Aerotech K550W reload with Case, Aero Pack 54/75 adapter photo...

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JP Morgan

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Thought I would share a photo.
I finally got all the parts I need to send up my LOC Precession Magnum 3, dual deploy I built this year. It may be next year before it goes up, I'm nervous and excited but first I have to pass the
Level 2 Exam.

Thank you Mike G. for the great deal on the case!
K550W and Monster Motor Case 54mm 1706.jpg

Thank you Red Arrow Hobbies for the K motor and others that were ordered
at the same time. By spending enough on motors they offered a Hazmat Fee
discount which equaled another 38mm H motor!
UPdated Simulation
LOC MAGNUM 3 weight reconfigured 10 pounds.png
I found parts that weighed too much! Dang I was off bad!

JP
 

Attachments

  • K550W and Monster Motor Case 54mm 1706.jpg
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    MAGNUM 3 stability CG CP K550W 3018 feet AGL.jpg
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JP,,
That Aeropac 75 to 54 adapter...
The ring at the aft side,,,
That has no clamp allen screw...
There is a right way and a wrong way..
In other words there is a forward face to that ring and an aft face to that ring...
If you get it facing the wrong way it won't allow the motor to go as deep into the rocket...
So it won't allow your retention to screw on as far as it should....

Please,, PLEASE,, don't ask me how I know this........lol...

Teddy
 
JP,,
That Aeropac 75 to 54 adapter...
The ring at the aft side,,,
That has no clamp allen screw...
There is a right way and a wrong way..
In other words there is a forward face to that ring and an aft face to that ring...
If you get it facing the wrong way it won't allow the motor to go as deep into the rocket...
So it won't allow your retention to screw on as far as it should....

Please,, PLEASE,, don't ask me how I know this........lol...

Teddy

That was the problem? I meant to ask you if that issue ever resolved itself :)

Nate
 
JP,,
That Aeropac 75 to 54 adapter...
The ring at the aft side,,,
That has no clamp allen screw...
There is a right way and a wrong way..
In other words there is a forward face to that ring and an aft face to that ring...
If you get it facing the wrong way it won't allow the motor to go as deep into the rocket...
So it won't allow your retention to screw on as far as it should....

Please,, PLEASE,, don't ask me how I know this........lol...

Teddy
Teddy,
I know what you're talking about. One way is for a snap ring closure, other way around is for a screw on closure.
It does allow the threaded closure to tighten down correctly with the case being fully inserted.
I've installed the case a few times checking the fit. It fit the case loosely so I placed 3 short pieces of black electrical tape
around the inside. I did the same on the forward piece too, it was a loose fit as well.

I'm glad you brought that to our attention. We learn from one another! Had it been incorrect I would have been made aware
of with your kind post!

Did yours CATO? I had to ask!!!

JP
 
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No,, No,, JP...
Nothing bad happened at all...
I just had my buddy Nate looking at me cross eyed because I built a rocket
with a 75mm mount that a 54mm motor was so big the tailcone retainer wouldn't screw on as much as it should.....

I really felt kinda dopey,,,
I sure hope Nate doesn't fine out....

Teddy
 
I see.
I bought the adapter months ago and was going to borrow the case so
I had looked over the constructions many times. Mike G. in our Club gave
me a sweet deal on the case so I bought it. The case arrived yesterday so
I was ready to mount the Aero Pack 5475 adapter.

JP
 
That's great JP..
I keep my eyes open for deals on hardware as well..
I was a bit leery the first time I saw the 2 rings as an adapter but they really worked perfectly...
Well,,, except for I had the aft ring on backwards....lol..

Teddy
 
UPDATE; So I marked the rear retainer with yellow paint, counted the threads as I screwed on
the end cap and came up with 2 3/4 turns. Just as the diagram shows for a screw on retainer...
rear closure magnum 3.jpg5475 Aero Pack adapter.jpg
Curious I turned the rear adapter around, as for a "snap ring" closure shown in the diagram and
came up with 4 turns of threads! So in my case I'm better off using the "snap ring" position for
the rear adapter.
Either way would work for my application but who wouldn't want more threads holding!

In Teddy's case with a cone I can see there's only one way for sure.

I'm really glad you brought this up Teddy! I'm going with the "snap ring" way...

JP
 
You’ll like that K500 motor. It put the “Reckless Endangerment”, a 7 ½ lbs rocket, to an altitude of just under 10,000 feet.
 
Very cool JP...
Your being quite meticulous...
That's the way to do it...
Nothing to rush..
Feel everything out...
Nice and easy in the quite comfort of your home...
There's no better way to bring confidence to launch day...

