RTI ramp for SCX24 and other scale crawlers

No glue required, no supports required. Come with indicator to read height directly.

RTI is a measure of the articulation an off-road vehicle can achieve, higher is better. Interestingly it scales with the wheelbase, so we can accurately compare all vehicles (from RC to fullsize) on an even field. Using this ramp you can see how your tuning changes effect performance of your truck. I have used this to double my trucks articulation. This system will work on all rc vehicles from about 1/16 to 1/24 scale (depending on suspension travel). If you want to use it for 1/10, you can scale the ramp 200%, but you will have to double the values of height.

What to print:

Stock SCX24 will only need the base ramp + indicator.

Heavily modified scx24 will need base ramp + indicator + joining pin+ extender.

How to use:
1.Line your crawler up with the ramp so that only one wheel (usually front) is going to climb.
2. Advance slowly up ramp until 1 wheel starts to lift off the ground.
3. Reverse slightly until that wheel is just barely touching (I shine a light under or see if a paper will slip under to check)
4. Move indicator so that it lines up with the middle of the wheel. Read height (this number is VERTICAL and is already corrected for sin(30)).
5. Measure wheelbase, the distance from wheel nut to wheel nut in mm (stock SCX are around 133mm, my 4 linked front scx24 is 142mm.
5. RTI= (Height measured on ramp / wheelbase) x 2924

Stock RTI for the jeep was around 700 if I remember correctly. My highly modified buggy can do around 1500.

It is critical for accurate measurement that you actually drive the truck up the ramp. If you place the truck or push down on it to fully articulate the suspension, it will displace the tires more than typical which will increase RTI. For instance if I push my truck on the ramp I can acheive ~1900, up from ~1500.

0.2mm no support required.