Early Semroc info?

[blackshire]

Hello All,

The good folks at Semroc Astronautics have given me exceptional service (and great value for my money), and I am making this posting--by my own initiative--to return the favor.

Does anyone here have any issues of Semroc's Astronautic Modeler? (A scan of the May 1970 issue is here: www.ninfinger.org/rockets/catalogs/semroc570/570semroccat.html ). (I'll explain why below.) The technical information and the rocket building & flying tips in Astronautic Modeler are just as useful today as they were then (plus the tech info is relevant to the "Retro-Repro" Semroc kits that are used as examples in the journal); also, the pre-personal computer illustrations and diagrams in the journal are beautiful examples of what creative people can do with basic drafting tools. Here is why I'm interested in the issues:

Sheryl McLawhorn at Semroc told me that they lost all of their old Semroc publications (and rocket motor & rocket kit tooling) in a hurricane in the 1970s. If copies of the other Astronautic Modeler issues could be found, Semroc could have scans of them on their web site, *or* they could re-publish all of the issues (either as individual issues or as a series of 12-month compilations, each in a single binding). They could offer these as model rocketry educational materials and as historical documentation of Semroc Astronautic's earliest years.

Since the original issues were produced with simple stapled bindings ("saddle-stitched," as these bindings are also called), any modern print shop could easily and cheaply reproduce them. Another option (which would be *completely free* for Semroc) would be to re-publish the Astronautic Modeler issues through a POD (Print-On-Demand) publishing service such as Lulu.com (see: www.lulu.com ) or CreateSpace.com (see: www.createspace.com ). This option would cost Semroc nothing, and the POD publisher could also (if desired) handle the shipping to the buyers while making a small amount for itself on each journal issue (or compilation) sold. I'd happily buy them, and I'm sure many other model rocketeers would as well!

Many thanks in advance to anyone who could help.

[Chas Russell]

I sent that catalog to Sven Knudson for scanning. I do not have anything else from them, except for a remaining A8-3 motor. I don't recall any advertisements that would shed much more light.

Chas

[blackshire]

I sent that catalog to Sven Knudson for scanning. I do not have anything else from them, except for a remaining A8-3 motor. I don't recall any advertisements that would shed much more light.

ChasThank you, Chas! Last night I tried to e-mail you at the address given on the Ninfinger Productions web site, but I just got a "no such address" message from AOL. Also, Sheryl has shed a bit more light on the Astronautic Modeler issues:

Apparently they only published two issues and were working on a third before Semroc went insolvent in the early 1970s. Also, Carl said that issue #1 was online somewhere. If you know where that one is hosted online, Sheryl said that they could provide links to it (and to your online issue scan on Ninfinger Productions' site) on the Semroc web site.

[Bill]

Apparently they only published two issues and were working on a third before Semroc went insolvent in the early 1970s. Also, Carl said that issue #1 was online somewhere. If you know where that one is hosted online, Sheryl said that they could provide links to it (and to your online issue scan on Ninfinger Productions' site) on the Semroc web site.


Google and you shall receive...

http://www.ninfinger.org/rockets/catalogs/semroc570/570semroccat.html


Bill

[BEC]

Google and you shall receive...

http://www.ninfinger.org/rockets/catalogs/semroc570/570semroccat.html


Bill

That's the same one linked to in Blackshire's first post....

[blackshire]

That's the same one linked to in Blackshire's first post....Yes, the one on the Ninfinger Productions web site is Volume 1, Number 2 (May 1970--here is the cover: http://www.ninfinger.org/rockets/catalogs/semroc570/570semrocf.html ). The other one is Volume 1, Number 1, and I presume its issue date was April 1970.

Those two published Astronautic Modeler issues, along with the partially-completed unpublished third issue (if they still have the masters for it) would make useful downloadable & printable Semroc technical guides as well as provide interesting views of the earliest days of Semroc Astronautics. Who knows, if enough model rocketeers took a gander at their old catalogs (there is one in the May 1970 issue of Astronautic Modeler) and liked what they saw, maybe Semroc could bring back old items like their LEK-TROL launch controller and again offer their special rocket finishing supplies such as their rubbing compound?

[Bill]

That's the same one linked to in Blackshire's first post....


