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$229 Street Price
First off the question you are asking is "Why a 4.5R
Brushless system on a Stampede?"
The answer is because no one else has done it, it brings just a stupid
amount of power to the Stampede Project Ultra-Pede that makes it almost
untouchable by a vast majority of electric and gas powered cars in almost
any configuration, and it scares the living hell out of everyone at the
track. The run times are a little on the short side, but what a
gloriously fun 7-10 minutes it is.
One of the big reasons I choose Novak for a brushless system
was because of my previous experience with their products and not so great
experiences with a couple other brands. My Novak Rooster still survives today
after surviving jumps, over gearing, over peaked packs, not following
manufacturers recommendations and warnings, and my general
driving style which in short is just abusive. Support from Novak is
also supposed to be some of the industry's best and when you are dropping
some serious cash on electrics, you want to know it will work.
Sensored
Brushless Systems
First off the Novak system is a sensored and brushless system, meaning Novak's design
specifically eliminates cogging by using a sensored motor/controller
system (indicated by an extra bundle of wires going from the motor to
the controller). Sensored motors are able to be more precisely controlled in theory because
the sensors can talk to the controller and tell it exactly what position
the rotor is in at any moment. The theory being that a sensored system can
provide much smoother exact control throughout the
RPM range than a sensorless system's method of motor control through
suggestion. Most brushless systems (sensorless or sensored) are
highly efficient and can attain much higher RPM and torque than brushed
motors.
By comparison, on a
sensorless system such as a Castle Creations Mamba Max, the controller makes suggestions to the motor to move forward, stop, or
backward and how fast to do each very similar to your old
"brushed" stock system. The thing people have noticed
on older systems as glitching and stuttering at very low speeds is called cogging and was
pretty annoying on older sensorless systems simply because the
intention of a brushless motor was to crank continuously at near max RPM
for hours on end, not rev up and down the RPM range. New sensored systems
and new sensorless controllers and higher quality motors such as the Mamba Max's almost
completely eliminate cogging. My experience is that I can take the Novak GTB 4.5R
equipped Ultra-Pede to a
obnoxiously slow dog teasing crawl with no cogging whatsoever. Need more information
on brushless systems see
this article by yours truly.
About
the GTB Controller
What is special about the new GTB controller from Novak is that it is
super crazy small with a 1"
x 1" footprint, extremely light, very high power, fully programmable,
compatible with all Novak's brushless 540 sized motors (even the old ones), and will
even run your old brushed motors with no turn limit restriction. The GTB is
also "water resistant", noting not waterproof, and can handle a
splash or two without blowing a circuit.
The GTB has four
brushless modes/profiles that can be tweaked via a simple but not the
easiest to use "blink and click" one button interface - you
really need to be paying attention.
The interface
allows control of Minimum
Brake, Drag Brake, Deadband, and Minimum Drive. The brushed mode is also
fully programmable with all of the adjustments of the brushless mode,
plus adjustable Drive Frequency. Novak was really thinking on the
design of this controller in that it's a class leading ESC for the
brushed motor racing but performs all the functions as a top end
brushless controller also. Although I am not that person that has
a need for both, there are a percentage of people that will use this
capability, should I be in a pinch, it's nice to know it's there.
Sadly
the GTB's cell count is from 4 to only 6 cells, and although this
produces more speed and torque than should be legal for an RC, it is a design limitation of a
sensored system. Sensored systems just don't have the voltage
flexibility of the sensorless systems. There will be some
speed freaks out there that want to turbo charge the setup with a few
extra cells, and on the GTB that would not be advised.
The GTB has included a industry standard
spec brushless fan to assure the controller is kept cool. An
opportunity for me to run GTB for a while without the fan occurred when
my fan suddenly stopped working and I waited patiently for my warranted
replacement from Novak. The GTB didn't thermal once, however I can see
that running 3 or more battery packs through it in a row would really
heat things up and the fan would be required. The fan really does need a
little protector or cage (which I later fabricated) as any little item
will remove a fan blade.
About
the Motor
Novak has been selling brushless motors for a while now. The SS
series motors and equipped systems were extremely popular and the SS5800
equipped system still remains a top seller and smoking deal direct from
Novak's refurbished equipment department. The new Velociti motor
series with accompanying GTB controller, promises more power, higher
RPMs,
higher reliability, more efficiency, and more features compared to the old system.
