The Launch Pad Nike Ajax On F & G Motors,Thoughts??

[rdunn12]

Ok so the Nike Ajax is one of my fave rockets,just got a kit from Sirius with intentions of modifying it to fly on F and G motors.I think I am gonna glass the tubes,install a 29mm motor mount,make ply fins and centering rings etc etc. But I think the lower body tube may be too short,I will have 13 inches beyond the motor tube for chute,wadding and shock cord.The paper transition at the bottom of the sustainer will have to go,I can turn a transition on the lathe.Any thoughts guys??What else would you do??Build thread ??

Ronald

 

[Stymye]

sounds like a scratch build at this point... hard to say

 

[rdunn12]

yeah it does,if I am gonna do a scratch build it isnt gonna be that small!!

 

[troj]

Definitely do a build thread!

My biggest concern for your plans has to do with stability -- the Launch Pad kits need to be modified with care, or you'll make it unstable.

Make sure you know where the CG needs to be, and when you're done with your modifications, add weight as necessary to get it where it needs to be.

-Kevin

 

[sandman]

I built mine stock with just Elmer's white glue.

It flew to about 500' ejected beautifully for a perfect flight.

It wasn't until the next time I flew it I had to look at the launch picture closer!

Only 2 motors lit!

Next time I flew it I only needed to get 2 motors out of my flight box.:wink:

Ya don't need to over build!

 

[Handeman]

You could us the whole lower end as motor and the transition modified as a baffle with the chute in the top. I would go with the 38mm MMT. Aerotech has three MPR loads for the 38/120 and the H73J would be great in the 38/240 case.

Other then building the baffle transition, I'm don't think you'll have to glass anything. 3mm ply fins would probably be a good idea.

There are a lot of possibilities with this one. You could 2 stage it. You could put a long tube and gap stage one or two of the D12-0 motors to an E9 in the upper and use D12-3 in the remaining MMT to deploy a chute for the booster.

Have fun.

 

[rdunn12]

Definitely do a build thread!

My biggest concern for your plans has to do with stability -- the Launch Pad kits need to be modified with care, or you'll make it unstable.

Make sure you know where the CG needs to be, and when you're done with your modifications, add weight as necessary to get it where it needs to be.

-Kevin

Kevin I scratch built a 4 inch diameter 8 foot tall Arcas that flies on J-350's,I think I can work out the stability :wink: or maybe not lol.

I will do a build thread if anyone is interested.

Sandman,I dont think of it as over building I think of it as preparing for the worst lol,the tubes are very thin and and so I thought one layer of glass would give me a little extra strength and add a little additional weight!

Thanks for the comments so far guys!

 

[sandman]

Definitely do a build thread!

My biggest concern for your plans has to do with stability -- the Launch Pad kits need to be modified with care, or you'll make it unstable.

Make sure you know where the CG needs to be, and when you're done with your modifications, add weight as necessary to get it where it needs to be.

-Kevin

Kevin I scratch built a 4 inch diameter 8 foot tall Arcas that flies on J-350's,I think I can work out the stability :wink: or maybe not lol.

I will do a build thread if anyone is interested.

Sandman,I dont think of it as over building I think of it as preparing for the worst lol,the tubes are very thin and and so I thought one layer of glass would give me a little extra strength and add a little additional weight!

Thanks for the comments so far guys!

What I mean is don't overbuild it if you want to fly it with the stock TLP design 3 D12 cluster. Build that one light.

If you want to build it for an H or bigger motor use the Launch Pad kit as reference and basically build it as high power from scratch using high power parts. Just use the Launch Pad kit as a guide.

Don't try to beef up the Launch pad kit. Paper centering rings and a flimsy BT-80 to BT-55 tubes just aren't worth beefing up. A LOC or PML 2.6" tube is plenty strong for an H and a lot easier than glassing a BT-80.

You could use most of the Launch Pad detail parts as templates to make ply parts.

And yes, do a build thread!

 

[sodmeister]

What I mean is don't overbuild it if you want to fly it with the stock TLP design 3 D12 cluster. Build that one light.