Oh, you are so right. I made a faulty assumption that if ninfinger had one, it was the first one.


Bill

[Pyro Pro]

I always wondered about this one:

[blackshire]

I always wondered about this one:Well...if you used a cluster of three Quest MicroMaxx motors in the Semroc Triton "Retro-Repro" kit (see: http://www.semroc.com/Store/scripts/RocketKits.asp?SKU=KV-23 ), it would have room for two of the new 6" Estes parachutes and a large (for the Triton) payload section...maybe (like USAF Captain Christopher in the original series Star Trek episode), the folks at Semroc got "a look ahead?" :-)

[Mark II]

I always wondered about this one:Well, they're really SMALL parachutes and very TINY engines!

And here is one! (http://www.rocketreviews.com/reviews/all/mod_sem_triton_cluster.shtml) :chuckle:

[blackshire]

Well, they're really SMALL parachutes and very TINY engines!

And here is one! (http://www.rocketreviews.com/reviews/all/mod_sem_triton_cluster.shtml) :chuckle:This one (streamer-recovered Semroc Triton with FlisKits 3-motor MicroMaxx cluster motor mount) could be a fun "joint venture" product for Semroc and FlisKits. I particularly like the fact that the above-linked EMRR review says that the flights, while reaching satisfying altitudes, were still low enough that all phases of the flights could be easily seen (rather like Big Bertha flights, just on a smaller scale!). Also, the clustered Triton made a safe (sufficiently high) and straight "engine-out" flight when one of the three MicroMaxx motors failed to ignite at launch. Maybe FlisKits and Semroc could join forces to offer these cluster mount-equipped Triton kits as, say, "Christmas Special" items?

[mojo1986]

I'm curious..................did Semroc actually have all of those engines listed in their catalog, including 'shorties', what appears to be 'shorter-than-shorties', and an 18mm 'D'? And who manufactured their engines for them?

And while I'm being curious, why don't we ever see vintage Semroc kits for sale on Ebay? I would LOVE to get one of their old Black Brant III kits!

Joe

[ghrocketman]

I'm pretty sure Semroc had all those engines plus some interesting port-burning B and C offerings.
They made their own engines on their own motor making machine.
I'm pretty sure they were a pretty small operation back then and NIB kits from their original days most likely are extremely rare; obviously Carl could confirm this if true.
I have been in rocketry for well over 30 years and I think I have seen exactly one Semroc kit from the original era.

I don't know how that original Triton could have possibly had 3-engine power; there were no engines back then small enough to cram 3 in a cluster into a BT-20 sized tube; the little AVI 10mm/BT-3 sized motors were not around until several years after the original Semroc was defunct; this is another question for Carl.

[Doug Sams]

I don't know how that original Triton could have possibly had 3-engine power; there were no engines back then small enough to cram 3 in a cluster into a BT-20 sized tube; the little AVI 10mm/BT-3 sized motors were not around until several years after the original Semroc was defunct; this is another question for Carl.My take, since the picture stated "2000 feet", was that it was 3x18mm.

Doug

.

[ghrocketman]

Doug-that was my take as well until I saw the entire rocket was only 18mm in diameter !
You can't fit 3 of anything that existed in 1970 into a BT20.

[blackshire]

Doug-that was my take as well until I saw the entire rocket was only 18mm in diameter !
You can't fit 3 of anything that existed in 1970 into a BT20.Since the masters for all of their publications from that era (and Carl doesn't have any left, thanks to a hurricane that destroyed all of their tooling and printed materials in the 1970s) were "pasted-up" manually, the incorrect descriptors for the Triton kit were no doubt due to an oversight.

[Doug Sams]

Doug-that was my take as well until I saw the entire rocket was only 18mm in diameter !
You can't fit 3 of anything that existed in 1970 into a BT20.Okay :o

The other thought I had was that the pic had extraneous and misleading info. I wondered if the block of text center-left wasn't a vestige that inadvertently got copied from another page in the catalog, perhaps from a Ranger-like rocket.

"
THREE ENGINE POWER
TWO PARACHUTES
LARGE PAYLOAD SECTION
EASY-TO-BUILD
"

Here, I think I found the source. http://www.ninfinger.org/rockets/catalogs/semroc570/570semroc12.html

What d'ya think?

