SD's USR Swarm C6-7 Build

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ScrapDaddy

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Well, I looked back at my "level one development" and i asked myself "WHAT THE HECK WAS I THINKING?" an I1299N for a level one? a 12" parasheet? 3/32 ply at mach 1.8? Well first of all, right off the bat i would like to apologize for doubting any of you. It's time to find a More practical way to do HPR :)

Ok, Well this is actually a clone build, But i figured it would get more attention if i left out the "Clone" Part :D
Ok so For those of you who dont know, USR was a Rocket manufacturer from 1979-2005, at its peak it had a full line of Motors and kits. They were Interesting, to say the least.

Ok the backstory is over, and here are some problems i have run into with the cloneing:

1: The 3.16" body tube, i have 2 sub-options:
a. I can roll my own tube, using a BT300 as a mandrel, maybe with something wraped around it
b. I can use a 4" tube and just use centering rings instead of the original "MMTs as the lower body tube"
So if anyone can find a 3.16" BT let me know please.
2: the 12 C6 engines that this kit was originally based around.
The C6 Contains 10.8 grams of propellent, and 12 of those would make it a HPR rocket. SO that limits my motor choices to the A8, A6, B6,B4, the D21 and D24T (12 motor cases FYI)

So those are the only problems i could see.
As far as the dimensions go, i will take the picture off the USR site and use the 3.16" as the BT diameter and go from there.

I have almost no other data on this so any help would be greatly appreciated. Oh and the USR page about the Swarm C6-7 Is here at https://v-serv.com/usr/kits/swarmc67.htm Here is one thing that i wanna point out upfront, the kit doesn't weight 0 grams as the page says! :roll:


Thanks,
SD
 
Well, if Jerry says it weighs 0g, I'd take that as true.
Seriously though, you can use a LOC 3.10" body tube or the same body tube that Estes uses for their "Big Daddy"; both of those are the same dimension.
As for 12 C6 motors, switch 3 of them for B4 or A8 or B6 motors and that should put you under 125 gramms of propellant.
To get a hold of Jerry Irvine, just use the "contact us" link on the USR website. Chances are he will reply. He has a lot of knowledge.
Daniel
 
Ok thanks, that solves the BT problem. Now, I really want this to fly on 12 D10's which would be really cool, aside from the $120 price for launching..... :y:
 
As far as the dimensions go, i will take the picture off the USR site and use the 3.16" as the BT diameter and go from there.

I have almost no other data on this so any help would be greatly appreciated.

Thanks,
SD

SD,

There is a RockSim file posted on EMRR for the Swarm and Swarm Jr. rockets. If you don't have a registered version of RockSim you can still use the demo version to at least open and view dimensions and such for scaling the design and for the fin pattern.

https://www.rocketreviews.com/cgi-bin/search/searchall.cgi?swarm#RS

A few years ago Jerry released RockSim files for almost all of the USR rockets and these are posted in the RockSim Library section at EMRR.

:)

.
 
Ahh - I misread it. It still shouldn't be $10 ea. though. Also, I would not recommend a cluster attempt like that - too much could go wrong. It would be a $60 H120 that would be incredibly prone to failure.

Woops, I thought apogee was the only one who sold D10's And as far as launching with 12XD10 goes, I will prolly throw only 3XD10 in there for a cook white flame, but you must think, 12 white flames is quite something!
 
SD,

There is a RockSim file posted on EMRR for the Swarm and Swarm Jr. rockets. If you don't have a registered version of RockSim you can still use the demo version to at least open and view dimensions and such for scaling the design and for the fin pattern.

https://www.rocketreviews.com/cgi-bin/search/searchall.cgi?swarm#RS

A few years ago Jerry released RockSim files for almost all of the USR rockets and these are posted in the RockSim Library section at EMRR.

:)

.

IIRC, those files were rocksim 7, so I believe openrocket souls be able o open it, Thanks!

SD
 
Woops, I thought apogee was the only one who sold D10's And as far as launching with 12XD10 goes, I will prolly throw only 3XD10 in there for a cook white flame, but you must think, 12 white flames is quite something!

3 D10s along with some Cs you mean?

You don't want to mix AP and BP like that - you'll never get them to all light correctly.
 
Ok guys, thanks for the help, right now I am kinda confused on the 12X18mm tube allignment and clustering
 
The way I would do it is get your 12 18mm motor tubes and put them in 4 groups: 1 group will have 4 tubes, 2 groups will have 3 tubes and the last group will have the remaining 2 tubes. Work on a flat surface like a kitchen table or desk top and you want to glue each group flat against the table. For example, get the group of 4 tubes and lay them flat on the table side by side in a flat line and glue them together Carefully so as not to get glue everywhere. You can use masking tape to keep them together and flat against the table so they don't move when the glue dries. Do this for the four groups. Once the glue is dry, you are going to glue one of the 3 tube assemblies to each side of the 4 tube assembly. When this dries, you will then glue the 2 tube assembly to either of the 3 tube assemblies. Does this make sense?
Good luck...
 
Do not attempt to cluster AP motors till you get some experience with clustering techniques. It will be enough of a challenge to get all 12 black powder motors to light. I would recommend ordering Quest Q2G2 igniters which will take much of the pain out of lighting this many engines. These igniters take very little current and the leads can be easily twisted together.
 
Do not attempt to cluster AP motors till you get some experience with clustering techniques. It will be enough of a challenge to get all 12 black powder motors to light. I would recommend ordering Quest Q2G2 igniters which will take much of the pain out of lighting this many engines. These igniters take very little current and the leads can be easily twisted together.

Q2G2's were my igniter of choice to start, clusters, or singles, it's pretty embarrising to have your igniter misfire :eek:

plus, I just did a *optimistic sim, and 12xD21 will take it supersonic! :jawdrop:
 
Interesting project, SD! Keep in mind that with an array of 12 motors tubes, you will have many possible cluster combinations and configurations; you don't have to fill every tube with a motor. I am envisioning lots of different motor "geometries" with it. Pretty cool! Keep the build light, though, to maximize your options. If the diameter will work, you can save some weight by using BMS T300 tubing instead of the LOC tube. The BMS tube has an OD of 3.0" and an ID of 2.93", with a wall thickness of 0.035". LOC's tube has an OD of 3.1" and an ID of 3.0", with a wall thickness of 0.05". The slightly smaller diameter and slightly thinner wall of the BMS tube saves a bit of weight. I haven't run any sims, but such a substitution may make it possible to launch the Swarm on, say, five or seven C6s, or four D10s, which would both still produce an awful lot of noise, fire and smoke without breaking the bank. Just something to consider.

MK
 
Thanks Mark! I hope I will have this project done by the June 12 launch.... Times a wasting! You can see the cluster configuration on the USR link I posted. The photo is hard to understand, so I will explain. First things first, the 18mm tubes are part of the airframe, they come out of the 3" bt and make up half of the length, The geomotry is centered around a trio of 18mm tubes in a pyrimid, and those tubes are slightly longer than the rest, they extend farther forward so that a centering rings can be attached, and will seal the tubes, only the center 3 motors will be "ejection active" as the rest will prolly be plugged. the 9 other motors are.... Well the sides of the pyrmid, there are 3 motors on each side of the pyrimid "in line with each other" Please reference the photo.

Mark, you clone your FSI kits, and ill clone my USR kits :)
 
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