I’d previously built an XRay M18 Pro so the build was very familiar.  XRay uses the same basic parts for their entire 1/18th (M18) line.  The main differences between each model is the main chassis, a-arms, and driveshafts.  All XRay M18s use the same adjustable ball differential/shaft drive set up that makes for a very smooth drivetrain and snappy acceleration.  The M18T and M18MT have very few differences.  The M18MT differs by having larger wheels than the M18T, four shock towers and eight shocks as opposed to having two shock towers and four shocks on the M18T, and the M18MT forgoes the roll bars so as not to affect ground clearance. 

Building the Kit

Opening the box I found the manual for an M18T, a manual amendment for the M18MT, the unpainted body, the wheels and tires (pre-assembled but not glued), a Hudy Phillips screwdriver, and a quite a few numbered bags containing parts plus an additional bag containing the “power pack” which is a 300 size motor, 1100 mAh Battery, XRay Micro ESC, and a high-torque metal gear steering servo. The manual is divided into sequential sections corresponding with the numbered bags.  The manual contained very clear instructions in plain English with full colour 3D images of every step and every part.  For parts that need to be tuned to a specific length, the manual included a 1:1 picture for direct reference negating the need for a ruler.  At the bottom of every page, every piece of hardware needed for that step is illustrated in a 1:1 diagram so that it is easy to identify the right screw for each part.  Other manufactures should take note, XRay manuals set the benchmark for the way every RC Kit’s Manual should be written.

Building the RC went quite smoothly except for my own foolish mistakes.  The manual very clearly shows the correct orientation and in a sleep deprived stupor (Note to self: don’t build RCs after midnight) I placed parts upside down despite the manuals clear instruction.  Luckily the simple and well laid out design of the RC allowed for these mistakes to be fixed without having to completely disassemble everything I’d done between making the mistake and realizing the mistake.  Anybody actually paying attention to the instructions and actually being alert while building the RC would not likely have made the mistakes that I did. 

There was only two parts of the build that were problematic for me.  The first was building the driveshafts.  The driveshafts use a pillow ball with 4 pins on it to connect the two parts of the drive shaft.  To put together the drive shafts you need to very carefully bend the sides of each side of the drive shaft to fit over the pins on the pillow ball.  If you bend it too the plastic becomes brittle and can (and as I found out) will snap when the car is driven.  XRay does offer an aluminum and a steel version of this driveshaft to negate this problem, and the steel driveshaft is standard on the Pro version of the M18T.

The other part of the build that was problematic was only so because of the tediousness of it’s nature.  The shocks come unassembled in an oil filled bag to keep everything lubricated. This made putting the shocks together a messy and tedious affair as all the parts stuck together.  The shock rods are held together using small C-Clips, one of which I managed to lose so I had to scrounge one from my spare parts bins.  Anyone who has ever used C-Clips will understand the hassle working with these little clips is.  I can’t fault XRay for this however as the only way around this would have been for the shocks to come pre-assembled which negates the point of having a kit.

One area where XRay did go above and beyond with their kit was with pre-built ball differentials.  It did need to be tightened after the RC kit was built, but XRay saved me at least half an hour of tedious build time by having the ball diffs already built.  To take it even further, XRay still included the instructions for building the ball diffs should you ever need to rebuild them. 

Because this kit included the “Power Pack” all that was needed to complete the RC was a Transmitter/Receiver, CA Glue for the tires, and Paint for the body.  I elected to use a Spektrum SR3500 Micro DSM Receiver which I bound to my existing Spektrum DX3R Radio. For paint I used PAINT NAME and to give this RC an extra little aesthetic pop, I dyed the stock wheels Orange using liquid Rit dye to match the Orange paint. 

First Run

To prepare the RC for it’s first run I had to first charge the included 1100 mAh battery.  To prepare the battery I discharged and charged the battery 5 times overnight to cycle the battery.  The final charge came to a total of 773 mAh.  Not quite the advertised 1100 mAh but this kit had been sitting in old stock for a couple years so it’s not surprising that it doesn’t quite live up to it’s rating. 

