Compute the BASIC DIA. @ the large end of the tapered hole-?

[RC-TANK-BUILDER]

Hi Everyone-!

I don't get on this site (YET) as often as I would like but if anyone can help me with this, it will certainly be MORE than appreciated-!

This is from blueprint reading class at my local Community College. Book is: Basic Blueprint reading & sketching by: Thomas P. Olivo Dr. C. Thomas Olivo, in case anyone has the very same book.....page no. 119 under unit 21, Dimensioning tapers & machined surfaces, question no. 13, {Compute the basic diameter at the large end of the/a tapered hole}.

Orthographic drawing (front view is on the lower right side) of a OFFSET CARRIER ARM with the ONLY dimension given as a ratio of: 0.062:1 This dimension is shown at the end of it's "taper-symbol", following a leader pointing directly at the hidden line which defines the shown taper.

Overall length of the object depicted using the top view (showing the {entire length} of the hidden line depicting the taper) is: 1.620"

The book shows us how to find the "Total-Taper" when two diameters are given and even if you only have one diameter "BUT" it doesn't show me how to find (one of the two diameters, the largest one or the smallest one) by means of the "missing formula" and this is my question........how do I figure out the answer to problem no. 13, {Compute the diameter of the LARGE END of the tapered hole} apparently using only the supplied ratio-measurement of: 0.062:1-??? / OKAY, My bad-! I just noticed I DO have one of the diameters-! it's one half inch, .500 at the small end of the taper, "BUT" the only two formulas the text book gives is how to compute TOTAL-TAPER again, I NEED to solve for the missing (larger) diameter. HOPE THIS HELPS whoever might be able to help me. Thanks.

If I were @ home, I'd have access to my digital camera / scanner etc. and I could include a copy of both pages in the text book so folks could see the problem up close and personal but I'm not and won't be able to for a few days.

So anyway, there you have it-! Again, any help with this will prevent any more of THIS type of activity - :wall: and therefore I THANK YOU "all" profusely-!!!

Jonathan

BTW -#1. - If I left ANYTHING out, let me know and I'll include it ASAP.

BTW -#2. - I'll be searching the internet using key-words & terms to locate as much info. as possible while awaiting any possible answers from this forum.

AGAIN.....THANK YOU anyone and everyone for your time and any help on this one. -

 

[Tin Falcon]

I THINK i found your problem Same book but may be different edition page etc.

so to find the size of the big end you need three things
1) The size of the small end .5 D given in the top view.
2) The length of the taper you need to add 1.125 from the end view and .375 from the side view this gives the answer to dimension (C)
3) the taper per inch which is given . (1/16th or 0.062)


You should be able to figure it out from there. if this is not the correct problem can you scan the page or part of it and post it. And yo may need to look at the previous or next page in your book.
Hope this helps.
Tin

 

[Tin Falcon]

And with an attempt to Highlight.

 

[Tin Falcon]

The hole increases 0.062 inches for every inch in length. so multiply

(L length of hole x 1.062) + .5 = Large end

Tin

 

[Charles Lamont]

The hole increases 0.062 inches for every inch in length. so multiply

(L length of hole x 1.062) + .5 = Large end

Are you sure about that?

 

[steam58]

Is it taper per foot or taper per inch?

 

[Tin Falcon]

Are you sure about that?

I will double check the formula.

Is it taper per foot or taper per inch?

it is given as a ratio 0.062 : 1 so it is unit-less+
.
I just uses in because everything else in is inches.

for example this can be used if you plug in tpf.
http://www.newmantools.com/tech/tapercalc.htm


multiply by length of taper, and add results to small diameter.

looks like that should be 0.062 times length + small end

Sorry

Tin

 

[rhankey]

The drawing does not make it clear whether the ratio is for angle of one side of the taper, or that of the cone (both sides). I am guessing it is the angle of just one side. If so, you would need to multiply the ratio X 2 to get the correct big end diameter.

 

[MachineTom]

If I was making a drawing the taper would be as finished. Look in the MHB all tapers are stated as ratio's .250 : 12 or included angles. Never as halfs.

Think drill points 118° not 59°, centers 60° not 30°, while drills are measured from the perpendicular, centers are measured from the axis, the angles are whole not half angles.

 

[kvom]

I agree with Tom. Taper is always change in diameter, not radius. To use trig, you'd use half the taper.

 

[Charles Lamont]

The drawing symbol also suggests that it is talking about a taper on diameter

 

[Tin Falcon]

look here
http://r-mceachern.com/data/edu/pdf%20files/Taper%20Curriculum.pdf
tin

 

[johnmcc69]

What a horrible way to dimension a taper. From being on both sides of the fence as a machinist & a designer, I would NEVER dimension a taper that way. I don't think it's. 062 per foot, that's only. 005" taper per inch giving you a diameter of. 514. (.062/12=.005 per inch X 1.5=.0075 SINGLE angle).
but, if I divide. 062 into a INCH, I get. 062 X 1.5=.093. (Per side)
Giving you a diameter at the large end of. 686.
If I were to give this part & print to the "Quality Control" department, they would beat me. They wouldn't be able to measure it.

My reasoning & math skills are failing me, so, please set me straight.

John

 

[sssfox]

What a horrible way to dimension a taper. From being on both sides of the fence as a machinist & a designer, I would NEVER dimension a taper that way. I don't think it's. 062 per foot, that's only. 005" taper per inch giving you a diameter of. 514. (.062/12=.005 per inch X 1.5=.0075 SINGLE angle).
but, if I divide. 062 into a INCH, I get. 062 X 1.5=.093. (Per side)
Giving you a diameter at the large end of. 686.
If I were to give this part & print to the "Quality Control" department, they would beat me. They wouldn't be able to measure it.

My reasoning & math skills are failing me, so, please set me straight.

John

John,

The taper is given as .062 unit per unit, NOT .062" per ft as you think.
The ratio is unitless. It could be feet, inches, centimeters, millimeters or quixels*, it doesn't matter. It is up to the reader to convert the ratio to what is needed to answer the problem.
In this case, it would be .062' per ft, or .744" per ft.
It could also be expressed as .062" per in or approximately 1/16" per in.

You have to remember that this is a math exercise.

The taper is given in a non-standard way because the purpose of the exercise is to require the student to find the answer by using the information given in the problem, not give him the answer.

Steve Fox

*A quixel is the distance from the elbow to the tip of the thumb of the Aztec king. After all, this is April 1st isn't it?

 

[Tin Falcon]

Cubits !!


You are correct the whole purpose of this exercise is to learn to read poorly drawn blueprints and use math and formulas to find information that is not clearly given.


I do hope there are examples in the book that show the preferred methods.

From experience it seems blueprint reading 101 and Mind Reading 101 are companion classes to be taken in the same semester.Place had on paper and read the thoughts of the Draftsman
Tin