Thread: trig? help

Try this Trigonometry Calculator - Measure Triangle Angles

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If the central hole is central to the other holes, then they will have a PCD of 49.767mm.

The vertical distance between the centre of the central hole and the horizontal centreline of the other two holes will be 12.439mm

Therefore using basic trig, the "?" dimension will be 24.882mm.

This was taken from the jig boring co-ordinates in my Zeus tables.

I got the same answer - 24.88, using my school trig and calculator.

Graham

Originally Posted by GDD

I got the same answer - 24.88, using my school trig and calculator.

Hmpfh; the quality of education these days is obviously sadly lacking. I mean; what trigonometry standard only goes to two decimal places?

Your answer is a whole two microns short! You could slide a (really tiny) bus through that ommission! Sideways!

Thanks guys
I'll read and try and understand this later. I'll just grab the answer for now.
PCD? I'm assuming you don't mean pussycat dolls. pitch circle diameter?
It's been awhile.
The other numbers I need are 21.55 and 37.55 right??

Stuart

What's PCD stand for?. I had cos(30) x 43.1 = 37.32 = ? assuming it's an equilateral triangle with 60 degree angles. Also 43.1 squared minus 21.55 squared gives 1393.20 which the root of gives 37.32mm which is the wrong answer come to think of it....... ok sin cos tan only work on right angle triangles...damn i'm rusty!, don't drink and do trig.

your pulling the p-ss correct.

24.88 is correct.

?=(43.1)/(2cos30)=24.88

edit : 24.883796602 if that is precision :P

To work out the short length (from the base to that centre)
L-?=(43.1/2)(tan30)=12.441898301

I had a look around and found: Equilateral Triangle -- from Wolfram MathWorld

which gives R= 1/3 x root(3) x triangle side = ?, so plugging it in gives 24.88mm

Originally Posted by Stustoys

Thanks guys
I'll read and try and understand this later. I'll just grab the answer for now.
PCD? I'm assuming you don't mean pussycat dolls. pitch circle diameter?
It's been awhile.
The other numbers I need are 21.55 and 37.55 right??

Stuart

Yes the Dolls are better looking than a Pitch Circle Diameter, but not as usefull here.

Ok, bore your central hole. Move up 24.88mm (1/2 PCD) and bore your uppermost hole.

Return to the centre hole. Move down 12.44mm, then left 21.5mm. Bore your lower left hole.

Move right 43.1mm, bore your last hole.

I'm not sure where you got the 37.55 dimension from?

what planet you guys from?....smart asses are'nt ya!!!

Thanks Chief Tiff, I checked my math. Not sure where I screwed up, part of it is that I took the ".55" from the 21.55. But the answer I have in my notes to Csquared - Asquared = Bsquared is 37.355 and thats not right either lol.
Lucky for me had some issues picking up the center of the bore last night so gave it away until this morning.

eskimo turns out I cant even write something down right :P

Stuart