Estes S and T motors

[UCBadger]

Sorry if this is supposed to be common knowledge, but when did Estes stop making the "s" (short) motors and start the "T" motors?

I see that there is a mini brute sprint (up for auction on e-bay claiming to be 37 years old. It is the "t" motor version (1215 K-15). I flew the "s" motor version (K-15) 38-40 years ago.

[hcmbanjo]

The changeover first showed up in the 1972 catalog.
http://www.ninfinger.org/rockets/nostalgia/72est038.html
Estes did sell 5/20 adapters for some of the older models that used 18mm S engines.

I went and looked through that catalog.
I'd forgotten about the "Series" engine designations.
Series I were standard 18mm x 2 3/4" engines
Sereis II were the B14
Series III were the shorter 18mm x 1 3/4" long S engines
Series IV were the D engines.


The "S" stood for short engines
I guess the "T" designation (13mm) is for tiny.

Hope this helps!

[CPMcGraw]

...The "S" stood for short engines
I guess the "T" designation (13mm) is for tiny...

I suspect "T" = Thirteen mm...

[Royatl]

Sorry if this is supposed to be common knowledge, but when did Estes stop making the "s" (short) motors and start the "T" motors?

I see that there is a mini brute sprint (up for auction on e-bay claiming to be 37 years old. It is the "t" motor version (1215 K-15). I flew the "s" motor version (K-15) 38-40 years ago.

The Mini-Brutes were first on sale at NARAM-13 in August 1971, but they had been shown over the spring at the various model rocket conventions as MPC introduced their Minirocs and Minijets.

The "Shorty" motors were phased out over the next year.

Also, I think you mean Sprite (the tumble recovery, ring-tailed rocket) not Sprint (the low drag form factor rocket which used standard motors.

[Royatl]

I suspect "T" = Thirteen mm...



Tiny would be much more obvious than thirteen. Especially since their competition, the MPC Minijets were labeled "m" for Mini, and their own "s" engines were for "short."

[UCBadger]

The Mini-Brutes were first on sale at NARAM-13 in August 1971, but they had been shown over the spring at the various model rocket conventions as MPC introduced their Minirocs and Minijets.

The "Shorty" motors were phased out over the next year.

Also, I think you mean Sprite (the tumble recovery, ring-tailed rocket) not Sprint (the low drag form factor rocket which used standard motors.You are correct......it should have read Sprite.

Thanks to all! I do remember the mini- kits coming out now that you mention it.

[UCBadger]

I really loved my short engine two stage midget.

http://www.ninfinger.org/rockets/nostalgia/70est036.html

edit: And birdie too!

http://www.ninfinger.org/rockets/nostalgia/70est056.html

[Royatl]

I much preferred the 'shorty' version of the Midget over the mini-brute version, but the mini-brute version of the Beta was beta-r than the shorty version.

[UCBadger]

Thanks, Sven Knudson, for posting the old Estes catalogs. What a trip to an earlier life. :)

[blackshire]

I much preferred the 'shorty' version of the Midget over the mini-brute version, but the mini-brute version of the Beta was beta-r than the shorty version.With a band saw, you could make more 1/2A6-2S Series III motors at least for an "S"-version Sprite, and if Quest brings out an A6-0 booster motor as Bill Stine hinted at last year, it might also be a candidate for "S-ifying."

[LeeR]

I really loved my short engine two stage midget.

http://www.ninfinger.org/rockets/nostalgia/70est036.html




OK, Doug must be at work, and not able to reply, so here is his website full of Midgets:

http://www.doug\79.com/DougsRockets/ (http://www.doug79.com/DougsRockets/)

[LeeR]

Tiny would be much more obvious than thirteen. Especially since their competition, the MPC Minijets were labeled "m" for Mini, and their own "s" engines were for "short."

I think that the "T" was just what came after the "S". And the Estes E motors are certainly the U-series motors (for "uber-D").

Then again, maybe not ...
:)

[Rocket Doctor]

A motor with the "T" is commonly referred to as the Mini motors

[Doug Sams]

I really loved my short engine two stage midget.OK, Doug must be at work, and not able to reply, so here is his website full of Midgets:

http://www.doug79.com/DougsRockets (http://www.doug79.com/DougsRockets/)I got one of my biggest thrills in this hobby flying one of these. I keep chasing that, hoping for a repeat of that thrill :)

Doug

.

[Doug Sams]

Tiny would be much more obvious than thirteen. Especially since their competition, the MPC Minijets were labeled "m" for Mini, and their own "s" engines were for "short."I always figured T for "tiny", too.

To add, as for "m" and mini, Centuri, too called theirs Mini-Motors, but used a capital M in the suffix of the motor designation versus a small m for MPC - eg, Centuri ¼A4-2M .

Doug

.

[Bazookadale]

I always figured T for "tiny", too.

To add, as for "m" and mini, Centuri, too called theirs Mini-Motors, but used a capital M in the suffix of the motor designation versus a small m for MPC - eg, Centuri ¼A4-2M .

Doug

.

I'll bet that since 2 competitors were using the M Estes went with the T to be different

All 3 companies came out with 13mm motors within a year but I think Estes was last

[Royatl]

I'll bet that since 2 competitors were using the M Estes went with the T to be different

All 3 companies came out with 13mm motors within a year but I think Estes was last


No, Centuri was definitely the last. Some time in 1973. I was doing my senior year in high school and was winding down my rocketry activities to a launch every few months. They were only on the market for a short while, and by the time I got to buy some more engines, they were off the market and they had switched to selling relabeled Estes mini motors. I managed to buy a bagful of mini-"B" motors in 1977 from a hobby store going out of business. Still have most of them.

[Bazookadale]

No, Centuri was definitely the last. Some time in 1973. I was doing my senior year in high school and was winding down my rocketry activities to a launch every few months. They were only on the market for a short while, and by the time I got to buy some more engines, they were off the market and they had switched to selling relabeled Estes mini motors. I managed to buy a bagful of mini-"B" motors in 1977 from a hobby store going out of business. Still have most of them.

I stand corrected on that - I do remember MPC showing off minijets at pittcon in 1971 and the following year Estes and Centuri having their minis advertised at pittcon '72 but maybe not in production yet