The
new motors delivers:
No Cogging--Thanks to constantly knowing the rotor position,
drivers experience instantaneous throttle response & smooth
transitions from neutral to drive. The rotor position knowledge is
attained due to the ESC & motor being continuously synchronized via
the motor harness.
Smooth
& Controlled Low Speed Drivability--Always knowing the rotor
angle is key to smooth acceleration without delivering abrupt and
uncontrolled bursts of power (i.e. cogging).
Strong/Consistent
Brakes & Starting Torque--Rotor position knowledge results in
consistent starts & stops, without hesitation or inconsistent lag
times before acceleration or braking--this translates to consistent lap
times.
Thermal
Protection--Position & temperature sensors inside motor provide
unparalleled thermal protection, letting you to run pack after pack
without worrying about overheating the motor, ESC, or magnets.
Cooler Operating Temps -- This new
aluminum ribbed case is supposedly lighter and radiated heat better to
keep the motors running cooler.
Complete Mounting Control--
This is via use of your choice of 6 motor mounting holes on the end
bell, and new higher current solder tabs on the end bell which allow for
a wider variety of soldering positions.
Novak
4.5R Specs:
Resistance 3.1 Mili-Ohms
Input Voltage 4-6 cells
Watts 415
KV (RPM/Volt) 9000
Some Considerations
A huge consideration is the quality, type, and capacity of the
battery. Let's say you understand a garbage battery compared to something
like a Trinity, GP, IB, or Sanyo and that you understand battery
capacities 1500Mh, 3300Mh, 4400Mh and the like. You may also know
that there is a difference between NiMH, NiCad, and the new high current
LiPo (Lithium/Polymer) batteries. Before you even think the
question - yes you will need the best batteries you can afford at the
very least Radio Shack GP3300s.
What you probably don't know is that a
good high quality battery such as a GP3300 fully charged in a Stampede running a 4.5R GTB wide open off road
in the grass
will last about 7-10 Minutes if you are lucky, with a IB4400 about 10-15
until full discharge. The motor is over stressing itself and is
drawing tons of current in the process. The simply fact is the motor
is attempting to hit supersonic speeds on speed limiting terrain with
gearing that is already geared down to its limits at 12/87 on the
Stampede. Those same
batteries in the Stampede with a 7.5R GTB and you are looking at nearly
double the run times and still about the same speeds off road.
Again a 4.5R is way overboard
on a Stampede and gets really quite un-drivable as the RPMs start to
spin up on flat surfaces.
The 4.5R is like putting a Ferrari motor in
a 4X4, it will work and be insanely fast, but it's going to work really hard
in the process. You should also consider that although a
4.5R in your Stampede would be nice and will be very fast, it's not the best choice from a
battery discharge perspective. You should consider a 7.5R or 6.5R for
the Stampede and leave the 4.5R and new 3.5R for the touring cars or at
least the high speed on road RC's or a road tuned Rustler. Honestly
with pretty much any brushless systems the biggest problem
will be keeping the tires from flying off the rims and having enough
batteries to make it through an hour or so.
Like
every other brushless system out there this system is
a current hog, big time (read below), so you will need to buy a Novak
4700mFor 5700mF capacitor and wire it to the receiver as described below to eliminate
almost certain glitching from receiver power brown outs.
Second, you WILL need either very high quality battery packs, ones that have
soldered connections between cells, or you will need to rebuild them (as
described here) to provide the current this beast requires to run
properly. I reformatted all my batteries both the cheap and expensive
ones to side
by side packs with Deans Power Pole battery bars. After the high current conversion
all worked well (although
the better batteries had noticeably more punch and/or runtime) with the 4.5R brushless
system.
Packaging and Installation
Novak has beautiful packaging with a nice
sturdy box, and full foam cutouts that securely hold the controller and
motor in place. Included in the box is the system pre-wired, a user manual,
programming manual, stickers, double sided adhesive gel tape, zip ties, and warranty card. The information
on the manuals is first rate, error free, contains lots of clear
diagrams, and easy and simple to follow.
The
system comes fully pre-wired, all that needs to be done is install in
the vehicle, connect battery, program, and go. Aside from the need
for a capacitor on the receiver (see below the Old Capacitor Trick)
installation was simple and easy.
