Astron Sprint XL

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Rex R

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here is mine, mostly finished still have to do the shock cord & chute. used Dupli-color high build primer (gray), Rusto white lacquer and Tamiya TS-34 camel yellow. I did attempt to round the fin edges :), deviated from the instructions by putting the launch lugs in the upscale locations (and gave them the same profile as the original, 3/8" long with the ends cut to a 75 degree angle).
rex

sprintxl 002.jpg
 
Beautiful job :clap: I have been waiting for this kit to be released, going to get one soon.
I am thinking about some mods, balsa tail cone with a Rocketarium Retainer. I know the retainer will effect the look of the tail end. Any thoughts?
 
for a balsa tail cone I think that I would cut it a tad shorter (leaving the aft end a bit larger in dia.) and do what I could to recess the retainer. got mine at the 'local' hobby shop end of march just before the monthly club(woosh) meeting. don't know if one needs to get that fancy for motor retention...some safety wire and or tape will work for a 24mm motor. thinking a D15 - 7 for a 1st flight :).
rex
 
Thank Rex, yes I was thinking of making it shorter to recess the retainer as much as possible. Good luck with her maiden flight and get pics.
 
BEAUTIFUL JOB Rex! Well done! I just glued the fins on mine today....my paint scheme will be the same as yours, as i want to match my little (18mm) Sprint scheme...! ill post a pic when its done..The Sprint has to be one of my all time favorite rockets....simple, clean lines, and GREAT performance!
 
thank you, I hope you do a better job of lining up the motor hook w/ the lugs than I did :). I waited to epoxy the tailcone in place until after the mount was in, well by the time I noticed the hook was in the wrong orientation the white glue had grabbed. there is a fair amount of sanding required to get the tail cone ready. I used an x-acto saw to separate the various bits. can't wait to see more sprints 'roll out'.
rex
 
I did attempt to round the fin edges :)

tumblr_ldow012jAt1qbwmdbo1_r1_500.jpg


FC
 
Nice slick finish.
Anything that someone who has only read about and never actually tried balsa tail cones needs to know?
 
you'll probably have to do some sanding/trimming in order to get the thing to fit, in particular the inside of the aft(narrow) end to get the motor tube to fit and a bit of work on the faring for the motor hook on mine was too narrow. finish wise and gluing the nose and tail cone are standard polystyrene plastic so painting shouldn't be a problem (wash them 1st), a bit of epoxy on the tail does the trick.
chad, weather permitting :). right now it looks to be damp Sunday.
rex
 
Great looking build Rex,always liked the looks of the Astron Sprint.
 
Only 20% chance for rain Sunday (where I look), so I'm staying optimistic. We've had so much rain the last three days, there can't be much left! If there is, I need to get my boat ready.
 
last forecast I heard sounded like ark weather. 'gonna make rain for forty days and forty nights and wait for the sewers to back up' (Bill Cosby).
rex
 
Nice work Rex. We all need to do the "No Rain" dance for JC, I'd like to see this one fly.

I like the placement of the lugs, did you upscale the diameter of them too? ;)
 
only sofar as to use a 3/16" rod...that said, that is one of the few estes parts I did not use. I used a Semroc 3/16" lug instead, the lug supplied with my kit has; thinner wall thickness, smaller inside and outside diameter(and a tighter fit on my 3/16" rod). it may fit a 5mm rod but with very little clearance. methinks that Estes ought to take a look at the spec.s of their launch lugs, they are getting non builder friendly wrt lug alignment.
rex
 
Great looking Sprint, Rex! Glad to see someone start a thread on this. I just started mine today, separating the tailcone and nosecone and opening up the rear (my fairing and tailcone openings were too narrow, as well. The razor saw is a good tip--I used one too, much faster than the #11 blade on a knife handle. Here is a pic of my original Sprint (saving this one) and my XL before opening up the package.

