[SS2S-Main] Re: Material for Nozzle fabrication

  • From: Rick Maschek <rickmaschek@xxxxxxxxxxxxxx>
  • To: "sugarshot@xxxxxxxxxxxxx" <sugarshot@xxxxxxxxxxxxx>
  • Date: Wed, 7 May 2014 11:51:41 -0700 (PDT)

Word of mouth, posting on various websites, etc.
After all, that is how any list gets populated.
On Wednesday, May 7, 2014 11:38 AM, Steve Peterson 
<steve_peterson@xxxxxxxxxxxxx> wrote:
But how would they know to look for it at freelists.org? Just word of mouth 
(I'd mention it here, of course, and maybe that would be enough?)


On 05/07/2014 10:41 AM, Rick Maschek wrote: 
If you start the list it will be repopulated very quickly, trust me. I will be 
the first 'subscriber'. 
>On Wednesday, May 7, 2014 10:35 AM, Steve Peterson 
>mailto:steve_peterson@xxxxxxxxxxxxx wrote:
>Hey Rick,
>I'd have started a freelist version of sugpro myself
                    but to really get it going again we need the old
                    subscriber list. I even thought about harvesting
                    some old subscriber email addresses from the
                    archives that are still around, but haven't felt
                    that it was my perogative to just go ahead and do.
                    Still, it *is* tempting....
>On 05/07/2014 08:29 AM, Rick Maschek wrote: 
>>I remember that thread on sugpro and have done something similar since I have 
>>had to make a 6" graphite/phenolic nozzle for an APCP motor we are doing. 
>>Having made steel nozzles on my lathe doing that graphite would have been 
>>I have many things I would have liked to post on sugpro if it were still up 
>>and running. When the sugarshot went down I suggested to Richard we go to 
>>freelists. Putting sugpro back up would be very easy on freelists if someone 
>>would like to do that.  
>>Here is the link: 
>>FreeLists - Free Mailing List Hosting  
>> FreeLists - Free Mailing List Hosting 
>>FreeLists provides free mailing list hosting for technology-related topics    
>>View on www.freelists.org  Preview by Yahoo  
>>On Wednesday, May 7, 2014 5:03 AM, Steve Peterson 
>>mailto:steve_peterson@xxxxxxxxxxxxx wrote:
>>(Can we PLEASE get sugpro up and running on freelists.org??)
>>The last time this issue came up
                                      on sugpro, the suggestion was to
                                      use one of those drywall sanders
                                      that run the air through water
                                      before exhausting it. I don't have
                                      a link handy, but as I recall the
                                      item wasn't that expensive and was
                                      available at home improvement
                                      stores and the like.
>>On 05/07/2014 04:15 AM,  (Redacted
                                      sender monsieurboo@xxxxxxx for DMARC) 
>>>Because I occasionally machine graphite and this is the first time I've seen 
>>>this particular concern raised, I did an online search for info.  I'd 
>>>characterize it as showing broad consensus but not unanimity.  Based on 
>>>that, I've formed my own conclusion but really think anyone who creates 
>>>graphite dust should review the literature yourself and assess your own 
>>>operations accordingly -- always keeping safety foremost.
>>>That's a fascinating
                                                  and clever use of
                                                  graphite in mining. 
                                                  LOX, like other highly
                                                  oxidizers, will
                                                  sensitize most
                                                  organics so I can
                                                  certainly see a
                                                  combination of tamped
                                                  graphite saturated
                                                  with LOX being
                                                  effective.  Here we
                                                  have three separate
                                                  cases (the mining
                                                  case, graphite dust
                                                  dispersed in workspace
                                                  air, and graphite dust
                                                  dispersed in the
                                                  shopvac canister or
                                                  bag).  The fuel
                                                  density and A/F ratios
                                                  are different for each
                                                  case, as is the
                                                  likelihood of an
                                                  ignition trigger. 
                                                  It's certainly
                                                  interesting to juggle
                                                  the variables involved
                                                  while pondering the
                                                  importance of "safety
>>>I rarely cross-post but this might be a good question to pose on arocket.  
>>>It's been pretty quiet over there for the past week and the response from 
>>>that bunch could be informative.  Any objections?
>>>Mark L.
>>>-----Original Message-----
>>>From: Cliff Bates mailto:cliff@xxxxxxxxxxxxxx
>>>To: sugarshot mailto:sugarshot@xxxxxxxxxxxxx
>>>Sent: Wed, May 7, 2014
                                                12:54 am
>>>Subject: [SS2S-Main] Re:
                                                Material for Nozzle
>>>    I might suggest here that carbon dust is "extremely" explosive if mixed 
>>>with the proper amount of air and ignited.  In fact carbon dust was used 
>>>back in the 1920's in mining to replace dynamite.  A cardboard tube of 
>>>packed carbon dust was soaked in liquid oxygen for 15 minutes, then stuck in 
>>>the blasting hole.  If the charge failed to go off for some reason, after 30 
>>>minutes the O2 evaporated enough that the explosive aspects of the charge 
>>>became inert, so it could be drilled out.  Unlike the dynamite filled holes 
>>>that the "new guy" got to dig out........... alone. 
>>>    Machining graphite is extremely dirty if a vacuum cleaner is not used, 
>>>as someone earlier pointed out.  THE THING TO WATCH is the arcing brushes on 
>>>the vacuum cleaner motor igniting the dust if the vacuum cleaner exhausts 
>>>through the motor housing, as most do.  I'd strongly suggest that the vacuum 
>>>cleaner bag be double bagged to assure the dust is all caught inside the 
>>>can.  If not, a dust explosion could very likely occur from the arcing motor 
>>>brushes as the air/carbon mixture flows by, and it will not be a nice thing. 
