6mm Reload composites?;dream or a possibility?

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Couldn't you solve the ignition problem by using a D slot configuration? that way you can use a mini copperhead?
 
First reaction.... NUUUUUUUUUOOOOOOOO!!!!!! Not more Copperheads!!!!

Second reaction: still not gonna work. You're talking about a really tiny Copperhead - almost thread-thin - and it's gonna be well-nigh impossible to get that into a teeny tiny nozzle without snapping it.

Let's face it - there is almost no way to get a 2-wire igniter or Copperhead, of any sort, with any pyrogen at all, into a 1.2 mm hole. It's not gonna be easy, and no way anyone is gonna make a commercial system out of it.

If you want one, then you are going to have to wait at least 6 years, until when you are 18, L2 certified, and possibly possessing a LEUP. And please, get some experience making larger motors first, because starting with a non-commercial case and tiny motor parts does not sound like a good idea...
 
Why dont you put 6 foot (diameter) reload composites on your bucket list, sounds more exciting to me.
 
How much do you think it would take to pay aerotech to start making 6mm propelent kits and produce them under my name? $10k? I bet I could get rouse tech to make the hardware, problem solved
 
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ScrapDaddy said:
How much do you think it would take to pay areotech to start making 6mm propelent kits and produce them under my name? $10k? I bet I could get rouse tech to make the hardware, problem solved
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Never heard of that company - "areotech." :confused2: And what is "propelent?" :confused: Has anyone besides Scrappy ever heard of them?

Mark K.
 
ScrapDaddy said:
How much do you think it would take to pay areotech to start making 6mm propelent kits and produce them under my name? $10k? I bet I could get rouse tech to make the hardware, problem solved
Click to expand...

I bet that wouldn't even pay the liability insurance!
 
For some reason, I missed this thread earlier in the month.

About 8 years ago, I made some 11mm composite motors with carbon-fiber casings. The casing material was made from larger-diameter arrow shafts. The nozzles were molded from furnace cement (some with a ceramic washer throat), and I also made some tiny graphite nozzles.

https://thrustgear.com/micro/

I've made up to 6" diameter P motors, but these tiny composites were by far the most challenging to make of any size!

To get a reasonable long burn, it has to be an end-burner. To get reasonable thrust from an endburner, it has to be a very fast propellant. This means handling additives and particle sizes that are riskier than normal. For example, the same propellant as a core-burner in a 38mm casing burned in 0.4 secs with 100 pounds of thrust!

Next problem is getting an igniter in the nozzle and getting it to light. I'd pre-coat the end of the grain with pyrogen and insert a very fine gauge nichrome igniter. Nothing else would fit through the nozzle. I'd get about 1 out of three to ignite.

The biggest problem with a long endburner is heat soaking into the casing and burning through. To get enough volume of propellant and keep the diameter small, the liner and casing can't be very thick. An aluminum casing (or ceramic) would be better, but too expensive and time-consuming to produce.

-John
 
instid of carbon fiber why not use aluminum arrow shafts.

I took some rcandy and stuffed into a used mmx case after i cleaned it out even reused the nozzle. i took a drill bit and drilled out the core about 3/4 the way through so i would have a delay put some power on top of the rcandy for ejection charge. took a standard igniter for mmx and lit it. It worked and about as well as the mmx motor even had almost a 2 sec delay. but i want do it again its just to much work for what ya get
 
kullas said:
instid of carbon fiber why not use aluminum arrow shafts.

I took some rcandy and stuffed into a used mmx case after i cleaned it out even reused the nozzle. i took a drill bit and drilled out the core about 3/4 the way through so i would have a delay put some power on top of the rcandy for ejection charge. took a standard igniter for mmx and lit it. It worked and about as well as the mmx motor even had almost a 2 sec delay. but i want do it again its just to much work for what ya get
Click to expand...

Kullas:
I'd be willing to bet if you measured the output your thurst is only about half if that of the original motor, at least that what we've observed in the past with AP.
 
i was using KNO3 and sugar with a little RIO. by the time ya rolled it into that small of a ball to stuff it in there it was hard :( just to much work for such a small motor
 
ben_ullman said:
Green Monkey Aerospaces name can be displayed on TRF, not sure why people have issues with that.

6mm reloads are not that hard. reloads would be a pain to assemble but not that bad.

Ben
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I checked out the Green Monkey website. Where do you get reloads?
 
This is all great, as long as you don't live in Cali.. if you do you would need a cal pyro 3 and a Level 1 cert to fly a 1/2 "A" motor :roll:
 
The E27 reloads were only about 22 N-s, and were available with a four second delay. The propellant grain and delay element filled the available space in the casing. You could only use this reload in rockets that weighed between 10 - 14 ounces. The E27 was discontinued probably for the same reason that the E25 single use motors were discontinued. They were barely an E and didn't offer enough value over the D21, D13, and D24 motors that are currently manufactured.