-Allan

sprints-sm.jpg
 
Funny this popped up, I just finished building mine today too.:wink:

The fin material in my kit was also very tough to cut and it was also split in two but it was nothing a little medium CA and some sanding couldn't fix. From what I could tell, it didn't split during transport but it looked like the factory just used two separate pieces of wood as the grain is going in different directions.

All it needs now is some paint, decals and clear coat and it'll be all set to fly.
 
kind words, hope it flies well, When it flies :). I would suggest a bit of prudence in your choice of motor, this bird looks to be easy to lose, the flight sims and personal reports (from Estes) are that it flies quite high on the suggested engines.
rex
 
Rex and Donaldsrockets -- Looking forward to reading some flight reports! If it flies like the original I built in '85, it will be easy to lose. I lost that one on the second flight on a C6-3.

Small hand files are great for widening the tailcone openings:

tailcone_file_web.jpg
 
Starting on one also. Just can't leave well enough alone so I am building mine to take a wide assortment of 24 mm motors BP or AP. Using BMS rings and the kit motor tube. Had to lightly sand the inside of the rings to get a snug fit to the motor tube. Made the motor tube a snug fit in the tail cone also. The entire assembly will be slid into place when ready.

Still deciding on a retainer. Thinking about modifying the kit retainer just a bit, don't want a metal hook inside the motor tube, but will have an engine block set in far enough to use my AT 24/60 case.

My fins have a slight warp in them so a bit of work to get them straight will be in order. Might just upgrade to basswood. Maybe even TTW.

These are slick kits and look to be excellent performers. And a high viz chute will be needed to aid in recovery.

Even thinking about adding one of the nose cone shock cord mounts right out of the latest Sport Rocketry issue. Only down sized for this model.

Kevlar cords will be added for these high performance flights.

The stock colors look great and a nice clear coat over everything will have it shining.

Will be fun to launch it at AIRFest.

Drawing up an upscale also, but no plans just yet to start building.

See ya,
Rod

Astron Sprint XL kit parts.jpg
 
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kind words, hope it flies well, When it flies :). I would suggest a bit of prudence in your choice of motor, this bird looks to be easy to lose, the flight sims and personal reports (from Estes) are that it flies quite high on the suggested engines.
rex
Rex beautiful build of a classic. Well done. :handshake:
 
well the fine folks at Estes do deserve some credit for coming up with the kit(please note they are not calling it an upscale...the length is a bit off). as a tribute to the fellow who designed the original(and a bunch of other rockets etc.). I would suggest that folks who plan on flying 'big' motors take a picture before launching :).
rex
 
Thanks Rex for pointing out this rocket. I can see it is going to be one of my favorites.

With the very slight mods to the motor mount and retainer hook, I can use D's, Single use AT's, and reloads.

Slip in the orange spacer and Estes D's can be used, keep the spacer in and single use AT E's, spacer will protect the thrust ring from ejection charges. Pull out the spacer and the AT reload case will slip right in and the ejection cap will extend out past end of motor tube.

In these pics you can see the change to the retainer hook, simply bent the tab to hook over the centering ring.

This is going to be a fun rocket to launch.

Thanks again Rex yours looks great. Hope mine turns out as well.

Now I gotta go work out the "Merrick mount" for the nose cone. Details for the mount can be seen in the March/April issue of Sport Rocketry magazine, page 34.

See ya,
Rod

Motor mount parts.jpg

Motor retainer hook mod.jpg

AT single use installed.jpg
 
one should use the spacer w/ the 24/40 rms case too. I didn't see a listing for the k-49 version astron sprint in the galleries so I started one hope I haven't gotten things all confused :). used 18 lb. newsprint to paper the fins.
rex
 
I have flown my protoytpe on an F35-11.. Ye haw.. 2,615' Not for the faint of heart.

The kit will do over 1,000' on a D12-8..

Grim
 
Mine is THAT CLOSE to being finished:D Will post a pic....hope to launch it Saturday, if the weather Gods approve! I hope everyone else who is building a Sprint XL will post pics! Rex, look what you started!:smile:
 
Moi? all I did was show off the rocket :) can I help it that it has good lines :).
rex
 
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