Geometry question

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DarthBish

Well-Known Member
OK all you geometry wizzes out there...

I have a pipe that is 1 inch in diameter that I want to enclose in a hexagonal "sleeve"

How do I calculate the sige lenghths of the hexagon??
 

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mverta

Sr Member
Originally posted by DarthBish@Feb 22 2006, 05:51 AM
OK all you geometry wizzes out there...

I have a pipe that is 1 inch in diameter that I want to enclose in a hexagonal "sleeve"

How do I calculate the sige lenghths of the hexagon??
[snapback]1190399[/snapback]​

Strictly mathematically speaking, each side length must equal .577". I did it in my CAD software, I don't know what the formula is. Keep in mind it would have to be slightly larger than this so there's a molecule of air space in there or whatever :p

_Mike
 

Macklin

Well-Known Member
Sorry to hijack, but I have a similar question.

What diameter should a press-fit part be in relation to the hole? Say I have a 1 inch hole, what diameter should a part be to press snugly inside it ans stay put?

Think Chen's Obi emitter from a few years back.
 

Prop Runner

Sr Member
Originally posted by DarthBish@Feb 22 2006, 04:51 AM
OK all you geometry wizzes out there...

I have a pipe that is 1 inch in diameter that I want to enclose in a hexagonal "sleeve"

How do I calculate the sige lenghths of the hexagon??
[snapback]1190399[/snapback]​


:D

- Gabe
 

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Prop Runner

Sr Member
Originally posted by Macklin@Feb 22 2006, 05:10 AM
Sorry to hijack, but I have a similar question.

What diameter should a press-fit part be in relation to the hole?  Say I have a 1 inch hole, what diameter should a part be to press snugly inside it ans stay put?

Think Chen's Obi emitter from a few years back.
[snapback]1190408[/snapback]​
To be honest, it depends on the material and tolerances, but typically you want the inserted object to be 0.0001" - 0.0003" larger in diameter than the receiving hole:



God, I hope this does't turn into an "Ask Gabe" thread. :lol
 

Macklin

Well-Known Member
Heh. Looks like it's headed in that direction. :)

I'm thinking T-6061 aluminum. Did you mean to say LARGER?

Thanks,
Patrick
 

LeMarchand

Sr Member
Originally posted by Macklin@Feb 22 2006, 02:10 PM
Say I have a 1 inch hole, what diameter should a part be to press snugly inside it ans stay put?


[snapback]1190408[/snapback]​

:lol :lol :lol :lol Oh god, i can't stop laughing
 

Prop Runner

Sr Member
Originally posted by Macklin@Feb 22 2006, 05:48 AM
Heh.  Looks like it's headed in that direction. :)

I'm thinking T-6061 aluminum.  Did you mean to say LARGER? 

Thanks,
Patrick
[snapback]1190433[/snapback]​
For Marc: yes, size matters. :D

Patrick: yes - think about it: anything that's press-fit HAS to be larger than the hole. The material around the hole will expand a bit to accept it. Aluminum is soft, so it's more forgiving than steel if tolerances aren't dead-on accurate. If the diameter was SMALLER by the same amount, it would then be considered a removable SLIP-fit insert.

- Gabe
 

Treadwell

Master Member
RPF PREMIUM MEMBER
Originally posted by Prop Runner@Feb 22 2006, 08:38 AM
God, I hope this does't turn into an "Ask Gabe" thread. :lol
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Dear Dr. Gabe:

What is this rash? Am I normal?

-Concerned in Milwaukee




:D
 

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LeMarchand

Sr Member
For proprunner :p ;)

Originally posted by LeMarchand+Feb 22 2006, 03:20 PM--><div class='quotetop'>QUOTE(LeMarchand @ Feb 22 2006, 03:20 PM)</div>
<!--QuoteBegin-Macklin
@Feb 22 2006, 02:10 PM
Say I have a 1 inch hole, what diameter should a part be to press snugly inside it ans stay put?


[snapback]1190408[/snapback]​
[snapback]1190465[/snapback]​
[/b]
Don't know what diameter you need, but you'd better stop dating Proprunner, BWHAHAHAHAHAHAHA..... :lol :lol :lol
 

airhead

Well-Known Member
I don't have the tolerences here, but there is always a thermal press-fit - where one part is heated to expand and then, when the other part is inserted, the first contracts for a tight fit (can be done the other way with the inserted piece being chilled - like with liquid nitrogen). Or, differential thermal expansion where both pieces are heated, but one has a higher thermal expansion rate for fitting or disassembly. Like the transmission cases on my bike - 350 degrees in the oven for an hour.

db
 

Prop Runner

Sr Member
Originally posted by Treadwell@Feb 22 2006, 06:34 AM
Am I normal?
You're a STAFF member and you're asking ME? :lol

To quote Leia, you're either very brave or very stupid. :D

All in fun, of course. From the descriptions in your PM, your rash sounds a lot like the Scottish Rosey, and that generally comes from intimate contact with sheep....

Is there something you wish to share with us? :love

- Gabe
 

Macklin

Well-Known Member
*gazes into the distance*

I know kung-fu...

Thanks, Gabe. Glad you're here to set us all straight.

Patrick
 

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Prop Runner

Sr Member
Originally posted by DarthBish@Feb 22 2006, 02:13 PM
Thanks for all the help, you are ALL legends :)
[snapback]1190828[/snapback]​
Like Kane, I continue to walk the earth, resolving the world's geometry and press-fit crises...

... The Legend Continues...

:lol
 

Mechinyun

Sr Member
Originally posted by LeMarchand+Feb 22 2006, 09:35 AM--><div class='quotetop'>QUOTE(LeMarchand @ Feb 22 2006, 09:35 AM)</div>
For proprunner :p ;)

Originally posted by LeMarchand@Feb 22 2006, 03:20 PM
<!--QuoteBegin-Macklin
@Feb 22 2006, 02:10 PM
Say I have a 1 inch hole, what diameter should a part be to press snugly inside it ans stay put?


[snapback]1190408[/snapback]​


[snapback]1190465[/snapback]​
Don't know what diameter you need, but you'd better stop dating Proprunner, BWHAHAHAHAHAHAHA..... :lol :lol :lol
[snapback]1190478[/snapback]​
[/b]
:lol kekeke
 

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