ScrapDaddy said:
Well I can see where you are going with the B and C reloads but what was the problem with the E27 reload? It really doesn't have a compeditor in the 18mm range.
Click to expand...
 
DaveHein said:
A 6 mm reload? We're talking about 6 millimeters, correct? Isn't that less than a quarter inch? I don't get it! :confused2:
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Neither do I, and I think that SD realizes now how unrealistic it would be. When I showed him a MicroMaxx motor this summer, he was shocked at how tiny it was.
 
DaveHein said:
A 6 mm reload? We're talking about 6 millimeters, correct? Isn't that less than a quarter inch? I don't get it! :confused2:
Click to expand...

It is the challenge to make it work! As others have mentioned, manufacturing gets progressively more difficult below a certain size. And if you are into research/experimental motors, the ability to launch in your back yard is a big plus.
 
making life too hard....

Thinking outside the box, the goal is cheep not reuseable,

1) why not make a nozzle AND case by swaging a piece of thin steel tube, when you swage the nozzle the material gets thicker, not a lot of erosion on something this small, is it optimized, nope is it good enough, maybe, is it cheep and strong, heck yes. Can do by hand, swiss screw machine would pop them out.

2) casting grains, cast a sheet and stamp them out, stack them like a roll of 'Smarties' (end burner) or Lifesavers (core Burner). put the igniter in from the top side and feed the wires out before pressing in the forward closure, could even have a black powder 'Smartie' on top of the stack.

3) forward closure, press fit /swage. Simple tool again cheep and good enough would not be hard to seal.

4) Ignition,
A) put the igniter in from above (see item 1 and 2)
B) treat one of the 'smarties' with conductive pyrogen, short the case for one wire of the ignition system and have a needle touch the pyrogen on the 'Smartie' on the inside. You will need to have some insulation where it passes through the nozzle but that can be as simple as magnet wire insulation (varnish).

make patent royalty payments to...
 
Once again, where is the market for this
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Not really a market at all, I thought that was a given at this point,

But, if you wanted to do it I just threw out one way to go...

the patent payment comment was a joke...

My latest patent cost around $10k by the time the dust settles. I don't think that the ROI is very promising for 6mm reloads.
 
It can (has) be done- Jimmy Yawn posted this to the SugPro list
in December 2008 -

...interesting gentleman in
Switzerland, Mr. Torbjörn Winther, who is active in sugar rocketry, and
has made some small motors.

Very small motors.

I've placed photos of a few of his works on the web at:
https://www.jamesyawn.net/winther/
Click to expand...
 
kramer714 said:
Not really a market at all, I thought that was a given at this point,

But, if you wanted to do it I just threw out one way to go...

the patent payment comment was a joke...

My latest patent cost around $10k by the time the dust settles. I don't think that the ROI is very promising for 6mm reloads.
Click to expand...
OK then. Way back when the thread started it was to ask why Company A or Company C didn't make 6mm diameter reloadable motors (or Company G or Company L). but it was so long ago I forgot how that particular question was resolved. But sure, I get what you are saying. Someone might want to build such a motor just for the coolness factor. I have been tempted to buy an RMS 18/20 motor just to have a miniature reloadable motor. It's pretty small, after all. A 6mm reloadable would be one third the size of it! As I mentioned earlier, when I met the OP at a club launch this summer and showed him an actual MicroMaxx motor, he was astonished. He told me that he had not realized how small 6 millimeters actually was. Now Quest can just barely fit 0.218 Newton-seconds of impulse (plus a vanishingly brief delay grain and a tiny but surprisingly capable ejection charge) into the existing MMX motor length (6mm x 25mm, roughly 1/4" by 1"). It's packed like an 18mm C6-7 - completely full end to end with not a hair's breadth of space left over. Granted, this is with black powder. And the opening in the clay nozzle is barely visible without magnification. In order to improve on the 1/8A impulse (increasing it to, say, 1/4A) would require a much longer case. So setting aside for now the issues of whether you can reliably cast propellant grains that small that can be handled and loaded and all of the issues with using truly tiny parts, has anyone ever successfully burned 2" or 3" long composite fuel grains that were loaded inside a 5.25mm to 5.5mm ID metal tube that was sealed at one end? Is a burn even stable and sustainable over that length within such a narrow space? I don't know what the answer is; does anyone?
 
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It might be cool if Quest would make an MMX that was a bit longer......maybe 1 1/2" to 1 3/4" long, like they did with the old Minimaxes
 
Gnomad said:
While looking for something else, I re-discovered this page on 6 mm reloadable sugar motors:

https://jcarter.privatedata.com/6mm%20Motors.htm

Be sure to follow the "more info" links, there are several pages with a fair bit of info and pictures.
Click to expand...

I guess the question of "can it be done" is now definitively answered.

Great post!

I found it interesting even if its not something I think I would want to try.
 

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