i have full resources to build the gear box separately if required(complete workshop of my friend).but i don't have much knowledge of gear ratio calculation and making of gear box.
can some one help me here?
You can get it from the number of teeth or the radius (which are proportional). I am a radius guy so let´s say one hae gear 1 and gear 2.
And that the angular speed of them are w1 and w2, respectively.
same for the radius, r1 and r2 and so on.
YOu can connect them two ways:
1- teeth with teeth, then the velocity on the outer will be the same and the angular speed ( w1 and w2 ) will be different by the ratio of r1.w1=r2.w2
2- both an the same shaft, then angular speed, w1 and w2, will be the same and velocity, say v1 and v2, will be different. You get them from angular speed, v1=w1.r1 and v2=w2.r2.
Keep in minde the faster you get with you gears less torque you will have.