Surprisingly good results with low-cost mods on Slash 4x4
01-28-2011, 12:28 PM
#1
Surprisingly good results with low-cost mods on Slash 4x4
We have three Slash 4x4s in the family. My 12-yr-old and 4-yr-old sons each found one under the Christmas tree last month, and daddy has had his hands full finishing them up and bringing them to race places. Finally occurred to me that maybe daddy should have one of his own, too. So found a roller in good shape in Oregon (courtesy of CraigsList) and have recently been hacking on it. Wallet is slow in reinflating after the holidays, so had to go with low-priced components instead of the traditional Velineon/MamboMax/Neu/4sLipo route.
MOTOR: KD36-50-06S 5900KV brushless, $28 from HobbyCity. Has a 5mm output shaft instead of the usual 3.17mm, it's probably intended for 1/8 scale or for model aircraft, helicopters etc. Well, what the hell, the size of the Slash is closer to 1/8 scale than 1/10 anyway. Fortunately HobbyCentral has 5mm 32P pinions. See it at http://www.hobbycity.com/hobbyking/s...idProduct=6667 (it's the short one of the three shown).
ESC: Hobbywing EZ-Run 60A brushless,$43 from HobbyPartz. Handles up to 9 cells NiMH or 4s LiPo. 60A continuous, 380A burst(!!), 0.0007 Ohm resistance. Has high-voltage fan for more than 7.2V batteries. Various startup modes and settings for punch, reverse, etc., that I haven't figured out yet. See it at http://www.hobbypartz.com/ezrun-60a-...-1-10-car.html .
STEERING SERVO: T-Pro MG996R 55G High Torque Digital Servo. $12 from HobbyPartz. 140 in-oz torque(10kg-cm) .20sec (60 degree travel) at 4.8V, run on up to 7.2V, metal gears. After munching a couple of model plane servos, figured it was time to become strict. Especially the way my 12-year-old son smashes, bashes, and crashes his Slash. If I want to keep up, I'd better have the tools. See it at http://www.hobbypartz.com/servo-mg996r.html .
BATTERY: Gens ace 4000mah 2S1P7.4V hardCase LiPo, $25 from HobbyPartz. Their ad says it's ROAR approved, but I don't see a ROAR sticker on it (what's a ROAR sticker look like, anyway?) See it at http://www.hobbypartz.com/98p-30c-40...-hardcase.html .
RADIO: FlySky FS-GT2 2.4gHz 2-channel. $19 (!) from HobbyPartz. Was expecting a cheap piece of junk, but this is surprisingly nice for a basic radio. Steering and throttle trim knobs have plenty of effect, you can actually steer the car around with the steering trim alone. Steering and throttle reversing switches are handy, and it came with a cable to connect to your computer for simulations. And it banished the range and interference problems I've been having with an older 27MHz set - this radio is rock solid! I've been in love with the $35 FlySky FS-GT3B, but this radio is every bit as functional, and I actually like trim knobs better than the hi-tech pushbuttons of the GT3B. Why anyone pays $100 or more for a car controller any more, I don't know. See it at http://www.hobbypartz.com/fs-gt2-24ghz-radio-black.html .
At first I ran this with a 7.2V 6-cell 3800mAh NiMH. Ran OK, but if you suddenly punched it at low speed, it would heave and buck and hesitate. Not cogging, this is when it's already moving at maybe 10mph. If you gradually applied throttle instead, it would accelerate smoothly and go nice and fast. I figured the battery voltage was sagging with the high current draw when I punched it, and maybe the ESC cutout was doing its thing.
Put in the 7.4V 30C 4000mAh LiPo, and man what a difference. Now this thing burns rubber on all four tires, on dry asphalt yet. Scary. If a 4x4 could do a wheelie, I suspect this thing would be doing it. I wonder what it will be like when I get up the courage to put one of my son's 3s 9.9V 4500mAh 30C LiFePO4 batteries?
Configured as shown, this thing is a real blast. I have to wonder how it would stack up against my son's Velineon Slash 4x4 with the LiFePO4. Maybe have to find out sometime.
It's got a yellow ProLine VW full-fender body, I like simple. My camera died after being left out in the car at Big Bear overnight (-5F), so no pictures, sorry. I may try to shanghai the upstairs laptop with its built-in camera, we'll see.
