TH407C Telehandler 1:14 scale

[Blender]

This project has been on and off for over a decade. It's closer than ever, but in a way i'm starting over. Original chassis in 2014 was brazed together. It worked well, but was not very square. My fabrication tools and abilities have improved a lot. The hand built models on the larger forums are always interesting to follow. I present my own build to you all. I hope this thread will keep me motivated as to not disappoint you all.

In the last incarnation I was able to operate the basic functions of the model. Lift tilt, drive and steer all functioned, but not to full ability. The 4WD was never connected and the hydraulic pump would run pretty hot. Body was only partially done.




That Machine still exists and many parts will be stolen from it. I split a solder seam on the boom years ago which was unrepairable since it was fully painted. The boom was rebuilt, but that showed how wonky the original chassis was. New chassis is slightly thinner material (1.5mm) and now stainless to prevent rust in hard to paint areas. CAD design was adjusted and reordered. Tiny welder did its job well. This time I was ultra careful to ensure components are placed perpendicularly using a machinists square. A few internal plates were added to ease cable routing and prevent a messy look when the boom is lifted. Rear steering was entirely redesigned to help fitment and serviceability. A little lower steer force is the cost when switching to a much smaller servo. Drive was originally N20 gearmotors 1 per wheel. This is preserved, but i will use a left and right ESC channel to allow mixing to slow the inner wheels.

Previous Losi Mini Rock Crawler CVD axles were used, but sadly no longer available. I do have 2 pairs on hand, but fear any kind of breakage. Instead Mini-T CVD shaft might be a viable substitution. Steering knuckles will be redesigned to incorporate. Lastly, The Magom HRC pump produced good pressure, but ran too hot. Start-stop pump operation was difficult because motor torque was too low with the alternate required for fitment. A larger diameter outrunner was sourced: Gartt ML3508 415kv. This is the smaller brother to the Garrt outrunner in my Metal Hobi excavator. It handles low idle very well and build very little heat. I hope for similar results in this machine.

Last generation I hit a roadblock with how to build the tubular cage of the cabin. I want it to be metal despite styrene being much easier. A simple techique used in full scale tube bending was applied to 4mm stainless steel tube. A simple tube bender and a end clamp produced favorable results. Once again the small welder will be used to assemble this structure.


Will be painted in Sunbelt rentals scheme.


Building 2 identical machines.


Tiny welder did good work. Central tabs will be body worked before paint


Boom which was rebuilt 2 years ago. May rebuilt yet again to make incremental improvements.


Larger Gartt outrunner. Every bit of space was used to fit this. Hole in chassis plate will be sealed from below via access cover.



Current status. Reprinted engine cover with slight geometry change. Shows one tube of the cabin guard. Need to rework CAD model of cabin to allow battery acces via small door. Battery is on order now 2S 4000mah transmitter lipo.