J's build

[CMD-J]

Hey all, so its me, Jules aka Commander-J from Hamburg/Germany.
I'm a somewhat longtime lurker on this board, recently started to post a bit more here and there.

I felt its time to finally come out with my own build thread now and show my rig.
I had the pictures ready for a while but never managed to write it up and post it all.
As I tested a couple of updates and new parts over the last weeks I want to document the previous setup somehow before posting about new parts.

I got her last may as a nib roller off ebay. It looked like someone has gotten a new MERV, ripped out the motor, esc and 2,4radio and put in a second series1 nimh+wallcharger and an old am radio and put it on ebay the minute later.
I took the chance and bought it. As i pried her of the box, she looked like this:



I was able to resell the included series1 nimhs + chargers and the Traxxas AM radio for a good price.
I later sold all stock parts i wanted to replace anyway. Like receiver box, knuckles, all rods and linkage, a-arms and the shocks. (Later regretted selling the shox) and the servo.
As all parts were brand new they sold well. I manged to get nearly even. Ending up with are really stripped down basic Mini E-Revo that has costed me bare nothing.

Tried to do a build on a budget then and do only reasonable upgrades. As if that was even possible..

So, this it how she sits end march 2012:

[CMD-J]

Here we go with the parts I used and some pros/cons i experienced:
Note this are only my (limited) experiences on parts i have run, others might disagree.

Lets start with the electronics, as i had none to begin with. I decided on a:

Quik/HK-100A Brushless Car ESC v2
Very happy with this ESC. Smooth startup. You can drive very controlled when going slow with no cogging and do full speed runs and it never gets hot. Comes with a fan, but i removed it. Rated up to 17V/100A. You can set Lipo Cut-Off, Start-Up Force, Break-Force, Drag Brake, Motor-Timing and a few other things via an 6$ programming card or key press sequences.
It comes splashproof and i used some plastidip and liquitape to make it waterproof and mounted it with 3M DualLock velcro at the receiver box place.
If your are on budget and dont mind the size i would recommend this esc, because on 2S it always stays cool (have not tried 3S yet), is very smooth, easy to waterproof and cheap ($38 +shipping), besides the on/off-switch has good and solid build quality and has some nice settings you can tweak to your liking. I would get the programming card too.
My only complain is weight and size. A bit too big for my taste.



Traxxas 380 Velineon motor 4000KV
The true and trusted stock beast of a motor. Got it unused of ebay for 20$ Still happy with it on 2S Lipo.
Had my first few 3S runs now and could not get the grin off my face.

KB28-47-08S motor 4900KV, rated ~50A, 11V max, 380 size
OK motor, but not really an improvement over the stock. More top end, little less acceleration. Shorter runtimes, so i guess it draws more amps then the stocker. Runs a little hotter. Cheap, about 18$ plus shipping, took forever to get delivered. Overall i think i like the Traxxas Velineon 380 more.

# GEARING
I mostly run 55/28 on the Velineon motor and 55/25 on the 4900KV china motor.
The Proline Gladiators are almost too much on this, only run them on the stock motor and 55/25
Depending on outside temps i probably should run them on 55/23 or even lower, but my ESC it to big for that gearing, the motor would rub.



I try to get more cooling area with two Align K10175A Motor Coolers
They came golden, some drano cleaner turned them silver. I think they are designed for helis, perfect fit for a 380 size motor

# JUICE
2x ***** 2200mah 2S 20C
2x ******* ********** 2200mah 2S 35-70C

[IMG]http://i1250.photobucket.com/albums/hh526/CMD-J/MERV/Slipstreamsideview*****.jpg[/IMG]
Always run them in pairs as 2S2P


# Radio
FlySky GT3B 2.4ghz AFHDS
modded with steering bearing, custom firmware, switching voltage regulator and foam wheel and waterproofed RX.
Cheap, reliable and solid performer reaches farther than i can see the car. Works for me.



