BALLS 32

[pugachu]

We stood down on launching the Yon Kárb Mán 2-stage spaceshot. The nearly identical Q12K booster I made with RDH8 cato'd on ignition in his 2-stager. Root cause analysis: some back-burning on the cast-into-liner segments, high mass flux, and about 1800 PSI max. Forward fasteners sheared the 1/4" wall case as designed. The tubes were new linen phenolic from China... great stuff but needs more ID surface prep. Testing to follow.

John,

Is the booster motor a complete redo, or can it be salvaged?

 

[jsdemar]

John,

Is the booster motor a complete redo, or can it be salvaged?

The hardware is definitely ok. The grains will depend on upon the testing we do on the liner material.

 

[jderimig]

The hardware is definitely ok. The grains will depend on upon the testing we do on the liner material.

Look into silanes for a liner adhesion promoter. "Recalling a tiny shred of Kodak memory...."

 

[FredA]

Did you glue the grains to the liner? Is that the interface that failed?

 

[jsdemar]

Did you glue the grains to the liner? Is that the interface that failed?

Cast into liner segments with abrasive prep and inhibitor pre-coat. Always worked on a dozen 6” motors. Only differences are new Chinese linen phenolic and using Jmax propellant.

I tested a 98XL load yesterday using propellant made at the same time. No issues.

 

[terryg]

Here's what a Q motor (the one @jsdemar described) CATO looks like from more than 1/2 mile away: (sadly, just one of many similar events – it was a cursed BALLS!)
View attachment 669137

Tony

Was this the Gloria memorial flight?

 

[manixFan]

Cast into liner segments with abrasive prep and inhibitor pre-coat. Always worked on a dozen 6” motors. Only differences are new Chinese linen phenolic and using Jmax propellant.

I tested a 98XL load yesterday using propellant made at the same time. No issues.

John – such a strange BALLS with so many failures by folks who have successfully made and flown many large motors. Very small consolation that you were in 'good company' at the event with all the others.

Can I ask what case pressure you were expecting on the Q motor vs. the 98mm motor? And did the 98mm motor use the same new liner? Just trying to get a handle on any new large motors we try.

Was this the Gloria memorial flight?

Yes, the photo I posted is of the memorial flight.


Tony

 

[tfish]

Click to gif

Tony

 

[FredA]

cool animation Tony

 

[pugachu]

Click to gif

Tony

How'd your flight go, Tony?

 

[jsdemar]

View attachment 669982
Click to gif

Tony

Graphics animation by Terry Stroud for flyrockets.com (now defunct).

 

[tfish]

How'd your flight go, Tony?

I put it off..until next year.
I was part of the Tripoli "liquid rockets" crew. It took more time then I had planned on.
My son AJ also came out. I did get to do 2 flights with him and his 20 year old rocket. Wimpy Red K500 (7K) and a SwampGas K650 (<10K)
I brought a pad out for Andrej (Slovenia) and Dennis (Austria) space shot. They used it 2 years ago and asked to borrow it again this year.
They gave me a couple of souvenirs for my troubles.




Tony

 

[FredA]

Nice gift - what ya going to do with it?

 

[3stoogesrocketry]

What's with that little guy? Rail guide / motor retention ?

 

[tfish]

Nice gift - what ya going to do with it?

Funny you should ask..

I've been collecting things for a 6" project for awhile now..6.5" Gas Pipe, casting tube and liner sets etc...




So, like this...but bigger


..and of course ..good old.. SwampGas....5.0


I figured I'm not getting any younger, no more free time, no more money and not much better looking ..
I've got 9 grandkids, from 22 years old to almost here..We fly rockets (A-C stuff) together a couple times a years.
I'm going to see which AeroPac launch works for the most of them and go fly it with them there.

Tony

 

[tfish]

@3stoogesrocketry

Unistrut buttons.

The unistrut is bolted to the 1515 rail.




Photos from Rob Grygar...

Tony

 

[FredA]

Sounds like a great plan Tony - all the best

 

[pugachu]

Funny you should ask..

