Thoughts on the new madcow nike-apache as first hpr 2 stager?

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Keep on the lookout for the return of the Easy Research Rocketry 29mm EX motors for the sustainer of this kit. New house is moved into, new lathe acquired, material purchased!

That sounds good. I have three unused long 29mm Loki EX cases from the Jeff Taylor era. Might be a possibility but retention could be a challenge. Kurt
 
Second lot sold out! It is good to see scale kits getting some love. I hope that will bring out more new scale offerings. Nike Asp, anyone?!!! This looks like a complicated build. I suspect many of us are going to be expanding our skills for this one...

Thank you again Mike at Madcow. You went beyond my expectations...and this is not the first time. Great customer service and good products!

Cheers,
Michael
 
I really wish we could get a picture of the interstage transition. It looks like it comes with a length of 38mm coupler that passes through and engages the base of the Apache.

I am certainly going for a 76mm mount in the booster but would like to see how feasible an MD sustainer would be. I can easily hang an EX motor out the back and run head end ignition. Then again, 29mm is really convenient for the sustainer and my 76-2G to 29-6G motors will probably get this to our 18,000’ waiver.

Time to start developing a fast burn booster motor and a slow burn sustainer motor!


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I managed to get one from the first run at 0700 yesterday, took a few tries to process the purchase though. Too good to pass up.
 
I really wish we could get a picture of the interstage transition. It looks like it comes with a length of 38mm coupler that passes through and engages the base of the Apache.

I am certainly going for a 76mm mount in the booster but would like to see how feasible an MD sustainer would be. I can easily hang an EX motor out the back and run head end ignition. Then again, 29mm is really convenient for the sustainer and my 76-2G to 29-6G motors will probably get this to our 18,000’ waiver.

Time to start developing a fast burn booster motor and a slow burn sustainer motor!


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Ahhhhh Don, Looks like some really smart people have it on tap and are likely to share some construction tips. I for one am not unabashed to copy another's
good ideas to further my flight enjoyment. Will be fun to hold on for the ride. Kurt
 
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I snagged one as well, and was considering the same thing Dan is. 75mm booster, long 29mm sustainer or possibly MD 38mm, but with the pre-cut slots etc, it might be more annoying than it's worth.
 
Got one from the second batch. Since getting my L3 cert I've been pondering another challenging project. Multi staging must be it! (Like I really needed more kits on my build pile):confused:
 
I managed to buy a second one out of the second lot... thinking I'll set them up slightly differently. Or maybe just drag race myself. :)
 
$35,000 in two-stage sales in one night with one kit? We better see some clever builds.
 
First ones to get these kits......I need detailed pics of Interstage/Transition parts...so I can see how it fits together and what extra parts needed to turn it into an electronics bay.
Also distance from rear edge of sustainer tube to rear edge of fin slot.

Thanks in advance.
 
First ones to get these kits......I need detailed pics of Interstage/Transition parts...so I can see how it fits together and what extra parts needed to turn it into an electronics bay.
Also distance from rear edge of sustainer tube to rear edge of fin slot.

Thanks in advance.

Agreed. I really hope it doesn’t just sit on the coupler. Looks like you epoxy the ring at the end of the 4” coupler which constrains the aft end of the 38mm coupler. You then sit the transition on the 4” coupler and the fore end of the 38mm coupler gets constrained by the transition.

If that’s the case, I will be tapering the fore end of the 4” shoulder to the angle of the transition for a more secure taper fit. It also looks like one could easily swap the 38mm coupler for a 38mm airframe and use the 38mm case from the sustainer as the interstage engagement if you hang it out the back.

I’ve already secured my 76mm tube for the booster. Planning to make the interstage able to accept both the 29mm Apache and any 38mm MD rocket. The sustainer payload tube is likely to be 100% dedicated to electronics and will employ a cable cutter for main deployment.
 
Oh jeez. Now I'm going to have to keep an eye out for build threads from Jim and Dan...
 
Agreed. I really hope it doesn’t just sit on the coupler. Looks like you epoxy the ring at the end of the 4” coupler which constrains the aft end of the 38mm coupler. You then sit the transition on the 4” coupler and the fore end of the 38mm coupler gets constrained by the transition.

I am building per the kit with only the minimal changes to make it a bona fide two stager. Constraint of the 38mm on the interstage coupler and a tether deploy on the booster seems all that is needed--pretty simple.

From the Ether...
 
Based on the exploded picture on Madcow's site, this looked to me exactly like the Double Shot, the ISC is the last thing I have to work on to finish mine, I'm across the country from it right now or I'd post a picture or two. But to try to describe that one, there's a fairly long coupler that extends into the bottom of the sustainer and is long enough to extend through the entire "transition" part of the transition (i.e. down past the part where it's a steady 4"). The transition openings are sized for this coupler OD at the top, and for the 4" coupler OD at the bottom. Then there's the 4" coupler, a centering ring with a center hole for the sustainer coupler and OD'ed the same as the 4" coupler OD (so it sits on top of the 4" coupler inside the transition, and keeps the alignment on the sustainer coupler), a solid bulkplate that was sized for the ID of the 4" coupler, as well as a bulkhead that goes inside the sustainer coupler for the upper seal on the ISC.

