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What did you do today in pyro?


dagabu

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My Grandbaby must've been running on lithium ion batteries last night. She was full bore until about 12:30 then she just passed out talking to Grandpatty!

 

Screen grab from my first cylinder shell on a rocket;

 

post-20116-0-37943700-1467568933_thumb.jpg

 

Pressed some 1 and 3lb rockets on the fullsize BP spindle to try out with some 75/15/10 made with willow charcoal I got from a fellow pyro. I made up some bag headers with star scraps just so there'll be some effect.

Edited by OldMarine
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I made some smoke today. Nothing fancy, KNSU and some wax. First batch ran a little long. Sugar caramelized and most of the wax cooked out (brown taffy in a pool of wax). Pretty energetic but LOTS of smoke.

 

I was kinder to round #2. Harder to light, I had to prime the tubes with a little BP/AL slurry in NC to get it to take fire without hitting it with a torch. Very long burning though the volume of smoke was somewhat reduced and a bit "grayer" than the first iteration. I need to land somewhere in between with work on my manufacturing technique.

 

I also got to set up a 1 ton arbor press and make a few mods to it. Got a 3/4 ratchet on the way. Made a few bags of discs with some punches improvised from hole saws. Thanks for the tip on the foam insert to release discs as you punch 'em Dag!

 

Pretty quiet 4th here (so far). The big party will be next weekend for us.

Pretty quiet 4th here (so far). The big party will be next weekend for us.

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Here's video of my first 3" cylinder shell on a rocket;

 

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pat that came out real good. I liked it

 

memo

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Ordered what just a few months ago would have qualified in my mind as a lifetime supply of perc but now seems to be enough to get me through the next month or two! I've gone from Tupperware to pool-chem buckets on several things.

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Patrick,

In order to gain some space in one of my shops, I had to build a block-n-pallet shelf set today -- and move 1600lb of about 100 different chemicals onto it! It's a disease, son!

 

Lloyd

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Patrick,

In order to gain some space in one of my shops, I had to build a block-n-pallet shelf set today -- and move 1600lb of about 100 different chemicals onto it! It's a disease, son!

 

Lloyd

Oh My GOD! I've got it! It was just one rocket....now I'm gonna die broke!

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Carbon,

 

You did not mention the jar diameter. The revolution speed depends upon BOTH the diameter of the jar and the diameter of the media particles.

 

Say both, and I'll run the formula.

 

LLoyd

 

Would you mind posting that formula? The revolution speed can be increased by making the non-drive roller larger diameter, correct?

 

I have sneaking suspicion my own jar doesn't have enough media. I need to pick up your book one of these days Lloyd.

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Azo,

 

The jar should be exactly 1/2 full of media (by volume), with 1/4 the EMPTY volume in material to be ground.

 

Here's the speed calculator:

 

Critical Speed (CS) is the RPM at which the media will centrifuge to the walls of the jar without cascading.

Optimum speed for dry milling is about 65% of critical speed.

 

CS=265.45/sqrt(jar i.d. inches - media o.d inches)

 

So, for instance, in a 6" jar with 1/2" media,

 

CS=265.45/sqrt(6-0.5)

CS=265.45/sqrt(5.5)

CS=265.45/2.3452

CS=113.19

 

So... the critical speed is 113rpm, and the optimum is:

113.19*0.65=73.57 rpm. (73 or 74... won't matter)

 

Lloyd

Edited by lloyd
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Lloyd, I've heard conflicting information on this, but do you know which interior dimension is appropriate when trying to use the formula to calculate critical/optimal rotation speed for polygonal barrels or if a different factor is used to calculate optimum speed? The above formula is a rearranged version of the force equation when the force of gravity is set equal to centripetal force. This assumption of a circular, free path sort of breaks down with different shaped barrels.

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Mumbles, because the forces rely upon the diameter vs. the speed, the major diameter (across the 'vees' of the hex) would be the one to use.

