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Silver Comet Upscale?

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ThirstyBarbarian

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Has anyone made an HPR upscale of an Estes Silver Comet?

I've always liked that kit. It was the first thing I built when I returned to rocketry as a BAR. It was also the first kit I built that used a motor larger than 18 mm. It was the first that I spent some effort on the finishing details. And it was my first experience with the nightmare that is silver paint. I like the retro-future style of that rocket, and it's inspired me to attempt similar 50's sci-fi looks on other rockets.

The Estes kit is basically just a modified V2. It's a V2 kit with a swoopy fin pattern and a special nose cone molded with a canopy detail. It seems like it would be easy to kit bash an upscale from any of the many HPR V2 kits on the market --- just cut a new set of fins, like Estes did. Imagine a 7.5" diameter Silver Comet standing 6 feet tall, built from an LOC V2 kit.

Has as anyone done it?

What kinds of problems or other issues do you see with the idea?

One issue I see is that those long, backswept, pointy fins could be pretty fragile on a heavy rocket.

What do you think?
 

rstaff3

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EMRR has one going the other direction. Didn't see the mod you want.
 

nh4clo4

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I had one that flew on an H-180, and it was not an upscale. I did fiberglass it, though...

I have often thought about building an upscale version but never got around to doing it. Will follow this thread with great interest :)
 

ThirstyBarbarian

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I had one that flew on an H-180, and it was not an upscale. I did fiberglass it, though...

I have often thought about building an upscale version but never got around to doing it. Will follow this thread with great interest :)
Wow! That must have really scooted!
 

ThirstyBarbarian

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I googled Silver Comet, Burl Finkelstein and got a couple launch reports. It was 7.5 inch (3x upscale).

Here's a link to a photo:
https://www.fototime.com/{0EFC4841-4F15-41BD-82F8-7CDD163760EC}/origpict/EPSN0015.jpg
Thanks for the help and the links, guys.

That is basically the kind of end result I have in mind. It sounds like he scratch built his, while I would probably start with an existing V2 kit.
 

ThirstyBarbarian

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Does anyone have any thoughts on the fins?

How would you go about creating the template to cut them out or have them cut?

Do you think plywood would be strong enough for a long, pointy fin of this shape? Or should it be strengthened? If so, what would you do to strengthen them?
 

Steve Shannon

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Does anyone have any thoughts on the fins?

How would you go about out creating the template to cut them out or have them cut?

Do you think plywood would be strong enough for a long, pointy fin of this shape? Or should it be strengthened? If so, what would you do to strengthen them?
Burl is very approachable and he's on Facebook.
It really depends on the thickness of the plywood but I would be tempted to wrap the fins in Kevlar or fiberglass. CF could look really nice!
 

jd2cylman

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I built a 4" upscale (which was 1.54X if I remember right). I used a Public Enemy V2 as the basis. Wish I wouldn't have, as the PE nose cone was the wrong length (too long).
I took the Estes fin to a copier place and set the enlargement to 1.54 and used that as a pattern. I cut the fins from 1/4" plywood. This was before I was any good (not that I'm much better now) in OR/Rocsim, so I used a good sized rope and did a swing test and added nose weight until it swung straight with the largest motor I had. I remember getting so dizzy, that I couldn't walk for 1/2 an hour :eyepop: I added 4 lbs of clay to the nose... Now that I know about swept fins and stability, I'm sure I added too much. But I flew it on a I161W just fine. I've flown it on some other 38mm motors (don't remember how big). I had Tango Papa do the decals. I haven't flown it in a while, now with the chute release, I should bring it out more. I'll have to put rail guides on it since it still has lugs...
 

ThirstyBarbarian

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Burl is very approachable and he's on Facebook.
It really depends on the thickness of the plywood but I would be tempted to wrap the fins in Kevlar or fiberglass. CF could look really nice!
Thanks for that tip. Maybe I'll reach out to him on Facebook. It looks like we have a few mutual FB friends.
 

ThirstyBarbarian

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I built a 4" upscale (which was 1.54X if I remember right). I used a Public Enemy V2 as the basis. Wish I wouldn't have, as the PE nose cone was the wrong length (too long).
I took the Estes fin to a copier place and set the enlargement to 1.54 and used that as a pattern. I cut the fins from 1/4" plywood. This was before I was any good (not that I'm much better now) in OR/Rocsim, so I used a good sized rope and did a swing test and added nose weight until it swung straight with the largest motor I had. I remember getting so dizzy, that I couldn't walk for 1/2 an hour :eyepop: I added 4 lbs of clay to the nose... Now that I know about swept fins and stability, I'm sure I added too much. But I flew it on a I161W just fine. I've flown it on some other 38mm motors (don't remember how big). I had Tango Papa do the decals. I haven't flown it in a while, now with the chute release, I should bring it out more. I'll have to put rail guides on it since it still has lugs...
Sounds like an interesting project. When you say the nose cone was too long, do you mean it didn't look right, or did the length and curve of the tail cone cause a problem with the fins?