>>> Years ago I accidentally sucked some coal gas fumes into my 5 gallon shop 
>>>vac while cleaning up after some blacksmithing.  The vacuum exploded, 
>>>splitting the can wide open and throwing the lid with a 1 horse motor still 
>>>attached, about 30 feet in the air.  Graphite/carbon dust is much more 
>>>energetic than coal gas fumes, and why air powered drills are used in coal 
>>>    If you doubt this, take a large coffee can with a slap on lid.  Drill a 
>>>hole in the side of it to fit a small 1/4" hose.  Attach a small funnel to 
>>>the hose inside the coffee can and put a small amount, half a teaspoon, of 
>>>flour in the funnel set up vertically.  Take a birthday candle and put it in 
>>>the can.  Light the candle, then snap on the lid.  Quickly blow into the 
>>>hose to mist the flour before the candle burns up all the O2 and goes out.  
>>>Be sure to be back about a meter or so from the can due to the exiting lid.  
>>>    You can use this method to test various dust samples, including powdered 
>>>sugar, coal, graphite, flour, corn meal, fine wood dust, etc., etc.  A 
>>>larger can with the same amount of "fuel" and candle will usually produce a 
>>>more energetic response than a large coffee can due to more air being 
>>>available to burn the fuel.  However the idea here is not to level your 
>>>shop, but just some food for thought about something that is normally not 
>>>----- Original Message -----  
>>>>From: Hans Olaf Toft  
>>>>To: sugarshot@xxxxxxxxxxxxx  
>>>>Sent: Tuesday, May 06, 2014 9:11 AM 
>>>>Subject: [SS2S-Main] Re: Material for Nozzle fabrication 
>>>>When using graphite for nozzles - keep in mind that it is a surprisingly 
>>>>good heat conductor.
>>>>On 05/06/2014
                                                        02:39 PM, Steve
                                                        Peterson wrote:
>>>>The Graphite Store (http://www.graphitestore.com/). Right now, 2" rod, 48" 
>>>>long (medium extruded) is selling for $66.50. That much steel would be a 
>>>>lot more expensive. Unfortunately, I don't see any smaller diameters in the 
>>>>medium-grained; they do have smaller diameters in the fine-grained but it's 
>>>>more expensive--for instance 1" diameter by 24" long is $43.90. I would not 
>>>>recommend trying to machine away a 2" diameter chunk if all you need is 1" 
>>>>diameter--a vacuum helps control the dust, but it's still messy. 
>>>>>I used 12L14 for
                                                        years before I
                                                        switched to
                                                        graphite and I
                                                        still make steel
                                                        nozzles on
                                                        occasion. I
                                                        never saw any
                                                        erosion with
>>>>>If you do go
                                                        with graphite
                                                        you can make a
                                                        "form tool" for
                                                        the convergent
                                                        and divergent
                                                        sections which
                                                        makes the
                                                        turning go much
                                                        grind down a
                                                        spade bit, it
                                                        doesn't have to
                                                        be that sharp to
                                                        get the job
>>>>>On 05/06/2014
                                                        03:59 AM, 
                                                        (Redacted sender 
monsieurboo@xxxxxxx for DMARC) wrote: 
>>>>>Strangely enough, the mid-grade (medium-grained) graphite tends to do the 
>>>>>job better than the high-end, fine-grained material.  Less erosion, 
>>>>>perhaps due to larger grains interlocking better and being ablated more 
>>>>>slowly.  And of course, less expensive.
                                                          definitely the
                                                          way to go, but
                                                          you don't want
                                                          fine dust
                                                          getting into
                                                          (such as a
                                                          mini-lathe) so
                                                          try to capture
                                                          the dust at
                                                          its source.  
>>>>>>Mark L.
>>>>>>-----Original Message-----
>>>>>>From: Hayk
>>>>>>To: sugarshot mailto:sugarshot@xxxxxxxxxxxxx
>>>>>>Sent: Tue, May
                                                          6, 2014 5:53
                                                          Re: Material
                                                          for Nozzle
>>>>>>Thanks for your input Jeff. Where do you recommend I buy graphite from? 
>>>>>>On Monday, May 5, 2014 4:58 PM, Jeff Moore <tnetcenter@xxxxxxxxx> wrote:
>>>>>>Graphite would probably be the most affordable of materials to use.  We 
>>>>>>had a machinist in our local group at one point and he made a titanium 
>>>>>>nozzle as a proof of concept.  That would more than likely be rather 
>>>>>>pricey for this project ( his was for a 54mm motor).
Aluminum is a good material to practice on or do mockups with, but I suspect 
that it's melting point is way too low to be used as the actual nozzle.  It 
might work as a carrier for a graphite or ceramic insert though.
Jeff Moore 
Bend, Oregon
>>>>>>On Mon, May 5, 2014 at 4:10 PM, Hayk Azatyan 
>>>>>><dmarc-noreply@xxxxxxxxxxxxx> wrote:
>>>>>>Hello all, 
>>>>>>>Would you all happen to know where I can get my hands on some scrap 
>>>>>>>circular steel bars for rocket nozzle fabrication?And if you have any 
>>>>>>>suggestions on the material I should use please let me know. I have 
>>>>>>>already started using the lathe, and currently I am machining a nozzle 
>>>>>>>out of aluminum. Although I will not be using this particular nozzle for 
>>>>>>>flight I figured I should practice making one out of some scrap metal 
>>>>>>>that I found(in this case aluminium). I know that you guys make some of 
>>>>>>>your nozzles out of graphite, but for now I am learning to machine metal 
>>>>>>>nozzles just for educational purposes.
>>>>>>>Thank you guys!  
>>>>>>>-Hayk Azatyan        

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