# Servo
******* TGY-390DMH Digital Servo
Read it was the way to go, so i sold my unused TRA2080 servo and ordered it right away.
I could not stand the green color and the logo standing upside down. So i deanodized it, turned the case, shorted the cable and waterproofed it while i was at it. Recently got a used Bluebird 390DMH off eBay as a backup. Really the same servo in a different color.



# Linkage & suspension
RPM A-Arms all around
You might have guessed it Not much to say, besides they work whatever you throw at them, they come back for some more abuse. My lower rear ones look pretty sandblasted and scratched, but still going strong

RPM knuckles
not used anymore, stopped working after ~10 packs. The bearing hole ovaled out, pillow balls would pop out on impacts, some of the tinytiny hex screws stripped.
-Would NOT recommend them as they are not durable. To their favor: When they worked they had the least play/slop from all knuckles i had tried.

GPM knuckles ERV021 alu silver in the rear
They are OK. The material seem to be quite soft. Much more scratches/dents/scars on them in comparison to my HR knuckles.
Two of threads for the retainer caps are not cut quite right on mine. I destroy the delrin cap everytime i unscrew it, plus the caps are pretty soft, its easy to strip the hex in them.
I would not buy them again.

Hot Racing knuckles VXS2101 in the front
Best knuckles i have run so far. Easy to install and maintain. Comes with alu screw-in caps and delrin spacers that faces the pillow ball. More durable surface finish than the GPM alu ones (less scratches/dents). Best overall look too
Do NOT use the supplied hextool, its a tad too small and might strip the caps. They need some readjustment every couple of packs on the lower caps, otherwise im very satisfied with them. This is the only Hot Racing product i would recommend without limitation. But i heard others had less luck with them?

GPM Steel Tierods/Pushrods SERV160
They help to reduce slop, but will not eliminate all play. The plastic rod ends wear and may break on hard side impacts/cartwheels. Just stock up on them regularly.
Oh, and they may be made from steel, but are certainly not stainless, mine rust on the stains/scratches if not WD40'd after wet driving.
If i have to buy them again i would get the titanium version to save some weight and avoid rusting.
I tried the Hot Racing Red aluminum turnbuckles VXS160R02. Tested them on the rear only. Because the HR ones have alu ends i hoped to reduce the slop the GPM plastic ends tend to develop on the back toe links. Well they lasted 1 pack, then bend and ovaled the hollow ball out, booh. Avoid them!!

[CMD-J]

# Shocks



GPM Aluminium shocks ERV348 Silver
Sigh. I sold my stock shocks, because i WANTED these for teh looks. And i thought, well aluminum bodies, caps are screwed on, they should work. Well imho they only sort of.
They come with a nice set of springs, 4x soft, medium,hard. all stiffer then stock springs. I run the black(softest) in the front and silver(medium) in the back with varying preload and 1000cps Oil (~75WT).
BUT: They are a disaster to maintain, once they start leaking they will never stop. GPM uses too soft aluminum for the shock body and endcaps. The shock shaft wear out the hole in the bottom cap, the shafts get scratched, will then damage the seals, will get caught and then bend or brake. Been there, done that. Its annoying to get the leaked silicon oil from the chassis everytime. As far as i have read im not the only one having these problems with them.
Overall i would NOT recommend them due to poor build quality/material choices, the actual design is good though.

Better spend your money on Traxxas Alu GTRs or threaded HR Alu shock bodies and use them with the stock Traxxas internals. I think the Exotek BigBores would be the top and most expensive choice. If you like to tinker a bit get the YeahRacing DP-1001Ti bigbores. You will need to fab a mounting solution for them yourself.



Traxxas steel CVDs 7151X
Great look The output cups on the diffs wear a bit too fast for my taste. They tend to bend when run by unskilled driver.. but dogbones are cheap to replace.
As i learned to drive better now they hold up suprisingly well, never lost a pin or o-ring. You cannot go wrong with them.

Integy Steel center driveshaft V2 T3501
The small front piece went kaputt after the second pack, pin broke and get lost. True Integy style. Back to the stock plastic for now, im on my second now.
The long rear center piece works a treat since then, but DO loctite the grub screws on them. If they get loose they will eat your chassis for breakfast!
One thing i didnt like is the diameter of the connection joints. There is only a very small gap between the rotating joints and the bulkhead. The slightest amount of dirt there will grind down material from your bulkheads.
The new TRA 7250R Steel CVDs for the center migt be a very good alternative. Their joints look smaller in diameter.

