Jason's Motor Porn Thread

I worked at AeroTech when the G300 motor was developed.

The G300 was created in response to the need of the Applied Physics Laboratory (APL) at Johns Hopkins University.
APL was working on a high speed tracking device. They were gluing two AeroTech H140 single-use motors together and firing the combination along a wire and tracking it.
The dual H140 combination was not providing enough velocity for their tests.

Gary Rosenfield took the call from the APL and asked for time to see what could be done.
He and Scott Pearce started brainstorming and came up with a multiple-grain coreburning motor concept.
It needed to be 29mm in diameter so APL wouldn't have to change their equipment.
A propellant used in another industrial contract seemed to offer the performance required.
Gary called APL back and told them about the new motor.
APL said great and wanted one-hundred of them immediately!
No delay or ejection charge was required so assembly of the motors would be easier and take less time.

There was just one problem.

We didn't have enough 29mm fiberglass casing to make the motors.

TBC..

Looking forward to more on this Bob. Thank you for your input.

Yeah, can't wait until Part 2..... and hopefully more parts. Really cool to hear some rocket history.

(Continued...)

So, what to do about some 29mm fiberglass casing?

A call was made to the manufacturer to find out how soon an ordered could be delivered.
The answer was an order could be made and ready to ship in four-to-six weeks.

YIKES!

A search of the building was begun to see if more 29mm fiberglass tubing could be found.
I was drafted into the search party.

In the back of the building, off to the side, was a 'collection' of miscellaneous stuff (junk).
Old production tooling, parts for equipment, rocket club newsletters, etc.
I began to dig through this stuff.

Soon I came across several medium-sized boxes.
I opened one up and could hardly believe it.
Inside were dozens of cut, 29mm natural fiberglass casings.
In fact, there was over one-hundred of these casings between the all the boxes.

I called Gary over and he looked at the casings.
He said the casings were good and we needed to start making motors.

The propellant was cast, Scott machined out the plastic nozzles to make the throats bigger while I sanded the inside of the casings to make a better bonding area for the adhesive.

Two test motors were made and fired on the thrust stand. The results were good and full production was initiated on the contract motors.
The order was finished and shipped a few days later.

But what was the origin of the 29mm casing?

TBC...

^ Interesting! *waiting for part 3

Cripes! Bob's keeping me in suspenders...

Adrian

Next I have a kind of strange one - A "North Coaster" F41. I think that these were made by AeroTech as there is an AT motor of the same designation.

This is the only old NCR motor I have laid eyes on and is not be confused with KCLO4 motors they made in the mid-late nineties.

J Blatz said:

Next I have a kind of strange one - A "North Coaster" F41. I think that these were made by AeroTech as there is an AT motor of the same designation.

This is the only old NCR motor I have laid eyes on and is not be confused with KCLO4 motors they made in the mid-late nineties.

View attachment 277067View attachment 277068View attachment 277069

Click to expand...

I've seen a lot of 'old motors' threads but don't remember seeing that one.

J Blatz said:

Next I have a kind of strange one - A "North Coaster" F41. I think that these were made by AeroTech as there is an AT motor of the same designation.

This is the only old NCR motor I have laid eyes on and is not be confused with KCLO4 motors they made in the mid-late nineties.

View attachment 277067View attachment 277068View attachment 277069

Click to expand...

Too cool.

(Continued...)

So, what was the origin of those 29mm motor cases?

I asked Gary about it.

He told me it was Enerjet casing.

WHAT!?

Yup, it's true.

You see, Gary Rosenfield is one of the biggest fan of the Enerjet motor products.
His collection contains an amazing variety of production and prototype examples of Enerjet motors.
Gary discovered Enerjet when looking for ways to fly his Estes Cineroc movie camera higher.
Four stage D13/D12 black motor rockets just weren't working well enough.
Once Gary discovered Enerjet he couldn't get enough of it. As a kid he would ride his motorcycle from LA to Phoenix to get Enerjet products.
Gary met and became friends with several members of the Enerjet staff.

When it was announced the Enerjet was closing, Gary made another trip down to Phoenix.
I don't know how he found out but he went 'dumpster-diving' behind the Centuri/Enerjet plant before everything was hauled away to the dump.
Among the items he recovered were all those 29mm cases originally destined for use as Enerjet motors.