I would also recommend applying tape over
the un-used mounting holes on the motor to further limit dirt getting into
the semi-sealed motor can, and be very careful with the fragile fan that
comes with the system, mine was missing one blade by the second day.
What
do I think of the GTB 4.5 System?
I was disappointed and very happy with the system at the same time. There
are some things that will annoy me about it and others which I was
ecstatically happy about.
+
Packaging is great as well as instructions. Novak is not some
slacker manufacturer that just tosses stuff in a box and leaves you to
figure things out. Complete instructions, warning sheets, configuration diagrams, and ESC setting
guides are supplied with plenty of links to supplemental info on their
website. The ESC and Motor is nicely nestled in formed foam in an easily
open-able and reusable box.
+ Installation was straight forward
however I would really like to see, Novak add paragraph or two about
running power and signal wires separately along the chassis as I believe
this reduces radio interference and is just good practice.
- The need for a capacitor on the receiver thing really ticked me off.
Novak included everything except the kitchen sink with the GTB 4.5 kit,
such as nice little wire ties, double sided gel adhesive tapes and other
little niceties,
which were great touches and I think for the price they are expected, but
left out a part that seems to be a known issue. I feel at the very least,
this potential issue should have at least been noted in the instructions
or a supplemental card tossed in the box as a warning.
+ My initial assessment was correct, the 4.5 system is about twice the
motor as my old reliable Titanite is from a torque perspective, speed
there is no comparison, the 4.5R is really fast, stupid fast. From what everyone
has been saying about the brushless systems I was expecting this just
wacky uncontrollable amount of power like the Hacker in Swami’s videos
which seems to spend more time on it's back or wheelie-ing than driving,
with so much power it is hard to drive, that in my opinion is just not the
case with the Novak system. Just a smooth but huge roll of power from top
to bottom. This would be an stellar racing setup. Kind of like 500HP
with the traction control and vehicle stability turned on - controllable
power.
+ Is it faster than just about anything you can put in a RC on
6-cells? With my
limited experience and according to Novak, YES! It is nutty fast on the
top end. Visually about as fast as my over gearing experiment so I am
anxious to see what the speed looks like at 15/87, 17/87 and beyond and
with peaked batteries. I can see where the mid forties are easy to hit
with this unit for everyone. That said the new Mamba Max from Castle
Creations is coming out, Novak now has a new 3.3.R motor coming, and
Reedy has just introduced a brushless motor also. Hold on to you
hats people the speed war has only begun.
+ & - Does it have the insane amount of wheelie popping torque which I was
expecting? Yes but not like I expected. It has that power wheelie-ing flip
on the lid power, but it does it in a more restrained way than I was
expecting. I was expecting rolling
20+ MPH wheelies which it did not do – may be I haven’t peaked my packs
yet before running or that I am a little over geared at 12/87, but unlikely.
+ To explain expectation further, let’s assume you have two cars racing, a
vintage Mustang with a huge powerful motor (what I was expecting), then on
the other side of the track you have a modern sports car like a Nissan
300ZX (the GTB 4.5R) which though the miracles of modern technology is
just a quick. Although both will hit the finish line at the same time, the
Mustang’s muscle-ly power is hard to control requires a wheelie bar and a
good driver, the 300ZX with vehicle stability control, power management
systems and the like is predictable enough your grandmother could drive
competitively at the track. The GTB 4.5R system is like the 300ZX, you
could drive is slow, you could drive is fast, it delivered a smooth power
band from beginning to end. Turns out I really like the smooth
output of the system.
+ Do you need a wheelie bar? Yes, buy a good one like Swami’s.
You will wheelie a lot with a Stampede but not on the Rustler. The
Rustler just jets off in a highly expedited manner.
+ Does the motor or ESC get hot? With my current 12/87 gearing and Moab
tires, it was not even slightly warm after 3 battery packs. We will see
hot it warms up at 15/87.
+ Another up is that I think my days of replacing motors which have been
eaten by our wonderful gritty clay Nebraska soil are history, the motor is
almost completed sealed. I did seal the other un-used mounting holes with
simple electrical tape cover.
+ Cogging? – Didn’t notice any at all even a
insanely slow tease the dog speeds. It's how I get my dog to chase
my RC's - it's good exercise for him.