MOTOR: KD36-50-06S 5900KV brushless, $28 from HobbyCity. Has a 5mm output shaft instead of the usual 3.17mm, it's probably intended for 1/8 scale or for model aircraft, helicopters etc. Well, what the hell, the size of the Slash is closer to 1/8 scale than 1/10 anyway. Fortunately HobbyCentral has 5mm 32P pinions. See it at http://www.hobbycity.com/hobbyking/s...idProduct=6667 (it's the short one of the three shown).
ESC: Hobbywing EZ-Run 60A brushless,$43 from HobbyPartz. Handles up to 9 cells NiMH or 4s LiPo. 60A continuous, 380A burst(!!), 0.0007 Ohm resistance. Has high-voltage fan for more than 7.2V batteries. Various startup modes and settings for punch, reverse, etc., that I haven't figured out yet. See it at http://www.hobbypartz.com/ezrun-60a-...-1-10-car.html .
STEERING SERVO: T-Pro MG996R 55G High Torque Digital Servo. $12 from HobbyPartz. 140 in-oz torque(10kg-cm) .20sec (60 degree travel) at 4.8V, run on up to 7.2V, metal gears. After munching a couple of model plane servos, figured it was time to become strict. Especially the way my 12-year-old son smashes, bashes, and crashes his Slash. If I want to keep up, I'd better have the tools. See it at http://www.hobbypartz.com/servo-mg996r.html .
BATTERY: Gens ace 4000mah 2S1P7.4V hardCase LiPo, $25 from HobbyPartz. Their ad says it's ROAR approved, but I don't see a ROAR sticker on it (what's a ROAR sticker look like, anyway?) See it at http://www.hobbypartz.com/98p-30c-40...-hardcase.html .
RADIO: FlySky FS-GT2 2.4gHz 2-channel. $19 (!) from HobbyPartz. Was expecting a cheap piece of junk, but this is surprisingly nice for a basic radio. Steering and throttle trim knobs have plenty of effect, you can actually steer the car around with the steering trim alone. Steering and throttle reversing switches are handy, and it came with a cable to connect to your computer for simulations. And it banished the range and interference problems I've been having with an older 27MHz set - this radio is rock solid! I've been in love with the $35 FlySky FS-GT3B, but this radio is every bit as functional, and I actually like trim knobs better than the hi-tech pushbuttons of the GT3B. Why anyone pays $100 or more for a car controller any more, I don't know. See it at http://www.hobbypartz.com/fs-gt2-24ghz-radio-black.html .
At first I ran this with a 7.2V 6-cell 3800mAh NiMH. Ran OK, but if you suddenly punched it at low speed, it would heave and buck and hesitate. Not cogging, this is when it's already moving at maybe 10mph. If you gradually applied throttle instead, it would accelerate smoothly and go nice and fast. I figured the battery voltage was sagging with the high current draw when I punched it, and maybe the ESC cutout was doing its thing.
Put in the 7.4V 30C 4000mAh LiPo, and man what a difference. Now this thing burns rubber on all four tires, on dry asphalt yet. Scary. If a 4x4 could do a wheelie, I suspect this thing would be doing it. I wonder what it will be like when I get up the courage to put one of my son's 3s 9.9V 4500mAh 30C LiFePO4 batteries?
Configured as shown, this thing is a real blast. I have to wonder how it would stack up against my son's Velineon Slash 4x4 with the LiFePO4. Maybe have to find out sometime.
It's got a yellow ProLine VW full-fender body, I like simple. My camera died after being left out in the car at Big Bear overnight (-5F), so no pictures, sorry. I may try to shanghai the upstairs laptop with its built-in camera, we'll see.
01-28-2011, 12:47 PM
#2
As far as roar approved batteries, they have a list:
http://www.roarracing.org/?page_id=259
Its not the best or probly most up to date list. I think they could do a better job of that, its all out of order/very random, or so it looks to me anyway. My batteries never claimed on the package that they were roar legal but i later found them on this list.
