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AT L-1000 DMS – flying case with a nose cone and 4 fins

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jbrracer

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2 of 4 JB done the glass one, 8 of 8 glass reinforcements done on the carbon one.
not to get off topic but what is the best way to blend the glass to the airframe and fins to make it less or not visible? Is it all under the fillets?

PS this is sick looks like you are getting closer! Good luck!
 

rfjustin

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not to get off topic but what is the best way to blend the glass to the airframe and fins to make it less or not visible? Is it all under the fillets?

PS this is sick looks like you are getting closer! Good luck!
Combo of light sanding the edges with a palm sander to knock down the high spots, then some bondo putty and more sanding to smooth it all out. I do plan to prime and paint the fin cans. I'll need to know which is which. :)
 

jbrracer

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Combo of light sanding the edges with a palm sander to knock down the high spots, then some bondo putty and more sanding to smooth it all out. I do plan to prime and paint the fin cans. I'll need to know which is which. :)
Would there be any value in glassing just the filleted area or would that be a waste of time?

Again not to get off topic but, Im working on my first rocket where the motor is close to the same size as the body tube but not Minimum diameter, what would be a recommended way to get a shock cord from booster to ebay? Ive got three centering rings with no room for a eye bolt or u bolt, Should I just bite the bullet and order a tapped forward like you made for your DMS with the pipe tap?
On that note is that a tried and tested viable way to make a DMS into a plugged threaded fore end>?

Last time I steal the thunder of this build and thanks for the advise.
 

rfjustin

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Would there be any value in glassing just the filleted area or would that be a waste of time?

Again not to get off topic but, Im working on my first rocket where the motor is close to the same size as the body tube but not Minimum diameter, what would be a recommended way to get a shock cord from booster to ebay? Ive got three centering rings with no room for a eye bolt or u bolt, Should I just bite the bullet and order a tapped forward like you made for your DMS with the pipe tap?
On that note is that a tried and tested viable way to make a DMS into a plugged threaded fore end>?

Last time I steal the thunder of this build and thanks for the advise.
What is the diameter of your project and what size motor mount please? Once I know that, start us a conversation and reach out. ;)
 

CPUTommy

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To say I'm impressed is an understatement, little do people know the time and problems we solve in our heads, some people solve those problems to a point of near perfection. Your in that zone in my world... It lets me know that I have alot to look forward to down the road, im no where at that level, im just happy with a smooth fin can and finish....... that hopefully comes back burned some day, Thats me where IM at. Just making things stay on is my goal now.., what you have done, gives me ideas that will forever try to incorporate. The boat tail is next level stuff, I personally think they finish a rocket off, And Give you MORE altitude (hey your up there anyways right) what you've shown me will definatley be used in my next build.

On another note: what your doing is radical and inspires alot of other rocketeers, PLEASE KEEP POSTING , your an asset to this sport, Your showing even new people the challenges of just little rockets.. your just doing them in a way diffrent way. please share more as proper building is problem 1, recovery/tracking ..problem 2.. I look forward to your continued work.
Respectively
Tom
(Speed freak striving to be at your level some day)
Orange, first self made boat tail
Red vagabond, 2nd attempt
Green was filets and JB weld instead of epoxy
3 fin boat tailed loc weasel
And my leading edges on my loc sandhawk

Any tips / advise ?
 

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rfjustin

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To say I'm impressed is an understatement, little do people know the time and problems we solve in our heads, some people solve those problems to a point of near perfection. Your in that zone in my world... It lets me know that I have alot to look forward to down the road, im no where at that level, im just happy with a smooth fin can and finish....... that hopefully comes back burned some day, Thats me where IM at. Just making things stay on is my goal now.., what you have done, gives me ideas that will forever try to incorporate. The boat tail is next level stuff, I personally think they finish a rocket off, And Give you MORE altitude (hey your up there anyways right) what you've shown me will definatley be used in my next build.

On another note: what your doing is radical and inspires alot of other rocketeers, PLEASE KEEP POSTING , your an asset to this sport, Your showing even new people the challenges of just little rockets.. your just doing them in a way diffrent way. please share more as proper building is problem 1, recovery/tracking ..problem 2.. I look forward to your continued work.
Respectively
Tom
(Speed freak striving to be at your level some day)
Orange, first self made boat tail
Red vagabond, 2nd attempt
Green was filets and JB weld instead of epoxy
3 fin boat tailed loc weasel
And my leading edges on my loc sandhawk

Any tips / advise ?
Thanks for the kind words. I treat TRF as a means to share with others and I appreciate others that do the same. :)
 

CPUTommy

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All true facts.. but guy.. your doing next to the impossible.. real next level stuff, pushing the envelope.. just sayin..
 

CPUTommy

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I have a question... your using 3 fins, (my personal choice on my favorite scratch builts) did you look at 4 fins, to possibly split the loads ?

3 fins at x amount of force (vertical)
4 fins at x amount of force should reduce the factor of X or no????
 

crossfire

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I have a question... your using 3 fins, (my personal choice on my favorite scratch builts) did you look at 4 fins, to possibly split the loads ?

3 fins at x amount of force (vertical)
4 fins at x amount of force should reduce the factor of X or no????
I see 4 fins.
 

CPUTommy

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Altitude diffrence? Is the 4th fin really that much drag or is it divided by all the fins present?
 

rfjustin

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Altitude diffrence? Is the 4th fin really that much drag or is it divided by all the fins present?
The question of "altitude difference?" on paper is a fair one, but lets delve into something more important (in my opinion). To truly max out performance, you need fins large enough to keep vehicle stable, but small enough as to not be wind plows. The trouble is trying to find the balance between too small (barely large enough to do the job under ideal conditions) and way too draggy set of fins that ends up killing performance.

Also another challenge with minimum diameter birds is that CP/CG relationship shift as speed increases and weight at the rear of the vehicle decrease quickly. When I typically fly anything minimum diameter, its almost always in KS where it tends to be windy (shocking I know), so anything on the ragged edge of stability is going to have an uphill battle. See examples below:

Example 1:

Example 2:
 

tfish

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and when you get things ( fin shape, material, thickness, straightness and attachment) just right, you get good altitude and have some ability to overcome flight irregularities...weird winds, high mach CP/CG shifts or loss of one side of the nozzles exit cone.
well above mach
son of speedy.jpg


Loss of one side of the exit cone
sp5.jpg



recovered with no damage and still went 24K 70G's mach 1.5

Tony
 

CPUTommy

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How about an Ebay sled that is controlled or even spring loaded? Predictable change of Cp/Cg by added or subtracted weight?

Ready... build...
 
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