Centuri Astro 1 dimensions ?

[Green Dragon]

Was looking at my builtup vintage Astro 1, that was in my attic l hoard I bought last month .

Seems the tube is 10.5" , and the fins are larger that the plans posted on Jim z.

I have a builtup ( Semroc parts ) fromt he Jim Z dimensions, looks good, but nto same size as this one I have .

Possible running change here ?

Just wondering , and wanted to make mention for historical sake :)

pic attached of the two, unpainted clone,a nd vintage builtup

~ AL

[tbzep]

The painted one looks closer to my Semroc clone. I'm already at work, so I'm going from memory. Centuri might have changed body tube length out of convenience, but I bet they kept the same size fin die-crusher for the duration.

BTW, my Semroc clone came with a sharp tipped nosecone. When I ordered a single nosecone to build a mini-motor powered Astro-1 clone, it had the rounded tip like the ones in your pic.

[Carl@Semroc]

We based our Astro-1 on a kit and did not look too closely at the Jimz site, until now. The kit was 1971 so it had the plastic nose cone. The nose cone was the two-piece one that was 5.0" long that never appeared in a catalog with a part number, to my knowledge. It was used on many kits as a replacement or equivalent to the BC-107 which was 5.25" long with a sharp tip. The plastic was rounded. The fins on Jimz match the kit I have. The body tube was 9.5" which was not a standard part. The 10.5" long tube was.

In retrospect, I never could resolve the 16.0" overall length that was always used in the catalogs. The fins overhang 2.6" and the tube is 9.5" which leaves 3.9" for the nose cone. The BC-103 is 3.9" and probably was used on the prototype and possibly early kits to come up with that value..

The old Astro-1 in the photos has a nose cone about 5" long, not 3.9" long. The fins on the new one look small, like our Astro-Jr. The tif file from Jimz must have lost its size when you downloaded it. The fins should have a root edge of 3.22".

Thanks for the history.

[timorley]

Here's my vintage Astro 1.

My Body tube is 9 and 3/8 inches. I printed the fin template out from JimZ to check against mine and they match my fins and Carl's root measurement. The nose cone is 5 inches.

[Green Dragon]

OK, have the two in my hands now.

vintage bird:

BT is 9 3/8" ( or just barely over, aprox 9.4" , not 9.5" as I had posted ) .

Cone is aprox 4 5/8" with rounded tip

Fin root is aprox 3 1/8"


my clone ( Jim Z plans )

10.5" tube ( as the info on the web )

Semroc cone aprox 5" ( dont recall what aprt #, but assume as listed on Jim Z )

fin root is 2.75" ( possible this is in error, although I generally check the scaling on any patterns, would have to print it again and see )

Just curious as to the history and running changes, if any - will keep both birds and enjoy em :)

~ AL

[Doug Sams]

fin root is 2.75" ( possible this is in error, although I generally check the scaling on any patterns, would have to print it again and see )

Just curious as to the history and running changes, if any - will keep both birds and enjoy em :) Al,

I'm wondering if you accidentally had something set wrong when you printed them. I know in the past, on my old computer, I had to take extra care to make sure "print actual size" was selected.

Doug

.

[timorley]

I bought an older Centuri Astro-1 kit that has the balsa nose cone and I remembered this thread and thought I'd provide some updated information on this earlier version. I will be scanning everything and sending it to YORP for posting, compared to the one on JimZ there are differences beyond just the nose cone and instructions that others cloning the Astro-1 might be interested in.

Let's start with the nose cone. It's exactly 4.7 inches long with a rounded point. So that's really close to Al's measurement for his vintage bird, which appears to have the balsa nose cone from the picture he posted.

The body tube is exactly the same length as my plastic nose version, just short of 9.4 inches, I still call it 9 and 3/8 inches long.

The fins are a pre-printed fin sheet, not die-cut. I printed and cutout one fin from the JimZ die-cut fin scans for comparison. It matches with one exception. The older pre-printed fins do not have the rounded fin tip, instead they end in a flat tip. It however doesn't impact the fins overall length, they still overhang the body tube by the same 2.6 inches Carl quotes.

Next is the motor mount. While it's comprised of the same parts as the plastic nose version, it's assembled differently with the lower ring being cut to allow for the engine hook to bend and mounted flush with the bottom of the engine tube and the upper ring is used to hold the engine hook down. This accounts for another difference where the engine mount is inserted with the engine tube flush with the end of the body tube, while the newer plastic nose version has the engine tube protruding a quarter of an inch out of the body tube.

The shock cord is mounted using the older Centuri method of what looks like a short piece of ST-10 coupling rather than the later foil sticker with the 3 holes.

The decal is different than the one on JimZ as well, although still red. Unfortunately it has what I'm certain is a manufacturing defect. The decal was printed at an angle on the decal paper and the cutting process cut into the upper left of the decal a little. On the bottom you can also see some of the previous decal on the sheet, so somebody else got a kit with a badly cut decal as well. Good news is that it's a repeating roll pattern and the scan can be easily corrected using the right side of the decal as reference in Photoshop.

Built I calculate this version will be approximately 16.675 inches tall. When I get it scanned I'll post some low res scans here so you can see some of what I'm describing.

[timorley]

In case any one is interested, here are low-res 72dpi scans of the decal, nose, fins and instructions. And this decal has been corrected for what was mis-cut. I'll be sending scans to YORP per submission guidelines.

EDIT: I forgot the Guide Image.

[GregGleason]

Thank you, thank you for all the posts. Either I or my brother built one of these in our youth. Those simple lines gave me a renewed appreciation for that kit. Really a Centuri Classic.

Greg

[Ltvscout]

Thank you, thank you for all the posts. Either I or my brother built one of these in our youth. Those simple lines gave me a renewed appreciation for that kit. Really a Centuri Classic.

Greg
Centuri's version of the Estes Alpha. A simple to build balsa kit for the beginner.