NCR SA-14 Archer

[Ntxrcrc]

Wanting to clone a NCR SA-14 Archer XL, actually a downsized BT80 version.
Does anyone have plans for this rocket? If not, anyone have a built one they can take some outside dimensions of? Fin dimensions, OA lgth, BT lgth, etc..?

Thanks,
JW

[jetlag]

Wanting to clone a NCR SA-14 Archer XL, actually a downsized BT80 version.
Does anyone have plans for this rocket? If not, anyone have a built one they can take some outside dimensions of? Fin dimensions, OA lgth, BT lgth, etc..?

Thanks,
JW

I do. Love mine! Hardly a launch where I do not take it. What do you need?
Allen

[Ntxrcrc]

Jetlag, thanks for the reply.
Looking for the overall dimensions of the fins and strake fins, body tube length, nose cone length, position of strake fins from the end of the body tube.

I take it from the old catalogs it is 4" diameter.

On the fins, measurements of the roots, tips, span, and offsets of the angles should be sufficent to reproduce the design.

Once I get some overall dimensions, I can model it up in CAD to design a clone, either 1:1 or a downscale version.

Thanks,
JW

[jetlag]

Jetlag, thanks for the reply.
Looking for the overall dimensions of the fins and strake fins, body tube length, nose cone length, position of strake fins from the end of the body tube.

I take it from the old catalogs it is 4" diameter.

On the fins, measurements of the roots, tips, span, and offsets of the angles should be sufficent to reproduce the design.

Once I get some overall dimensions, I can model it up in CAD to design a clone, either 1:1 or a downscale version.

Thanks,
JW

I'll get them for you in the am, JW! Need pics of it as well? I still have all the old instructions, also.
Allen

[barone]

I'll get them for you in the am, JW! Need pics of it as well? I still have all the old instructions, also.
Allen
Allen, Allen, Allen. If you can scan those, I'd like to get a copy of all that stuff as well, if you don't mind. :D

[Ntxrcrc]

Allen, that would be great.
Don't need pics.
A scan of the old instructions would be excellent.

Thanks!
JW

[Ltvscout]

If you contact Matt Steele here via PM (ManOfSteele), I'm fairly certain he'd help you out in getting you the info you need for re-creating an NCR SA-14 Archer. I know that he's helped others out in the past with these types of requests. At this time he does not want NCR plans posted publicly.

[jetlag]

The NCR Archer has 2 BT's : Top one is 16.5 inches long, bottom one is 25 and 5/8 inches long. The nose cone is a 4:1 Ogive and is 16 inches long, not including its 4 inch long shoulder. The strakes are 16.75 inches long at the root, 15 inches long at outer length, 2 inches wide, and 1/4 inch thick balsa. They are mounted even with the main fins, 8 inches from the rear of the BT. I enclosed a sketch of the lower fin dimensions below, along with some pictures. The lower fins are mounted flush with the rear of the BT. The BT diameter is about 4 inches (inner diam. is less than that, of course).
The graphics should be fairly easy to duplicate from pictures.
PM me if you need a copy of the instructions; Scott (and Matt Steele) really prefer I not post the instructions here. However, I can answer your questions about my NCR Archer. ;)
Allen

My sketch of the lower fin is too large a file when my scanner scans it. I've tried posting a picture of the sketch.
Also, I used an Aerotech 29mm motor mount, as the NCR mounts were somewhere around 28mm, to fit their own F62-4 and G70-5 Dark Star engines. I never saw the G70-5, but owned quite a few F62's. Still have one somewhere :rolleyes: . Launches are most successful using AT G80-4's (or the newer G77 or 79's). 36 inch nylon 'chute.

[Ntxrcrc]

Allen,
Thanks for the info!

Scott,
No problem, I can respect someone's propertary information.

JW

[Eagle3]

The original pre-Estes Archer was a cluster with a center 29mm and two 24mm. The tube was also a single piece of 34" LOC 3.9 tubing. You really needed to add nose weight to make it stable especially on cluster flights. I used to fly mine with an AT G-42 and airstart two D11-9's. :D I may fly it in two weeks with an Ellis G37 and two D12's.

[Bob Kaplow]

I have the pre-estes Archer. It's a single 29mm MMT, plus an extension, and an ACE nose cone. Obviously, there were different versions of the kit over time.

I didn't like the strakes, so I never put them on mine.

[Eagle3]

Good seeing you here Bob.

I think the one you have is the 2nd version of the Pre-Estes design. The extra tubing and single 29mm must have been measures to increase stability. Mine is a 1st version and had a LOC 3.9 cone.

Buzz

[ghrocketman]

I don't think the NCR G70-x ever actually was produced or existed in anything other than prototype form.
Based on information from several sources, that one appears to be pure "Vaporware", just like the 18mm Enerjet D21, and the 18mm Quest composite D that was "coming soon" for several years before they wisely decided almost nobody would pay what they were planning on pricing a chinese made 20n-sec motor for.

[Bob Kaplow]

I've got a NCR G70 Darkstar in my collection. True they were never sold, but some were made. IIRC they even got NAR certification for them.

[ghrocketman]

I stand corrected !
I knew they were never sold, and several told me protoypes were actually made, but i had no idea they actually certed them.
Any ideas why they would bother to cert a motor they never produced in large enough quantities to sell ???
One would think if they got that far, they should have produced them.

[Bob Kaplow]

I guess you'd have to ask Matt Steele what happened back then, but that was probably when the NCR connection was imploding. I remember they claimed they made an additional run of 2000 F62s (a days run of BP motors is in the tens of thousands), and that was the last of the NCR stuff.

Here's a link to the G70 cert

http://www.nar.org/SandT/releases/R049.html

[Doug Sams]

(a days run of BP motors [at Estes] is in the tens of thousands)I'm wondering about that right now. I can't find any Estes stuff at Wal-Mart these days, and that's in a good rocketry market (DFW). Plus, Target seems to be winding down. Neither Michael's nor Hobby Lobby presents the volume potential of Wal-Mart and Target, so I'm wondering how business is at Estes these days. I don't wish them any ill will - quite the contrary - their health is important - but I do wonder about how they're doing.

Doug

.

[ghrocketman]

That G70 was a real "baby" G at only 90 n-sec total impulse.
Essentially a full "F" plus an Estes C6.

Once I saw that NAR S&T document, it makes sense to me why the G70 was not produced.
Hardly worthwhile from a production complexity standpoint having a 2-engine lineup with one being 80n-sec and the other 90n-sec.
Of course I would find it better if they would have chose to produce the G70 instead of the F62.

If the G70 would have been at least 120n-sec (a 50% G) it would have made sense to produce it as it would have actually offered a different flight profile.

As it stood, the G70 made less sense than those low-thrust "dud" Estes E9's that are only 28n-sec (if LUCKY)

[Initiator001]

I have a G70 DarkStar in my collection, also. :D

From talking to Matt Steele many years ago, the F62 used two propellant grains in the case while the G70 used three propellant grains in the same case (The delay bulkhead/ejection charge cavity just stuck out of the front of the casing further).

There was even 'discussion' of an 'E' motor using one propellant grain and the same casing.

Bob

[Initiator001]

Here's a picture of a DarkStar G70-10 alongside a F62-6.

Bob