Just a word on a radio. Im not a fan of spending big bucks on one either, but after looking around some, the best for the price that i liked was the airtronics mx-3x. Has more than enough to adjust and didnt break the bank. Probly one of the best in its price range and competes with the radios that cost 2-300 bucks more. Plus it is digital, computerized, and has a fail safe you can program rite from the radio itself. I use the model memory and run 2 electric and a nitro truggy all with the same radio. The down side was that extra recievers are kinda pricey. No biggie if you are going to use it with one vehicle though.
It is glad to hear about you guys having a blast with them though. Especially the inexpensive way. Dont need to spend big bucks in the name of fun, esp with the family!
http://www.roarracing.org/?page_id=259
Its not the best or probly most up to date list. I think they could do a better job of that, its all out of order/very random, or so it looks to me anyway. My batteries never claimed on the package that they were roar legal but i later found them on this list.
Just a word on a radio. Im not a fan of spending big bucks on one either, but after looking around some, the best for the price that i liked was the airtronics mx-3x. Has more than enough to adjust and didnt break the bank. Probly one of the best in its price range and competes with the radios that cost 2-300 bucks more. Plus it is digital, computerized, and has a fail safe you can program rite from the radio itself. I use the model memory and run 2 electric and a nitro truggy all with the same radio. The down side was that extra recievers are kinda pricey. No biggie if you are going to use it with one vehicle though.
It is glad to hear about you guys having a blast with them though. Especially the inexpensive way. Dont need to spend big bucks in the name of fun, esp with the family!
01-28-2011, 01:22 PM
#4
2 Great sites
Hobbyking and hobbypartz
In regards to motors.
Here's the 1/8th motor of the same type
http://www.hobbycity.com/hobbyking/s...idProduct=6678
it's a 36 - 74 can. Try that one in your 1/8th buggy's (not truggys) or your 4X4 sct's and you'll be amazed.
In regards to motors.
Here's the 1/8th motor of the same type
http://www.hobbycity.com/hobbyking/s...idProduct=6678
it's a 36 - 74 can. Try that one in your 1/8th buggy's (not truggys) or your 4X4 sct's and you'll be amazed.
01-28-2011, 01:27 PM
#5
Hobbyking and hobbypartz
In regards to motors.
Here's the 1/8th motor of the same type
http://www.hobbycity.com/hobbyking/s...idProduct=6678
it's a 36 - 74 can. Try that one in your 1/8th buggy's (not truggys) or your 4X4 sct's and you'll be amazed.
In regards to motors.
Here's the 1/8th motor of the same type
http://www.hobbycity.com/hobbyking/s...idProduct=6678
it's a 36 - 74 can. Try that one in your 1/8th buggy's (not truggys) or your 4X4 sct's and you'll be amazed.
What is the advantage of this motor over the one I'm using?
01-28-2011, 01:41 PM
#6
Gearing, the lower the KV (within reason) allows you to gear up and maintain heat a little better.
Some people like the 2600KV range for 1/8th some like the lower end.
The motor that I pointed out is 1900KV and is a 74mm long can so you have TONS of torque and can gear up for speed.
I'm far from a motor expert. You'll find better explanations from others. But a buddy of mine has that engine and it performed awesome.
Some people like the 2600KV range for 1/8th some like the lower end.
The motor that I pointed out is 1900KV and is a 74mm long can so you have TONS of torque and can gear up for speed.
I'm far from a motor expert. You'll find better explanations from others. But a buddy of mine has that engine and it performed awesome.
01-28-2011, 01:58 PM
#7
When I ordered this 5900 KV motor from HobbyCity, I also ordered a 2600KV motor (also with 5mm shaft) for kicks and grins. Might swap it in sometime to see how it goes. It's the same diameter, but a little longer than this 5900KV motor.
01-28-2011, 09:29 PM
#9
I just recently put a 3S LiPo in my Slash - and it makes quite a difference.
If you found going from NiMh to LiPo was fun, 2S to 3S is just as fun. If you
have a 3S pack lying around, I say run it.
Although now I find the need to replace the ProLine baja body - from all
the traction rollling, and cartwheeling...
If you found going from NiMh to LiPo was fun, 2S to 3S is just as fun. If you
have a 3S pack lying around, I say run it.
Although now I find the need to replace the ProLine baja body - from all
the traction rollling, and cartwheeling...
