Vintage Estes Scorpion Build #1333

I have a couple of these kits but never built them. This is an older Scorpion with a different fin can than the later version that came out. Looks to be a simple build but the directions call for orange spray paint on the bottom portion, but the face card looks red to me. Oh well I will have to decide when I get to the part of the build.

Red. It'll look so much better in red as well as with trapezoidal fins.

Satin Fire Orange will adroitly accept decals without silvering, and be ready for a glosscoat?

I still need to get a can myself, but I'll try it on at least one of my Ram Jets.

It seems a really solid Red Orange, check EXPjawa's work.

I think I will go with red to match the face card. Without having to mess with balsa sure made this a fast build. The Estes Mongoose looks pretty close to this design but there are some little differences with the parts. The fins on the can slant down more from the top on the Mongoose and the nose is one piece vs the two piece Scorpion nose. I will do a little sanding on the plastic and then hit with primer today.
https://www.estesrockets.com/rockets/kits/skill-1/002092-mongoosetm

I always liked the lines of this rocket, but didn't like the idea of the plastic fins.

SCIGS, can you tell me more about that two part nosecone? That is pretty uncommon for an Estes kit.

BTW, the instructions on plans.rocketshoppe.com (https://plans.rocketshoppe.com/estes/est1333/est1333.pdf) have a different nosecone, and the decals that were scanned were in pretty bad shape. Any chance you could scan yours (along with a ruler (for scale))?

I'm trying to sim this in OR now, but I don't have any info on the fin can (dimensions of the shoulders, thicknesses, dimensions of the actual fins). I've got guesses, but I'd like to make this really accurate.

Thanks!
Jim

I will scan what I have from this kit. The 2 piece nose cone was used in a few Estes kits back in the day. The Kadet, Sam-4, Challenger-1, Star Trek Missile and Star wars missle rockets both used them. The fin can is still used today but the shape has changed a little.

SCIGS30 said:

I will scan what I have from this kit. The 2 piece nose cone was used in a few Estes kits back in the day. The Kadet, Sam-4, Challenger-1, Star Trek Missile and Star wars missle rockets both used them. The fin can is still used today but the shape has changed a little.

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Thanks for the info, I didn't know about that nosecone. The Nosecone Guide (https://www.rocketshoppe.com/info/Estes_Nose_Cone_Reference_10.1.pdf), indicated that the only nosecone used for the Scorpion was the PNC-50YR (the two piece injection molded nosecone where the shoulder is glued to the exposed nosecone). So, now we clearly know better.

Any chance you could get me the measurements of the fins in your kit (and the newer one if you have it)? I am thinking that the Scorpion would lend itself well to an upscale, and I'd love to get the shape right.

I could also use the length/width of the shock cord (my guess is 18" long, and 1/8" wide), and the length of the launch lugs (I'm guessing 5/8"). However, I'm trying to sim it very accurately.

Thanks!

So this is basically a mongoose?

Kruegon said:

So this is basically a mongoose?

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I think it's the other way around... The Mongoose is basically a Scorpion (with a slighly different fin can).

The original Scorpion has a two-piece nosecone (split lengthwise) & trapezoidal fins with a diamond-like airfoil; the booster typically tumbled back safely. It's the one SCIGS30 is building here.

The Mongoose nosecone is different (split NC + shoulder, not sure about the shape); the fins are (weird?) clipped delta with a wedge airfoil. They unfortunately changed the booster arrangement so it comes in ballistic (engine block at rear with the motor further forward). The colored body tubes appear somewhat weaker than the regular tubes.

Somewhere along the way, Estes starting messing with the Scorpion design. The instructions at Ye Olde Rocket Shoppe show parts similar to the newer Mongoose. One piece mold vs two-piece to save cost?

I personally prefer the older styled trapezoidal fin unit better, as per the Star Wars Proton Torpedo. You can also get the Eliminator and do an upscale.

Have fun!

Still have to post the plans and decals with the fin can shape, but I have the rocket painted and will apply the decals in the next day or so.
Painted with Rusto Stop Rust spray paint and went with red and not orange.

I applied the old fragile decals today and she is ready for flight.

SCIGS30 said:

I applied the old fragile decals today and she is ready for flight.

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Nice Job!

Here's my guesstmate...



Once I get the details, I'll update the .ork (and modify it as a clone with balsa fins). As I don't have a two-piece split lengthwise nosecone simmed, and the JimZ instructions show a two-piece injection molded PNC-50Y (glue shoulder on version), I went with what I had.

Here is the scan of the instructions sheet and drawing of the plastic fin unit. The decal sheet online is better than my scan.

View attachment Scorpian 1.pdf

View attachment scorpian 2.pdf

View attachment Estes Scorpion Fins and instructions.pdf

SCIGS30 said:

Here is the scan of the instructions sheet and drawing of the plastic fin unit. The decal sheet online is better than my scan.

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Thanks for those.

Problem is, I can't make out the dimensions of the fins from the drawing. Any chance on getting the fin root chord, tip chord, and length?

Thanks!
Jim

I've purchased the Scorpion Decal Set from Sandman. Can I expect them to cleanly-transfer to my appropriately-painted Mongoose Kit?

I added the updated fin PDF with measurements.

SCIGS30 said:

I added the updated fin PDF with measurements.

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Thanks for the update... I've got the basic rocket done... now onto the decals.

Well done on the Scorpion. It's sleek looking 2 stager.
I built mine back in early 1981 and then sadly sold it to a friend. Today I wish I hadn't done that.

I built this from a Mongoose kit with reprinted decals. The good thing is that you can always use a mongoose booster as a spare.

Ok... I'm back on this again... I lost it all in the HD crash. So this is a fresh start.

In reading the instructions with the PRP-1H nosecone, I've found that the aft motor tube is trying to occupy ~1mm of the space that the forward motor tube is occupying. Huh???

I suspect that the dimensional drawings I've received in Post #14 are slightly off. So, I'd like to request someone check the dimensions of the BT-50G, and the PRP-1G (PN 32493) Plastic Fin Unit. I need the length of the exposed section of "body tube" of the fin unit (and its shoulder length).

I could also use some help to answer more questions about the PRP-1G .
Shoulder OD/ID Diameter
Aft End ID, and is there a "step"? that locks the Aft AR-2050 Adapter Ring in place? If not, how does it not just slide forward until hitting the back of the fwd shoulder?

While someone is at it, I'd also like to know more about the flat bottomed "Fin Unit" from the newer Scorpion (1333) (the one with the wedge profiled fins, rather than the diamond profile of the PRP-1G fins).

Photos would also be a big help here.

Thanks!
Jim

Ok... The file is pretty much finished, I just need that info on the fin can and the BT-50G body tube segment before I can post it.

guess I'm gonna have to find one of these...

fm

ps. TRF, you guys are soooooo bad for me and my wallet

Forever_Metal said:

guess I'm gonna have to find one of these...

fm

ps. TRF, you guys are soooooo bad for me and my wallet

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We're just your friendly neighborhood enablers.