Upscale Astron Sprint

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Well-Known Member
Jan 17, 2009
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While I was waiting for some more of the MMX parts to come I I thought I'd try another project.

Always liked the Astron Sprint so i though I'd try an upscale with a 24mm motor mount.

Mount will take up to an E9 or an F21!

High performance!!!:cool:
I had all of these wedge shaped slabs of balsa that I just couldn't throw away so I thought I'd try some "carving" and fancy shaping of the fins.

This is a rough cut...javen't started sanding yet. They are about 1/4" thick at the cord and will taper to about 1/32" at the tips.
I like the looks of the Sprint as well. I'm just curious, but how many rockets do you have that are in some stage of completion?

A 24mm Sprint.....on a F21!

That thing will will you see you don't...

I like it :D
how many rockets do you have that are in some stage of completion?

At LEAST 12 maybe more...People keep giving me custom nose cone orders!


A 24mm Sprint.....on a F21!

OK...maybe not such a good idea.
I still have to attach a launch lug yet and some paint maybe this weekend.

She looks fast!
Lookin' good.

A simple, yet elegant design. Are you going to go with the standard white/yellow paint scheme?

(You might want to beef up those fillets for the F21 though):D

Gold & white sounds cool - even copper and white.

I've laid out a few upscales on paper and the fins always look "bigger" (relative to the rest of the rocket) than the original. Even though I double check the scaling, it still *seems* that way. Your sprint appears to fall in this category. Another couple that come to mind are the Rogue (mini-brute) and the Sark.
still one of my favorites!

i want to do a Big Sprint Daddy
won't allow the link to work...

it's a 3-letter word means "donkey" featured quite prevalently in the Bible...

funny that words found commonly in the Bible aren't allowed to be 'spoken' here.
not 'funny' haha, but 'funny' strange...

sure makes linking files (in this case, anyway), and thereby the free flow of information, in fact simple clarity, impossible...

oh well, i guess it's the price we pay for playing in the same room with 12-year-olds
You mean this one.

The Fat A$$tron Sprint:D

I just saw that the other day...cute
Sorry, no additional pics yet. It's been too humid to paint.

A few people have PM'd me on making this a kit...well...yes/no!

I put a few partial "kits" together without shockcord, instructions or parachutes.

Nose cone, tail cone, fins, motor mount and body tube. (the hard parts!)

I made these up out of my "oops" parts from my lathe mistakes,(some are BT-55 tubes and some are BT-56 tubes).

I have these made up for "barter" only...not for sale but I am willing to "trade" for one.

Can someone do a rocsim on a BT-56 sized Sprint with a 24mm motor mount for me?

I just wondered if I'll ever see it again if I fly it on an E9-8 motor.
Rocsim has been on my mind for this bird. I am heading out right now, but will bang together a rocsim file tonight.

OK, Here is a quick and dirty rocsim. I used the rocsim 'elliptical' fin pattern setting, but it is not quite true to the Sprint fin design. If anyone is better at Rocsin, please go ahead and give it a whirl. The calculated CG is off as well, and I will correct it once I finish the model.

Short and sweet:

C11-5 gives 450 feet
D12-5 850 feet
E9-6 1550 feet, may need some nose weight.

This is with a 40" x 4" streamer for recovery (I would want to get this model back!!)

Originally posted by Elapid

oh well, i guess it's the price we pay for playing in the same room with 12-year-olds

i really dont like that comment... not trying to start anything but i think taht is kind of rude
Originally posted by karatekicker271
i really dont like that comment... not trying to start anything but i think taht is kind of rude

please don't trash sandman's thread...

i find censorship to be rude.
if the reason is not the 12-year-olds, then i apologize.
Dad, He's touching my side of he seat again!!

Are we there yet???

I do like that rocket, your nosecone making skills are amazing... heck i have a hard time painting pre-made nose cones! :D That boattail is also nice!

One more quick note- cencorship is not jus because of 12 year olds. I am exposed as are many other 12 year olds to cussing on TV, movies, school, stores, ect.

Im not going to screw up sandmans thread so thats the end of it!


Very nice Astron Sprint. IMO, all BT-55 and bigger rockets should be D12 capable. I've built 3 or 4 of them like that [2 Sidewinders and an Astrobee]. Trouble is, I keep loosing them when I load an E30 in.

Some years ago, a couple of guys in CT built a 5.5" Astron Sprint that flew on an L750.
A great painting day today!

75 degrees and 30% humidity!

I settled on the gold for the nose cone.

Filled all the spirals, filled the balsa grain, filled the tailcone seam...this one came out purdy.

Gonna let it set for a few days before I put the decals on It.

phred, John...let's see yours!
I am a-workin' on it!! I have had a TON of rain lately... I am looking at primer today...

I finished putting the decals on from Astronboy.

I cannot say enough good things about his decals!

Thin but heavy enough to take my heavy handed installation methods and a PERFECT fit!

My wife was even amased at how easy they go on...and she doen't even care!

This, in my opinion, is my best work yet!

The fillets and the tapered fins were a challange as well as fairing in the launch lug. A very cool effect This was no simple 3FNC model! I will have to put something (probably Future) over the metallic gold to protect it.

I have made some extra parts for these but the "kits" aren't available for sale...just for barter.

If you have something I want well, maybe we can do business;)

Yes...I am afraid to fly it but I have more so a replacement is in the wings.

Yes...I have a new favorite model! for a new design I've been thinking about...


A three engine cluster with a three motor tailcone!
Hey, that looks really cool! I just might have to make one someday after my other 40 billion project ideas! :p