I understand I can take an existing fin template and enlarge it to scale, but because the fins are mounted on the tail cone section, which might have a different curve and slot position than the original, it seems like it could be tricky. Maybe it wouldn't be that tough with the parts in front of me...

Thanks for the tips.
 

jd2cylman

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Sounds like an interesting project. When you say the nose cone was too long, do you mean it didn't look right, or did the length and curve of the tail cone cause a problem with the fins?

I understand I can take an existing fin template and enlarge it to scale, but because the fins are mounted on the tail cone section, which might have a different curve and slot position than the original, it seems like it could be tricky. Maybe it wouldn't be that tough with the parts in front of me...

Thanks for the tips.
The Public Enemy nose cone was longer than the upscale calculated out to be, so I had to shorten the body tube. The tailcone worked OK for the curve of the fins, if I recall. I don't remember any huge gaps under the fillets anyway... I think the LOC IV cone I had was too short, so neither one was what I wanted, so I just used the PE one.
 

ThirstyBarbarian

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8 months of radio silence, and now I have an update. LOC Precision is going to make me a kit!

I sent them a scan of the fins from Rocket Reviews, and they will scale them and cut them for me and package it together with some 5.5" V2 parts. I was actually amazed at how easy the process has been so far working with LOC. I sent them an email with the basic idea, and Jay got right back to me and said he thought they could do it. A few more emails to clarify some things, and we are almost at the point of ordering parts.

The 5.5" body tube will yield a 2.13 upscale and a rocket that is about 6 feet tall. One thing I didn't like about the original is that it had 4 fins, and I think a lot of possible paint schemes and just the overall sci-fi look would work better with 3. So I asked them to slot the tail cone for 3 fins, which they have agreed to do. I'll do my own paint and decal design on it. It's not exactly an upscale Silver Comet, but it is inspired by the original.

One decision I have to make before placing the order is what nose cone and tail cone to use. They have a longer one and a shorter one in 5.5" diameter, and neither one matches the original, which would be almost exactly in the middle between the two. I'm leaning toward picking the longer one and using a shorter body tube. I think it will make for more a graceful curve from nose to tail to have the longer cone. I think that would be better than having a more blunt nose and tail with a longer cylindrical section.

What do you think? Here's tha page with their nose cone options: https://www.locprecision.com/product/nose-cones/

I wanted to update this existing thread, because this is where I first started talking about the project, but I might start a new one for the build when the parts get here. I'll be building it for use at LDRS, and I think I want to do an LDRS Project-Themed build thread.
 

dhbarr

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I believe I have this kit, unopened in the build pile. Is there anything you need imaged / measured?

Heck, I'd ship it to you if it'd be useful.
 

ThirstyBarbarian

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I believe I have this kit, unopened in the build pile. Is there anything you need imaged / measured?

Heck, I'd ship it to you if it'd be useful.
Thanks for the offer! I actually have an Estes Silver Comet that I built a few years ago and is still functional enough to fly, despite several mishaps over the years that probably should have doomed it. I think I am probably set for now, but if I think of something, I'll let you know. Thanks again!
 

rharshberger

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For those interested in cloning the original Silver Comet I may have a source of original nose cones.
 

qquake2k

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One decision I have to make before placing the order is what nose cone and tail cone to use. They have a longer one and a shorter one in 5.5" diameter, and neither one matches the original, which would be almost exactly in the middle between the two. I'm leaning toward picking the longer one and using a shorter body tube. I think it will make for more a graceful curve from nose to tail to have the longer cone. I think that would be better than having a more blunt nose and tail with a longer cylindrical section.
I agree, I think the longer nose and tail would give it a better curvy look overall, and be more SciFi-ish. Are you going to add steam punkish details?
 

ThirstyBarbarian

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I agree, I think the longer nose and tail would give it a better curvy look overall, and be more SciFi-ish. Are you going to add steam punkish details?
I’m definitely going to be adding retro-future type details, but I’m not sure if it will be exactly steam punk. Might be more 40’s, 50’s, or 60’s than Victorian. I’m still not exactly sure.
 

qquake2k

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Regardless, it should be a very cool build.
 
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