01-30-2011, 03:29 PM
#10
The LiFePO4 batteries are like LiPos, but they don't catch fire. They can puff, though, so they're not perfect. And they have slightly lower voltage. Where LiPos have 3.7V per cell, the LiFePO4's have 3.3V nominal per cell. So these 3s LiFe PO4s give 9.9V, instead of the 11.1V I would get from a 3s LiPo.
The Slash 4x4 is a ball of fire (well, not literally, but it really goes) with this 3s LiFePO4. I'm going to get a few more of them - the safety is a great trade-off for the slightly lower voltage. They still go like a rocket.
The ESC in my Slash 4x4 has the cooling fan with a max of 7.2V allowed, so I can't put the 9.9V LiFePO4 battery on it yet. Got some high-voltage fans ($2.50 ea) coming from HobbyPartz. Then look out.
01-30-2011, 05:54 PM
#11
How well does your 4 year old handle the truck? My kid just turned 6 and I bought him a Slash 4x4 but I keep him on the 50% power setting, and he does pretty good with it. At 100%, I'd be afraid of lawsuits.
01-31-2011, 02:43 PM
#12
He's learning. Right now, steering while moving forward at the same time, is a challenge for him. But he thinks it's funny to hit Daddy with the car, so I keep walking around behind him. He still hasn't figured out what I'm doing. Gives him lots of steering and handling practice. Our last running session ended when he hit HIMSELF fairly hard with the car. I saw no need to point out that hitting people with your R/C isn't nice.
01-31-2011, 04:30 PM
#13
Very nice write-up. Lots of great information to point people toward saving money with great products 
02-04-2011, 10:24 PM
#14
I just modified this car to use the 4500mAh 30C 3s LiFePO4 batteries my son's Velineon Slash 4x4 uses. These LiFePO4 batteries provide a nominal 9.9V instead of the 11.1V a LiPo would provide. But it's still a higher voltage than anything I've put in it so far.
DamnNATION this thing is fast. Our cul-de-sac isn't long enought to test it properly - it runs the length of it in about three seconds, and I have to use the brakes carefully but strongly at the end to avoid disaster.
Several weeks ago my son and I chased his Velineon Slash in our Toyota. Me driving the big one, him driving his Slash while sitting in the right front seat. When we matched the Slash's speed, my speedometer read just a hair over 40mph. Haven't tried that with this one yet, but it wouldn't surprise me if this one turned out faster. Same battery, same chassis, different (and cheaper) motor and ESC. But DAMN it goes like a bat out of Hell.
At these speeds, the fact that this one has a Pro-line full-fender VW bug body (one of the most streamlined, low-drag passenger cars ever designed) may actually make a difference in its top speed. My son's Velineon Slash 4x4 has a Ford F-650 body from Pro-line, supposedly for a Revo 3.3 but who's counting. The F-650 body is probably aerodynamically draggier than the VW.
This KD36-50-06S 5900KV brushless motor from HobbyKing, is a real find. $28 plus shipping from China.
Somebody contact Traxxas. Tell them that we're about to put them out of business.
(Well, I can dream.....
)
DamnNATION this thing is fast. Our cul-de-sac isn't long enought to test it properly - it runs the length of it in about three seconds, and I have to use the brakes carefully but strongly at the end to avoid disaster.
Several weeks ago my son and I chased his Velineon Slash in our Toyota. Me driving the big one, him driving his Slash while sitting in the right front seat. When we matched the Slash's speed, my speedometer read just a hair over 40mph. Haven't tried that with this one yet, but it wouldn't surprise me if this one turned out faster. Same battery, same chassis, different (and cheaper) motor and ESC. But DAMN it goes like a bat out of Hell.
At these speeds, the fact that this one has a Pro-line full-fender VW bug body (one of the most streamlined, low-drag passenger cars ever designed) may actually make a difference in its top speed. My son's Velineon Slash 4x4 has a Ford F-650 body from Pro-line, supposedly for a Revo 3.3 but who's counting. The F-650 body is probably aerodynamically draggier than the VW.
This KD36-50-06S 5900KV brushless motor from HobbyKing, is a real find. $28 plus shipping from China.
Somebody contact Traxxas. Tell them that we're about to put them out of business.
(Well, I can dream.....
)
02-05-2011, 09:01 AM
#15
Suspended