If you want to build it for an H or bigger motor use the Launch Pad kit as reference and basically build it as high power from scratch using high power parts. Just use the Launch Pad kit as a guide.

Don't try to beef up the Launch pad kit. Paper centering rings and a flimsy BT-80 to BT-55 tubes just aren't worth beefing up. A LOC or PML 2.6" tube is plenty strong for an H and a lot easier than glassing a BT-80.

You could use most of the Launch Pad detail parts as templates to make ply parts.

And yes, do a build thread!

I wish somebody would do a large scale Nike Hercules.....like say a 4 x D cluster

Gordy......E-mail comming your way !



Paul

 

[rdunn12]

Sandman,

My intentions were to beef up the kit to fly on f and G motors nothing more! I dont like clusters at all!! I agree that the Loc or PML tubing would be better but that was'nt what I wanted to do.I want to make THIS kit fly on F's and G's,yes it will be a challenge,yes it willl take some work but in the end I think I can make it work!And no there wont be any paper centering rings all that will be ply.And by the way if I do a build thread where do I post it? Remember I am new here.Thanks for your help!

Ronald

 

[MaxQ]

I wish somebody would do a large scale Nike Hercules.....like say a 4 x D cluster

Gordy......E-mail comming your way !



Paul

I think I saw a kit like that...Gordo.

 

[sodmeister]

I think I saw a kit like that...Gordo.

Yah i know.....I got to the forums(or rather Roachwerks) too late and found out about the kit after they went OOP..............

Total BUMMER

Although now that I found Gordy ,it`s given rise to many,many scratch projects.But I would still give one of my kidneys for his big Herc.


Paul

 

[sandman]

Yah i know.....I got to the forums(or rather Roachwerks) too late and found out about the kit after they went OOP..............

Total BUMMER

Although now that I found Gordy ,it`s given rise to many,many scratch projects.But I would still give one of my kidneys for his big Herc.


Paul

The parts are coming for it! Open something else in the meantime and start another build thread.

I will contact you after the holidays. I promise!

Gosh, I hope nobody else heard that.

 

[MaxQ]

The parts are coming for it! Open something else in the meantime and start another build thread.

I will contact you after the holidays. I promise!

Gosh, I hope nobody else heard that.

I'm inherited - (bought second hand) Gordo's custom made 4" NC and TC for a Herc...

I've been sketching out the rest of the build and think it will be my winter project...
Thing is pretty big...loads of issues to work out, espc. if it goes DD.
https://rmpitzer.syr.edu/launch/Schecter.html


Gordo...do you do ply centering rings?...I need four sets of offset 38mm MMT centering rings for the booster fin can...I'd like to slightly cant the motors in the four booster tubes....

 

[grog]

I built mine for 29mm motors back in 2000. Besides the 29mm motor mount, I replaced the lower fins with plywood TTW. Everything else I left stock. I have only flown it on F motors.

 

[rdunn12]

Cool Grog that looks good!!

 

[sandman]

I'm inherited - (bought second hand) Gordo's custom made 4" NC and TC for a Herc...

I've been sketching out the rest of the build and think it will be my winter project...
Thing is pretty big...loads of issues to work out, espc. if it goes DD.
https://rmpitzer.syr.edu/launch/Schecter.html


Gordo...do you do ply centering rings?...I need four sets of offset 38mm MMT centering rings for the booster fin can...I'd like to slightly cant the motors in the four booster tubes....

I can do rings but I just use a lathe and a drill press to make them. No laser cutter or cnc machine.

Send me a drawing and I'll see what I can do.

In the mean time could this help? I don't remember what size I made your nose cone for.

View attachment 4INCH HERC.pdf

View attachment 4inherc.pdf

View attachment 4in sustainer fins.pdf

 

[sodmeister]

I can do rings but I just use a lathe and a drill press to make them. No laser cutter or cnc machine.

Send me a drawing and I'll see what I can do.

In the mean time could this help? I don't remember what size I made your nose cone for.

:y::y::y:...you got to be kidding !

