Question on FlisKits 5-engine cluster mount

[illini]

Do I understand correctly that the 4-13mm motors are ejected? Looks like the 3rd ring blocks the BT-5's. Hate to be under *that* rain!

 

[BobH48]

I would use the A10-PT plugged engines. No ejection charge.

 

[illini]

Good call. Thanks!

 

[UncMikesRktShk]

Originally posted by illini
Do I understand correctly that the 4-13mm motors are ejected? Looks like the 3rd ring blocks the BT-5's. Hate to be under *that* rain!

I have one of those mounts for a kit Im making. I have not yet assembled the mount yet, but it sure looks like to me your going to under the "incoming" fire from 4 13mm motors

Unless you use plugged engines, which is possible because of the way the mount is layed out the ejection charges from the 13mm's have no effect on recovery deployment. At least thats IMHO having not built the mount yet but just looking at the pieces.

 

[r1dermon]

i believe you can plug estes motors with 5 min epoxy. just a thought. i've seen it done before, i just dont know if estes recommends it... i wouldnt do it to an E or D motor though, they seem to have 3 grams of BP in the eject charge. lol.

 

[hokkyokusei]

Originally posted by r1dermon
i believe you can plug estes motors with 5 min epoxy. just a thought. i've seen it done before, i just dont know if estes recommends it... i wouldnt do it to an E or D motor though, they seem to have 3 grams of BP in the eject charge. lol.

If you use booster motors they're OK, but if you use motors with an ejection charge, there's a good chance of them going bang!

Saw this in a glider once, just started into it's glide, with a nice smoke trail from the delay grain, then BANG! So much balsa confetti!

 

[illini]

There are no 13mm booster motors any longer, so I think the only choices are A10-PT or go ahead and let them eject.

 

[hokkyokusei]

Still see them from time to time over here. Long supply chain, I guess.

 

[UncMikesRktShk]

Originally posted by r1dermon
i believe you can plug estes motors with 5 min epoxy. just a thought. i've seen it done before, i just dont know if estes recommends it... i wouldnt do it to an E or D motor though, they seem to have 3 grams of BP in the eject charge. lol.

Wouldnt that be a violation of "NAR"? to modify a motor in any way. I cant imagine an RSO letting an epoxy plugged motor onto the launch pad. I could be wrong but just a thought before you do it.

 

[lalligood]

Originally posted by UncMikesRktShk
Wouldnt that be a violation of "NAR"?

Yes. Big safety code no-no... :kill:

With the plentiful existence of Estes Blurzz A10-PT motors, there is no excuse for not using them in that MMT.

 

[r1dermon]

good point. those motors are available by the thousands. lol.

 

[rbeckey]

Just so you know, I tried to plug A10-0 boosters and A3-4T motors with spectacular results. Both CATO'd about half the time. Code violation aside, it doesn't work. I had some Applewhite saucers I tried them on and I lost one to a rather gruesome CATO that split the motor completely up one side. Don't bother.

 

[n3tjm]

I believe it is not a violation of the safetly code to plug a booster motor. Here is an known example: aerotech has endorsed plugging of thier motors. All of their certified RMS motors are allowed to be flown at Nar launches, even though they have not been certified as such.

That falls under the same category of gluing a thrust ring to the motor (which was also decided to be allowed)

 

[n3tjm]

Here is my Titan, which uses the 5 cluster motor mount kit from Fliskits. The titan is flown here with a D12-5 surounded by 4x A10-PT's. I do not use a clip whip.

Here is the video.

 

[r1dermon]

sweet video. i remember that one going off, i forget what i was doing though. heh.

 

[jflis]

There's another answer for this question too.

As pointed out in the instructions, if you wish, you can ommit the two CRF-50-70 centering rings (save 'em for another project) so that the 13mm tubes don't get plugged. This way the ejection gasses have a place to go.

Just be sure to do your motor selection carefully. You want to make sure that your 13mm burn-time *plus* delay-time is a good match for the central 24mm motor.

For example, don't use E9 motors as the ejection charge of the 13mm will occur shortly after burnout, even with the A3-4T motors...

The rings were included to address just that issue. Keeping the rings in place allows you to use any 24mm in the core without regard to what the 13mm motors are.

jim