# calculate blades going around a diameter

I got a question for you engineering guys. I recently got interested in modeling jet engines I just find them fascinating. Heres the problem I have. As you can from the images below the compressor blade has a sort of a trapezoid shape and it locks in place with the other blades. So my question is how can I accurately calculate the base of the blade based on a certain diameter so a given number of blades will lock exactly with each other in place as seen below. Another thing is the base of the blade is nor arched following the diameter of the given circle its flat and has the locking teeth at the bottom. So is the base of blade calculated based on Arc length? I can do it by eye in assembly but I was hopping for more accurate calculations

### 5 Answers

I'd draw a segment on the hub (360 degrees / number of blades) and then draw the required feature in this segment. Then use the 'Circular Pattern' to crate the others.

On the blade, draw an identical segment and equivalent interlocking feature.

Sorry lekaimadh I do not understand the question 100% could you please re - write it is possible?

thank you

:)

look at the second picture. You see how the the blade has a bottom base and a top base that lock in with each other . So my question is how do I figure out the dimensions of the base based on a certain diameter. Say I have a diameter of a compress drum. 3500 mm. there 100 compressor blades How would i figure out the base of the blade you see it locks in with the other blades.

Draw an arc of radius 1750mm and 3.6 degrees between its ends. This should be the base of the blade.