Teddy
 
You’ll like that K500 motor. It put the “Reckless Endangerment”, a 7 ½ lbs rocket, to an altitude of just under 10,000 feet.
Wow, 10K! We don't have that kind of clearance.
Another poster used the same motor first time out in his Magnum 3. I haven't seen him in a while but that's
the motor I could afford and seemed to be plenty of thrust off the rail, with enough altitude, 3K, not breaking
our waiver.

JP
 
JP,,
I sent my "Green Hornet" up on an Aerotech K 550 W and it did 9300 ft....
That really is a super sweet load...
You're really going to like it...

Teddy
 
I made a huge error on the Weight!
after finding a couple of incorrect weights for components and going back through every part
I now get 10 pounds with some change. I feel so much better now about the J motor I may
use it instead of the K550W for my Cert. Level 2 flight attempt.
LOC MAGNUM 3 weight reconfigured 10 pounds.png

JP
 
I made a huge error on the Weight!
after finding a couple of incorrect weights for components and going back through every part
I now get 10 pounds with some change. I feel so much better now about the J motor I may
use it instead of the K550W for my Cert. Level 2 flight attempt.
View attachment 247009

JP

JP
I don't know if this has been brought up but your image shows the motor located as if the rocket has no tail cone. Doesn't this throw off your CG or did you manually over ride the weight?
I like Tail cones and make sure to move the components to the correct locations to ensure the simulations are correct.
UltEndeavour_98mmTL3-actual.jpg

Good luck on your Cert 2 flight.
 
I made a huge error on the Weight!
after finding a couple of incorrect weights for components and going back through every part
I now get 10 pounds with some change. I feel so much better now about the J motor I may
use it instead of the K550W for my Cert. Level 2 flight attempt.
View attachment 247009

JP



WOW! That is half of original sim. You do not weigh or check CG (fully loaded, minus motor) after completing your rockets? I do that to all of mine LPR to HPR and over ride the mass calc./ CG of the sim. Only a scale truly knows the real weight of all the components, epoxy, chutes, paint, etc., etc.
 
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JP
I don't know if this has been brought up but your image shows the motor located as if the rocket has no tail cone. Doesn't this throw off your CG or did you manually over ride the weight?
I like Tail cones and make sure to move the components to the correct locations to ensure the simulations are correct.
View attachment 247210

Good luck on your Cert 2 flight.



His motor is recessed, see post # 8.
 
WOW! That is half of original sim. You do not weigh or check CG (fully loaded, minus motor) after completing your rockets? I do that to all of mine LPR to HPR and over ride the mass calc./ CG of the sim. Only a scale truly knows the real weight of all the components, epoxy, chutes, paint, etc., etc.

Jeff,

Next time I see you I'm going to hug you!!!! What you state above is what I believe to be the root cause of the majority of unstable rockets out there! People assume all the time that the CG and mass represented in the sim is actual and thus the stated calibers of stability is correct in the sim. If people would measure actual masses and actual CG's of the actual rocket, the world would be a much safer place!:D

-Eric-
 
His motor is recessed, see post # 8.

What about the Krushnic Effect? Not having the exact measurements I may be wrong but it appears to be close to the one diameter threshold for rocket or motor damage to occur. I know questions about Aerotech's 54 mm tail cone aft closure and what motors it could be used with were raised earlier this year. No short or Medusa nozzles were allowed because they were recessed. This was also put out as the reason why there are no 38mm AT tail cone retainers. Not that they wouldn't work just that they would only work with specific reloads. I know the 54mm retainer appeared to be less than 54mm long so it, in theory shouldn't have been a problem.
Not that they wouldn't work just that they would only work with specific reloads.
I just don't want to see a very nice looking rocket and/or hardware damaged.
Just my :2: .
 
I had to borrow a scale for the lower half after it was completed.
No idea how I had 2 of the components way too heavy.
I tried to weigh parts as it was built. And override the CG in Open Rocket.
The nozzle sticks out pretty far for the K550W. 1 1/2" shy of the tail cone.
The J460T I'm not sure about yet, it may melt the tail cone a little.

If the tail cone under goes a melt down I'll remove the screws, touch up
any paint on the rocket and call it a not so good idea to recess it as deep.

So right now I'm at 1.84 caliber stability with the K550W. I think that's enough...
I may add 1 ounce of weight to the back side of the nose cone to add a bit of stability.

And 2 calibers for the J460T... This will probably be my Cert. Level 2 attempt motor.
I've never flow a HPR over 1,500 yet. 4,000' VS 2,000' for a Cert. Attempt!
I'm thinking go big or go home too (K550W)!
It may depend on how many of my friends/family I can talk into the 90 mile trip for support!

I've read each post and appreciate the input for sure! Thank you one and all.

JP
 
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