Centuri Argus Clone (KB-9)

[timorley]

I previously printed an Enerjet 1340 fin can in red graciously created by Jack Hydrazine. I decided what to do with it, clone a Centur Argus. But I still needed the plastic reducers if I didn't want to use balsa. Last night I created 3D models for the plastic reducers PSR-78 and PSR-813. I have a few of the original nose cones for the Ogive type option in the instructions, so I decided to use one of them on this project to pay homage to Centuri, although it appears both types are available on Thingiverse by dholvrsn for 3D printing.

Here are the Thingiverse links to all the parts:

Fin Can: https://www.thingiverse.com/thing:3641770
PSR-78: https://www.thingiverse.com/thing:3912950
PSR-813: https://www.thingiverse.com/thing:3913869
ST-7 Cones: https://www.thingiverse.com/thing:560706

Tube Lengths found on this forum:

ST-13: 12 Inches
ST-8: 5.5 Inches
ST-7: 7 Inches

Plans: http://www.spacemodeling.org/jimz/cen5309.htm

[ghrocketman]

I have always wanted to build an Argus to fly in it's SCALE flight profile.
Ramming into the ground UNDER POWER !

[the mole]

timorley, these are very nice parts and now you have made it possible for others to clone rockets that use these parts.

I have always wanted to clone this rocket by Centuri the SR-71. This rocket was one of the last that Centuri did before ESTES took them over. What I'm saying is I would like to see these parts made available for 3D printing. I have a printer but not the ability to draw the parts for this rocket. Do you think you might give these parts a try in the future? guesshttp://www.spacemodeling.org/jimz/cen5349.htm

[timorley]

Do you think you might give these parts a try in the future?

Maybe someday I'll give it a try. I am really new to creating parts, my skill level is still pretty primitive using common geometric shapes. The SR-71 Centuri rocket I'd like to clone as well.

[timorley]

Had to fix a problem with the PSR-813, I made a mistake that resulted in a week point where the ST-13 shoulder joins the cone shaped transition. I also noticed I mistyped a number and shorted the ST-13 shoulder by a tiny amount. Printing a replacement test print now.

Cut all the body tubes to length. Thankfully stumbled into the PSR-813 issue before I glued it to the ST-8.

Decided to give myself the option of a 24mm D for the engine mount, figuring I can always adapt down.

Also thinking about not doing the two parachute, recover in two pieces, Centuri has in the plans and just recover under a single chute with a longer shock cord.

[timorley]

Dry test fit of all the parts. Everything fit together nicely. Some glue, paint and decals and it will be ready for our next club launch.

[A Fish Named Wallyum]

Dry test fit of all the parts. Everything fit together nicely. Some glue, paint and decals and it will be ready for our next club launch.
I did the decals for one of these several years back. As I recall, they were an easy inkjet job. That looks great. One of the birds I always wanted to clone, but I kept getting waylaid by Enerjet birds. :o

[ghrocketman]

Looks great !

[the mole]

Really looks nice. What was old and out of production is new and doable again.

[Earl]

Tim-

Here's the Argus decals with a ruler for scale, JIC you need them (I saw the Jimz plans had no ruler for the decal scan). Self-adhesive paper for the decal media. The sheet is too long for an average size scanner bed, so it is in two parts, but technically you do not need the 'part 2' because they are just multiples of what is already on part 1. These are compressed somewhat from my original TIFF files, but hopefully will work for you.

That is a good looking clone. I always like the 'two chute' recovery for bigger pieces like these, but to each his own. But to be *truly* nostalgic, ya gotta go with two chutes! ;)


Earl

[timorley]

Thank you! Should have asked on the forum first, I spent some time last week cleaning up the decals from JimZ and moving them around so they would print on one sheet. Yours are much better scans to begin with than what is on JimZ. Now I have a choice to make. It's good to have choices. :)

[timorley]

I'll try 2 chutes on the first launch, I can always tie them together later if I want.

[timorley]

All glued up, engine mount installed and painted. Before painting, I temporarily installed the ST-13 tube in the fin can, drew a reference line around the tube at the top of the fin can. I then masked off the part of the tube that would be inside the fin can so it would not be painted. Much easier and cleaner than masking it off after installation.

Ready for decals.

[timorley]

Finished the Argus up tonight. Weather permitting, all ready for our next club launch.

[timorley]

Earl,

Thanks for posting the decals, but since I'd already printed mine out and they looked fine, I went ahead and used what had rather then waste them.

I thought I'd also post the ones I used and cleaned up some from JimZ.

Tim

[CenturiKid]

Tim,

What body tube do you use to fit the Enerjet fin can? I've printed a few of them hoping to clone the Challenger II to fly an Astrocam. It looks like BT-56 is not readily available anymore, will ST-13 from erockets work? If so, do you know if an Astrocam will fit in ST-13?

[Earl]

Tim,

What body tube do you use to fit the Enerjet fin can? I've printed a few of them hoping to clone the Challenger II to fly an Astrocam. It looks like BT-56 is not readily available anymore, will ST-13 from erockets work? If so, do you know if an Astrocam will fit in ST-13?