# TYRES
My Talons, besides new, constantly unglued on 2S. Then my rims (wheels?) started to crack and the foams ended in a pulp of dirt, sand and water.
The thread on them is still ok, but the beads are badly ripped and unusable. I now run:



Proline Dirt Hawgs I 2.2 buggy rear on RPM Clawz Wide Rock Crawler Wheels #82212
Good for hard surfaces. Not so much grip on gras and deep underground and too lose gravel. But more grip and more durable then stock Talons.
You want to tape the Dirt Hawgs to prevent balloning. First i run them untaped on beadlocks, uihuih. I used one layer of ducttape cut to the width of the thread, much reduced ballooning now.
The RPM Clawz wheels have the same meassures and insane offset as the RPM Revolver wheels. They need to be modified to fit the MERV axles.
See this thread for the barrel nut mod: http://traxxas.com/forums/showthread...=1#post5011904
If you care to bother to make the fit to the 4mm merv axels i would totally recommend them for the superb handling.



Proline Gladiator 2 2.2" M2 #8170-01 on HPI Black Dish Wheels #3091
I love these tires for the looks and insane traction they provide an any surface i haven driven them on. You can pull wheelies at WOT on loose terrain with them on a nearly drained pack. They give a nice "cushioned" ride as if you have double dampers.
Downside, they are quite heavy, so more stress on the linkage and heat on the motor. They will kill a shimmed front diff roughly every 10 packs, rear diffs no problem.
It got better since i run the T-Bone front bumber. Running them prevent the bulkheads a bit from warping under load at least a bit. I think alu bulhkeads would really help here. Oh, and you can not tape the Gladiators as they have a thick rubber crossprofile on the inside.

I have a pair of Axial plastic beadlocks too, but dont run them atm.




Other odds and ends
T-Bone Racing Thrasher/Monster bumper set fr/rear #2CC04 with T-Bone Racing T-Bar wheelie bar #1AE02
Indispensable lifesavers on various occasions. Front need some trimming if you run nice big tyres. I took the 2 piece version over the allinone brace, cause i thought i would be easier to work on the diffs independently not to have unmount the whole boogaloo everytime when only one diff needs attention. And to save some weight. Still a bit heavy.
I ordered all the T-Bone stuff directly from their website, nice fast oversea shipping with fair rates. Recently broke my front bumper, but the car was saved. They have a lifetime warranty and I'll get a new front bumper for free.

Hot Racing alu front body post
Last longer then stock plastic ones, before shaved down to much to get the clips in. They are too long from the factory, and need to be shortened, or they will scratch the rockers an full suspension compression.

Hot Racing alu transmission case
Have to admit, i bought it for the looks, justified it by saying, well it might act as a cooling thingy for the motor, sucking up heat, i put a tiny bit of thermal compound between the motorplate and transmission case. It get rather warm so i think it helps dissipating some heat. Not too happy with the build quality, i had to re-thread the four mounting holes. They were only threaded halfway through and from the looks HR cut the thread first and applied the anodizing afterwards, filling up the thread again, uooh.

Hot Racing front shock tower
The stock one flexes badly, at least with GPM shocks, they are a tiny fraction longer than stock shocks. HR got this on right, it fits without modification
Flex might be a design choice by Traxxas though, to channel some stress on impacts. But too much flex with the GPMs for my taste. My rear shock tower is still stock.

Ofna 1/12 Hi Force Wing CRT.5 #40906
I always thought the stock wing was to small. After finally breaking mine i had an excuse to get it.
Killer lock, the plastic feels more rigid than the stock one. Have now some packs run with it on concrete surfaces.
Less scratches then i expected and the wingmount seem to hold up so far.

