and sold my xray to the xray sponsored truggy guy at that race... hey it was cheaper to buy mine than his sponsored price hehe.... Xray quality is very good and about the most tuneable buggy on the market

sounds like you are set. in fact the xray guy was here today and saw my rc monster mount on my rc8 and he's going to order his now. he was going to get the rc product designs setup, but Mike's machining and finish is way nicer.... mike can you make a nice integrated battery holder like the rcp one ;) (stupid question right?) ok when can you make an integrated use the stock mounting holes battery tray?

So the conversion is progressing along fine. Pls see the attached images and comment pls? Any thing that I did incorrectly so can be improved?

All comments welcomed. Thanks!

Having difficulties with soldering the Dean's Ultra connector to the battery leads. The solder just refuses to attach to the connector. Do I really need the 2% silver stuff? Currently using 60/40 solder.

Also, is it correct that the motor is mounted only with 2 screws? Kinda dodgy if you ask me.

There are a few threads on this forum that talk about soldering and elsewhere as well. I actually think there are a few youtube videos that show the process in detail.

I find the soldering to the Dean's connectors works best when you use a hot iron. Hold the Dean's plug secure in something like a vise or a pair of pliers held shut with a rubber band. Hold the soldering iron to the metal on the connector for a few seconds and the push the wire of solder into the crack where the soldering iron and the connector metal are touching. The solder will melt and when it hits the right temperature it will adhere to the connector metal and spread out along the sureface of the connector like a drop of water - the surface tension of the hot solder will prevent it from running off the side.

Then take you pre-tinned wire end and put it into the hot solder drop until the solder on the wire melts and runs together with the solder on the connector plate.

Remove the soldering iron and hold the connection together without moving it until the solder hardens enough for no movement.

The whole process should take no more than 15-20 seconds so that you don't risk melting the plastic on the Dean's connector.

Also (as I forget to do this at time) don't forget to put the heat shrink tubing over the wire before you solder the wire and connector. ;)

VintageMA, thanks for the detailed response. Had a look at the Videos and followed your instructions but still unable to get the solder to stick to the tabs. I think I will need a solder with a higher precentage of Tin and 2% silver for this to work.

Going to purchase the multicore stuff that comes with flux etc etc and we will see if that improves the situation.

Not sure exactly what the mix of the solder I use is, but I just use the basic (60/40) solder you can get at Radio Shack. It's nothing special, but I've been using for years since I was soldering circuit boards during EE classes without a problem.

Also - what is the power of you soldering iron? I use an old 35 watt Weller or a Weller pyropen (portable butane powered) and never have a problem with either.

If you are having trouble making the solder stick. Try coating the surfaces you are soldering with some flux. It really helps the soder stick easier.

http://www.radioshack.com/product/in...entPage=search

40W Soldering Iron in my case.

Issit ok to use a pre-fabricated Deans connector and just connect the bare leads together and heat-shrink it? The wire thickness will be different on the battery lead and the pre-fab'ed lead.

Hi Guys,

Finally managed to assemble everything together and attached is the final assembled state.

Now lets see how it runs..

Looks great! Lets see a couple with the lid off :yes: