F20W Econojet motor data file

[dpower]

I was looking at the F20 engine data in my RASP .eng file, and the total impulse doesn't match published F20W Econojet motor. The F20 .eng file at thrustcurve.org specifically mentions the F20EJ, and matches the data on nar.org, which makes me wonder if I have the right data.

Is the thrustcurve data the F20W Econojet or the F20EJ? Aerotech doesn't mention the F20EJ, presumably this is an OOP motor?

- F20W Econojet - Aerotech Total Impulse 55.0 N-s
- ThrustCurve.org F20EJ .eng Total Impulse - 60.5 N-s
- NAR F20 total impulse 60.5 N-s

Thanks!

 

[als57]

Its possible when they changed case styles a couple years ago the total thrust may have changed.

Looking at a year old package of F20-7W it says the total impulse is 55.1n/s.


Al

 

[bobkrech]

Old 29 mm SU Casings - OOP

https://www.aerotech-rocketry.com/c...structions/MR-SU_Instructions/EJ_F20_4Wv2.pdf

https://www.aerotech-rocketry.com/c...structions/MR-SU_Instructions/EJ_F20-7Wv2.pdf

Old NAR cert

https://nar.org/SandT/pdf/Aerotech/F20.pdf

(Note .eng file can be copied and pasted from last cert page)

New 29 mm LMS/SU Casings - Current Production

https://www.aerotech-rocketry.com/c...ns/MR-LMS_Loadable/f20w_2-pk_lms_in_20200.pdf

Current NAR cert

https://www.aerotech-rocketry.com/c...ments/NAR/lu_reloadable/f20w_lur_nar_cert.pdf

I'll try to get the latest cert posted on the NAR S&T web pages ASAP

Bob