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-   -   Afternoon Project (http://www.oldrocketforum.com/showthread.php?t=20352)

MarkB. 03-16-2022 12:33 PM

1 Attachment(s)
Druziv:

So a picture was requested. Here you go.

But I thought the group would like to see the other artifact: From an eBay rescue group I got last year: a short body, two-piece fin, balsa nose, stand-off lug, Cherokee-D now in the restoration pile. No chute, no shock cord but it will fly again. I enjoy deep-diving the old posts on this site and there is a surprising amount of data on Cherokee-Ds which I confess to never having given much thought. I was reading through them and then I remembered I had this out in the pile and sure enough . . . . So apparently, this is a very rare beastie to have survived over 50 years.

The new build is coming along. I'll seal the fins over the next few days and then it's ready for paint.

ghrocketman 03-16-2022 06:00 PM

I have built at least 7 Estes Cherokee-D kits, all with the full-length BT-55 and PNC55AC cone.
Never built a short-tube Estes early kit.
The only short -tube kit I built was a PDR or Thrustline clone.
Did the early Estes kit use a balsa BNC55AC cone ?

LeeR 03-16-2022 07:20 PM

Quote:
Originally Posted by A Fish Named Wallyum
The nice thing about the Cherokee D is that the paint masking is easy. :D I've built A, B, C, D and E so far, some of them multiple times. I have the MicroMaxx one from Semroc waiting for me to decide I can work on something that tiny, and I have the fin pattern drawn up for a BT-70 Cherokee F. Good choice. :cool:


I’d get going on that MicroMaxx Cherokee pretty soon. If you wait until your my age, working with those tiny parts is close to impossible.

mwtoelle 03-16-2022 10:39 PM

Quote:
Originally Posted by ghrocketman
I have built at least 7 Estes Cherokee-D kits, all with the full-length BT-55 and PNC55AC cone.
Never built a short-tube Estes early kit.
The only short -tube kit I built was a PDR or Thrustline clone.
Did the early Estes kit use a balsa BNC55AC cone ?

I think that Cherokee-D switched to plastic nose cone sometime in late 1974 or during 1975.

A Fish Named Wallyum 03-17-2022 08:56 AM

Quote:
Originally Posted by LeeR
I’d get going on that MicroMaxx Cherokee pretty soon. If you wait until your my age, working with those tiny parts is close to impossible.

Oh, I'm WAY more advanced than you are. Those parts have been impossible for me for over 20 years now. :D :rolleyes:

A Fish Named Wallyum 03-17-2022 08:58 AM

Quote:
Originally Posted by MarkB.
Druziv:

So a picture was requested. Here you go.

But I thought the group would like to see the other artifact: From an eBay rescue group I got last year: a short body, two-piece fin, balsa nose, stand-off lug, Cherokee-D now in the restoration pile. No chute, no shock cord but it will fly again. I enjoy deep-diving the old posts on this site and there is a surprising amount of data on Cherokee-Ds which I confess to never having given much thought. I was reading through them and then I remembered I had this out in the pile and sure enough . . . . So apparently, this is a very rare beastie to have survived over 50 years.

The new build is coming along. I'll seal the fins over the next few days and then it's ready for paint.

Very cool. I'm bummed that the number of worthwhile eBay lots has dropped off precipitously in the past couple of years. This is a great find. :cool:

tbzep 03-17-2022 09:01 AM

Quote:
Originally Posted by ghrocketman
Did the early Estes kit use a balsa BNC55AC cone ?

Yes. It started its life as an ARCAS balsa nose cone.

MarkB. 06-07-2022 06:46 PM

1 Attachment(s)
Druziv:

Nothing, and I mean NOTHING, helps the outgassing like 104 degrees in the shade with 20% relative humidity. Three on the paint sticks drying this afternoon. My Cherokee-D with the alternate black nose, the school project Aerobee finally getting a "real" paint job after 50+ launches and five or six years of launching and an eBay rescue Bandit that I'll post more about in the Rescue thread after I get the decals on.

It is definitely sunny outside.

MarkB. 06-30-2022 07:23 AM

So,

OCD can be a bad thing. I wanted to put the Center of Pressure decal and the Center of Gravity decal in the correct locations. I found both a D12-7 and a C11-5 for use in the CG measurement

Using the Bruce Lee worksheets Dave posted in another thread, I calculated the CP of my Semroc Cherokee-D as 17.18" from the tip of the nose. With a D12-7, the CG is only .875" ahead of that and with the C11-5, 1.625" ahead.

The Semroc kit is short body (16.35") like the original and I added a hardwood dowel to the nose cone to give the screw eye something to bite into. Still need a bit more nose weight.

If anybody wants to check my math, great. I'd note that using an 18" body tube moves the CP slightly forward (1.46") but this is offset by the CG having a longer moment arm.



Addendum: For fun, I measured the CG on the old Estes Cherokee I mentioned above with the same D12-7 and I don't know if the paint is heavier or the balsa cone denser, but its CG is 1.375" ahead of the CP. So it's OK.

MarkB. 07-04-2022 08:40 AM

3 Attachment(s)
Well,

Here's the finished product. Total time decalling ended up being just over an hour mostly because of trying to do a good job cutting close to the images and lining everything up. I did it in two sessions about 45 minutes for the fins and the other bottom end decals and about 20 minutes for the wraps and the CG/CP markings.

The Semroc decals were, as usual, a little translucent, but they went on well. I used a little Walther's Solvaset decal solution. A coat of Tree House Acrylic Clear and this one's ready to go.

I was going for the original 1970 catalog look. Pic. 1 is the right side. The CG/CP decals are in their correct locations for a D12-7. It took a couple of weights under the screw eye to get that all sorted out.

Pic 2 is the other side. The decal layout seems to suggest a rocket in a cradle so the other two sides of the rocket are pretty plain. Also, I noticed that, in addition to not following that general visual layout, the "NASA" on the sheet was in two different font sizes, an error which apparently cares over from the original Estes sheet. So I cut them off and used the larger of the two to make the bottom end decal you see here. The larger NASA plus the decal sheet part number and the small numerals provided on the decal sheet make up a new marking for the bottom of this side. I used my NAR number. Lining up the individual number decals was, shall we say, challenging. The CP/CG markings on this side are farther apart as those are the measurements for a C11-5.

Pic 3 is a close up. The Semroc kit number is KV-84 whereas the Estes kit number K-47. The number on the Semroc decal sheet reflects this difference on the United States decal as well.

A fun project that came out well. Now I'm debating refinishing the eBay rescue Cherokee, but I definitely need an Estes decal sheet.


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