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How do I make a gear for a purchased rack?

Posted: Wed Oct 21, 2015 3:23 pm
by joel coulter
I plan on buying a rack for a rack and pinion gear project and would like to know if it's possible to make a gear for it?

Is it possible?
How do I find the rack's details to plug into Gearotic so they would match?

Jbc

Re: How do I make a gear for a purchased rack?

Posted: Wed Oct 21, 2015 5:07 pm
by BobL
Joel;

Simply fill in all details of your pinion gear into Gearotic's non circular tab with rack selected, should do it.


Cheers
Bob
:)

Re: How do I make a gear for a purchased rack?

Posted: Wed Oct 21, 2015 5:47 pm
by joel coulter
I plan on buying one that fits my need and then making the gear. What info am I looking for?
Distance between teeth? pitch? Depth...I have no clue.

Here is how I envision this;
I find a rack I want to purchase online.
I look at the specifications of that rack and plug that data into Gearotic which then makes a gear that works for me.

I see on a website selling rack and pinion gears.
The pitch=10. OK
The degree pressure angle=20. OK.
I made the rack.

The gear I try to make with the program is coming out wrong.
How do I make the gear?

Re: How do I make a gear for a purchased rack?

Posted: Thu Oct 22, 2015 2:30 am
by Hessel Oosten
Also good demo of making a rack:

TubalCain (Mr. Pete) on YouTube.

https://www.youtube.com/watch?v=Dipd0ohrYzg

https://www.youtube.com/watch?v=mXU-URNdUFU

Hessel

Edit: Sorry, I saw too late that you problem is the other way.

Re: How do I make a gear for a purchased rack?

Posted: Thu Oct 22, 2015 3:39 am
by BobL
Joel;

To make a pinion gear for any rack you'll require the DP or Module of your pinion gear, the pressure angle of it, and the # of teeth it has, that's pretty much it. You do not require anything else.  If you want however to create a rack, then you first create your pinion by selecting Gearotic circular gear module, add the wheel to your project, then select non circular module, click the rack check box, then input properties of your pinion gear to make the rack, and add to project.


Cheers
Bob

Re: How do I make a gear for a purchased rack?

Posted: Thu Oct 22, 2015 3:56 am
by joel coulter
Thanks Hessel.
I'll look at those links. I saw your post's edit but might help nonetheless.

I went onto the SPD/SI website and saw the details I need for racks. A lot better than some of the other sites I've visited that just sell metal with teeth on a side lol.
Their gear specs might help me with the matching gear and hence plugging that info in might make the angels sing.

BobL
Thanks Bob.
That should help quite a bit.
The thing that stopped me cold the most was the lack of specs from some merchants. Now that I have SPD/SI's specs to make this work I should be ok.
Thanks for your help.

Other than SPD/SI and McMaster Carr what other merchants sell racks with good spec listings/ ones others have liked?

jbc

jbc


Re: How do I make a gear for a purchased rack?

Posted: Fri Oct 23, 2015 1:17 am
by ArtF
Joel:

Just to kick in,  A Rack, noncircular gear and round gear are all related, you need only a Module or DP, and the pressure angle to generate any of them. So long as those two are identical between them , they should work together. There are other settings that negate this
but if you leave other settings along, you should be safe in saying a mod.5 gear of 20PA runs on a rack of mod.5 20PA. etc..

Art