Doug

.

[ghrocketman]

Doug,
I think you hit the nail on the head squarely with that find. :)
Must have been some sort of typo of mis-set type from the Goliath.
At the bottom description it states no-chute recovery but in the sidebar it shows two chute recovery and a large payload section, which it does not have either.

[Carl@Semroc]

I'm curious..................did Semroc actually have all of those engines listed in their catalog, including 'shorties', what appears to be 'shorter-than-shorties', and an 18mm 'D'? And who manufactured their engines for them?

And while I'm being curious, why don't we ever see vintage Semroc kits for sale on Ebay? I would LOVE to get one of their old Black Brant III kits!

Joe
We did have all the engines. The Shorties and Micros were cut on a lathe to the correct size after they were made. We manufactured all our engines.

When we closed in early 1971, we did not go bankrupt. We went insolvent. Our accounts receivable were tens of thousands of dollars and our accounts payable were zero (except for salaries.) We were left with much inventory that we placed in a warehouse for the day that we could start the company back up. There was probably about 15,000 cubic feet of boxes of kits, engines, and documentation. Most of my early prized possessions (Rock-a-chute, catalogs, MRN, etc.) were in a footlocker. On April 4, 1984, a tornado hit the building and left nothing behind. Everything was scattered over a three mile stretch of mostly swamp land. I never found anything intact, including the footlocker. That killed any chance of restarting Semroc.

I did have a small box with a few copies of our documentation, some catalogs, a few chutes, several nose cones, and a sampling of the evolution of our engines. I had pulled this out of storage years before the tornado to show some friends at Telex. The stuff from that box is about the only surviving pieces of Semroc.

The engine machine and nose cone machine were stored in a separate location that was missed by the tornado, so they still survive, although neither is servicable. There is some nostalgia value to me, so I keep them anyway.

I know if I saw some of the original kits on eBay, I would buy them. When I started the mad buying spree for old kits on eBay from 1998 through 2002, I was looking for old Semroc and some of my favorite old kits from all the early companies, it became apparent that with Semroc having less than 1% of the market, there would not be any kits that would be surviving. Even finding an early RDC was almost impossible and they had much more market share than we did.

I do not have anything left from the Black Brant III. It was our last kit and for some reason, I missed pulling any of the instructions, decals, pattern sheets, or anything concerning it from storage.

[blackshire]

I'm pretty sure Semroc had all those engines plus some interesting port-burning B and C offerings.
They made their own engines on their own motor making machine.
I'm pretty sure they were a pretty small operation back then and NIB kits from their original days most likely are extremely rare; obviously Carl could confirm this if true.
I have been in rocketry for well over 30 years and I think I have seen exactly one Semroc kit from the original era. -SNIP-

I only saw one of their "first go 'round" model rocket kits, an early-version Lune R-1, at Orange Blossom Hobbies in Miami in the early 1970s. (This initial version had a motor clip and no card stock simulated "conical bell" nozzle; the later version had the simulated nozzle and used friction-fit motor retention.)

Semroc Astronautics really has risen again, Phoenix-like, from nothing. Sheryl told me that after the company went insolvent, they stored all of the tooling (including their "Mabel" machine), leftover parts, and publications in a barn, which in the 1970s was destroyed by a hurricane that scattered everything all over their county, and nothing from it was ever found. Someone gave Carl a Semroc motor that he had, and that is all that remains from those earliest years of the company, besides the scan of the May 1970 issue of Astronautic Modeler on the Ninfinger Productions web site. I admire that family for their persistence and for refusing to give up! [NOTE: I stand corrected on the details of the company's demise in its initial form, thanks to Carl's reply just after this one!]

[Carl@Semroc]

The Triton was a misprint. It was correct in the Volume 1, Number 1 issue. When we went to a smaller form factor for the second issue, it slipped by. I think it was corrected later, but all my copies have the wrong data.

I think I was counting blocks on the graph sheets from the test stand to get the NEXT page correct and missed it.

