Author Topic: Math for machinist tapers...  (Read 11266 times)

Offline mklotz

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Re: Math for machinist tapers...
« Reply #25 on: February 09, 2013, 11:06:15 AM »
Quote
(that is another measurement i dont understand)


It's primary use is for quick, in-the-head*, maths for navigation. Powers of 60 factor (i.e. can be divided exactly) by 2,3,4,5,6 etc. making division by those factors easy and accurate.

eg. 25 34' 18"  divided by three =   8 31' 29" 

Easy, yes, except

(25 34' 18")/3 = 8 31' 26"
Regards, Marv

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Offline BillTodd

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Re: Math for machinist tapers...
« Reply #26 on: February 09, 2013, 12:56:44 PM »
 :doh:   

(You know why ? -  I was going to divide it by two  then thought "no, I 'll be clever and divide by three" ...)

Where's the kicking-oneself-up-the-arse emoticon ?

Bill (:LOL:)
Bill

Offline mklotz

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Re: Math for machinist tapers...
« Reply #27 on: February 09, 2013, 01:09:12 PM »
Murphy's extended law says that, if one is to make a computational error, it will always be in a widely viewed public venue.  (It's a corollary of the buttered toast lemma.)

Knowing this, I check every computation in a forum response three ways to Sunday yet I still manage to bugger up a few.  It's the math gods' way of keeping us humble.
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Offline dsquire

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Re: Math for machinist tapers...
« Reply #28 on: February 09, 2013, 04:10:23 PM »
:doh:   

(You know why ? -  I was going to divide it by two  then thought "no, I 'll be clever and divide by three" ...)

Where's the kicking-oneself-up-the-arse emoticon ?

Bill (:LOL:)

Bill

No need to feel to bad, We all make them once in a while.

I was sitting back at the original post trying to figure out in my head how to do it and couldn't get it to work out. I figured that I must have forgot how to divide degree's. Now I know it was a trick question just to see if we were all paying attention.  :lol: :lol: :lol:

Cheers  :beer:

Don
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Offline PekkaNF

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Re: Math for machinist tapers...
« Reply #29 on: September 12, 2017, 05:33:43 AM »
Old thread but same type problem.....

Good old 4.500" TPF.

I'm trying to get my head around what it actually means and how do I make it meaningfull:

1) Aproximate angle in degrees to make rough check (included angle)

2) Exact numbers to make the taper in the lathe (top slide method = half angle)

So, this is the bugger: 4.500" TPF big end is 0.87"
http://www.wmsopko.com/images/D-00108-R.jpg

Great. I assume that 4.500" TPF stands here for included angle, which ratio is 4,5" for 12,0" and half angle would be 2,25" displacement at 12" distance? Is this correct and if not what actually then this 4.500" TPF stand for and what it is when setting the machine to do this taper?

I think I know but after reading this thread and being raised on ratios of half angle I am having this WTxxxx moment.

Pekka

Offline seadog

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Re: Math for machinist tapers...
« Reply #30 on: September 12, 2017, 05:49:36 AM »
Hi Pekka, Abom79 shows an accurate way to set up for a taper. He has a taper attachment but still uses a method to check accuracy which is valid for setting a compound too.

https://www.youtube.com/watch?v=1Vsi8WQhtps&index=3&list=UUw3UZn1tcVe7pH3R6C3Gcng

Graham

Offline seadog

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Re: Math for machinist tapers...
« Reply #31 on: September 12, 2017, 05:51:03 AM »
It starts at aound 18 minutes in.

Offline AdeV

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Re: Math for machinist tapers...
« Reply #32 on: September 12, 2017, 06:06:51 AM »

Great. I assume that 4.500" TPF stands here for included angle, which ratio is 4,5" for 12,0" and half angle would be 2,25" displacement at 12" distance? Is this correct and if not what actually then this 4.500" TPF stand for and what it is when setting the machine to do this taper?


Sounds right to me. If it makes it any easier, 4.5" TPF is the same as 45mm per 120mm...
Cheers!
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Offline PekkaNF

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Re: Math for machinist tapers...
« Reply #33 on: September 12, 2017, 07:35:41 AM »

Great. I assume that 4.500" TPF stands here for included angle, which ratio is 4,5" for 12,0" and half angle would be 2,25" displacement at 12" distance? Is this correct and if not what actually then this 4.500" TPF stand for and what it is when setting the machine to do this taper?


Sounds right to me. If it makes it any easier, 4.5" TPF is the same as 45mm per 120mm...

Great, I didn't want to change the language to make matters even more confusing :lol:

Basically my question is that is this TPF just a straight ratio on orthogonal coordinates, no funky stuff here? The funky part is that it is included angle i.e divide by two to get something usefull?


Graham, Abom79 vids are allways worth checking. Thank you. Another person that makes a lot of stuff very clear is that al-bundy looking guy that sounds like my physics professor...what was his name Piezak or something. Spot on, without too many practical omissions.

Pekka

Offline seadog

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Re: Math for machinist tapers...
« Reply #34 on: September 12, 2017, 07:42:16 AM »
Joe Pie, as he jalls himself bejause noone can pronounce Pieczynski   :Doh:

I thought a video might be worth a thousand words.

Offline Pete.

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Re: Math for machinist tapers...
« Reply #35 on: September 14, 2017, 04:24:17 PM »
I only watch some of the youtube lot, I get bored with some where they waffle on with a bit of practical in between but I like Joe P, he does short and to the point vids.