TechnoRC
Revo Brushless Conversion
By Tony Arnold – StampedeProject.com
With Dremel wounds from engineering
and fabricating two different NTB (Nitro to Brushless) Revo conversions
still fresh scares (Revo’Lution - May 2007), I could not wait to review
the bolt-on Revo 2.5/3.3 brushless kit from TechnoRC. Excluding motor,
battery, and ESC, every part is included to deliver a factory looking
brushless
conversion all for the price of two month’s of nitro without
even scraping a knuckle. The kicker is it even drives like a nitro powered
Revo thanks to TechnoRC’s patent pending Elektri-Clutch clutch bell
adapter.
NTB Conversion
Flashback
The Project Revo’Lution article
taught us different Revo conversions have different problems. The EMaxx
transmission swap conversion requires chassis Dremeling, an Emaxx Tranny,
and a half-shaft trim and swap. The upsides were a lighter and cleaner
install that was faster, delivered a more direct feel, easier to tune, and
offered more durability with stock parts. However it also delivered a
wheelie prone design with less braking feel than stock, and a higher CG
with the motor hanging up top. The direct style NTB conversion is heavier
and typically has a goofy transmission and shift point feel due to the
absence of a clutch and the complexity of the Revo transmission. The
direct conversion like TechnoRC’s is the best racing option, however the
already cramped chassis makes finding places to mount the ESC and
batteries challenging. The “F” word – “Fabrication” is also
required, but TechnoRC’s conversion may have the best of all worlds in
one kit.
TechnoTour
TechnoRC is one of the first
companies to offer a complete brushless bolt on Revo kit. The kit
addresses all the major fabrication issues of a NTB Revo conversion
including, motor, ESC, battery & servo mounts, procuring battery
straps, hardware, and receiver box. The Elektri-Clutch is of course the
trick part of the kit that could also be handy in those NTB 1/8th
scale buggies we are seeing now.
The battery, servo and receiver
trays are durable quality plastic that rival any typical factory mold
formed part. The real show shoppers are the stunningly finished CNC
machined,
polished and anodized motor and ESC mounts.
The idea is simple; bolt up your
motor of choice with the included TechnoRC motor mount where the nitro
engine resided, and adjust the Elektri-Clutch tooth gap with the stock
nitro mounts. Install the battery tray and strap on your favorite Lithium
pack(s), bolt on the ESC mount with ESC above the transmission, and swap
the huge stock receiver box for the smaller TechnoRC unit. You could go
for a forward only conversion at this point with the included servo mount
plate, however I decided to retain reverse and the stock servo box to show
the flexibility of this kit. I did tighten
down the shift setting to eliminate shifting.
TechnoRC recommends one of the
large format premium brushless motors with 5mm shafts such as a Neumotor
1512 or 1515 or the Hacker C50 11L motor I used. Due to the voltage and
torque requirements, I recommend a motor in the 2200-2700Kv range for more
torque and lower ESC operating temperatures.
The
Elektri-Clutch clutch bell
adapter is in reality a special pinion that still needs all the stock
Traxxas clutch parts to work. Pull your entire clutch from your nitro
engine and bolt them on the Elektri-Clutch adapter then attach to the
motor as simply as you would install a regular pinion. The Elektri-Clutch
effectively provides a Nitro engine shaft and clutch on any 5mm shafted
electric motor – handy.
Testing
I tried a number of setups. The
battery tray is flexible enough to handle everything from twelve GP3300
cells, a massive 10,000mh 14.4V MaxAmps Lipo pack, dual 8000Mh Max Amps
7.4V packs, to the dual 4600 A123 6.6V packs featured. For optimal tray
fit and battery protection, stick with LiPo packs under 8000Mh to prevent
overhang. I also cycled through several motor and ESC combinations
including a Castle Mamba Max and Tekin’s new R1 Pro ESCs and motors from
Hacker and Neumotor. Although TehnoRC states Novak’s 3.2mm shafted HV
system won’t work with the Elektri-Clutch, I got it working by ditching
the massive motor heat sink in favor of a more compact unit and using
RC-Monster’s handy 3.2mm-to-5mm adapter sleeve.
For the photo shoot and initial
testing we used a fan cooled Tekin R1 Pro, dual A123 4600Mh packs, and a
Hacker C50 11L 2215kv motor. Since braking and reverse are handled by
stock equipment, I turned off or minimized brakes and reverse on the ESCs
tested. You will need a servo Y splitter adapter to assure the ESC gets
the go signals and the brakes the stop signals. Due to a tight deadline, I
really didn’t have enough time to really work through all the various
combinations, tuning, and testing as I would have liked, however Stephen
has committed to a long-term update, so we’ll keep you posted with nerdy
temp, rpm, voltage, and current data from my Oracle Data recorder later.