Various other small mods i did over the time
Dyed chassis + rockers
Bearings for the rockers and servo-saver. The two at the steering post constantly need attention, rust magnets.
Deanodized bulkhead tie bars + motorplate + servo housing and servo guards.
Shimmed axles
Sealed center drive-line
DIY glitchbuster. 3800µF 10V low ESR capacitor to support the BEC
Stainless steel screws. Stock screws are ok, usually they will not strip easy, if you use good tools, not the supplied cheap hextools. But the stockers start to rust as soon as you turn your back, if not properly wd40'd. If you run in wet conditions ss screws are nice to have, but shurely not necessary. I dig the look

I mainly run on black and grey tar and hard dirt with some loose gravel and gras mixed in. If it rains i have the chance to tackle some small puddles. But no jumps were i drive only some very small kickers.




Incoming/new parts i'll have to test a bit more to write about.
Traxxas Center diff + 100WT Oil, i hope to prolong front/rear diff life with it and get more power to the ground.
2x ******* ********** 1600 3S 25-50C LiPo, could not resist anymore
Yeah Racing 50mm Shocks DP-1001TI
+ New Era Racing Aluminum Shock Leveling Brace TX6326BKT - fresh attempt on my shock maintainance problems.
******* 60A Car v2 ESC smaller/lighter then my current ESC.
Traxxas TRA 7250R Steel CVDs for the center
HK-401B Gyro

Still eying the JConcepts Illuzion body to get more room in the back, its very tight there with he Slipstream body. Undecided on alu bulkheads, hope to avoid that with the center diff.

Finally i want to say a big Thank You to all of you for lotsa great ideas and information i got from this board!

And Sorry for some long read..

[krallopian]

..... WOW!

What a WICKED setup man! Great posts, awesome pictures those are some pretty serious capacitors in there! I love the bodym, the wheels, motor, everything hahaha! You've got a ideal Merv for sure! Totally awesome, I'll be showing people these pictures when I show them "online" pics of these cars!

Great work, keep it up!

[bentrocker]

Nice merv you have there.

[korn0307]

Nice build! Im glad i read this because i was just about to order the GPM shocks. I have the traxxas GTRs and it seems like the leak fluid non stop or im just horrible at rebuilding them. Im running purple springs and 80wt oil and filled them yesterday. Today they are sagging in the front.

[krallopian]

Springs prevent sagging, not oil? The oil dampens the shock, and return.. the spring determins it's rate or "distance" and so if suddenly it is sagging... that should be the spring being worked in, not loss of oil. If anything, it would sag more with oil than without. If the oil is thick, the spring will not be able to push the shock all the way back out, causing sagging. Hope this helps! *cheers

[Slono]

Evgen runs Hot Racing shock bodies using the GTR shock parts with 120wt oil. It seems to work for him.

[korn0307]

Springs prevent sagging, not oil? The oil dampens the shock, and return.. the spring determins it's rate or "distance" and so if suddenly it is sagging... that should be the spring being worked in, not loss of oil. If anything, it would sag more with oil than without. If the oil is thick, the spring will not be able to push the shock all the way back out, causing sagging. Hope this helps! *cheers

Hmm im running purple springs with GTR shocks and 80wt oil. If i push the rear to the ground itll only come up to where its all level with the ground.

[krallopian]

That's because of the 80wt oil, your shock pistons' holes are too small for that thick of an oil.

With suspension there are four basic things to take in to consideration:

Shock Oil
Spring
Shock Piston
Pre-load

The shocks can be made to act similar to others by changing only ONE thing. The worst modification to a shock is pre-load, the more you put (by adjusting the ring making the spring shorter, in affect making it seem stiffer) on, the less suspension travel you have. Second to that is really up to the task you're trying for...

Thicker oil, with stock pistons will really slow it down in regards to how fast it rebounds and of course absorbs the shock. However, to counter-act that you would put stiffer springs. A lot of people want stiffer springs but don't adjust the oil, so you have a bouncy car. Then you adjust the oil, but now it's too stiff! You need to adjust the pistons.. so in YOUR case, your oil is too thick for what you want you have two options:

Reduce the wt
Change shock pistons

Reducing the weight is very easy, the pistons are a pain in the butt to get off and change, I just drilled mine out with a tiny drill bit. The piston is the "plunger" part that moves up and down inside the shock body.

