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.