- This is a love hate thing with the fan. In
my case - I hate it, I hate it, I hate it. This thing should have a
thermal switch that kicks on when needed. I am sure it will be needed as
gearing ratios are up’ed and the ESC heats, but it seemed kind of stupid
to have it running all the time when un-needed and …I already broke a
blade on the fan, isn’t heavy duty by any sense of the imagination.
The fan did just stop working completely about a week in. I did
notice that you DO need it after a few runs with 3 or more packs in a row. Novak did replace the
fan with no questions asked.
+ Stellar
post sale support - see above fan issue.
+ The GTB 4.5R is a current hog, no doubt about it.
I can't give them a negative for this because every brushless system hogs
current. Not a big issue but in
light of the required capacitor for the receiver, I think it should be
noted that a person really needs some decent long running batteries to
take advantage of the system. My run times are a little shorter than with
my old Rooster and Titanite and average about 7-10 minutes in grass and
around 15 on hard packed and smoother surfaces.
+ Changing of profiles
via the "blink and click" interface was a little tricky
if you are a instruction manual skimmer vs. reader or not paying complete
attention. You have to read the
manual to make it work. Follow the directions and all works great.
I like the profile 5 with 20% brake, reverse, and zero drag brake. The zero drag
brake makes the car coast with zero braking effect from the motor and really seems to extend run times.
+
Long term testing and use has been great, I
cannot think of a better setup for the Stampede. I am lying of
course because the 7.5R or 6.5R would be a much better fit for a normal
person but just not as much fun on smooth surfaces. I also love the
look on people faces at the track when I warp by them with a Stampede. I would have
however liked to see a broader cell input range so that I could drop 8-12 cells on the system. Still very impressed with the power of this
system and really is un-needed for it's intended purpose - racing.
+ So far I think I would do it again - the Project Stampede Ultra-Pede
Lives, It's ALIVE!!!!
-
Installation Problems
So I slapped that puppy in there
and glitching problems galore. Initially geared 13/87 - which from the
online threads seems to be a little under geared.
Da..da..da..da..daaaaaaaaaaaa.. Like it's attempting to send Morris code.
I get Zero glitching and almost
non-existent cogging (as advertised) when running with the wheels off the
ground, however the moment the Pede hit the ground I get Glitching when
attempting a full throttle take off. If I do a slow start no glitching
then I can punch it full throttle without glitching. I also get some
glitching at extended 20+ foot ranges.
I also seem to only get a feel of
the full power and speed when the wheels are off the ground otherwise when
on ground it only seems to only have let's say about twice the power of
the old Titanite.
Attempting to move the antenna
around to see if it was a antenna/power wire related issue, but did
nothing. Tranny is packed with plenty of Lithium Grease to minimize
radio interference. Dropped a new battery in and thought for a second that
cured the issue but started glitching just as before. The ESC was
set at factory default, with the exception of running Drive Profile 2
(100% F/R mode). But have tired other profiles with the some glitching
results. Drive frequency is fixed in brush-less mode.
The Install Resolutions from conversation
with Novak
Talked with Novak tech support. Their
recommendation was two fold.
A. Separate the power and signal wires, currently my are all zip tied
together in a 1/2" bundle. That did nothing.
B. Purchase a 4700 or 5700Mf capacitor to plug
into the battery pack slot on the receiver or use a battery pack. That should provide enough
juice to the receiver to get through the power hit on the battery
during hard acceleration.
What they say occasionally happens
is that the is such a huge initial current draw that the receiver current
drops low enough (a brown out of sorts) that you momentarily loose signal,
then of course everything rebounds and the process starts over again and
then the voltage pogos until you let off the trigger.
Novak was correct in diagnosing my
issue. Moving the cable did nothing, although I left them separated as it
seemed like a good idea.
I tucked the cap around the front of the
receiver. The esc is mounted in standard placement with the power wire
side of the ESC on the left (antenna side of the Pede) and the receiver
and wire harness bundle is on the right. This points the blinky ESC lights
forward and allows the two separate groups of wires to go around each side
of the rear shock tower. I also twisted each group of wires to shorten
them and hopefully cancel out any potential other interference problems.
That process in itself did not relieve the major glitching issue but may
reduce any other issue that may have occurred - i.e., still need a
capacitor. Just covering all the bases in advance.
