Clearance/allowance in Rack and Pinion system

[miner00]

I am working on a binding problem with a rack and pinion system. We are using a 14.5PA 48P 22 tooth pinion on a 14.5PA rack. Should the Pitch lines be lined up exactly, or should there be some clearance/allowance allowed in the system? Due to manufacturing tolerances, we are having trouble lining them up exactly and as a result we are seeing binding.

Any information here would be helpful.

miner

 

[diamondjim]

Miner,
Almost all gear meshes need backlash to overcome
the expansion due to heat build up or manufacturing
errors. Depending on the material, different backlash
recommendations would be needed. You have a very
fine dp set and I would start at .004 min. and see
if that does not free up the system.
You cannot beat first hand knowledge. Keep us
informed.

 

[miner00]

Just to answer your question, the system has a SS pinion in mesh with a hard annodized aluminum gear rack. Thanks for your help.