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Nozzle forming rammers, whats the even part on the convergent part for?


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Posted (edited)

That inserts into the tube and holds it vertical.

 

Oh wait, you mean the internal one... That prevents "sticking" and making it hard to pull out. Personally, I wouldn't buy one with that ring. Who cares if you have to twist it a little hard to get it unstuck! You get a better rocket without it.

Edited by usapyro
Posted
The portion of the nozzle convergence which meets the tube wall can easily chip or break if the forming rammer does not have that shoulder. It also keeps the first increment of comp from being too short and interfering with the clay nozzle. And the third reason the shoulder is used deals with keeping the rammer pressure pushing down rather than out.
Posted

Neighbor nailed it. The tube usually expands a bit while compacting the clay nozzle. Without that little flat, the clay is more likely to extrude up between the rammer and the side of the tube and fill the space. If that happens, a portion of the rammer is encased in clay and becomes extremely difficult to remove.

Posted

I disagree with usapyro 100%.

Posted

I disagree with usapyro 100%.

 

Just tap your tube on the table after you press your nozzle, anything that will fall off, falls off. Easy!

Posted

Yeah, once you get the drift out you can do that! I only ever used one set of tooling that did not have the flat ring on the first drift. Even in the 1/2" size, it was a PITA to get the drift out! I see the value of the flat area, and I think it's important enough that I come on here to disagree about it with you again, usapyro. Caleb is a friend of mine, and I use his tooling all the time. It is very good tooling that will do exactly what it is sold to do. Just sayin'.

Posted (edited)

Yeah, once you get the drift out you can do that! I only ever used one set of tooling that did not have the flat ring on the first drift. Even in the 1/2" size, it was a PITA to get the drift out! I see the value of the flat area, and I think it's important enough that I come on here to disagree about it with you again, usapyro. Caleb is a friend of mine, and I use his tooling all the time. It is very good tooling that will do exactly what it is sold to do. Just sayin'.

 

I didn't even put a hole through the back of my homemade tooling to assist with removal, and I have no issues pulling it back out! This tool I made shapes the internal nozzle on my end burners now. Of course, I do just ram everything.

 

post-11032-0-06892700-1498177259.jpg

 

I bet Caleb's tooling is great, but I'm just saying... I don't like the ring. It means a few sparks are going to get trapped on it and not make it out the nozzle, or take longer to make it out the nozzle... Were only talking like a 10% loss of tail effect at most, but any loss of tail effect I don't want! It's a bigger problem than you think. I was running a 90% loss of tail effect using a flat internal nozzle on my new higher pressure rockets when using very small nozzles. That was before I shaped the internal nozzle with the above tool.

 

My process. I just ram the nozzle in, pull this back out, tap it on the table to get the weak/loose bentonite out, and switch to a flat faced rammer... In goes the BP increments! I use custom made U shaped drills now for drilling out the nozzles. I use many different sizes... I tune them with a angle grinder for different powders, lol...

 

It got me thinking though... Perhaps I should do 1/3rd of the nozzle... The back internal part with a +15% paraffin Bentonite clay. Anyone do anything like that to hold a more consistent tighter edge on the internal nozzle? I am looking for the BEST optimized delivery of pine sparks/FeTi/etc to the nozzle.

 

 

Here is an experiment for you to do... Take an end-burner with a flat faced internal nozzle, put two guide sticks on it, and then put two angled fins beside each to generate some spin. Doesn't need to be that fast The centrifical force will cause all FeTi/Pine Sparks/Etc to just pile up in the tube against the outside of the internal nozzle. You will see hardly any tail effect at all.

Edited by usapyro
  • Like 1
Posted (edited)

Little overkill... But now I do my nozzles with a increment of powdered +10% paraffin kitty litter*, then normal 15-20 mesh kitty litter*, and then another increment of powdered bentonite with +10% paraffin. If I get lazy, I will probably just use the powdered waxed bentonite only. Just worried the waxed stuff will erode a bit more.

 

This makes for a VERY tight edge where clay meets the tube... Even after tapping it on the table to get rid of loose/weak clay.

 

*Bentonite, scent crystals screened out. Not sure what brand... Label is gone. Bought it years ago. Stuff comes out solid with no erosion. It's not the soft bentonite I have gotten from pryo suppliers. Stuff requires some serious hammering to compact!

Edited by usapyro
Posted

Thanks, now i understand it.

 

I thought this little step would be a hindrance for the gasses, especially in Endburners.

But since many reputable pyro toolmakers use it this should not be much of a problem

Posted

Thanks, now i understand it.

 

I thought this little step would be a hindrance for the gasses, especially in Endburners.

But since many reputable pyro toolmakers use it this should not be much of a problem

 

Probably less than a 0.5% effect on performance. No, it only really could noticeably affect your tail effects.

Posted

Then I better ask my toolmaker to include this. Thanks.

Posted

See, I press all my rockets, and I use a pretty high pressure too. usapyro, for me, yours or similar tooling would be a problem. But, if you are hand-ramming- which I never do- I could see how your tooling would be good. I meant no disrespect by disagreeing, and actually should have thought more about it before commenting. There are lots of different ways to make good rockets and I appreciate knowing of your way too. :)

Posted

See, I press all my rockets, and I use a pretty high pressure too. usapyro, for me, yours or similar tooling would be a problem. But, if you are hand-ramming- which I never do- I could see how your tooling would be good. I meant no disrespect by disagreeing, and actually should have thought more about it before commenting. There are lots of different ways to make good rockets and I appreciate knowing of your way too. :)

 

I'm thinking about building a motorized drop hammer, or whatever they call them.

I could also automate it to drop in an increment of powder upon each lift of the hammer... The trick is getting it to accurately guide the rammer back into the tube each time. Hmmm...

 

But, wouldn't that be sweet, fully automated way to make rammed rockets!

 

Anyone here have a automated increment press? Would be much more complicated with the hydraulic switching involved... Because it needs to reverse once a specific PSI is reached, then pull out, increment powder, then press again.

Posted

USA,
My prior employer has such a press to automatically make highly-consistent gerbs and line rockets. One loads bulk tubes in one hopper, bulk gerb or rocket comp in another, and bulk clay in another.

 

Then you select one of about 50 different products from a screen menu, and press 'Go'. It presses until you stop it, or it has a jam, in which case it pauses for the operator to clear the issue.

 

Air-powered, not hydraulic. But it dwells on each stroke until the pressure reaches the desired preset point.

 

A couple of people here in the forum have actually seen the press, so it's a more-realizable goal than you might think.

 

Lloyd

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