Posted by on Jan 31, 2017 in Tech | 16 comments

Welcome to something new for us at RPP Hobby. The staff at RPP are known to be scale enthusiasts in the off-road world, but pavement is something relatively unexplored for us. Let alone our latest build endeavor, the Tamiya Grand Hauler kit. We have always admired the R/C big rigs, and the attention to detail put into them by the builders. Since we are scale junkies and wanted to build something completely different the Grand Hauler kit was the winner! We also decided to document the entire build here on the RPP Blog to let people see an inside look at the build process. Needless to say the Grand Hauler kit is fairly complex, but it can be built by anyone as long as you follow the instructions carefully. Ready to see more?

As usual with any kit build we like to open the box, locate the instruction manual and take a look through it a few times before starting the build. We do this to familiarize ourselves with the steps and parts involved along the way. Tamiya manuals are very detailed and some pages can be very busy. Double check yourselves during each step to ensure some small part doesn’t get missed during the build process. Next we selected a few parts we would need to get started on the build. We chose Hitec’s 645MG servo for the steering duties, and Hitec’s 322HD for the shifting responsibilities. Axial’s AE-5 ESC will provide power to the motor. A full set of Fast Eddy Bearings to keep our drivetrain buttery smooth by replacing the factory metal bushings with quality ball bearings. Lastly we have our Team Orion 3500mah 2S Lipo battery to keep us trucking down the scale highway!



Step 1 remove the stock servo horn from your steering and shift servos.



Notice the 645MG servo has a machine screw and the 322HD servo has a self-tapping plastic screw. Keep the correct screw with the corresponding servo.



Located the required servo saver parts for the servos you have selected to use. Most servos have either 23, 24 or 25 toothed splined outputs. Also, always trim any excess flashing after removing your plastic parts from the part’s trees with a sharp hobby knife. Makes for a cleaner, more professional looking build.



All the parts required to build and install both servo savers, minus servo screws.



Assemble both servo horns per the instructions. Backside shot of the steering servo saver.



Shift servo saver done!



Next you will want to make sure your servo outputs are perfectly centered before installing the servo horns. First plug your servos into a receiver, plug your ESC in next and power everything up to center your servos. Make sure your servo trim settings for the proper channels on your radio are set to zero.



Once centered carefully install the servo savers onto the proper servo and secure with the supplied screw. Steering servo done.



Shift servo ready to grind some scale gears.



Moving on to Step 2. Attach the servos to the servo mounts per the manual.



Got frame rails? These grand Hauler frame rails are by far the biggest we have ever worked with! Build the cross member in Step 3 and you have all the parts require to start assembling the chassis.



Per the instructions, start with one frame rail and install all the cross members into place. Then, flip to the other side and repeat.



Locate the parts require to assemble and install the bump stops.



Bump stops installed!



Moving on to Step 6. Locate all the parts required.



Start by installing the front leaf spring mounts. Plastic spacer sits up against the frame, then the flat suspension stay and the formed suspension stay goes on last.



Repeat above step to complete the passenger side.



Install the front shock mounts with the supplied hardware.



For the last step in Part 1 of our Grand Hauler build install plastic parts F10 and F13.



Overall we are always impressed with Tamiya’s quality and scale realism. This semi build is definitely no different! So many scale chrome parts, and the cab is amazingly detailed. We are really enjoying this build so far, and can’t stop wrenching on it. Stay tuned for Part 2 where we will get into building the shocks, installing the leaf springs and start building the axles. Until next time, breaker 19 over and out!