The receiver was in fact
experiencing a "brown out" during full acceleration and with the addition of a Novak 5700Mf capacitor and the glitching issue was resolved
completely.
The day after update and the snap judgment April 2006
and apparent need for better batteries.
Three things are needed
to prevent glitching, an RC antenna
of the correct length, very good or
re-built
batteries, and a receiver capacitor. Without all three glitching
will continue.
Adding the cap worked. No glitching at all out to about 1/2 block
then everything went nuts until I replaced my antenna wire with the
correct length instead of "kind of the right length", and rebuilt the
battery packs. Aside from the power wires routing one side of
the rear shock tower and the harness and signal wires the other and the
capacitor, everything else was left in stock placement.
Once that was done:
A. All Problems were resolved. If you buy one you will need the following:
1. Novak 5700mF or 4700mF capacitor and do the below explained simply wiring and attachment to your receiver external
battery slot. Last week I went to the Novak 5700mF from the humongous the cap I had previously due
mounting issues of the cap. The Novak is small enough it can be easily mounted to the receiver on the
right side and works just dandy.
2. You will need either good quality "soldered" stick or side-by-side- brick packs,
a good pack like a Trinity, GP, IB or other pack, or rebuild you old
packs to for high current use with battery bars such as Dean Probar 3.
Converting all my old packs made an enormous difference and made that motor come alive and
perform like it should. If you have some lower quality packs you will need to re-build them see
this
on rebuilding battery packs.
3. Your antenna at the exact correct length.
B. I really love this setup know, after getting over the cap and low output battery issues, this thing
is a monster and would highly recommend this to anyone looking for some serious speed and power from
their Stampede.
PS. I still hate the fan.
Conclusion
Novak is a great company and the support with the glitching and the fan
replacement was first rate with no complaints.
The system is reliable, fast as anything I have driven, and makes the
Ultra-Pede just a blast to drive. Love it.
Testing the GTB 4.5R in
something Else?
Ultra-Rusty
goes Brushless
So let's say you are not quite as insane as me and
have something like a Rustler or Bandit that needs a little help in the
propulsion department. I am here for you. I ended up
hi-jacking the Novak GTB 4.5R Brushless setup from the Ultra-Pede
temporarily. In my opinion this is about as good as it gets for a
race legal brushless setup for the Rusty (although the rumor is that Novak
will be releasing an even faster 3.5R soon, no word on whether it will be
race legal). The thought was that I need to know whether it's going to do
the job or not before slapping down more cash, so why not do a test drive.
I kind of wanted to see how the Rustler would handle the power anyway.
Wonderfully by the way, but I am sensing that idler gear will need replacing
quickly if I don't swap back to the 15T (the 4.5R later shredded the
idler gear in less than 10 runs). Again I was really
expecting some wheelies with the 4.5R locked into the Ultra-Rusty's motor
mount, but instead I experienced warp-like but controlled acceleration.
The acceleration was fantastic, racing winning in fact, but in some way
Novak's linear power curve took a little of fun out of the equation. The
4.5R is NOT a bashers motor for wheelies but a purpose built brushless
system for
winning races. Kind of like trying to do donuts in the snow with your
real car with the "Traction control" and "Vehicle stability control on".
Sometimes you want to punch it and have the car launch forward in wheel
spinning wheelie-ing madness the 4.5R does not do that, just zip and gone,
at stunning speed. The Novak has that refined racing pedigree thing going
on that has knocked some of the fun edges off the power plant for the
average basher. All that noted, I don't know that I would want anything
else in my Rustler on the track. Out on the street and the backyard
I would like something to scare the heck out of the nitro guys, like a
Castle Creations Mamba Max setup that I could put a big ugly stack of
batteries on and move into the lutricus speed category. Overall I
really liked the 4.5R system on the Rustler and is probably what I will
go with when it comes to that point. Although I would also
consider the Reedy system, the GTB 4.5R is just a really nice efficient
system that just works without having to pile on a bunch of batteries to
see power and speed. I am going to play around with gearing a bit and
have a little fun then it will go back on the Ultra-Pede where it
belongs.
Perhaps Novak will
grant me a test 3.5R when they come out to test on the Ultra-Rusty.
The Old Capacitor Trick - and some background on why and when to use it.
