Camroc Carrier balsa reducer, rocket length, and Camroc fit.

[Tramper Al]

Do Estes catalog rocket length specs include engine hook? I kind of doubt that they would.

You see, my Camroc Carrier as built (using the Semroc 1/2" BT5060 balsa reducer) is about 0.4" shorter than the (1976) catalog spec of 17.76". Since the body tube and payload tube lengths are specified in the kit, and I am using the vintage plastic nosecone (sourced from an early but post-balsa Big Bertha), it seems the only remaining variable is the balsa transition length.

The reason this is important (other than historical accuracy, and I am really not that compulsive!) is that the Carrier is of course designed to hold the Camroc as well. The paper shroud is positioned precisely using the kit's balsa transition, and then the Camroc should fit (and form a nice seal with the shroud. And I would like my Camroc Carrier to be the correct length AND be able to carry a Camroc.

Other data points I have:

In an old forum thread, someone was kind enough to include measurements of the original kit transition, which by subtraction indicates the transition was 15/16" or 0.9375".
https://forums.rocketshoppe.com/archive/index.php/t-3395.html

An .ork file posted recently by K'Tesh, using measurement from the Camroc, indicates a transition length of 0.591".

It seems to me that the balsa transition in Camroc Carrier could be longer than on the Camroc, but it could not be shorter (because then there would be a gap between Camroc and shroud). So I am thinking I may be on the wrong track using the 1/2" transition (from Semroc, though no longer available). 1" would seem to be closer to correct. I've not found that either Semroc, Balsamachining, or anyone else makes a 1" BT5060 reducer.

If I end up asking someone to make a couple of balsa reducers for me, and the 1/2" isn't available anyway, I'd like to get it right.

Thanks in advance for any help or guidance on this . . .

 

[Buzzard]

View attachment Camroc Carrier 1.pdfhttps://www.ninfinger.org/rockets/catalogs/estes74/74est50.html

View attachment Camroc Carrier 2.pdf
The Camroc Carrier plans are from the Design Booklet that Estes presented contestants at NARAM-11 in Colorado Springs in 1969. I did not find plans for the kit that was available in the catalog reference above, so I do not know if the plastic payload section had a molded plastic adapter or a balsa one. Since it was a purpose built piece to match the actual Camroc, you might have to make one yourself or go with what is about right.
BTW, Craig Streett of the CSAR section in Columbus, OH sent the original design in to Estes for a design contest. They later released their kit without credit to Craig. At one point Craig was working at the NASA Glen Center on Cleveland.

Chas

 

[K'Tesh]

The Camroc's transition is made from plastic. However my research shows that the payload version used balsa.

One method I can think of to solve your problem, is to create a transition that uses a pair of centering rings. Glue it up much like a 24mm motor mount in a BT-60. Then slide that into the payload section, and then glue in a 24mm balsa nose block to create the shoulder. Slide a paper cone (shroud) over it to complete the illusion, and there you have a custom transition. I did something like this for my Comet Chaser Upscale, but ended up getting custom parts made by Semroc. I'll try to photograph it when I get home.

If you're a member of Semroc's SAM club, you have access to their custom cone creator (and if you can figure it out), to create a custom one of your one.

BTW, Estes catalogs are full of length errors (e.g. the Cherokee D was the same length (21.6") throughout it's production run, despite growing 2 inches in 1970's). If I can't measure from my own, I like to look up part numbers when I can, and find info using that.

 

[Buzzard]

https://www.ninfinger.org/rockets/custom_estes/custom_estes.html

Page 8 of the Custom Parts Catalog lists replacement parts for the Camroc and Cineroc. The Camroc used the TA-5060c adapter. It does not list any dimension.

With the passing of Carl last year and Bruce's medical issues, I am not sure that the SEMROC custom cone creator is currently a viable option.

Hopefully someone who still has a Camroc will respond with the actual dimension for the adapter.

Chas

 

[K'Tesh]

https://www.ninfinger.org/rockets/custom_estes/custom_estes.html

Page 8 of the Custom Parts Catalog lists replacement parts for the Camroc and Cineroc. The Camroc used the TA-5060c adapter. It does not list any dimension.

With the passing of Carl last year and Bruce's medical issues, I am not sure that the SEMROC custom cone creator is currently a viable option.

Hopefully someone who still has a Camroc will respond with the actual dimension for the adapter.

Chas

Hi Chas,

My measurements were taken from my Camroc. Mind you, I was using a metal ruler and an eyeball, rather than a micrometer.



I'm wondering if Tramper Al's info is including the entire length of the transition of the Camroc, or the external (visible) length of the Camroc. One thing to keep in mind about my nosecone measurements is that they are composed of several transitions in order to create an accurate (or nearly accurate) profile. The Camroc's visible transition (seen in the image above as medium grey) is composed of a section of a flat portion, and a conic portion (then there's the shoulder).

I'm at school right now, and I can't access OR from this computer, so I can't open the .ork and verify the dimensions until I get home.


Here's a website with some good Camroc info (no measurements).

 

[Tramper Al]

Hey all,

Thank you for the suggestions, and you've given me some more ideas.

Just to be clear, I am confident in K'Tesh's measure of the Camroc shoulder at about 0.59 in - and will plan to use the 0.50 in shoulder balsa reducer in my Camroc clone. That's not really the issue.

The problem is really with the Camroc Carrier, in that I think building it with its paper fairing sized to the 0.50 inch balsa (this is a very precise fit) likely means it will not fit a genuine Camroc (that I'd like to get my hand on someday).

I am going to take Chas' reminder as to the contest winner nature of this design (I do have the old Model Rocketry News issue) and look at which 50-60 reducers were actually available from Estes at the time.

Close enough is fine for these projects, especially for the parts are not easily seen. One approach I can use is to let the Camroc Carrier's payload kit "sit high", that is not push the transition down flush when I position (and glue) the paper fairing. I could even lengthen the BT50 end of the reducer (by adding a bit more B-50 balsa) for stability.

I do still have to problem, though, of owning only one 50-60 0.5 in reducer, and need at least one each for clone Camroc/Delta and for the Camroc Carrier. I bought what must have been among the last from Semroc, and don't think that putting that back in stock low volume balsa items like this will or should be a high priority for them.

Addendum: OK, the Camroc Carrier is Plan No. 60 in the February 1969 Model Rocketry News. It is actually another design (like the Delta) that has not nosecone/payload, other than the Camroc itself. You are supposed to use your Camroc to position the paper fairing for gluing. So doesn't help too much. Maybe I will start looking at the 1974 era Estes parts lists, when the Carrier debuted as a kit with payload, and we what sort of 50-60 reducers were available.

And it turns out that the only 50-60 reducer offered separately by Estes in those years was the 2" kind, #70016. The Camroc Carrier kit instructions indicate #70019, and I am not finding that anywhere else.

 

[vcp]

... not sure that the SEMROC custom cone creator is currently a viable option
Chas

I'm about ready to release a spot on my Etsy store where you can order any transition to your specifications, 3D printed. Should have it ready within the week.

Gary

 

[K'Tesh]

I do still have to problem, though, of owning only one 50-60 0.5 in reducer, and need at least one each for clone Camroc/Delta and for the Camroc Carrier. I bought what must have been among the last from Semroc, and don't think that putting that back in stock low volume balsa items like this will or should be a high priority for them.

Email them, and ask. I doubt that they've eliminated them from their stock, they just need to know that there's a need for more to be made.

 

[K'Tesh]

ok... as promised...