[blackshire]

We did have all the engines. The Shorties and Micros were cut on a lathe to the correct size after they were made. We manufactured all our engines.Cut down after they were made...hmmm...Estes could make 1/2A6-2S and 1/2A6-0S "Shorty" motors today.When we closed in early 1971, we did not go bankrupt. We went insolvent. Our accounts receivable were tens of thousands of dollars and our accounts payable were zero (except for salaries.) We were left with much inventory that we placed in a warehouse for the day that we could start the company back up. There was probably about 15,000 cubic feet of boxes of kits, engines, and documentation. Most of my early prized possessions (Rock-a-chute, catalogs, MRN, etc.) were in a footlocker. On April 4, 1984, a tornado hit the building and left nothing behind. Everything was scattered over a three mile stretch of mostly swamp land. I never found anything intact, including the footlocker. That killed any chance of restarting Semroc.

I did have a small box with a few copies of our documentation, some catalogs, a few chutes, several nose cones, and a sampling of the evolution of our engines. I had pulled this out of storage years before the tornado to show some friends at Telex. The stuff from that box is about the only surviving pieces of Semroc.So that material is what enabled you all to re-create your original kits--I understand now. Also, I stand corrected regarding the details of the demise of the company in its original form that I posted above. The engine machine and nose cone machine were stored in a separate location that was missed by the tornado, so they still survive, although neither is servicable. There is some nostalgia value to me, so I keep them anyway.Carl, you really ought to write a book about the history of Semroc Astronautics! If you have any photographs of these machines (now and perhaps from back then), they would be very interesting pieces of history to include on the Semroc web site.I know if I saw some of the original kits on eBay, I would buy them. When I started the mad buying spree for old kits on eBay from 1998 through 2002, I was looking for old Semroc and some of my favorite old kits from all the early companies, it became apparent that with Semroc having less than 1% of the market, there would not be any kits that would be surviving. Even finding an early RDC was almost impossible and they had much more market share than we did.If you happened to "snag" any Bo-Mar Development kits, they would make good "Retro-Repro" model rocket kits.I do not have anything left from the Black Brant III. It was our last kit and for some reason, I missed pulling any of the instructions, decals, pattern sheets, or anything concerning it from storage.The Black Brant III kit's nose cone was the same one that is used in the "Retro-Repro" Lune R-1 kit, and with the scale documentation from Peter Alway's Rockets of the World...voila! Another "Retro-Repro" kit is born! :-)

[blackshire]

One more question, Carl (and I apologize for asking so many--I just find the history of you all's company fascinating!): Were the old Semroc parachutes the same design (with the same logo at the apex) as the current 'chutes?

(Also, photographs of the old Semroc items in your one box that escaped the tornado, if placed on the Semroc web site, would make a nice little online "museum" of the company's history!)

[Doug Sams]

hmmm...Estes could make 1/2A6-2S and 1/2A6-0S "Shorty" motors today.Yes, and so can you :)

A8-5S, A8-3S, 1/2A6-2S and B6-0S can all be made from 18mm motors. But you need to be careful to get the line square and also take care to not let a stray sawing spark light the top end :rolleyes:

Furthermore, you can make ¼A3-3TS, ½A3-2TS, ½A3-4TS, A3-4TS and A10-3TS from T motors. I'm sure you know this, but I state it to illustrate the good number of options you have for making your own ersatz shorties.

There are a couple bits missing such as a ¼A booster which existed long ago as well as a few others, but overall you have a fairly good selection without Estes cutting a single motor :)


Doug

.

[Mark II]

Yes, and so can you :)

A8-5S, A8-3S, 1/2A6-2S and B6-0S can all be made from 18mm motors. But you need to be careful to get the line square and also take care to not let a stray sawing spark light the top end :rolleyes:B6-2S and B6-4S, too, I think. At least hypothetically. Messing around with BP motors is asking for trouble, though. Estes Industries called their 18mm "shorties" Series III motors. In 1971, they replaced them with the Series IV "Mini-Brute" or 13mm "T" motors that we are all familiar with today. So Estes never stopped making motors in that length (1.75" or 45mm); they simply decreased the diameter. I'm guessing that packing so little propellant into such a thick-walled case was wasteful and inefficient. If I'm not mistaken, Estes did the same thing that Carl described. They packed the regular 70mm long cases for their small motors, and then cut them down. Doing that on a mass production scale created a lot of waste; they were throwing away nearly half of the case for each Series III motor that they made. I suspect that the inner diameter of the 13mm minis is identical or very close to the ID of the 18mm cases that Estes was using at the time. They simply "removed" (figuratively) many layers from the outside diameter because the smaller impulse motors didn't need as much confinement. Producing a motor with a smaller diameter also opened up new design possibilities that weren't possible before, as we saw. Simultaneously with the release of the new motors, Estes introduced the first items in a new line of Mini-Brute kits: the Mosquito, the Screamer and the Mini Bertha.