After Gary told me the story I went into the warehouse and picked up one of the remaining 29mm cases for my collection.
Gary saw me and asked if I wanted a molded pre-production Enerjet plastic nozzle and ejection bulkhead.
Enerjet was working on replacing the graphite motor nozzles and ejection bulkheads with plastic parts which would be cheaper and faster to produce.
Before these new parts could be integrated in production motors the product line was closed down.

Jason, it appears you have one of those Enerjet case G300 motors.
There was a number of those cases leftover after the APL order was fulfilled and I know Ross Dunton at Magnum ordered some G300s.
Delay and ejection charges were incorporated into the motors but their reliability was questionable.
Many times the delay charge didn't light or stay lit due to the fast burn time of the G300 motor.

TBC..

(Continued...)

The non-ejection of the G300 motors was confirmed when Scott Pearce flew his NCR Enerjet 2650 clone at a Lucerne launch with three G300-15 motors.
I filmed the launch with a Super-8mm film camera.
In one frame there was the rocket. In the next frame the rocket was gone.
Neither of us saw the rocket or it's parachute.
Later, another rocketeer looking for his rocket, found the wrecked 2650 and returned it to the rangehead.
All three ejection caps on the motors were intact. One motor was cut open and found the delay material had hardly burned.

At AeroTech we started to get reports of G300 motors not ejecting.
A decision was made that all future G300 motors would be Plugged versions without delay or ejection charges.

I don't know about that black cased G300 motor.
The casing looks to be phenolic. If so, the extra length could be due to the need to use a liner and therefore smaller diameter propellant grains.
These grains would be longer to keep the performance similar.

As for the G345, that's a story for another day. :wink:

J Blatz said:

Next I have a kind of strange one - A "North Coaster" F41. I think that these were made by AeroTech as there is an AT motor of the same designation.

This is the only old NCR motor I have laid eyes on and is not be confused with KCLO4 motors they made in the mid-late nineties.

View attachment 277067View attachment 277068View attachment 277069

Click to expand...

Yes, that is a relabeled AeroTech motor.

Over the years AeroTech has produced motors for other companies.
The latest was Estes for their Pro Series II product line. Other companies include NCR, PML, Rocket Vision. I can't remember all of them.

J Blatz said:

This is the only old NCR motor I have laid eyes on and is not be confused with KCLO4 motors they made in the mid-late nineties.

Click to expand...

Thanks for sharing these pictures! Love the vintage. I didn't realize NCR made KCLO4 based motors, I knew there was a time they had their own motors while they were still independently owned, but I've never found much info on them. Anyone have details on those motors? From pics I recall them having a smokey exhaust?

FYI I'm talking about *before* the Estes take over and the advent of the Dark Star motors...which were actually Vulcan Smokey Sam propellant! Those were great.

Great story Bob! Thanks for sharing.

marcusSRG said:

Thanks for sharing these pictures! Love the vintage. I didn't realize NCR made KCLO4 based motors, I knew there was a time they had their own motors while they were still independently owned, but I've never found much info on them. Anyone have details on those motors? From pics I recall them having a smokey exhaust?

FYI I'm talking about *before* the Estes take over and the advent of the Dark Star motors...which were actually Vulcan Smokey Sam propellant! Those were great.

Click to expand...

You are welcome. I am enjoying doing it.

The KCLO4 motors were mid 90's I believe. NCR was using the different oxidizer to work around legal issues. They had a pinkish flame from the potassium... Imagine White Lightning with a pinkish flame.

I flew probably half a dozen of them, and had one of them CATO.

Initiator001 - Thanks for all the input, quite interesting.

More to come!

J Blatz said:

You are welcome. I am enjoying doing it.

The KCLO4 motors were mid 90's I believe. NCR was using the different oxidizer to work around legal issues. They had a pinkish flame from the potassium... Imagine White Lightning with a pinkish flame.

I flew probably half a dozen of them, and had one of them CATO.

Click to expand...

Very cool. Thanks!! Some of the old NCR catalogs in on ninfinger.org talk about the motors and show several of their rockets flying, but hard to tell if it's one of those motors or not. If anyone else has some pics of these in action please share!

J Blatz said:

You are welcome. I am enjoying doing it.

The KCLO4 motors were mid 90's I believe. NCR was using the different oxidizer to work around legal issues. They had a pinkish flame from the potassium... Imagine White Lightning with a pinkish flame.

I flew probably half a dozen of them, and had one of them CATO.

Click to expand...