What We
Liked
TechnoRC’s bolt on brushless conversion is a
beautifully elegant and flexible kit and that even gives you little
details like multiple motor bolt patterns and a slot to slip in a hex
wrench to tighten down the Elektri-Clutch
on the mount plate. The kit includes every little bolt and tie-down
strap you will need – all nice touches.
With the torque of our previous NTB Revo setups
trigger control was essential in keeping the front wheels on the ground
for fast lap times. With a clutch, it’s more forgiving in the first 1/3
of trigger pull. The clutch also removes any perception of cogging.
Instead of punching a wheelie, the power is less peaky – racers will
love this, wheelie-ing bashers will hate it. Using a standard Mega Motors
extended shaft MOD1 pinion instead of the Elektri-Clutch
will please the bashers with expected wheelies.
So it
drives just like a higher torque Nitro powered Revo, but isn’t it
overall less efficient with a clutch? Based on my Medusa Research Oracle
Data Recorder, runtimes varied only slightly between the Elektri-Clutch
and the standard Mega Motor pinion. Interestingly I observed significantly
lower operating temps on the motor and ESC with the Elektri-Clutch
installed versus a fixed pinion – but I later duplicated the same effect
and drive feel by simply loosing the slipper.
Driving
was like running a nicely tuned Nitro Revo with earplugs in. The featured
Tekin R1 Pro was a trooper and easily handled the 14.4V at a reasonable
temperature with a fan applied to the solder posts. For initial testing
the 14.4V MaxAmp and dual 6.6V A123 packs used produced some impressive
speeds but was quite under geared, however for the speedsters in the group
that want to go head-to-head with the Nitro guys they should bump up the
pinion teeth and target a 5S-6S setup, with one of upcoming big voltage
Tekin and Castle ESCs.
What
We Would Change
Included instructions were thorough
and well thought out, but electric combo recommendations were missing. The kit is still a little ahead of it’s time as far as monster truck
brushless systems are concerned. Sure the MaxAmps powered Tekin R1 Pro
kicked out enough juice to the Hacker C11 motor that it shredded the Revo
tranny in the first 45 minutes, but both the R1 Pro and Mamba Max test are
10th scale units happiest with fan cooling. Just for extra
insurance I used an industrial 12V+ fan that moved some serious air at
14.4V. At time of publishing the obvious ESC choices of bigger power Tekin
and Castle units were still unavailable. With the noted tranny
destruction, slipper tuning is still needed to prevent transmission
damage. The shift point transition was still a little notchy, however our
single speed tweak resolved that issue. Brushless motors like a load at
start and with the clutched freewheeling starts, cogging was more audible
with every motor ESC tested – the clutch made any cogging invisible to
the overall system.
Conclusion
The TechnoRC kit is super simple – bolt it on and go. In
about an hour you could convert a stock Revo to brushless with results
that look factory perfect. The conversion is reversible, flexible to
handle about any motor and ESC, and can even use fixed extended pinions
for the wheelie lovers. The Elektri-Clutch
is a winner for brushless racers, the “nitro feel” people, and
a no-brainer for potential NTB buggy conversions. The initial abrupt power
of a high power brushless system is smoothed out by the clutch and makes a
much more driver friendly RC and most likely faster lap times. For those
that have resisted a Revo conversion due to tuning limitations, the
TechnoRC brushless conversion will offer even more tuning flexibility than
nitro with not only clutch tuning, but also in the form of the new breed
of PC programmable brushless ESCs now on the market. Fit and finish,
quality, and high flexibility - I would be stunned if the TechnoRC Revo
Brushless Conversion kit isn’t a huge hit.
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Highs – Full bolt on kit looks factory installed and
performs like nitro. Easy reversible install.
Lows – Still need motor, ESC, LiPo pack and servo Y
adapter.
Final Call – The most complete brushless conversion kit yet
to hit the market.
Competing Kits: RC-Monster.com Motor Mount, Blue Groove
Concepts Revo Kit.
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On the Other Hand – Tony Arnold
I am split, the EMaxx transmission is simpler and handles
brushless power better, but the Elektri-Clutch and disk brakes are the
obvious answer for racing. I like the idea of the Elektri-Clutch because
it reduces stress on motor and ESC, but as a basher the direct one-to-one
feel of a fixed pinion and non-freewheeling transmission is a lot more fun
on the dirt pile. The clutch
is cool, but couldn’t we just loosen our slipper clutches a little –
GASP!
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Sources: TechnoRC – www.TechnoRC.com, Tekin –
www.TeamTekin.com, Castle Creations – www.CastleCreations.com, Novak –
www.TeamNovak.com, A123 Racing – www.A123Racing.com, MaxAmps –
www.MaxAmps.com, RC-Monster – www.RC-Monster.com, Neumotor –
www.Neumotors.com, Hacker – www.HackerBrushless.com, Medusa Research –
www.MedusaProducts.com, Mega-Motor – www.MegaMotorUSA.com, Traxxas –
www.Traxxas.com.