After popping the battery in and turning it on the car quickly came to life.  I had previously bound the receiver to the Radio so I instantly had control.  A quick systems check revealed that the steering servo end points were quite a bit over the physical limitation of the steering.  A quick adjustment on the radio put the steering right where it should be.  I wasn’t however to line up the stock servo completely flat with the recommended bellcrank length so I had to adjust the subtrim to get the RC up and running.  As usual this is never the recommended method so I will be adjusting the bellcrank length later. 

Steering servo response is very quick and there is plenty of torque to move the wheels full lock (and then some) at a dead stop.  Even with a bit more weight applied to the RC the stock servo had no issue turning the wheels.  XRay made sure to include a solid servo as part of this power pack.  The metal gears also help ensure that the servo doesn’t strip and lasts a long time. 

The first blip of the throttle and I was already impressed with the power of the included 300 size motor.  I’m used to brushless power but this little brushed motor was able to hold it’s own.  Indoor driving was quick and controllable.  The car had no problem climbing over things taller than the wheels.  It handled indoor jumps with no problem landing squarely on it’s wheels every time.  Everything was going well until one of the front driveshafts snapped.

Taking off the wheel and removing one screw I was able to quickly access the broken part.  The drive shaft had snapped where it was bent open to connect to the pillow ball.  This was likely due to overbending it when putting it together, something all too easy to do with a design like this. 

The RC still functions without the driveshaft, though it now tends to veer off in the opposite direction of the wheel missing the driveshaft as it is unable to handle the power.  As such I have ordered a replacement composite driveshaft and will test the RC outside and continue the review after I receive the replacement.

Stay tuned.

E-Revo Dual Mambas

This has been my RC project as of late.  A Traxxas E-Revo with the following Hop-Ups:

• Dual Mamba Max ESCs
• Dual Mamba 5700KV Motors
• RPM A-Arms (Front)
• RPM Tru-Track Rear
• Spektrum DX3R Transmitter/Receiver
• Orange/Gold Springs on Progressive-2 Rockers
• Traxxas Sway Bar Kit
• HPI Phaltline Wheels/Tires (For On-Road)
• Proline Racing Crime Fighter Wheels/Tires (For Dirt Track Racing)

Build Information and Pictures after the jump:

Still in the plastic

Switching out the Receiver for a DX3R

Receiver Size Comparison

Installing the Receiver

Installed and back together (Before I fried the stock Titans)

So at this point I fried my Titans after running them through water and getting debris in them. I was intending to simply replace them with another set of Titans until the Castle/Neu Combo was released, but I couldn’t even get a set of Titans anywhere soon as my LHS’s suppliers were all out. 

That’s where going with the Mamba Max twin idea come in. I already had a spare Mamba Max 5700 combo from another vehicle that I wasn’t using, and my LHS had one in stock. Two hours later and three of us working on the RC at the LHS, we had a working M-Twin. I can’t say it was the first however, because that morning the Hobby Shop owner had already put a pair of Sidewinder 4600 Combos in his E-Revo. (He likewise fried his motors on the third run)

Mamba Maxes Installed

Three Quarter View with Mambas

Sway Bars

I must say this thing flies. It’s easily as fast as a Nitro Revo now. (Which is exactly what I was going for) I’m using 12T pinions and I have the timing on the ESCs set to Lowest. I intend to experiment until I find a good Speed:Temp ratio.

I’m using a Castle BEC and a variant of the “Unslow Harness” I’ve connect the ESCs power directly together and I use a parallel Y-Harness to power both ESCs. It’s being powered by a pair of Venom 5000mah 7-Cell NiHMs, though I have MaxAmps 4700s as well.