I`ll keep it a secret ,I promise. OBTW -I have 3 on the go.I`ll post my TLP HARPOON build soon ,then I want to start that 3" AIM-9 Sidewinder right away......

so you have a bit of time

Paul

 

[rdunn12]

ok started the build today pics coming soon!

 

[sodmeister]

ok started the build today pics coming soon!

Right on ,I look forward to this very much.Might give me some ideas on how to do mine, when the time comes.

Cheers

paul

 

[rdunn12]

cutting the centering rings,just using regular 1/4" Birch thats what I had on hand.The circle cutter has been modified to cut both the inside and outside of the centering ring.

after they are cut I put them on a 7mm pen mandrel on the lathe and sand them to fit the tube

then back to the drill press to cut the hole for the motor tube

Then test fit

Then I bore a 1 1/2" hole in a piece of 1/4" Poplar to act as a spacer to get the rings an even distance from the ends of the motor tube.

Motor mount assembled with centering rings in place,still have to put fillets on the rings,will do that tomorrow.

This is my first time to do a build thread so please let me know if I am doing anything wrong!!

 

[terryg]

I scratch built a copy of the TLP Nike Ajax with plywood fins and stronger materials to fly with 3 engine AP clusters. I eventually got tired of trying to get reliable ignition of all the engines and converted it to fly with single G impulse engines (cheaper flights also). It is a great flier but it has a drawback that is not immediately obvious when you start the project. As you add weight to the rear, you have to compensate with added nose weight for stability purposes. The problem with this is that the upper tube is of a small diameter and getting a chute to fit into it and give reliable deployment is a challenge. Upscaled versions would give more room for the chute and might be more practical. Mine flies great but the fins need to be repaired often and the needed nose cone weight make it prone to zippering.
__________________

 

[MaxQ]

I can do rings but I just use a lathe and a drill press to make them. No laser cutter or cnc machine.

Send me a drawing and I'll see what I can do.

In the mean time could this help? I don't remember what size I made your nose cone for.

That's pretty much it...with some minor adjustments.
4 inch diameter sustainer body tube.
Booster tubes around 2.6 inch dia. (not exact scale but close enough).

Rather than hijack this thread, I was going to start a new one and post a picture of the sustainer in progress, and sketches.
Making the sustainer a traditional dual deployment is going to be a real challenge.
The very long fins on the sustainer run across all the possbile division/separation points in the sustainer, requiring each fin to be segmented in as many as three segments each...unless there is a better way to do dual deployment.

I'll be starting the thread soon in scratchbuilt...although I 'm starting with a nose and tailcone made by Sandman.

 

[sandman]

That's pretty much it...with some minor adjustments.
4 inch diameter sustainer body tube.
Booster tubes around 2.6 inch dia. (not exact scale but close enough).

Rather than hijack this thread, I was going to start a new one and post a picture of the sustainer in progress, and sketches.
Making the sustainer a traditional dual deployment is going to be a real challenge.
The very long fins on the sustainer run across all the possbile division/separation points in the sustainer, requiring each fin to be segmented in as many as three segments each...unless there is a better way to do dual deployment.

I'll be starting the thread soon in scratchbuilt...although I 'm starting with a nose and tailcone made by Sandman.

Start that thread, I have some ideas on that.

OK, back to the Nike Ajax

Nike Herc thread coming.

 

[rdunn12]

cool Kevin looking forward to that one,mine is going kinda slow,had to wait on the new tubing and then the holidays!!

 

[MaxQ]

Start that thread, I have some ideas on that.

OK, back to the Nike Ajax

Nike Herc thread coming.

OK...the thread on the 4 inch Nike Herc has started.

Any ideas?..design by committee, all are welcome to share your thoughts on this one...

https://www.rocketryforum.com/showthread.php?t=18035

 

[jpummil]

Actually purchased the same TLP Nike Ajax kit a couple of weeks ago on eBay with the very same intentions...flying it on 3ea "F" motors.
Haven't opened the kit yet though, so this thread was very informative with respect to what lies ahead ;-)