Estes Colossus 1326 fin drawing

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rewilfert

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I'm looking for a scale drawing of the plastic fins used on the Estes Colossus (kit 1326). I believe they are the same fins used on the Estes Maxi Alpha 3 (kit 1903). Anyone out there have either of these kits available to make a drawing or know if one is already available somewhere?
 

kuririn

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Glad I read this, I have the parts just ordered for a Colossus clone, did not have the fin template but was going to measure and eyeball it off the instructions. Did not know that it was the same as the Maxi Alpha 3. Here's a scan of the Maxi Alpha 3 fin without inch scale from YORP:
http://www.oldrocketplans.com/estes/est1903/est1903.htm
And here's the Colossus instructions, for cloners:
https://www.estesrockets.com/media/instructions/001326_COLOSSUS.pdf
Hope this helps. Cheers.

EDIT: Printing the fin scan from the .jpg file will be undersized. Printing from the .pdf file will be more accurate. Also, the distance between the fin tabs appears to be the same as the length of the WBT-80MA tube which is 3.22" (from John Brohm's reference). That can be used to verify the dimensions.
 
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rewilfert

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Thank you for the help. What parts did you purchase? I believe the nose cone of the Maxi Alpha 3 (kit 1903) and Executioner (kit 1951) are the same shape as the Colossus.

One thing I haven't been able to find is the overall height of the Colossus.
 

kuririn

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Here is John Brohm's invaluable "Estes body tube list" reference:
http://rocketshoppe.com/info/Estes_Body_Tube_List_3.1.pdf
It gives the lengths of the various tubes used in the Colossus kit.

And from the 1979 Estes catalog on the Ninfinger website:
http://www.ninfinger.org/rockets/catalogs/estes79/79est34.html
Total length is 51.25"

As far as the nose cone, will use the PNC80-K. Not quite the same as the PNC-80KR, but close enough.
A friend who recently moved to a new job left me with some heavy duty BTH-80 tubes, one was slotted for three fins. So my clone will be heavy duty, plywood TTW fins, 4X24mm cluster.
IMG_20181215_091613.jpg
Should be fun. Cheers.
 

rewilfert

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I bought an original unopened Maxi Alpha 3 (kit 1903) from the early 1980's and an Executioner (kit 1951). I compared the nose cones in both kits and they are exactly the same shape and size. The only way I can tell the two apart is that the nose cone from the Maxi Alpha is a little "softer" than the one from the Executioner. I'm going to attribute this to different materials used in their construction, since they are around 35 years apart in age.

Since the Maxi Alpha used the same fins as the Colossus, I now have a pattern for the fins.

At this point, I am planning to use the Executioner as the basis for my Colossus clone. To extend the body, I will need to buy an additional BT-80 body tube and coupler. I'll need to get a BT-50 body tube and coupler to extend the engine mount. Then I'll cut new wood fins that match the shape of the ones on the Maxi Alpha III. I could use the fins from the Maxi Alpha III, but I remember the plastic fins having a tendency to break off on the Colossus I had as a kid. Using the Executioner as a basis will give me the ability to use both D and E engines and have through the wall fins.

Once I get an accurate scale drawing made for the Maxi Alpha III fins, I'll have to see if I can post it up somewhere for others to use.
 
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