The following are already installed and I will update here soon with pictures and information:

• RPM A-Arms & Tru-Track
• HPI Phaltline Wheels/Tires
• Proline Racing Crime Fighter Wheels/Tires

The following are planned upgrades:

• Castle Creations Mamba Monster Max Combo (Replacing Dual Mamba Max ESCs/Motors)

I didn’t purchase this car with high expectations. I expected a mid level electric RC car that I’d have to put some decent coin into to make it work the way I wanted to. I was wrong.

I opened the box to be pleasantly surprised by the quality of the build and the parts. Admittedly I didn’t do the research I should have before buying this car so all the extras came as a surprise to me. The car already had all the common upgrades installed:

• CVD Driveshafts
• Aluminum Oil Shocks
• Adjustable Ball Differential
• Adjustable Slipper Clutch
• FM Receiver and Controller designed by Futaba
• Ball Bearings all the way around
• Metric Hex Screws

And a few other things that are probably worth mentioning but I haven’t thought of them yet.

The main thing that did catch my eye when I selected to purchase this RC was the fact that it supported a seven cell battery without modification (I did technically have to remove a small piece of foam first) and the Price. It was priced competitively below the price of it’s direct competition Traxxas Bandit and seems to offer a lot more for standard parts. The base Bandit (not the VXL) does not have any of the extras I mentioned above.

The car is no slouch for speed either. Even with an old six cell battery pack installed it has a good speed and a good runtime. The included 20T motor provides a good speed and a runtime of over 20 minutes on a 1500mah battery. Putting in a 7 Cell battery yielded above-average results. The speed is easily over 40 km/hr and I can only imagine the ridiculous speeds I’ll get out of the eventual Mamba Max I’ll stick in there.

The off-road capability of the car is better than I expected as well. The low clearance of the buggy is high enough that it can handle grass and with the adjustable suspension I can lower it for road usage and handling.

The stock tires are horrible for road usage so I intend to get a different set of tires for it. However for off-road it handles quite well. The soft edge style front tires just get shredded by asphalt.

Overall I’m very satisfied with the Duratrax Evader BX. Great price for an above-average electric RC. I have since added a Mamba Max 5700kv motor which it handled the power of very well. On the arbitrary scale I just invented, I give it a 7 clutchbells out of 9.

Product Information

The instructions had six different languages in them so space was certainly limited leaving the written instructions fuzzy.  Fortunately for me, the illustrations were excellent and easy to follow.  It took me about six hours from start to finish to complete the project including paint.  Originally I had planned to paint the RC the same colors as my real MINI Cooper but I decided to wait until I get my hands on the BMW MINI body instead of the classic Rover Mini body. 

The Tamiya Rover Mini uses a M-03 platform which is unique in it’s front wheel drive design.  This allows for incredible steering however acceleration is adversely affected by the weight shifting to the back wheels, not unlike a full size FWD vehicle.  To compensate for this I will be replacing the rear shocks with stiffer springs to transfer the weight back to the front of the vehicle under acceleration. The front wheel drive design does allow for a predictable level of understeer and makes the vehicle much easier to steer than any of my other RCs which are all rear wheel drive.

The kit came with an ESC and motor but not a transceiver.  The stock ESC and motor are not terribly powerful but for a car of it’s size with the stock gearing it does make for a decently quick vehicle out of the box.  The braking however certainly lacks in the stock motor.  I have already ordered the Tamiya sport tuned motor to upgrade the stock one but eventually intend to install a Mamba Max 7700 ESC/Brushless motor kit with a 2s LiPo battery for additional speed and run time.  I installed one of my Spektrum transceivers and servos into the car and find them to be an excellent match for the vehicle.  Response is very quick and allows me to make controlled hairpin turns.

Overall I am incredibly impressed with the build quality of this Tamiya RC.  I’ve never owned a Tamiya RC before but I would certainly say it’s a safe bet that I will purchase another Tamiya RC in the future.  Driving an on-road car is certainly a change for me and while I enjoy the handling of an on-road car I’ve been using the web site RC-Mini.net for information on a rally tire and suspension set up for the car to increase versatility.