rack design

[mm davari]

after some search in internet and according to prices we decided to design our steering box.
i have looked for in some books like "handbook of gear design" and some other related books.
but i cant find a direct approach for rack design, i.e. like other gear design equations.
so, can some body help me find out the equations for design of rack&pinion.

[mm davari]

after some search in internet and according to prices we decided to design our steering box.
i have looked for in some books like "handbook of gear design" and some other related books.
but i cant find a direct approach for rack design, i.e. like other gear design equations.
so, can some body help me find out the equations for design of rack&pinion.

[Ryan Schoffer]

i'm sorry - but you guys need to stop trying to rely on this site for all your basic questions.

the boards are more of a discussion thing about competing concepts rather than a direct question and answer sort of idea - figuring out steering rate, force etc is a relatively easy problem with a standard rack and pinion setup

[kwancho]

1 tooth on the pinion = 1 tooth on the rack. If there's 10 teeth on the pinion, and it's 5 teeth per inch on the rack, it's 2" per revolution.

[terra_dactile]

mm davari,

When designing a steering system you have to set some goals, eliminating friction is always good, next you must find how much torque is needed to turn the wheels and then add a safety factor for extreme manovers.You should chose the angular displacment you wish the steering wheel to travel, which should be under 360 deg lock to lock. Next choose the steering lever needed at the wheel to be able to turn the minimum radius of a endurance or autocross course, this will guide you to the travel needed at the rack, (linear motion) next chose your number of teeth and p.d of pinion( spur or helical gears) which meets these requirments, once you have approximate sizes for components you can use any machine design book to evaluate if your teeth on the gears can resist the tangential force applied at the Pitch Diameter.
You might not get a size that meets all of the requirment the first time so you have to repeat the process untill you can find a happy medium.
Remember the steering system should be very stiff and that safety should be at the top of your priority list, for your first vehicle it is better to be over built than to try and save a few grams in the steering system which might cause injuries or devastationg result in an endurance failure.

please excuse the long post,

It is advisable to check out the documents of Advice and Feed back on the Formula Student and FSAE Germany, their are many document for new teams so as to help guide your team in chosing priorities and goals.

Jude Berthault
ETS Formula SAE
Steering & Brake System Leader
2003-Current

[RiNaZ]

c'mon now bell ... we all know our country has a nuclear program too and possibly something even wayyy destructive than nuclear.

Let's stick to the program and set all political agenda aside.

[jonnycowboy]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by SpdRcr:
And fuck your nuclear program </div></BLOCKQUOTE>

haha stop being such asshole, you're probably some redneck prick, i hope iran does get some nukes (i'm from canada, btw!) so it can tell you to shut up! At least Iran hasn't attacked anybody lately!

Anyways, you should just buy a rack if its your first time.. buy a Junior Dragster steering rack, they're perfect for fsae. Later on you can modify it (longer rack) or rebuild it based on the original one.

[Richard Pare]

Geez, guys, try leaving the ignorant political BS out of Engineering, will ya?

Try also to have a bit of empathy for a guy from a partof the world where the knowledge on how things are built and work isn't inbred and a part of their every day culture!

His questions are perfectly legit for someone entirely new to this type of stuff. If you don't like the questions, go somewhere else for your entertainment!

[mm davari]

hi everybody
Politic is a devil and a nasty politic can show the feature of a country so different ,even that country is good or not .as an Iranian student i respect to other countries peaceful aims and as a patriot i believe my countries peaceful ends. So thanks everybody who doesn't tricked with politics and who don't mix science and politics together.
OK guys let back to our main discussion.
i completely found out the procedure of rack design ,equations and its calculations and i am ready to help anybody who needs help in this field.

[Cement Legs]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by SpdRcr:
the only reason canada hasnt been taken over is because of the U.S. so shut the hell up. </div></BLOCKQUOTE>

Actually you did invade us once but we kicked asssssssssss http://fsae.com/groupee_common/emoticons/icon_razz.gif

[Drew Price]

Gopi,

Please read post #2 by Ryan in this thread.

Same rules still apply.

[Dr Tron]

there is nothing that you are asking that you should not EASILY be able to figure out on your own as an engineer. There is a wealth of information contained on this forum as well as a ton more referanced. Ask the right questions and show that you have actually made attempts and people will generally help. Ask things like "please give me some idea of rack and pinion deisgn" and you will find that it annoys people. Any basic design of machine elements should give you a look into gear design for application.