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Green Dragon
08-25-2007, 06:07 PM
Not sure if this is the best place to post, but figured these aren't ' kit collecting' ,lol ....

IN the late evening at the recent NyPower launch , was chatting with some guys from Syracuse, and he says someone had given him these motors - they thought about flying them at the exp launch, I cringed.
Went and inspected same, trying hard to not droll all over and ruin the motor wrapers :)

At first the gentleman had not wanted to sell, and had estimates of the 'cash value' from various sources, which gave him sticker shock, and the realisation not to fly them - I would up swapping a pile of Aerotech Reloads for the three as follows :

1 - Mini Max E3.5-6 Special
Max thrust 5 lb
caoded 000263 ( anyone decipher this ? is it Feb 63 ? )
this one has the endcaps torn off, so someone might have been prepparing to fly it.
any comments on what the 'special' means ??

2 - Mini Max F14-4 Single Stage
max thrust 25 lb
coded 000309
flawless mint wrapper, no smudges, caps intact, a wild peice of history

3 - Mini Max F25-6 Single Stage
max thrust 40 lb
coded 000123
this one also beautiful with end caps and very minor wear.

a great historical find, why doesn;t someone find these in an attic and give some to me, since they know I like rockets, lol ....

ENJOY !

( might entertain offers if any ' serious' motor collectors want these for thier museums, lmk :-P )

~ AL

dwmzmm
08-25-2007, 08:57 PM
Wow, great find, AL!! And that F25, it has 40 lbs of thrust?! Wow, and I thought the FSI
F100's were something with the 35 lbs of thrust for the .5 seconds it burns.....

stefanj
08-25-2007, 10:15 PM
Any instruction materials with those? That's something I've never seen.

The F14 and E3.5-6 are listed in the 1967 catalog:

http://www.ninfinger.org/~sven/rockets/catalogs/centuri67/67cen64.html

There's an F25-6 listed in the 1965 catalog, but as a "Hercules" not Mini-Max.

I'm going to guess that your F25 is from 1966, which might have been when the Mini-Max name replaced the old "Hercules" and "Atlas" labels.

In any case, amazing find!

Royatl
08-25-2007, 10:41 PM
1 - Mini Max E3.5-6 Special
Max thrust 5 lb
caoded 000263 ( anyone decipher this ? is it Feb 63 ? )
this one has the endcaps torn off, so someone might have been prepparing to fly it.
any comments on what the 'special' means ??

~ AL

I once had an E3.5 motor in '69 or '70. Never flew it, but have no idea what happened to it. A kid in our club flew a few Mini Max F motors until he switched to FSI F100. I actually liked the Mini Maxes, but he liked the F100, and Centuri quit making them anyway.

Initiator001
08-25-2007, 10:41 PM
Al,

That's a fantastic find!

I ended up getting some Mint condition Coaster motors from a seller who bought them off a guy who was out flying them one day. :eek:

Bob

Bazookadale
08-25-2007, 10:45 PM
Any instruction materials with those? That's something I've never seen.

The F14 and E3.5-6 are listed in the 1967 catalog:

http://www.ninfinger.org/~sven/rockets/catalogs/centuri67/67cen64.html

There's an F25-6 listed in the 1965 catalog, but as a "Hercules" not Mini-Max.

I'm going to guess that your F25 is from 1966, which might have been when the Mini-Max name replaced the old "Hercules" and "Atlas" labels.

In any case, amazing find!

That F25 is super interesting - what is the length of the casing? Mini Max were 7.75" long, Hercules were 8" if it is the longer casing with a MM label it might have been right at the transition from one line to the other. Ninfinger does not have a 1966 catalog but my fading memory recalles the '66 to be a reprint of '65 with the Mini-Max introduced in the '67 catalog which came out the fall of '66

pyrovette20
09-20-2007, 10:51 AM
I recently came across 3 mini-max motors also.Mine are all F55-4 with a date code of 000094 . Could not find those in the centuri catalogs. The labels look like all the rest with peach colored lettering and stripes

Doug Sams
09-20-2007, 12:11 PM
I recently came across 3 mini-max motors also.Mine are all F55-4 with a date code of 000094 . Could not find those in the centuri catalogs. You couldn't find the F55-4 or the date code? The motor is here: http://www.ninfinger.org/~sven/rockets/nostalgia/69cenp86.html

HTH.

Doug

Rocket Doctor
09-20-2007, 12:17 PM
I have the following motors.

Enerjet E24-10

Pro Jet E20-10

Mini Max D2-3 (4)

Mini Max F14-4

Doug Sams
09-20-2007, 12:20 PM
...discussion of Mini-Max motors I'm confused. For a while now, I've had it in my mind that Mini-Max motors were composites (and that the earlier Hercules/Atlas were BP) but from looking the specs on Ninfinger, it looks to me like the Mini-Max were also BP. Is that correct? Judging from the data - specifically, the ability to stage using booster motors - they look like BP motors. Furthermore, at less than 1 Ns per gram of propellant (F55: 62.5g prop, 46.8Ns) the specific impulse is consistent with BP.