I don't want to take over this thread though, so if you have any questions just PM me!

Back on track:

Still love your car J! Hahah

[Petertje60]

Great car and very nice explanations and pictures. Very valueable thread. Living not that far away from you I am curious where you buy most of your parts.

[CMD-J]

Thanks all for the kind words.

I certainly dont mind a little shock talking..
Good info Krall! My new shocks came with 1,2 and 3 hole pistons. Currently running the 2 holes.

@Korn: i think you really should look up the HR alu shock bodies. I read they a worth a try. Best thing you can get all four bodie for $13 incl. shipping from liquidrc, look for part #VXS15502. In the meantime shrink tube over the caps could help maybe?
For maintainance: Always check the shafts, caps and o-rings very acurately for wear like scratches, dents etc. The smallest nick in a shock shaft can damage the o-rings in no time. Damaged seals will inevitably leak oil.
I use a grease, called "green slime" by Team Associated to seal/lube the o-rings on the shafts, dunno plain old vaselin would likely doit too and DONT overfill your shocks.

@Pertertje: I got most off my parts overseas. All my electronics and lipos came from china/hongkong. Lots of the other hopups i ordered from the states. Mostly from rc-shops on eBayUS, a few parts from thetoyz, and i like liquirc (their shipping to the EU is only $1 + their shipping is way faster than thetoyz, no idea why.)
Its really crazy even with the shipping/customs factored in it it mostly cheaper to order overseas then to buy local.

And I developed a bad habbit for chasing cheap replacement parts from parted cars off private ebay auctions at the weekends.. I'm sitting on a pile of bearings, bulkheads, slippers and servo-savers that should last me the next century.

[Petertje60]

@Pertertje: I got most off my parts overseas. All my electronics and lipos came from china/hongkong. Lots of the other hopups i ordered from the states. Mostly from rc-shops on eBayUS, a few parts from thetoyz, and i like liquirc (their shipping to the EU is only $1 + their shipping is way faster than thetoyz, no idea why.)
Its really crazy even with the shipping/customs factored in it it mostly cheaper to order overseas then to buy local.

And I developed a bad habbit for chasing cheap replacement parts from parted cars off private ebay auctions at the weekends.. I'm sitting on a pile of bearings, bulkheads, slippers and servo-savers that should last me the next century.

Sounds about the same as me. Lol. I have better experiences with The Toyz lately compared to Liquid when it comes to shipping times. I thought you would have mentioned this site: http://fortuna-racing-cars.de Lots of GPM stuff for not too bad prices and of course no customs issues.

[CMD-J]

Yeah, i forgot about fortuna-racing I bought my GPM knuckles there. Nice when you have your parts after only two days shipping.
Still waiting on my Traxxas center CVDs, ordered on 18.03 from eBayUS..

[Petertje60]

Yeah, i forgot about fortuna-racing I bought my GPM knuckles there. Nice when you have your parts after only two days shipping.
Still waiting on my Traxxas center CVDs, ordered on 18.03 from eBayUS..

Bad luck. I got those in about 10 days. Maybe they are waiting in customs and they are considering how much tax they are gonna charge you

[CMD-J]

I got the feeling german customs collects all rc-like packages in a big box an only work once a month through it and only if it full moon and the stars are correctly aligned or something like that.

Anyone interested in how the Ofna 1/12 Hi Force wing dwarfs the stock wing, just found an old pic:



And i kept a secret:



I found them local for 15€ a pair and couldnt resist.



They are a bit small and very "drifty" to drive. I thought foams would hook up better?

[korn0307]

I think there are different compounds like rubber. Are they stiff?

[CMD-J]

Somewhat, yeah. I have nothing to compare it to and they are not rated for stiffness.

The foam is 0,5cm (~0.20") thick and i can compress it down to the rim with my finger applying some force, not too easily.
Ok, not that an accurately discription..

[dwmoss]

Great thread CMD-J, I've enjoyed reading it and looking forward to the future installments!!!