To help with the available area for electronics, I epoxied the bulkplate to the bottom of the 4" coupler (inset just enough for a good fillet on both sides), cut the 54mm coupler (DS is 4"-to-54mm instead of 4"-to-38mm in the Nike-Apache kit) just short enough to reach past the centering ring, and epoxied the 54mm coupler to both the top of the transition and the centering ring, which is also epoxied inside the transition. So for me the separable part is where the 4" coupler goes into the transition, I figure I'll use rivets there. So I'll have access to most of the ~4x6(?)" for the electronics, though my GPS antenna will likely stick up into the 54mm coupler for some extra length. My thought was to secure the electronics to the lower bulkplate, but there will be a threaded rod that runs all the way up to (and capturing) the upper bulkplate, so that I can load the separation charge and then insert the works into the transition and rivet the pieces together for flight.
 
I plan to build mine with MD capabilities in both stages. Motor adaptors (and tail cone potential) for 75mm MMT, 54mm MMT in the booster and of course the 29mm adaptor for the sustainer for low wallet impact days.
 
But to try to describe that one, there's a fairly long coupler that extends into the bottom of the sustainer and is long enough to extend through the entire "transition" part of the transition (i.e. down past the part where it's a steady 4"). The transition openings are sized for this coupler OD at the top, and for the 4" coupler OD at the bottom. Then there's the 4" coupler, a centering ring with a center hole for the sustainer coupler and OD'ed the same as the 4" coupler OD (so it sits on top of the 4" coupler inside the transition, and keeps the alignment on the sustainer coupler), a solid bulkplate that was sized for the ID of the 4" coupler, as well as a bulkhead that goes inside the sustainer coupler for the upper seal on the ISC.

That does not sound very robust and relies too heavily on the strength of adhesive.
 
I snagged one as well, and was considering the same thing Dan is. 75mm booster, long 29mm sustainer or possibly MD 38mm, but with the pre-cut slots etc, it might be more annoying than it's worth.

Titan II said:
Having slots for the fins is not that uncommon for a MD build.

Definitely not. I was hesitant when building a 75mm beast, so I tried out my technique on a 54mm version first. Wrap a single layer of parchment paper around a motor casing. Carefully slide casing and paper into rocket. Cut tabs minus airframe wall off fins, and glue in place with JB Weld.

They both came out crazy strong. I now have the smallest L3 rocket in town, and a tiny K550 cruiser for bonus fun.
 
I plan to build mine with MD capabilities in both stages. Motor adaptors (and tail cone potential) for 75mm MMT, 54mm MMT in the booster and of course the 29mm adaptor for the sustainer for low wallet impact days.

As long as you have the venue with the waiver and good tracker capabilities, go for it. Kurt
 
Definitely not. I was hesitant when building a 75mm beast, so I tried out my technique on a 54mm version first. Wrap a single layer of parchment paper around a motor casing. Carefully slide casing and paper into rocket. Cut tabs minus airframe wall off fins, and glue in place with JB Weld.

They both came out crazy strong. I now have the smallest L3 rocket in town, and a tiny K550 cruiser for bonus fun.

Sounds remarkably similar to my technique! Is it "Great minds think alike" or "Fools seldom differ" :)

Here is my 54mm MD build with slotted in fins: https://forum.ausrocketry.com/viewtopic.php?f=6&t=4758&p=58844
Mach 1.8, no tip-to-tip.

I would highly recommend the technique if you have the capabilities (or friends!).
 
That does not sound very robust and relies too heavily on the strength of adhesive.

Not sure what you mean. The force transfer is direct from the 4" airframe, through the transition to the sustainer airframe, the couplers just ensure things stay in place but don't take any vertical load, so there's nothing depending on adhesive there. But a good bit of the transition's inside volume is lost, the area above the centering ring gets sealed off and only the diameter of the sustainer coupler is left above that point, while below the centering ring is the full 4" coupler ID.

So on my Osprey 75 2-stage (3" to 3") I load my ISC electronics through the top, here it makes more sense to load from the bottom or else everything has to fit down a (rather long, at least, but) narrow coupler tube.
 
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Anyone else grab a 4" Nike Smoke cone to make the booster into a Smoke?
 
Not exactly, I have sent the link to loving wife in hopes that it arrives on Christmas Day.....

Gregg
 
Anyone else grab a 4" Nike Smoke cone to make the booster into a Smoke?

I just did! Bought some bulk plates too, need to figure out how I want to turn the one piece done into an after/tracker bay.
 
I just did! Bought some bulk plates too, need to figure out how I want to turn the one piece done into an after/tracker bay.

I sank a threaded rod into the tip of the cone with West 105, then trimmed down a couple lengths of PVC to space it out. The aft most PVC got a chunk of wood epoxied on and that became the sled. The bulkhead got a U bolt for recovery attachment, a hole for wires, a hole for venting back into the vented body, and the original center hole is where the threaded rod goes through to be secured with a nut between the U bolt prongs.

You can get a little clever with the PVC used as spacer, jam nuts, and rod couplers to make it a little more precise and easier to maintain.
 
I will be installing a length of 54mm or 3” canvas I have laying around and won’t use otherwise. I’ll be using a Raven with Simple Circuit for deployment in the Nike Smoke configuration with tracking performed by an Eggfinder.


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