e45 / f55 motor details?

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dhbarr

Amateur Professional
I'm trying to find out everything I can about these extinct AT 18mm motors.

Propellant? OAL? Same basic design as d21, or something else?

( If anyone has some to send dead or alive, I could probably arrange something ).

I'm guessing they both used the equivalent of the WT propellant, and they were essentially the d10 only longer....

E45 is 4 1/8"
F55 is 5 3/8"

https://www.rocketryforum.com/showt...ant-Us-Going-Supersonic&p=1453765#post1453765
The AT 18 mm x 138 mm SU F55-4,8,12 Blue Thunder motor is listed as a 60%F = 64 N/s with a 0.9 second burn time

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dhbarr

Amateur Professional
D21-4,7,10 Aerotech 70 1.0 21.0 100.0 Blue Thunder
E25-4,7,10 Aerotech 70 0.9 25.0 55.0
E45-4,8,12 Aerotech 105 0.9 45.0 100.0 Blue Thunder
F55-4,8,12 Aerotech 138 0.9 53.4 60.0 Blue Thunder

So it looks like the e25 was probably WT, sharing lineage w/d10; e45 & f55 were longer d21's.

Curiosity partially satisfied ; if anyone wants to measure the nozzle on one that'd be cool, but I can work the math myself when I pick this thought up again next time.

Still interested in cadaver cases, though

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E25 was blue.

MikeyR.Saginaw

Well-Known Member
Remember the B or C reloads for the 18 case?

Mikey (still have a couple of them...)

cwbullet

Obsessed with Rocketry
Staff member
Global Mod
I still have some Cs. I wish I had some Es and Fs.

mrwalsh85

Well-Known Member
Someone send me a PM reminder... I have some F55s at home I can check out. Maybe E's can't remember.

NAR29996

Well-Known Member
I tried an E25 in a Death Star. It was an interesting flight.

dhbarr

Amateur Professional
Well nifty:
Particularly:

Couldn't dig up the same or similar for the f55, but I certainly learned a lot about the c12t and e27t
... so for one brief period in the late 80's and early 90's, 18mm fliers had a stunning array of reloadable and disposable options from around a b6 up to an e45. Wish I'd been there

The c12 would be particularly nice for a short heavy rocket with a narrow tail on a small field or a windy day. Ah well....

Initiator001

Well-Known Member
The F55 was certified by TRA not NAR.

The reloadable 18mm B & C motors did not sell very well and were discontinued less than a year after they were released.

75Grandville

Well-Known Member
Were they end-burners or core-burners?

dhbarr

Amateur Professional
Were they end-burners or core-burners?
In my research on 18mm composites, I've found end, bates, case-bonded core, c-slot, d, and moonies.

C-slot seems to be the most common. Someone prove me wrong and show a white finocyl

dhbarr

Amateur Professional
The F55 was certified by TRA not NAR.

The reloadable 18mm B & C motors did not sell very well and were discontinued less than a year after they were released.
Yup, can't find the relevant TRA docs on ATs or TRAs websites, though.

I understand the same guys who failed to develop an 18mm g were responsible for killing everything but the D's we have left. :-D

I kid, word is almost no hobby shop ever made a second order. It's just too bad since now I could buy singles no-haz via e-commerce. Materials have come a long way, too.

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dhbarr

Amateur Professional
So... does anyone have a bead on the TRA paperwork for the f55? Assembly instructions?

These would likely have to come from someone's personal collection as neither the web nor usenet seem to have them.

mwtoelle

Flying since 1977
So... does anyone have a bead on the TRA paperwork for the f55? Assembly instructions?

These would likely have to come from someone's personal collection as neither the web nor usenet seem to have them.
I don't have any, but the E45 and F55 were single use motors. Aerotech never announced any longer cases for 18mm reloads. Aerotech has produced a lot of interesting motors during their 35 year existence that that I would have liked to have tried over the years.

dhbarr

Amateur Professional
I don't have any, but the E45 and F55 were single use motors. Aerotech never announced any longer cases for 18mm reloads. Aerotech has produced a lot of interesting motors during their 35 year existence that that I would have liked to have tried over the years.
Yup, I wasn't thinking straight.

Anyone to speculate on the grain configuration, nozzle size?

Initiator001

Well-Known Member
Yup, I wasn't thinking straight.

Anyone to speculate on the grain configuration, nozzle size?
The E45 & F55 both used single grain Blue Thunder propellant with a C-slot core.
Phenolic casing with bonded molded nozzle.

Total impulse: E45 40 n-sec, F55 50 N-sec

We couldn't do a 'G' motor with the phenolic 18mm casing, it would blister and fail. It barely lasted for the F55.

dhbarr

Amateur Professional
The E45 & F55 both used single grain Blue Thunder propellant with a C-slot core.
Phenolic casing with bonded molded nozzle.

Total impulse: E45 40 n-sec, F55 50 N-sec

We couldn't do a 'G' motor with the phenolic 18mm casing, it would blister and fail. It barely lasted for the F55.
Thanks so much for coming out to answer! It is very much appreciated.

It's clear that to do an 18mm G some metal would have to be involved. Fun to think about.

Initiator001

Well-Known Member
I have been digging through my files to find more information on the F55 motor.

I found a sales sheet dated 12/17/90 which gives some information on the F55:

F55 (-4, -8, -12)

Dimensions: .69" x 5.438"

Peak Thrust (lbs.): 20.75

Thrust Duration: .92 sec.

Propellant Mass: 24.0g

Initial Mass: 45.7g

I am still looking for a copy of the thrust curve.

dhbarr

Amateur Professional
I have been digging through my files to find more information on the F55 motor.

I found a sales sheet dated 12/17/90 which gives some information on the F55:

F55 (-4, -8, -12)

Dimensions: .69" x 5.438"

Peak Thrust (lbs.): 20.75

Thrust Duration: .92 sec.

Propellant Mass: 24.0g

Initial Mass: 45.7g

I am still looking for a copy of the thrust curve.
Awesome, initial mass and peak were two of the missing pieces! Burnout mass should be fairly straightforward to calculate since the length is known.

dhbarr

Amateur Professional
Courtesy of Ken Good, passed on to me by Darrin Plumer
Code:
; Aerotech F55 Data from data insert
F55 18 138 4-8-12 0.024000 0.034650 AT
0.025 88.846
0.05 89.295
0.075 89.744
0.1 89.744
0.15 90.641
0.2 91.090
0.25 91.987
0.3 91.090
0.35 90.192
0.4 89.295
0.45 85.256
0.5 76.282
0.525 67.308
0.55 53.846
0.575 40.385
0.6 26.923
0.625 22.436
0.65 17.949
0.675 13.462
0.7 9.423
0.725 8.974
0.75 7.179
0.775 5.385
0.8 4.487
0.825 4.038
0.85 2.692
0.875 0.897
0.9 0.000
;