pushing pinion against gear rack

[DanOSB]

i have few questions and open to suggestion.. im going to make timing belt reduction box and that box will be aprox 5x5 or longer on one side and there is no room for arm route so i cant have spring and arm route and was hoping i could do sliding route but do anyone have suggestion how to slide metal to metal or metal to plastic teflon (Forgot the spelling for that thing then metal but how to hold those two parts together im open for options

it will be inside a 6x6 x 1/4 thick alumium square tube

and how much pressure do you suggest for the pinion to gear rack.. (how stiff spring should we use.. i was thinking of car valve spring as i can get those for free..

let me know what you guys think.. and im open to ideas and suggestions

[Al_The_Man]

Did you see this previous post? rack and pinion backlash
You may be able to adapt one of these Rosta products as I did, the one I used has the torsion element built in at the pivot point, so there is very little to none in the way of external tension components. They are part of the line of motor mount/belt tensioners.
Al.

[NC Cams]

If you are going to wing it, a car valve spring will either be WAY too heavy, Not quite enough or just about right.

However, if you know the gear specs (IE: diametral pitch and pressure angle) along with the anticipated loads that will be applied to the rack, you can calculate the separation forces and choose an appropriate spring.

Sadly, "I don't know" doesn't work with the gear/rack design formulae.....

There was a prior post on this websiter involving gear rack separation force but I don't recall the link. A site websearch may uncover it.