Isn't it the BC-20107? It is the equivalent of the FSI NC-191 per the conversion list on Carl's site.

Thanks, that's the one - I was just too lazy to look it up.

S.

Carl,

Thanks for the compliment; I do appreciate that! I thought about adding a paper shroud to the sustainer aft end like the original version Lune R-1 but I wasn't sure of the dimensions. The Lune R-1 and booster parts are on my list of Semroc items I intend to get with my next order



Sean,

I hope you are feeling better today and recovery from the surgery you had is a complete success. I'm going to pick your brain soon about your FSI clones. The Voyager, OSO and Mach-1 Dart were my favorite F engine rockets. I'll have to check the Semroc site to see what sizes the conical shaped cones are available in, I only looked for ST-13 and LT-125 sizes. I was working on some Mach-1 Dart simulations with Semroc parts last night and here is what I came up with.



*** Semroc Mach 1 Dart with Thruster System ***

"FSI presents the mach 1 system - A model rocket system with the ability to BREAK THE SOUND BARRIER". As a teenager when I first read those words in the FSI catalog I rushed to buy one. I had to have it. Most are familiar with the original design with the fins glued directly to the F100-0 booster and all the versions I had the D20 for the sustainer slipped directly into the top of the F100 and it looked as if perhaps a couple of cardboard layers of the id of the F100 were removed to accomplish this slip fit. I'm not sure, because I don't remember but I don't think a standard FSI D20 would slip fit in the top of an F100. I thought I read somewhere that some users had a coupler for the stages but all of the ones I built the sustainer motor slipped directly into the top of the F100.

Since the 24mm and 29mm Semroc PB port burners will be last in the production schedule, I can't guess if this type of coupling the booster and sustainer could be duplicated. Instead of having fins glue directly to a 29mm motor I used a LT-125 tube for the booster with a small sleeve to allow the 24mm sustainer motor to slip through to couple the stages. I'm not real fond of this configuration because it shifts the CG back by moving the booster motor aft one inch and would probably require about 1/2oz of nose weight. This may not be necessary when we have the Semroc 29mm port burners in hand, so consider this "a work in progress".

I'm sure the Semroc PB's will have no problem with achieving the needed velocity in a two stage rocket and I'm convinced the reason the FSI version was so efficient was due to a good design and PB motors. The F100 was barely an F at only 41.6 ns and the D20 was 17 ns. It could quite possibly be done with Semroc PB's staged E to D depending on the final designs.

Since both stages of the Semroc design use airframes, this could easily be adapted for 15mm and 18mm Semroc PB's for a smaller field and you don't waste gluing the booster fins to a disposable motor, making the booster reusable.

Although not a new idea, this would be a model rocket system design that would only be able to be achieved using Semroc PB engines. None of the other rocket companies could make this claim.

It could be a fun design challenge for Semroc Virtual Design Team to improve on the original design. Creativity is certainly not lacking with the members of SVDT! Possibly make something uniquely Semroc. I toyed with the Lune R-1 as a sustainer with only 3 fins and with a redesigned booster. Any other ideas?

What do you guys think?

.

Attached Thumbnails

       

Attached Files

Semroc Mach 1 Dart with Thruster System.rkt (42.2 KB, 5 views)

__________________
Steve Naquin
TRA# 677 L2
NAR# 85518 L2
SAM# 0052

🚀 In Construction: Der Blue Maxx/Minie-Magg 5.5” & Vander-Burn MDRM Clone w/Stickershock23 Custom Decals
🚀 In Paint & Detail: USR Banshee
🚀 In Build Queue: Estes Doorknob w/Vander-Burn Rocketry Upgrade Kit [Sport Decor], Semroc Centurion-F, Semroc Egg Crate
🚀 In Repair: SLS Lil’ Hustler, SLS Aero-Dart 1969 Trim
🚀 Stay Tuned For Fall 2021 Launch Dates

Cool! I like the idea. Machs my day!
James

Ouch! Just go easy there, Stevie-boy - there's mighty slim pickins up there at this point

Sean

Steve,

I like the idea. I only got to fly my Dart once (I thought it blew up when it hit mach....you know those pesky, prone to cato, FSI motors). And, as you've mentioned, the current assortment of motors just can't make it work now. Another interesting configuration would be for the FSI Intrepid. It used a cluster of one F100-6 and two D20-0s. I'd sure like to fly it the way it was intended.......

__________________
Don
NAR 53455
"Carpe Diem"

Hey Don,

I remember the picture you posted a while back of your Mach 1 Dart. IIRC you had a white dart and booster on top of a tall tripod.

I never owned the FSI Intreped but I remember when I came out. I waited too long and FSI went out of business before I hand a chance to get one.

It goes without saying that Semroc port burners will change the way we fly rockets. It opens up a lot of welcomed new possibilities. I would imagine the longer burn EB motors will set new contest records.

.

__________________
Steve Naquin
TRA# 677 L2
NAR# 85518 L2
SAM# 0052

🚀 In Construction: Der Blue Maxx/Minie-Magg 5.5” & Vander-Burn MDRM Clone w/Stickershock23 Custom Decals
🚀 In Paint & Detail: USR Banshee
🚀 In Build Queue: Estes Doorknob w/Vander-Burn Rocketry Upgrade Kit [Sport Decor], Semroc Centurion-F, Semroc Egg Crate
🚀 In Repair: SLS Lil’ Hustler, SLS Aero-Dart 1969 Trim
🚀 Stay Tuned For Fall 2021 Launch Dates

Yep, I remember that somewhere. That tripod sure makes it easy to hook up igniter wires......

You know, you can almost clone it. Instructions and templates are here http://www.oldrocketplans.com/fsi/fsi1032/fsi1032.htm and Carl has a partial partslist here http://www.semroc.com/Store/scripts...arts.asp?ID=695 (well, two items with add buttons)

__________________
Don
NAR 53455
"Carpe Diem"

When looking for parts to clone old kits, always ask Carl if he has the other parts available that aren't listed. He has many parts for kits that haven't been posted to his site yet.

__________________
Scott D. Hansen
Ye Olde Rocket Shoppe - Your One Stop BAR Shoppe!
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Ye Olde Rocket Forum
WOOSH NAR Section #558

FWIW,

Years ago, I flew a FSI Dart system at the (only) night 'velocity' launch outside of Las Vegas.

The D20 didn't ignite (my mistake) but the F100 booster pushed the model to 460 MPH.

Bob