For a brief period Estes also sold an adapter kit that allowed the new Series IV motors to be used in kits that had been designed for the Series III motors. It was essentially a 13mm engine mount. This could be viewed as an early example of "backward compatibility."

But I digress....:o

[blackshire]

I know that I could "roll my own" (or cut down my own, in this case) Series III motors, but I'd rather buy factory-made, NAR-Certified ones that would be covered by the NAR insurance. However, I'd be just as happy if a lot of the discontinued 13 mm impulse & delay combinations were put back into production, as 13 mm/18 mm adapter mounts (when needed) are common and cheap.

[Royatl]

B6-2S and B6-4S, too, I think. At least hypothetically. Messing around with BP motors is asking for trouble, though. Estes Industries called their 18mm "shorties" Series III motors. In 1971, they replaced them with the Series IV "Mini-Brute" or 13mm "T" motors that we are all familiar with today. So Estes never stopped making motors in that length (1.75" or 45mm); they simply decreased the diameter. I'm guessing that packing so little propellant into such a thick-walled case was wasteful and inefficient. If I'm not mistaken, Estes did the same thing that Carl described. They packed the regular 70mm long cases for their small motors, and then cut them down. Doing that on a mass production scale created a lot of waste; they were throwing away nearly half of the case for each Series III motor that they made. I suspect that the inner diameter of the 13mm minis is identical or very close to the ID of the 18mm cases that Estes was using at the time. They simply "removed" (figuratively) many layers from the outside diameter because the smaller impulse motors didn't need as much confinement. Producing a motor with a smaller diameter also opened up new design possibilities that weren't possible before, as we saw. Simultaneously with the release of the new motors, Estes introduced the first items in a new line of Mini-Brute kits: the Mosquito, the Screamer and the Mini Bertha.

For a brief period Estes also sold an adapter kit that allowed the new Series IV motors to be used in kits that had been designed for the Series III motors. It was essentially a 13mm engine mount. This could be viewed as an early example of "backward compatibility."

But I digress....:o

Page 27 - The Old Rocketeer: Engines Full Circle

http://www.ninfinger.org/rockets/ModelRocketry/Model_Rocketry_v03n09_07-71.pdf

Note that no mention of any Estes mini motors is made in this issue of the magazine (not that Harry would've mentioned them in his article even if he'd known about them, since he was working for MPC). The August issue did have an item in the new products section that said Estes announced them at a trade show in June. The NAR certification list shows the certification of the MPC motors but nothing on the Estes motors.
So it can be assumed that Estes was responding quickly to the MPC motors (MPC ran their first Minijet ad in the June issue, which would've been out late April/early May).
Both Estes and MPC gave everyone at NARAM 13 a pack of their respective mini-motors, but I can't recall if the Estes motors were contest certified for NARAM the way the MPC motors were.

[Mark II]

Actually, I never heard of MPC (or Semroc 1.0) during their lifetimes, and I have only been learning about them since becoming a BAR. I still know very little about them or about most of the other model rocket companies that existed between 1958 and 2004. I knew about Estes and had heard of Centuri, but that was it. From what I have been able to glean, many of them were the originators or earliest proponents of quite a few of the technologies that we all take for granted now. And even now I am still hearing for the very first time of companies that were in business and had that a following at some point during the past 52 years. I'm also still periodically discovering the actual origin of yet another thing that we use all the time.

[blackshire]

Another "innovation" (which isn't really that because it started with MMI) that fascinates me is hardwood nose cones. They appeared at the very beginning of the hobby, then were quickly superseded by balsa nose cones, although some MMI Aerobee-Hi kits and their Arcon kit used vinyl nose cones (and some production runs of their Aerobee-Hi kit may even have had hard rubber nose cones).