The problem - Bought a GTB 4.5R
- Had tons of Glitching
So I slapped that puppy in there
yesterday and glitching problems galore. Geared 13/87 - which from the
online threads seems to be a little under geared.
Da..da..da..da..daaaaaaaaaaaa.. Like it's attempting to send Morris code.
I get Zero glitching and almost
non-existent cogging (as advertised) when running with the wheels off the
ground, however the moment the Pede hit the ground I get Glitching when
attempting a full throttle take off. If I do a slow start no glitching
then I can punch it full throttle without glitching. I also get some
glitching at extended 20+ foot ranges. Any ideas?
I also seem to only get a feel of
the full power and speed when the wheels are off the ground otherwise when
on ground it only seems to only have let's say about twice the power of
the old Titanite.
Attempting to move the antenna
around to see if it was a antenna/power wire related issue, but did
nothing. Tranny is packed with plenty of Lithium Grease to minimize
radio interference. Dropped a new battery in and thought for a second that
cured the issue but started glitching just as before. The ESC was
set at factory default, with the exception of running Drive Profile 2
(100% F/R mode). But have tired other profiles with the some glitching
results. Drive frequency is fixed in brush-less mode.
The Solution from conversation
with Novak
Talked with Novak tech support. Their
recommendation was two fold.
A. Separate the power and signal wires, currently my are all zip tied
together in a 1/2" bundle. That did nothing.
B. Purchase a capacitor to plug
into the battery pack slot on the receiver or use a battery pack. That should provide enough
juice to the receiver to get through the power hit on the battery
during hard acceleration.
What they say occasionally happens
is that the is such a huge initial current draw that the receiver current
drop low enough (a brown out of sorts) that you momentarily loose signal,
then of course everything rebounds and the process starts over again and
then the voltage pogos until you let off the trigger.
Novak was correct in diagnosing my
issue. Moving the cable did nothing, although I left them separated as it
seemed like a good idea.
The receiver was in fact
experiencing a "brown out" during full acceleration and with the addition of a simple 1000uf (1000mf) 35V polarized capacitor from Radio Shack
the glitching issue was resolved.
What I used was a 1000uf 35V Axial-Lead
(polarized) Electrolytic Capacitor .
What Capacitors do for your RC
car: Caps store energy, like a battery, so think of a capacitor as
very short term battery backup for your receiver or ESC. They can be used
on the ESC or the Receiver whichever needs it. I found one article
which indicated that your should have a cap on both your ESC and receiver
as a standard piece of equipment to prolong the life of each which is
typically shortened from continuous voltage fluctuations. Think of it
also as a power conditioner for your electronics.
How
do I make one of these things: I thought a simple Google search would
turn this up, but it took some digging. What I found was that sure the
more expensive and preferred 4700mf caps available at Towerhobbies.com will work, but so
will the $2 ones from radio shack. The key is that it needs to have arrows
on the label of the cap (a polarized capacitor), be of decent quality, 10+
volts (35V is the norm) and
be at least 1000uf (same as 1000mf). The bigger the number the more current
it stores, but keep in mind there is a point where bigger is just bigger,
on the big side the Novak caps at 4700uf (4700mf) and 5700uf are plenty huge.
The arrow on the cap. points in
the direction of current flow (from + to -) so the tip of the arrow is -
and
the back of the arrow is +.
Scrounge a spare receiver jack and
solder the red (+) lead to the + end of the capacitor. And the Black (-)
lead to the - end of the capacitor. I also picked up the variety grab bag
of Radio Shack shrink wraps and shrink wrapped everything up so no
sparking could occur. I also put a nice big shrink wrap over the whole cap
for protection -
gee looks just like the Novak on the ESC. Then plug it into the spare
battery slot on receiver, the same one you would use if you were using a
battery pack on your receiver. That's it. The capacitor will charge
from the power supplied from the ESC as needed and will discharge when
current drops suddenly.
Crude picture but you get the idea
of how to solder it together. Make sure
you shrink wrap everything well. Capacitors can spark. Also note that
Capacitors generally don't last forever, so if you get a year or two with
heavy use you are doing great.
The glitching issue was history
after this very minor upgrade.
I later gave in and picked up a Novak
5700mF cap, which I should have done
in the first place it was only $5 from the hobby shop. The big
difference is that although it is still 5700mF it is 10V versus 35V and is
about half the size and is much easier to mount on the Stampede.
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