The ST-13 tube and the BT-56 are the same. The Astrocam will fit it and so will the Enerjet fin can.

That tube was originated by Centuri. Then, Estes used the same tube for the Astrocam back in '79 when it first came out. The Astrocam may have been the first Estes kit to use that Centuri tube, but I'm not positive on that.

Earl

[timorley]

Yes, I used a Centuri/Semroc ST-13.

[timorley]

Beautiful and fully successful flight out of the ARGUS on a C6-5. It really got up there. Both chutes deplored successfully recovering the nose and fins seperately with no damage. I used 12 inch chutes for both. I think the actual Centuri may have used a 10 inch chute for the nose.

[Earl]

Tim-

Nice flight! And you went for the full nostalgia factor on the recovery! :)

I believe the original Centuri kit used two 12” chutes, one for each section. I had my open one out just a month or so back doing some scanning (instructions, decals, etc.) and pretty sure the kit contained two 12” chutes.

Looks like you had several good flights at your recent launch.


Earl

[timorley]

There was a post on this forum from someone that had an original mentioned a smaller chute for the nose. The instructions on JimZ do mention in step 15 if one chute is larger attach it to the lower assembly. The picture in the instructions also shows 2 different chute sizes. Maybe it varied what chutes went in the kit since it is worded “if”?

[timorley]

Oh, and everyone thought it was cool it came down on two chutes.

[Earl]

There was a post on this forum from someone that had an original mentioned a smaller chute for the nose. The instructions on JimZ do mention in step 15 if one chute is larger attach it to the lower assembly. The picture in the instructions also shows 2 different chute sizes. Maybe it varied what chutes went in the kit since it is worded “if”?


Yes, here's the Step 15 you referred to. Centuri sometimes did some parts substitutions, and as you mentioned, some kits may have contained a larger and smaller chute and some may have come with just two smaller chutes. I'll go back and double check mine at some point and verify. I got another sealed one, but I don't believe I'd be able to discern chutes sizes in it.

Earl

[Earl]

Ok, checked my open Argus and it did have a black and yellow 16” chute and a blue and white 12” chute. So, two different sizes in mine. They were both folded fairly small so at my earlier glance I thought they were both 12” chutes.

Earl

[timorley]

Thanks for checking! 16 inches, hmm, actually might not be a bad choice, the 12 inch worked fine for the bottom assembly, it's pretty rugged, but 16 sure would have brought it down closer to the nose.

[ghrocketman]

I'm thinking anything with the Enerjet 1340 fin-can should have a 29mm mount.
Argus, Phoenix Bird, Challenger 2, etc.

[mwtoelle]

The ST-13 tube and the BT-56 are the same. The Astrocam will fit it and so will the Enerjet fin can.

That tube was originated by Centuri. Then, Estes used the same tube for the Astrocam back in '79 when it first came out. The Astrocam may have been the first Estes kit to use that Centuri tube, but I'm not positive on that.

Earl
Actually, the first Estes kit that used Centuri tubing was the Space Shuttle (1284). It used the following Centuri tubes:

ST-20 (BT-67) for the external tank.
ST- 8 (BT-46) for the SRBs.
ST- 7 for the trailer fin tubes.

[Earl]

Actually, the first Estes kit that used Centuri tubing was the Space Shuttle (1284). It used the following Centuri tubes:

ST-20 (BT-67) for the external tank.
ST- 8 (BT-46) for the SRBs.
ST- 7 for the trailer fin tubes.


What I was stating was the first use of the *ST-13* tube by Estes, not the first ever use of a Centuri tube. But, it is a good trivia question to know the first ever use of Centuri tubing in any Estes kit. I knew the shuttle used the ST-20, but did not realize it also used the ST-8 and -7. Thanks for the info!

Earl

[nerys]

I am getting back into fabricating rockets again. my life took a severe turn a few years back. poor as hell now (thanks covid) but while I can't fly rockets right now I can sure make them as I have a nearly unlimited supply of plastic. (3D printing youtube channel) I really do have an insane amount of plastic. Flying costs money. Can't do that. but fabricating them? that costs me nothing but some electricity :-)

I saw the Argus on the Centuri group on facebook and fell in love with it. I now have micro maxx 13mm 18/24mm and 3" 29/38mm models in the works!

I need a victum.. errr Volunteer to test the big one 3in class 78mm airframe 1.4meters tall.

should use around 500-600g of plastic. Modular (all the parts thread together no glue needed except to glue the 29mm MMT to the Motor Mount thread in)

If someone is willing to print and fly one in say the next month I will provide the STL's to them for free. Attached are pictures of the 13mm one and a screen shot of the parts for the 3in (printer is busy printing a QCC Explorer right now)

I have been rather obsessed with fabbing up rockets from the past that I always wanted as a child but could not have. I even did up an Aquarius Explorer. can't wait to print the micro maxx version. should be around 8 grams !! :-)

oh and with a little "nose job" change you can clone a lot of rockets with this. Enerjet sounding Maniac etc..