How do I plug the forward closure

[maxpower]

I have a 24/40 case and built up a D15 reload in it. I realized I forgot the oring in the forward closure but the delay element was so tight, I destroyed it trying to get it out. So now I have a D15 reload without a delay. The no delay part is OK because I can use it in a cluster or with a timer but how do I plug the forward closure?

Thanks

 

[heada]

Call up Aerotech and explain it to them. More then likely they'll ship you a new delay.

-Aaron

 

[Dipstick]

See the thread where I asked the same question...

https://www.rocketryforum.com/showthread.php?s=&threadid=35044


Bruce

 

[Chicagonative17]

If you still have the forward closure of the casing, you can take the grease you use to grease up the case and stick it into the forward closure hole. you keep filling it until you can't anymore, then cover it with masking or electrical tape. this should do the trick. I was told this from Ken at Al's Hobby shop, the guy who worked on the outlander project. He says it works with any motor that uses a motor ejection system.

 

[maxpower]

chicagonative17, You are talking about the hole that is forward of the delay element (if it were in place) and not the whole chamber that the delay fits into?

Dipstick, did you actually try the G339 without a plugged closure?

 

[jj94]

I always thought you needed a delay no matter what. But for future reference when you want to plug the closure for a saucer flight or dual deployment you can:
put dogbarf in the well and put masking tape over it.
fill the well with grease.
put some clay in the well.

 

[Chicagonative17]

I always thought you needed the delay anyway too, maybe if you just stuck the screwed up delay in there knowing it wouldn't work but then plug it with grease.

 

[Dipstick]

Dipstick, did you actually try the G339 without a plugged closure?


-Nope, not yet. I'm in Canada, and Warp9 isn't approved for use up here...yet.

Bruce

 

[SpartaChris]

How badly damaged is the delay?

I've used standard closures without ejection charges in them. Just grease up the o ring really well and splash some on the top of the delay grain and you'll be fine, provided you can still get the delay in there. Or else just pick up a new delay.

 

[hokkyokusei]

You really don't want to fly it without the delay!

 

[maxpower]

The delay is completely destroyed. It fit tight to begin with and since I put it in without the oring, getting it out undamaged was impossible. There is essentially nothing left of it since I had to dig it out piece by piece.

Other than sealing the front end and providing a delay for the ejection charge, what purpose does the delay serve? If I can find another way to plug the front end and use a timer or a second delay in a cluster for the ejection, why do I have to have a delay?

I will contact AT and see if I can buy another 24mm delay.

Thanks for the help everyone.

 

[hokkyokusei]

Originally posted by MaxPower

Other than sealing the front end and providing a delay for the ejection charge, what purpose does the delay serve? If I can find another way to plug the front end and use a timer or a second delay in a cluster for the ejection, why do I have to have a delay?

Well, exactly, but I doubt you can find another way of satisfactorily plugging the forward closure.

I will contact AT and see if I can buy another 24mm delay.

That's what I would do. Or scrounge one from another flier.

 

[ben]

I did the same on my first load. Call AT. They will hook you up! They were very nice and helpful and I got a new delay in a week.

You REALLY don't want to fly without a delay.

Ben

 

[DumasBro2]

Originally posted by ben


You REALLY don't want to fly without a delay.

Ben

Please elaborate.

 

[shreadvector]

The delay is there to keep the intense pressure of the burning propellant in the casing. Without a delay the hot flaming gas/plasma will shoot upward and into your rocket just like the normal exhaust flame will shoot out of the nozzle.

Your forward closure and rocket will be destroyed. Your warranty will be void.

When people plug a motor, they install the delay and then install grease and/or wadding instead of black powder above it. And you should only do so if the manufacturer's instructions say that it is allowed.

I recall seeing this in Aerotech HPR reload instructions, but never in their Model Rocket Motor reload instructions.

 

[m85476585]

If there is no delay with the proper O-ring, the pressure of the motor could go out the top, causiung ejection under thrust, and probably burning the inside of the rocket (there would probably be flames shooting out the top). Using no delay might be OK with a true plugged forward closure (although I still wouldn't try it), but there is no such thing for the hobbyline cases.

 

[DumasBro2]

Well, I understand you have to have something in the forward closure to seal off the combustion chamber. It just doesn't have to be the delay grain. Personally I'd get a new delay or use the grains to start a campfire.

 

[maxpower]

Thanks everyone.

I have emailed Aerotech asking if they can just sell me the delay but haven't heard anything yet (I just emailed this morning). I will call when I get home from work tonight.

 

[RocketRick]

You need to have *something* in the well to keep the pressure from causing flames to shoot out the forward closure's hole.

First choice is, of course, to get a replacement delay grain from Aerotech. You should pursue this possibility before attempting any sort of "workaround".

Failing that, as long as you don't need motor ejection, then I don't see a problem with installing the O-ring, and then inserting an appropriately-sized piece of wooden dowel rod, wrapped tightly with a few wraps of masking tape (if needed to make it fit tightly in the well). Make it long enough so that, when fully inserted against the o-ring, it extends about 1/16" out of the top of the delay well, to allow the forward seal disk to push against it when the closures are tightened.

Grease everything well to help make removal and clean-up easier after the flight.

- Rick "but, try Areotech first!" Dickinson

 

[shreadvector]

Originally posted by RocketRick
You need to have *something* in the well to keep the pressure from causing flames to shoot out the forward closure's hole.


- Rick "but, try Areotech first!" Dickinson

I hate when that happens....


you should add "LIII" to your signature. you can add it in crayon if you like.

(yes, it's in your profile...)

 

[jraice]

Take the delay insulater and pack it full of a high temp epoxy...?

Maybe put some grease on the ends just incase the epoxy melts (keep case clean)...

Assemble it like normal (with o-rings and everything) and you should get a great plug... will void warranty and personally I would weight for a new delay...

But if it was a short time frame (like I was at the field) it is what I would do.

 

[jsdemar]

Originally posted by jraice
Take the delay insulater and pack it full of a high temp epoxy...?

Maybe put some grease on the ends just incase the epoxy melts (keep case clean)...

Assemble it like normal (with o-rings and everything) and you should get a great plug... will void warranty and personally I would weight for a new delay...

But if it was a short time frame (like I was at the field) it is what I would do.

Not only would it void the warranty, it would also turn it into a non-certified motor.

 

[gonogo]

Not only would it void the warranty, it would also turn it into a non-certified motor.

geez, finaly someone said it.

 

[dgreenapple]

Purchasing an RDK (Reloadable Delay Kit) is a standard product. You can get them at:

https://www.redarrowhobbies.com/aerotech_rdk_delay_kits.htm

https://store.alshobbyshop.com/index.asp?PageAction=VIEWCATS&Category=218

And through many others, like Hangar11 and Countdown Hobbies.

See the following cross reference at my website (copied from Red Arrow Hobbies) for which delay kit to purchase:

https://www.astralisrocketry.com/files/MotorRDKDelays.pdf

Since the D15 reload is not listed there, contact Technical Suport at Aerotech.

You DON'T want to fly the rocket without the delay, an O-ring and a spacer / insulator. It will destroy your rocket when the flames shoot up out of the top (as described by others earlier).

 

[Sailorbill]

dgreenapple
This is a great list but, MaxPower has a 24-40 case. No RDKs for them.

 

[maxpower]

I have emailed and called Aerotech but haven't gotten any response from them. I will keep trying though.

Thanks for all the help!