Maybe I was confusing Mini-Max with the later Enerjet motors from Centuri.

Doug

shockwaveriderz
09-20-2007, 12:27 PM
Doug:

My research indicates there was a BP mini-Max series and then a Composite Mini-Max series just prior to the Enerjet debut.

hth

terry dean
nar 16158 :o

Initiator001
09-20-2007, 01:09 PM
I'm confused. For a while now, I've had it in my mind that Mini-Max motors were composites (and that the earlier Hercules/Atlas were BP) but from looking the specs on Ninfinger, it looks to me like the Mini-Max were also BP. Is that correct? Judging from the data - specifically, the ability to stage using booster motors - they look like BP motors. Furthermore, at less than 1 Ns per gram of propellant (F55: 62.5g prop, 46.8Ns) the specific impulse is consistent with BP.

Maybe I was confusing Mini-Max with the later Enerjet motors from Centuri.

Doug

Doug,

The Mini-Max motors used BP as did the earlier Hercules/Atlas motors.

The Mini-Max and Enerjet motors were both in the 1970/71 Centuri catatlog.

By 1972 the Mini-Max motors were no longer in production.

Bob

Royatl
09-20-2007, 01:46 PM
Doug:

My research indicates there was a BP mini-Max series and then a Composite Mini-Max series just prior to the Enerjet debut.

hth

terry dean
nar 16158 :o

Nope, Mini-Max was a big honkin black powder motor series.

Enerjets were the only composites.

Bazookadale
09-20-2007, 02:56 PM
I'm confused. For a while now, I've had it in my mind that Mini-Max motors were composites (and that the earlier Hercules/Atlas were BP) but from looking the specs on Ninfinger, it looks to me like the Mini-Max were also BP. Is that correct? Judging from the data - specifically, the ability to stage using booster motors - they look like BP motors. Furthermore, at less than 1 Ns per gram of propellant (F55: 62.5g prop, 46.8Ns) the specific impulse is consistent with BP.

Maybe I was confusing Mini-Max with the later Enerjet motors from Centuri.

Doug
Mini - Max were BP -Coaster had made the Atlas/ Hercules for Centuri, Centuri later bought the presses from Coaster and tweeked the design slightly to make the Mini- Max line. Enerjets were composites made by Rocket Development Corp. - Centuri bought that company and redesigned the Enerjet line

Now in the 1962 catalog it says "watch for new Mini- Max engines" http://www.ninfinger.org/~sven/rockets/catalogs/centuri62/62cen12.html so it's a name Lee Piester had in mind for a while . A recent article (I think Launch magazine) it was stated that a composte Mini Max motor was under develoment at that time, it was never sold

ghrocketman
11-15-2014, 03:21 AM
The Mini-Max motors were definitely BP and replaced the Atlas/Hercules series.
The only composites Centuri offered were the Enerjet E24, F52, F67, and 'professional' G-something.

Rich Holmes
11-15-2014, 07:28 AM
Why did these motors go out of production? Why did Estes not produce Es until the 1990s?

Earl
11-15-2014, 09:32 AM
The Mini-Max motors were definitely BP and replaced the Atlas/Hercules series.
The only composites Centuri offered were the Enerjet E24, F52, F67, and 'professional' G-something.

The sequence is a bit backwards: The Centuri BP large scale motors were originally called Atlas and Hercules. THOSE were then replaced by the 'improved' BP motors called Mini-Max around '67 or so.

Earl

stefanj
11-15-2014, 09:38 AM
Why did these motors go out of production? Why did Estes not produce Es until the 1990s?
I'd read that the production equipment for the Mini-Max line motors was destroyed "by lightning" in the early 70s.

I've also read that they weren't terribly reliable.

There was also the problem of shipping. If you read the old catalogs, you'll see references to a special shipping form. The motors had to go by Railroad Express, an expensive and not always handy method.

(I don't know how FSI got away with shipping its E and F motors by mail.)

I imagine that Estes simply didn't want to get involved with all that.

Earl
11-15-2014, 09:43 AM
Why did these motors go out of production? Why did Estes not produce Es until the 1990s?

I think Lee Piester stated in the Launch Mag article that a combination thunderstorm/accident caused a fire at the Mini-Max motor facility around the '71 timeframe. Centuri had just recently rolled out the Enerjet composites within the previous year, so they decided not to try to restart the large BP production facility for the Mini-Max stuff and just focus on the new Enerjet composites.

What I hated was that not only did they stop the Mini-Max motor production, they stopped making the Mini-Max kits, which I thought were just as good if not better in design and construction (heavy walled tubing, etc) than the Enerjet kits that were issued a bit later. The Enerjet kits basically all used the standard Centuri low power body tubes. Not 'bad' kits per se, but I wished they would have at least kept the Mini-Max kits, even if they dropped the large BP motors.

Earl

ghrocketman
11-15-2014, 11:36 AM
It would not surprise me if FSI just shipped the 27mm E and F motors completely ignorant of any ridiculous regulations.
I can understand disallowing BP motors from being shipped via air; ANYTHING more than that for individuals or businesses is STUPID OVER-REGULATION.