Here's a picture of a NCR G50-7 motor.

The simplest and least expensive hobby rocket motor propellant is black powder that uses KNO3 as the oxidizer. While the specific impulse is low, BP motors can be made quickly and economically with an automated hydraulic turret ram press at the rate of ~10 per minute.

The most efficient hobby rocket motor propellant is APCP that use Ammonium Perchlorate as the oxidizer. While they can have high specific impulse, APCP motors are expensive to manufacture because the formulation and casting of the propellant grain and subsequent loading are typically labor intensive multiday operations.

A lesser known intermediate efficiency hobby rocket motor propellant is KPCP which use potassium perchlorate as the oxidizer and sodium benzoate or similar organic molecule as the fuel. The specific impulse is intermediate between BP and APCP but it is produced in a hydraulic ram press similar to BP so the time and labor required to make a motor is similar to BP motors so the manufacturing costs are lower. Unlike BP however the optimum ram processing conditions are far more restrictive than BP, and if the process goes slightly out of optimum, the motor operation can be pulsed instead of continuous and the bonding of the propellant to the case may be not be good resulting in CATOs. Today the European Kilma motors use this propellant system.

Bob

Next I have for your viewing pleasure a Vulcan F52. This is a full-house F class 24mm motors with Low Smoke propellant. In the past AeroTech also had some nice 24mm full F's...I wish they would bring them back, or something else like them, as CTI really has a lot more selection the 24mm and I prefer to buy AeroTech.

Isn't AT F32 a nearly full F?

Ari.

NAR S&T calls it at 56.9N/s.

iter said:

Isn't AT F32 a nearly full F?

Ari.

Click to expand...

Initiator001 said:

As for the G345, that's a story for another day. :wink:

Click to expand...

Keep it coming!

J Blatz said:

Next is a 54MM AeroTech I140. This is obviously not be confused with current 38mm SU I140.

C-slot, full I class with old low smoke classic propellant. Closest thing made today would be the J-180 for the 54/852 case.

View attachment 276729View attachment 276730View attachment 276731

Click to expand...

Thanks Jason and Bob! What a great chunk of History to fill in..It gives the Tripoli numbers before 5000 a chance to fill in the blanks....What were all those mystery Motors during the 80's?

JStitz said:

Thanks Jason and Bob! What a great chunk of History to fill in..It gives the Tripoli numbers before 5000 a chance to fill in the blanks....What were all those mystery Motors during the 80's?

Click to expand...

Yeah, I agree wholeheartedly. I'm #3135 and still missed out on a bunch of this stuff. To the extent I've heard of anything 'exotic' it was only through reading about it in HPR magazine, aside from a few odd and ends seen were I was in the right place at the right time. Speaking of which, here's my contribution: https://www.facebook.com/buyrocketmotors/posts/1632673910326624. These are spent motors from a local club member's collection. He has some NCR motors new in package as well.

I am loving this thread! I wasn't plugged in to all that good stuff back then. Which is an answer to the "what to you regret" thread. Some day I'll stumble across a Silver Streak and may all your unburned ones a tad more valuable. I'm not holding my breath.

Yeah, I was fortunate to have at least seen a few Silver Steaks but never had the opportunity to own let alone fly one. I'd love to learn the history behind RocketFlite, Vulcan, and the others. Perhaps a new thread is in order??

Thanks for all the comments guys. There is more to come. Maybe some TRM stuff next.

It is worth mentioning that my TRA (lapsed) is #2405, and at the first HPR launch I attended (LDRS X) a lot of these motors were already OOP. So much of the stuff I am posting I have personally never seen in flight, or maybe have but didn't know what I was looking at. This is leading me to think that it might really cool to make a project out of documenting not just the motors, but the motors in flight.

LDRS is at Lucerne this coming year....what could rightly be called the birthplace of High Power Rocketry...maybe I'll get my act together and fly and document a few of these classic motors...

Dale Windsor had a large collection of photos of old rocket motors, but alas his site seems to be gone.

Here's 3 versions of an Aerotech G125. 2 have dates but 1 doesn't so I'm not sure where it fell in the transformation. The 1987 version has the nozzle and delay section flush with the end of the casing. The 1988 version has the nozzle flush but the delay extends beyond the casing. The last motor has the nozzle extending from the casing but the delay is recessed.








Any incite into why each version turned out the way it did?

Love hearing about the background to hows these evolved. Thanks all.