Then later in the 1960s, small companies like AMROCS (see: http://www.ninfinger.org/rockets/catalogs/amrocs67/67amrocscat.html ) and Bo-Mar Development Company (see: http://www.ninfinger.org/rockets/catalogs/bomar69/69bomarcat.html ) reverted to hardwood nose cones, although some small manufacturers such as Rocket Development Corporation (see: http://www.ninfinger.org/rockets/catalogs/rdc66/66rdccat.html ) appear to have never discontinued hardwood nose cones. I wonder if safety concerns or cost considerations drove the move away from hardwood nose cones?

Although the NAR Safety Code doesn't specify what *kind* of wood can be used in model rockets, balsa nose cones are more frangible in the event they strike something, their wood may be cheaper to obtain than maple and other hardwoods (although balsa itself is botanically classified as a hardwood!), it is easier to turn nose cones from (and doesn't wear out tooling blades as quickly), and balsa nose cones are much easier to sand-down-to-fit if they fit too tightly in body tubes.

However, hardwood nose cones are less susceptible to "smileys" (gouges of that shape caused by nose cones snapping back after ejection and striking the front edges of body tubes), and their greater weight usually makes nose cone weights unnecessary. Also, screw eyes are less likely to pull free from hardwood nose cones. In addition, they should be easier to sand and seal due to their greater density and more closed grain. Basswood would seem to be a good "intermediate" wood (between balsa and maple) for nose cones when these qualities are desired or needed.

[Mark II]

Hardwood nose cones may have been less susceptible to damage by rebound during the recovery system deployment, but that means that they had even more potential to heavily damage any part of the rocket that they struck. :eek: A couple of other companies that used hardwood nose cones were Flight Systems, Inc. and Crown Rocket Technologies. It was in the fields of mid-power and early high power rocketry that hardwood nose cones made their last stand. I think that balsa nose cones were originally favored in the early days precisely because of their relative fragility. Pioneers, especially GH Stine, were intent on removing as much of the newly invented model rocket's potential for damage as possible. A stray rocket with a hardwood nose cone has the nearly the same potential for damage as a large caliber bullet. They wanted to design rockets that would disintegrate in the event of a high-speed impact, rather than punching a hole in whatever they struck.

I suspect that it was the advent of injection-molded styrene nose cones that made hardwood nose cones obsolete. Not only were they cheaper and much faster to produce (once a company had made the steep initial investment in the molds), but they had less mass while still retaining a relatively mar-resistant exterior. Switching to plastic also, of course, made it possible to design shapes that weren't possible to execute on a lathe-turned wooden cone. You can still get hardwood nose cones custom made out of nearly any wood available, but no one specifies them anymore as standard equipment in kits or keeps them in stock as a component for scratch-building.

[blackshire]

I wouldn't really want to use one--I was just going "hmmm..." after looking at the instructions for Semroc's "Retro-Repro" kit of the Rocket Development Corporation Rawhide (see: http://www.semroc.com/Documents/pdf/Rawhide.pdf ), which originally had a hardwood nose cone. To avoid a really big "Estes Dent" on the front end of the body tube, an even longer shock cord might be needed because the heavy hardwood nose would have a greater tendency to snap back even with a normal-length shock cord.

[blackshire]

Okay :o

The other thought I had was that the pic had extraneous and misleading info. I wondered if the block of text center-left wasn't a vestige that inadvertently got copied from another page in the catalog, perhaps from a Ranger-like rocket.

"
THREE ENGINE POWER
TWO PARACHUTES
LARGE PAYLOAD SECTION
EASY-TO-BUILD
"

Here, I think I found the source. http://www.ninfinger.org/rockets/catalogs/semroc570/570semroc12.html

What d'ya think?

Doug

.Also, the Semroc Goliath's early (1970) paint scheme looks like it might have been inspired by the similar "partially-striped" finish on the Explorer 1 satellite (see: http://en.wikipedia.org/wiki/Explorer_1 ).

[Chr$]

Those 18mm Long D's look pretty cool.