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Discussion in 'Propulsion' started by gorillamotors, Jul 19, 2019.
Here is a poll to determine which nozzle composition you prefer?
Relaunching Gorilla motors?
There are times when you want a lower weight, single-use or an eroding orifice you might choose a phenolic nozzle.
Or, as most do, use a graphite in a re-usable snap-ring system.
Or some mixed variant in a holder for larger projects.
So - depends
Or, "yes" to all.
What gets the job done, reliably, with good cost/weight/availability?
What size motor?
To answer your question...Graphite
I mean high quality Graphite
54mm thru 98mm
To the zoo crew , Jim will get that , I would stay old school . Do not change any hardware . You are the only other snap ring motor company . A large selection of the flyers already have GRM hardware or comparable hardware . Keep it classic .
If I recall correctly, one of the nozzle "manufactures" made a statement on TRF a while back that the lower/mid grade graphite actually made better nozzles and worked better for nozzles than the "high grade" graphite and was cheaper. The reason he didn't make nozzles with the better mid grade graphite was because customers demanded the "high quality" graphite despite the fact it actually made a lower quality nozzle.
100 percent correct. I will let the manufacture speak for himself if he wants.
before I started making graphite nozzles, I bought some that turned out to be large particle and they are very porous
don't clean one and then use it the same day without thorough drying, the soaked up liquid will flash to steam and explode the nozzle
I make all mine from iso molded
You should not soak any graphite nozzle, even iso will absorb water
High density is the most important factor.
Partical size is second. Medium to fine will go along with density.
For >98mm or longer burn, isolmolded high density is worth the cost.
For <98mm and <4-sec burn, moderate density is ok.
Make sure it is graphite and not molded carbon electrodes. Graphite will be dark gray when rubbed on a surface. Carbon will be black. Carbon is good for maybe one firing.
not sure why you said that (You should not soak any graphite nozzle, even iso will absorb water)
my iso never has, maybe yours is different
I interpret your "soaked up liquid", not as actual immersion/soaking but simply some cleaning fluid absorbed during cleaning. I think some people might/did interpret your statement a bit wrong due to at least one comment following your post.
I don't have any examples to show of the large grain graphite nozzles as they all shattered after 2 or 3 uses, one I have to guess from soaking
I have iso nozzles that have been fired 15 to 20 times
take your choice, YMMV
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