sui

@Brightstar

I had very good luck with just a pinch of granulated bp in the core along with the fuse. I normaly use this methode only for hard to light motors like the colored MgAl rockets,but then again .., i use fine Ti around 40 micron in that pinch of bp. It never failed me on these motors and with normal bp coreburners bp is all it needs. To keep the bp from falling out of the core i just push some wadding around the fuse and let the granulated bp do its thing. The Wadding get pushed out very relyable. So waht do you think ?

Regards

Sui

Hello ,

I dont post much, but here and there i have some experience.. and when it comes to tubes i need to throw in my 2 Cents.

Im mostly doing rockets in various sizes the past 5 years or so and i obtained loads of different tubes during the time. And if there´s something you learn by that , is that wall thickness isnt all (in some cases it doesnt matter at all) . The strenght of a tube comes from the paper and more important from the glue which was used during manufacture. I got a lot of different tubes from germany (since its where im located) but also got tubes from sweden , Uk and US . The tubes which were sold by an english site not so long ago (europtubes .pyrotubes for europe or something like that) were actually the same precocious pyro sells in the US , and they come with 6mm wall thickness or so . First time i got these tubes i thought..damnit ..finally you found the "holy grail" of the tubes, since they seemed so sturdy and hard .. well ,they worked not too good . During the pressing ..bulged , ripped inside the support sleeve and so on .
To make a long story short ..i tried the Nept tubes, which are sold by Mr. Biersach (US) and found these to be the " holy grail" of the tubes. Once you used them at least one time you´ll never look back at any tube you used before.

So..talking about ordering tubes large scale , i would think one would go for the best tube he could get , and this would mean tubes made from virgin lightweight paper with phenol resin or other compareable resins. Tubes made that way dont need such a overkill wall thickness...3mm is all it needs . Of course you still need a sleeve, but if you pound em..you wont get these easy to bulge or to crack.

Well just my two cents

Sui

Nice rocket, pudi !

It sounds indeed like a fart-rocket , but man thats fun ! Can you give some details of the construction ?


Keep the vids comin´

Sui

Well, i agree with you guys on doing some dummy lift tests first, just to be on the safe side. Esp if you dont have an exact idea what the motor is going to lift. Sure its useful to do your math , but for my part dont think its really nessecary.. IF you have the right place (without the crowd which could get injured..) to do your tests, it doesnt matter much if your rocket goes upward or crawls to the launch tube..you´ll see what happens. I dont see that trial & error is such a bad thing esp with homade rocket motors. If the motor isnt pushing your shell high enough, adjust it ..till it does .Of course adjusting the power of your motors with live shells is indeed stupid, but you dont really need much tries to get em right. Simple rammed bp motors can lift alot.. why to do the overkill with the calcs ? Is that really needed ?

Sui

Hey ,

it´s maybe a bit unconventional, but if you are (or anyone else is) looking for just a few discs , you should be able to find an Uk shop for
building bears. The discs you can buy there are rock hard and remind one of solid wood (you cant crush such a 10cm disc with just hands..) , but it´s just a very hard compressed cardboard about 3mm thick. One drawback have these tho..they all come with a hole in em about 3 -5mm in dia, ..but well, they call the discs pin joint discs. Did a quick google on it and found the site www.christiebears.co.uk

I have to say that im located in germany, and the discs go from 10mm to 140 mm in dia .

Hopefully someone is helped with this info .

regards

Sui