Have any of you out there tried Sleeters method?

[Aquarius]

Hi.

 

I have bougth ( and read! ) the book "Amataur Rocket Motor Construction" by David Sleeter

I wonder if any of you have had a go at constructing motors "his" way for making firework, using Red Gum as a binder with alcohol or acetone.

 

I will try out some of his methods on different BP variations, and would apperciate feedback on your experience or comments on the matter.

[Aquarius]

So I tried some of this stuff, and it was messy, very messy.

My tube ID is no more than 12 mm, so that explains some of the problems.

The acetone dissolved the glue on some layers in the tube, my rammes got stuck because of vacuum in the ramming prosess and the center hole in the rammer got filled with the comp.

 

Maybe this method is ok for bigger ID's, but for smaller ones it was a royal pain in the neck.

 

But using acetone and red gum was a new experience, I'll just add some more coarse charcoal to the rest of the comp and make comets...

[Mumbles]

I don't have the book. Are you positive that it is meant to be rammed wet? Wetting, granulating and drying is fairly standard proceedure to keep dust down, and prevent blow out of the fine dust.

 

With the comp in the tooling, you have to clean it out with an awl or something.

[Aquarius]

Yepp, the comp is wetted with acetone or alchol (red gum binder) and rammer wet.

And it is a messy buisiness, since some of the liquid shoots up along the rammer and makes a mess, wet and weaken my tubes and promotes sticking of the rammer.

As for the comp sticking inside my rammers, I clean them out when the need is there.

 

I know the standard method, I myself have mill/wetted/granulated/dried and rammed my drivers so far.

 

So I went out trying his way, but it didn't offer much to me.

I might have overdone the wetting, maybe I'll try it again some day.

 

As for now, I am working the "oldie goldie way", ramming with granulated BP, and finding the right formulations for a good,

t(h)rustworthy config.

I'm getting there, but it takes a bit of experimentation.

 

PS: My driver ID are probably too small for such a project, since 1/2" is the smallest of the projects mentioned in his book.

They vary all the way up to 2 inches...

 

But the book gives a good understanding of making coreburnes, fuel, tools etc. I would rate it as a good book for beginners since there is a lot of theory and tips in it.

[h0lx]

Maybe you wet it too much? Try adding just a tiny bit of acetone, like granulating BP or even less.

[TheSidewinder]

I have the book, and I read the section on loading in detail.

 

Yes, you use acetone to wet it. You ALSO have to experiment with each batch to see what percent of wetting agent to use.

 

Too little and you dont get proper grain compaction, leading to a CATO.

 

Too much, and you trap air in the grain, leading to CATO again.

 

His book goes into great detail on the proper methods and procedures. Keep in mind that his book is aimed at Amateur Rocketry, where it is necessary to wring every bit of performance from the motor as is possible.

 

It is WAY OVERKILL for Pyrotechnic Rocketry.

 

For our uses, dry-ramming after ricing will work perfectly. Steve LaDuke presses his BP rockets with a bone-dry formula, and look what he can do with THEM, eh?

 

M

[Aquarius]

Yep, I know the book and have read it. I tried the formula(s) in Sleeters book, but I still have problems with the comp sticking. I believe it's from the small I:D: of the tubes; I suspect it will work out better on bigger I.D. tubes. I'll make some new toolings in say 1 inch and see how that goes.

 

I ram my comp "bone dry" and are getting some very good results from it. If you look at for instance Estes motors, they are endburners. So I kind of drifted into trying a few. My first one flew, but had little thrust. Too little for lifting anything more than 10 grams..

 

I'll try a hotter BP and see how that goes. But I am still looking for a harder, more compact grain, so they take a bit rougher handling without cracking the grain.

 

As a thought, has anyone tried ramming BP the same way as comets/crosettes and used a BATES-configuration in a rocket motor?

[Aquarius]

I fired a rocketdriver, used the Sleeter method for the propellant, and it worked well. Don't know if I'll use it as a standard, still need to work a bit on the procedure to make it more managable. I have now two different coreburners of 12 and 15 mm ID. Working on a enddriver, but that's not going to well. Eigther CATO or no lift...

 

I don't know how well my motors preform compared to others on the forum. My 15 mm coreburner lifted a dummy lead-load of 195 grams to about 50 meters. I find that quite good, any comments?