How to make a 3 inch Blackstar go from cool, to really cool: 2 stage upgrade Build!!!

I got my Wildman blackstar a few weeks ago, and got to thinking, how can I make mine different? I have an obsession with two stage rockets, so I figured, Why not make it two stage! I am going to build the kit, and then retrofit it to hold a sustainer. The only part that does'nt come with the kit, will be the drop in sustainer section.The booster that comes with the kit, will remain the bottom of the rocket, and the stock E-bay, payload section, and NC will be on top no matter what configuration the rocket fly's in. More to come...

Very cool idea!

This morning I got the build started, with the motor mount. As previously mentioned, I will start by building the kit stock. The supplied booster will be the booster in the 2 stage configuration. I was contemplaing going minimum diamiter in the booster, but a coupler wouldn't fit (I dont own any 75mm casings). I decided not to inject fillets, so I only epoxied on the top CR, with the intention of manually putting in internals. I am Using 9/16 TN for the recovery harness.
Here is the dry fit. Please excuse the mess!

The top CR was attached with a hefty carbon fillet. Try and break that, L935!

I Decided to go with a polished aluminum tailcone retainer. I thought it would compliment the aluminum NC tip.

At the last minute, I realized the potential problem that the nylon could face; melting from an ejection charge. My solution? I used spray adhesive to bond aluminum foil to the shock cord. Despite the protection, I will try to remove the ejection charge whenever possible.

Interesting idea. I like the thought of making it a two stager, and the tinfoil is a new idea to me entirely.

MasonH said:

the tinfoil is a new idea to me entirely.

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Me too, I needed something fireproof to cover the nylon with, and foil is the first thing that came to mind.

Today I got the motor mount in place. I don't have any pictures, but here is the process: First, I create tape "tabs" on the aft CR. The Cr needs to be in place to align the MMT, But needs to be removable to install internal fillets. I then put thickened epoxy on a stick, and put a thick bead where the forward CR will go. I then slipped on the aft ring, and inserted the MMT into the body tube. Then, I put the aeropac on, and recessed the motor mount the proper distance. Up next, Forward fins!

I have to ask, Is anybody actually following this? if so, please let me know, If not, I won't waste my time.

I am interested.

I'm here lurking away.
Next time use aluminum duct tape rather than foil.....it'll hold up better & is easier to apply since it has glue already on it.

By the way, Wildman has already cut fincans for making a 2 stager. Some others are doing it too.
He can move the slots up 3in. so the interstage coupler will fit nice. Don't know if ya can get it in black though.

Was wondering how you're gonna handle that?[ sustainer fins needing to be higher] Are ya making your own?

I am following along as well. Just reading at this point.

Matt

yup.. following


plus... NO build thread on here is a 'waste of time' of ANYONE.. I love searching through peoples build threads and have learnt so much in the last year just be reading how others build their rockets.

Carry on buggering on.

Salvage-1 said:

yup.. following


plus... NO build thread on here is a 'waste of time' of ANYONE.. I love searching through peoples build threads and have learnt so much in the last year just be reading how others build their rockets.

Carry on buggering on.

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You got it... I'll keep it going.

blackjack2564 said:

I'm here lurking away.
Next time use aluminum duct tape rather than foil.....it'll hold up better & is easier to apply since it has glue already on it.

By the way, Wildman has already cut fincans for making a 2 stager. Some others are doing it too.
He can move the slots up 3in. so the interstage coupler will fit nice. Don't know if ya can get it in black though.

Was wondering how you're gonna handle that?[ sustainer fins needing to be higher] Are ya making your own?

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I am planning on scratch building the sustainer. I probally won't even use darkstar fins, instead using a long triangle.

Just to add encouragement... following as well. Picked up the 3" DS and am figuring what do do with it - great kit as is... but making it 'special' is indeed intriguing! Keep going!

I got the forwrd fins tacked on. I plan on filletting these before I tack on the booster, as it will allow me to sand around the fin, and not be blocked by the aft fin.

I got the first set of fillets on. I used the standard "tape and pull" method, however I mask off the entire rocket. For epoxy, I am using US composites medium cure, thin epoxy, phenolic microballons, and black epoxy pigment.

Eat said:

I have to ask, Is anybody actually following this? if so, please let me know.

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I'm here, too. Posting is never a waste of time, a few extra sets of eyes on a project always helps. The true beauty of the Forum... it combines the collective experience pool, and in that we live vicariously through each other. Press on.

P.S. Nice looking fillets.

Yup, I am following this!

blackjack2564 said:

I'm here lurking away.
Next time use aluminum duct tape rather than foil.....it'll hold up better & is easier to apply since it has glue already on it.

Click to expand...

Eat said:

At the last minute, I realized the potential problem that the nylon could face; melting from an ejection charge. My solution? I used spray adhesive to bond aluminum foil to the shock cord. Despite the protection, I will try to remove the ejection charge whenever possible.

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Adding this may just make the heat transfer quicker. I have had mixed results doing something similar.

UncleVanya said:

Adding this may just make the heat transfer quicker. I have had mixed results doing something similar.

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It shouldnt be an issue anyway, I will remove the ejection charge from the motor, and use redundant altimiters. Plus, there were at least 10 layers of foil.

Eat said:

It shouldnt be an issue anyway, I will remove the ejection charge from the motor, and use redundant altimiters. Plus, there were at least 10 layers of foil.

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Metal conducts heat - so I don't know if the number of layers helps or has any significant impact at all. I do know that removing the ejection charge is a good idea in this case but beware that there may still be some flame pushed through the hole at the end of the delay burn. I would suggest that if you can't use a closed fwd closure you can add some "dog barf" or add some fireproof cloth between the shock cord and the motor.

Nylon is much more rugged than people think however so you may get away without doing anything for quite a while.

Subscribes and. salivating like a Pavlovian dog. Great idea!

I have all of the upper fin fillets done, and lightly sanded, so I tacked on the lower fins with super glue.

I then taped off the first set of lowers for fillets.

I then pulled the fillets with a piece of 1/2 inch PVC pipe. The picture makes the fillets look horrible, but they actually arent that bad.

Well, Time gets in the way of posting, and epoxy in the way of the camera. The Kit part of the rocket is complete, but I have yet to start on the sustainer. The rocket flew successfully on a CTI J250 yesterday. The kit was built stock, except for the nose cone, which holds a tracker. Here are some pictures.

It was a picture perfect flight! A slower takeoff than I was expecting, but that just made it more dramatic. Pretty close to recover too, heck of a lot closer than that DS jr.! How many miles do you think your trek was for that?

chadrog said:

It was a picture perfect flight! A slower takeoff than I was expecting, but that just made it more dramatic. Pretty close to recover too, heck of a lot closer than that DS jr.! How many miles do you think your trek was for that?

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As the hawk flies, probally a mile, but frosen marshes, thick weeds which were significantly taller than us, a foot of snow, and trying to follow the tracker signal (which took us a while to get in the first place, since the rocket got buried in snow) made it seem like much more than that. The worst part was that in was no more the 40 yards from WI-43, and would have been easily visible from the road. The Raven data shows that the rocket got a main at apogee (tangled booster shock cord caused a 90 G peak... more than enough to shear any pins known to man) and caught a thermal for over 30 seconds, falling at about -5 fps, which is how it landed (it was airborne for almost 2 minutes, and only had an apogee of about 3100 ft).