 

It won't make that much difference, anyway. Run the numbers on the max, the mean, and the minimum, and you'll see that there's not enough difference to take things out of the realm of 'efficiency'.

 

LLoyd

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It was like Christmas in Pattytown today. Received packages of Red Stem Willow and SYP charcoal, my new cordless glue gun and some perc. Too rainy to do much so I waxed rocket tubes and cut end discs.
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Other than miraculously remembering my APC password, I also did "pyro chores" today. Two magazines to mow around. Was a 2 hour job (2 and a half if you count washing all of the allergies off of me afterwards). There's a short but steep slope that separates a lower and higher part of the mow radius. The ZTR can't access the lower part, so I use my old lawn tractor for that. The slope itself can only be done with a weedwacker. In hindsight, I should have located the magazines such that the mow radius was all at one elevation, but it's too late now! Always gotta do stuff the hard way! I also nearly ran right into a massive bee hive with the weedwacker. Another miracle, I somehow didn't get stung! It was dusk at that point so I didn't get a good look at them, maybe they are a non-aggressive species.

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Not exactly today, but on the 4th, I had a successful launch of a 1/2" semi-endburner rocket! I attribute my success to ramming small increments (as usual) on a fence post for better compaction than before, and making the bulkhead as long as the tube ID instead of half the ID. I'm very excited to fly more rockets, both model and firework.

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I finally achieved the zen of star rolling. ^_^

 

http://imgur.com/a/9ROCU

 

Rolled by hand in a stainless steel kitchen mixing bowl. They are currently at 15mm, I'm planning on bringing them up to at least around 30-40mm+prime for the 12". I'm debating what to do for the next layer now (any requests/suggestions are always welcome)...

 

Bright Streamer w/ Dragon Egg Cores

67...Meal Powder

09...Barium nitrate

09...Aluminum (Firefly Flake)

08...Aluminum (Alcoa 120)

07...SGRS

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Impressive. Getting that coarse Al to pick up is one of the hardest things to do in star rolling. I have noticed that SGRS seems to help. Maybe it's a bit tackier or less effected by stearine coatings? It's also easier with the toro method.

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All other factors being equal, i notice a night and day difference between SGRS and dextrin, i would describe SGRS as gummy and dextrin as pastey.

 

Rolling is like shaving imho ,most of the issues people have could be eliminated with a bit of patience. And practice.

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Finally got all my latest chem acquisitions in containers and labeled. Got my new 4" and 5" formers plus a couple of insert formers from Mikeee and I'm going to build some cases w/passfire tomorrow. I've got my next batch of Spanish Blue #1 ready to wet and cut, this time with acetone/parlon rather than with water/dextrin. Also got my Surebonder cordless glue gun and high temp sticks and I love it.


I pre-weighed 5-1lb batches of BP so I can go to the hill and do some milling while I do some barn repair this weekend.


Not a bad day for a Wednesday.


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Had to lay out of work today due to a torn bicep and took advantage of the free time to regranulate some Spanish Blue#1 I had tried to cut earlier and failed at miserably. I wetted it with a little water and tried my new 1/2" star plate. I'm impressed with the results:

 

 

post-20116-0-84300800-1468882651_thumb.jpg

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I feel small. Hell I'm still using rolled paper

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Squirrel, you should have seen me trying to cut those boogers! I wetted them with alcohol to activate the red gum and they became a sticky, unmanageable puddle.I couldn't bring myself to just consign them to the burn barrel so we'll see how they work after dark.

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  • 2 weeks later...

If you have never heard of double voice crackers, you are in for a treat! I made a few dozen of them today for PGI and tested a few of them to dial in the lift. Sorry, but no video from the build site, I was too busy watching them.

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I've spent that last couple of weekends experimenting with a new crackling flower prime/titanium combination I devised myself, which finally seems to have paid off...

 

Here's a ground test of 5 stars:

 

And a small mine with about 30 stars:

 

I'm very happy with the results. Next I intent to test them in a small bombette, before I try to repeat the results with a larger batch.

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