I've been collecting things for a 6" project for awhile now..6.5" Gas Pipe, casting tube and liner sets etc...

So, like this...but bigger

..and of course ..good old.. SwampGas....5.0

Tony

Your ice cream spoon, and your forearms will get quite a workout mixing that much APCP...

 

[FredA]

The batteries that control the deployment lasted less then 2 hours?
What was your power sorce asking so I don't make that mistake next year.

I think I found the root cause.
When prepping for Balls, I pulled the last pair of 9V Duracell's from a [CostCo] bubble pack in my fridge and their age and their 2025 expiration date fooled me into thinking these were old-style Duracell's.

One got flown - and one didn't.

We dissected the one that didn't get pounded into the ground and were disappointed.

Pictured here compared to a brand new Amazon Basic 9V that I'll be switching to for future flights.

The batteries pictured managed a [quick] short-circuit current of 6.1A for the Amazon while the Duracell flashed 2A and started to crash from there.

Avoid all Duracells!
OK for smoke detectors - not high performance flights pulling over 20G's off the pad.

 

[3stoogesrocketry]

I think I found the root cause.
When prepping for Balls, I pulled the last pair of 9V Duracell's from a [CostCo] bubble pack in my fridge and their age and their 2025 expiration date fooled me into thinking these were old-style Duracell's.

One got flown - and one didn't.

We dissected the one that didn't get pounded into the ground and were disappointed.

Pictured here compared to a brand new Amazon Basic 9V that I'll be switching to for future flights.

The batteries pictured managed a [quick] short-circuit current of 6.1A for the Amazon while the Duracell flashed 2A and started to crash from there.

Avoid all Duracells!
OK for smoke detectors - not high performance flights pulling over 20G's off the pad.
View attachment 670728

I only use these on everything 2.5 inches in diameter and up. They will hold a charge all year. I've flown one without a recharge from the year prio because it still ohmed out good. If you splice a pig tail below the plug you can then just leave it in the av bay and use the jumper cord to charge it. You can buy male and female ends fir these. It's worth the added oz or 2 in my opinion.

 

[FredA]

No interest - a quality 9V is all I want.

 

[tfish]

fixed...

@FredA
Best 9v battery these days!

Martin Quanci for the win..

Part 1
https://www.rocketryforum.com/threa...d1ssmwTugOpAplfjJA_aem_mbnihTu2PuPLRdVhgYUhbQ

Part 2
https://www.rocketryforum.com/threads/9-volt-batteries-part-1-the-tear-down-no-6-thru-no-11.176939/

Tony

In an effort to keep an eye on Amazon 9V batteries construction..
These batteries weigh 45.7 and 45.8 grams. If you get batteries that weigh differently..they may not be of the same construction/output.
Tony

 

[manixFan]

give me a few minutes to post the right link...standby

@FredA
Best 9v battery these days!
View attachment 670730
Martin Quanci for the win..

https://www.rocketryforum.com/threads/9-volt-batteries-part-1-the-tear-down-no-6-thru-no-11.176939/

Tony

I agree, but…

Amazon will change suppliers for their ‘Basics’ branded items without notice. It all depends on who can supply the most at the least cost. So there is a good chance the internals will change at some point but the labeling will stay the same, exactly like what happened with the Duracells.

It’s always buyer beware these days.

So, @FredA, does this mean you’ll publicly apologize for blaming everyone else for the battery failure?


Tony

 

[FredA]

Amazon "advertises" 6LR61 construction on the side of the battery.
Hopefully they will keep the inside matching the outside.

Tony - my battery failed.
Could be the crappy battery construction.
Could be the G-load.
Could be it couldn't source the firing current.
Could be the extra hot temps. from sitting on the pad.
Could be that it was depleted after sitting on the pad.
Could be a blend of all of the above.

WTF do you want me to say?
Sitting on the pad forever still sucks.

 

[tfish]

Amazon "advertises" 6LR61 construction on the side of the battery.

took me some thinking and a google search to figure out the above..

Tony