Homebuilt crawler stretched and torque twist gone!
 

Hi Guys, just wanted to share a success I had recently with my own scratch built crawler 'thunderfoot'.

When I originally built it the wheelbase was just 280mm which with 4" under belly cleanance gave me 45 degrees ramp breakover angles using 2.2" tyres. However, I suffered really severe torque twist on the axles. I have now stretched the wheelbase to 330mm (13") and the less severe prop angles have made nearly all the torque twist vanish 8)

I also fitted a Hitec 5745 13Kg steering servo because the original servos just couldn't cope when crawling. This one works great and you can put all the weight on one tyre and it still won't budge the servo, steering remains perfect.

I also relocated the steering drag link to mount it above the steering uprights which has given me some extra clearance and I have fitted skid plates to the diffs after experience proved the unprotected diffs got damaged.

The increase in wheelbase has reduced the ramp breakover angles a little bit but the extra length means the truck can drop down much steeper slopes without rolling on its end.

The increase in length of the 4 links has also given me more articulation, it is now 9" from previous 7" which I'm also happy about.

http://www.tamiyaclub.com/getuserima...4800_1_350.jpg

http://www.tamiyaclub.com/getuserima...4800_2_350.jpg

http://www.tamiyaclub.com/getuserima...4800_5_350.jpg