Modules on Rack and Pinion

[Mehul Botadra]

Hello,

What are the general modules of the gears on custom cut Rack and pinion used by teams? Also the depth of gear if its possible? I've calculated the depth to 3mm, but I dont feel its enough!

[BillCobb]

Talk to your front suspension rep and negotiate what the steer arm length is going to be. The pinion radius required is then defined approximately by the ratio of the steer arm to the steer ratio required to manage the steering effort and overall steering gain of the car with constraints on how much maeuverability your driver needs/prefers (say +-100 degrees SWA) and the maximum effort they can tolerate. at the rim.

[Mehul Botadra]

Already done that. But a module of 1.5 seems pretty less. Probably someone could throw light! Gear depth of 3mm hardly gives any area to mesh, the teeth may also bend!

[Dash]

Maybe you don't understand what a module means. Module is just the diameter of the gear over the number of teeth.

[Mehul Botadra]

Lesser module makes the teeth spacing sparce and the gear depth becomes lesser. Maybe we need to go back to secondary school to learn trigonometry! http://fsae.com/groupee_common/emoticons/icon_smile.gif

[BillCobb]

Take a few production racks apart and examine the non-standard designs and materials used. This may give you some insight on the methodologies employed to get gear cuts that work and live.

[Mehul Botadra]

We already have a gear hobber! He also has hobs of various modules to cut my gears. The only issue is the module, the reduction in module also makes the material vulnerable.

[buggaero]

Originally posted by Mehul Botadra:
We already have a gear hobber! He also has hobs of various modules to cut my gears. The only issue is the module, the reduction in module also makes the material vulnerable.

I have got small pinions done for one of my projects some of which were of Module 1.
Your hobber will have to take extra care and get an appropriate size mandrel for the job. Obviously such small sizes become vulnerable to excess wear or shear damage because of small module, it all depends on the material used considering the power transfer in its operation. Steering is something - relatively higher torque and low rpm. So the material should sustain it pretty fine.

[Francis Gagné]

We have been using rack&pinion of module 1.5 for the las three years, the first gearbox had a center-to-center to short which created a lot of wear and eventually bent the rack. With the new gearbox it runs smoothly. The gears had no problem of cracking at the bottom or at contact point at all with the high force and low speeds seen in the steering.

We use KHK gears that have been donated by QTC Gears.

[Mehul Botadra]

No undercutting issues with less module?