#### opcon

##### Active Member

Greetings!

I'm trying to model the boat tail of the MAC Performance FireStickXL - 3" dia. rocket and I've hit a wall.

After researching and some trial and error (/cough manual searching in the 'data') in Excel I figured out how to calculate the Ogive radius thanks to this website but I'm still a bit off track. I'm working backwards from an OpenRocket file provided by MAC Performance to provide dimensions.

Likely, my maths are off, but I'm unable to spot where. Basically, the aft throat of the tail is off, it should measure 60mm in dia, but I'll be darned if I can get any closer than 58.569mm.

If anyone has time or inclination to let me know what I'm doing wrong, I suspect the Ogive radius (p) is not correct.

Attached spreadsheet, ork and ipt inside attached zip file.

-With love, Opcon

Attached rendering

I'm trying to model the boat tail of the MAC Performance FireStickXL - 3" dia. rocket and I've hit a wall.

After researching and some trial and error (/cough manual searching in the 'data') in Excel I figured out how to calculate the Ogive radius thanks to this website but I'm still a bit off track. I'm working backwards from an OpenRocket file provided by MAC Performance to provide dimensions.

Likely, my maths are off, but I'm unable to spot where. Basically, the aft throat of the tail is off, it should measure 60mm in dia, but I'll be darned if I can get any closer than 58.569mm.

If anyone has time or inclination to let me know what I'm doing wrong, I suspect the Ogive radius (p) is not correct.

Attached spreadsheet, ork and ipt inside attached zip file.

-With love, Opcon

Attached rendering

#### Attachments

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