Help a dunce day

[sunnybob]

I need a clever person mathematically wise please.

Imagine a truncated cone 100 mm diameter across the small end.
The sides slope outwards at 11 degrees from the vertical, and the cone is 48 cm tall.
How wide is the cone at the top end?

Ta :roll: 8)

 

[novocaine]

28.6cm

SOHCAHTOA

tan(11) =o/48

o=tan(11)*48
9.3cm
o+5=r= 14.3
d=2r =28.6

can't be arsed doing the calc
here you go.

http://www.carbidedepot.com/formulas-trigright.asp

 

[mynamehere]

I got 118,66mm, but then again, I'm not very good at maths...

Cheers!

Ferenc

 

[sunnybob]

Novocaine, that doesnt work because it assumes the starting point is a point.
I need a four sided figure,not a triangle. Where the small vertical is already 50 mm high and the base line is 48 and the angle is 11 degrees

 

[sunnybob]

I got 118,66mm, but then again, I'm not very good at maths...

Cheers!

Ferenc

I think you may be even worse than me, The question STARTED with a 100 mm base diameter and 48 cm taller youve only got to 118 mm wide :shock: :shock: :roll:
OR... just realised, i think you mean thousands of mm? Thats even worse.

 

[novocaine]

draw it out please as I'm confused by you terminology.. it doesn't ignore the fact it's a truncated cone at all. it calculates to difference between top and bottom then adds the radius of the top to get the bottom.

here is what I think you are meaning.

 

[NickM]

draw it out please as I'm confused by you terminology.. it doesn't ignore the fact it's a truncated cone at all. it calculates to difference between top and bottom then adds the radius of the top to get the bottom.

here is what I think you are meaning.
View attachment 20200306

That's how I understood it and agree with your method and answer.

 

[jeremyduncombe]

Assuming the OP described the problem correctly, Novocaine is correct - the wide end of the truncated cone will be just over 28.6 cm across.

 

[jeremyduncombe]

Novocaine, I didn’t realise you had already posted a diagram while I was drawing mine. At least we got the same answer !

 

[novocaine]

yer but yours is nicer and uses a ruler and everything.

 

[sunnybob]

Did you get the "dunce" clue in the title? :shock: If there was an equivalent test of english and maths, my maths result would come out as severely dyslexic.
I looked at your link and it had a triangle. Ergo, its working out a triangle.

I've just done it the old fashioned way and drawn it all out on my workbench and got 29 cm, so allowing for thick pencil lines (and operators thereof!) Thats pretty damn close. Thanks for the confirmation. 8) 8)

 

[whiskywill]

My very accurate Autocad drawing says that the bottom end is 286.60509677mm diameter.

 

[sunnybob]

I dont think I have that number on my stanley tape measure :shock: :roll: 8)

 

[jeremyduncombe]

I dont think I have that number on my stanley tape measure :shock: :roll: 8)

Just scale up your project then, and make your cone 26,860,509,677 mm across. You might need a longer tape measure though. Anyway, what are you planning to make ?

 

[whiskywill]

Anyway, what are you planning to make ?

Ice cream?

 

[Sheffield Tony]

You can have the top bit of the cone you cut off for your hat :wink:

 

[sunnybob]

Due to the complete absence of any meaningfully sized cyclones i'm scaling up the one I have.
Its a 3/4 sized traffic cone that very conveniently fell off a lorry that I wasnt quick enough to note the number of. :roll:
its about 75% or even 80% efficient for my small hobby workshop, but I'm running 62 mm pipe, through a 75 mm home made cyclone, connected to a 100mm extractor. Can you spot the issues?
I want to make the cyclone 100 mm, and then run 100 mm pipe along the wall, reducing to 62 mm blast gates until I can either afford to buy or get time to make my own 100mm gates.
There are a couple of local sheet metal fabricators, but due to the language difficulties I need a fully detailed set of drawings with ALL the dimensions clearly marked.

 

[Inspector]

You could plug the data into Bill Pentz's spread sheet and it will make up the plans for the cyclone. Then the metal bashers can do the rest.

http://billpentz.com/woodworking/cyclon ... e_plan.cfm

Pete

 

[sunnybob]

Did you see the title of the thread :shock: :lol:
I have tried several times to wade through bill pentz exhaustive files.
I just ended up exhausted. :roll:

That site is the epitome of information overload. I found one page that seemed to be what I was looking for, the next time i went in to copy it I gave up searching after a half hour.
My little cone is, by pure chance, very efficient for most of my needs, but when using the thicknesser it just gets overloaded and blocks at the 3" bottom opening. So I have scaled it up to achieve a 100 mm bottom opening, at the same time as using 100 mm in and out ports. The new size will fit the space available for it, whereas i have no room for an 8ft monster.

time will tell. 8) 8)

 

[Inspector]

I'm sorry I suggested it. I won't bother anyone with dust collection help anymore.

Pete