oldguy Posted March 22, 2012 Share Posted March 22, 2012 (edited) Was at a pottery & ceramics supply place today, picking up some Manganese Dioxide. Browsing around a hand operated clay extruder caught my eye. It was built on the same principal as hand lever pull down stroke soda can crushers. Then the pyro genie whispered in my ear, "you could build a star extruder"…… Pondering that thought, it would not be all that tough (or expensive) to build a fair size hydraulic press type extruder with Schedule 80 PVC pipe as the hollow cylinder, with a round Acetal/Delrin piston type ramming rod with -O- rings on the rod (to maintain pressure). Both plastics (that thick) will withstand quite a bit of pressure. If one also built a guillotine type pneumatic cutter to sever the extruded composition into small pellet like pieces, as they are extruded. Bing bango, it seems to me one could knock out a lot of consistent sized cylindrical stars in very short order. Trouble is, cylindrical is not the optimal shape for a pyrotechnic star. Round is. So, how do you change a cylindrical shape to round? I seems to me either rolling them (fresh) or a flat bottom vibrating shaker table would do the job. Either way, while they were being rounded, one could spray in a little mist, along with some ignition primer comp while they are rolling, or bouncing around. Bingo bango, fairly fast mass production of primed round stars. Is this lunacy? Or what? Edited March 22, 2012 by oldguy Link to comment Share on other sites More sharing options...
gelamex Posted March 22, 2012 Share Posted March 22, 2012 I built something similar to make sausages years ago. The pipe used was 4 inch waste pipe, the piston was turned from seasoned timber with several grooves for nitrile washers. The system worked by placing twenty or so kilos of minced and mixed sausage meat into the pipe, placing the piston in and pushing it well into the pipe. An endcap was fitted with a water valve. This was connected to the water main and water pressure forced the piston down the tube, this in turn extruded the meat though the sausage nozzle. As long as the mix was not too dry it worked a treat. I see no reason why a similar system would not work with star comps as long as you were careful not to have anything that would chemically attack the pipe. Link to comment Share on other sites More sharing options...
dave321 Posted March 22, 2012 Share Posted March 22, 2012 i have thought this should be possible, with research and time and effort, whether its economical is another matter. the end of the extruding pipe should be internally tapered to form a nozzle.on top of that the compositions would have to be optimised so they are suitable plastic, this would help you turn the cylinders into spheres if required by rotating a pile of them on a fast spinning horizontal plate with herring bone serations......look up the process of ofspheoronisation, its widely used in the pharma industry to produce spheroids to put into capsules. http://www.caleva.co.uk/5_3.htmlhttp://www.caleva.co.uk/5_2.html as examples. appropriate binder choice to give plasticity to the mass also needs to be taken into account dave Link to comment Share on other sites More sharing options...
warthog Posted March 22, 2012 Share Posted March 22, 2012 This has been bandied about a few times on another forum. I think what they found was the stars made this way don't work too well but why that was is not something I can remember. Before I spent much time or especially money on this I would check it out. Link to comment Share on other sites More sharing options...
Arthur Posted March 22, 2012 Share Posted March 22, 2012 A tablet press as used in the pharma industry would take tools for spheres and as they press powder would not need much moisture to bind them ot drying to remove the water. EBAY AND YOUTUBE will show examples. Trouble now is that most tablet presses on the open market are for the illegal narcs industry and would bring you into disrepute for purchasing such a machine. Link to comment Share on other sites More sharing options...
oldguy Posted March 22, 2012 Author Share Posted March 22, 2012 With a tablet press, if you use MCNC in the Stars, you don't need a binder. That is fact. Link to comment Share on other sites More sharing options...
warthog Posted March 22, 2012 Share Posted March 22, 2012 The way a tablet press actually works though is contraindicative to the use of pyrotechnic substances. There is a fair bit of friction and shearing going on that can ignite the stuff you are trying to make into a tablet. YMMV Link to comment Share on other sites More sharing options...
oldguy Posted March 22, 2012 Author Share Posted March 22, 2012 (edited) True with metals in the mix & with impact or friction sensitive comps. That is why I am looking towards building an "extruder" type device. Edited March 22, 2012 by oldguy Link to comment Share on other sites More sharing options...
Mumbles Posted March 22, 2012 Share Posted March 22, 2012 Have you ever actually seen a pill press in action? I worked at a company that used several pill presses to make hundreds of pounds of stars per day. They function only slightly differently than a rotating single star pump. They offer no real extra safety issues except for the relatively large amount of comp one must keep around if you have the slightest idea how to use them. They are hungry machines when it comes to using up composition. Said company was the one that developed the MCNC star by the way. They never really commercialized them, but I believe they do still use a bit of solvent in the mixture to aid in compaction. Link to comment Share on other sites More sharing options...
allrocketspsl Posted March 22, 2012 Share Posted March 22, 2012 Was at a pottery & ceramics supply place today, picking up some Manganese Dioxide. Browsing around a hand operated clay extruder caught my eye. It was built on the same principal as hand lever pull down stroke soda can crushers. Then the pyro genie whispered in my ear, "you could build a star extruder"…… Pondering that thought, it would not be all that tough (or expensive) to build a fair size hydraulic press type extruder with Schedule 80 PVC pipe as the hollow cylinder, with a round Acetal/Delrin piston type ramming rod with -O- rings on the rod (to maintain pressure). Both plastics (that thick) will withstand quite a bit of pressure. If one also built a guillotine type pneumatic cutter to sever the extruded composition into small pellet like pieces, as they are extruded. Bing bango, it seems to me one could knock out a lot of consistent sized cylindrical stars in very short order. Trouble is, cylindrical is not the optimal shape for a pyrotechnic star. Round is. So, how do you change a cylindrical shape to round? I seems to me either rolling them (fresh) or a flat bottom vibrating shaker table would do the job. Either way, while they were being rounded, one could spray in a little mist, along with some ignition primer comp while they are rolling, or bouncing around. Bingo bango, fairly fast mass production of primed round stars. Is this lunacy? Or what? the reason i was asking you how difficult a cylinder is to operate is I was thinking of the cylinder acting a the pushrod and then use those play doe dies to make comets!Just got to complicated but for you a piece of cake mate,got a wheel full of drivers and your charcoal sunday! And two rockets.Hoping for long tails Link to comment Share on other sites More sharing options...
oldguy Posted March 23, 2012 Author Share Posted March 23, 2012 Have you ever actually seen a pill press in action? No expertise, but an acquaintance has a single station press, that will knock out around 1 per second. Link to comment Share on other sites More sharing options...
Arthur Posted March 23, 2012 Share Posted March 23, 2012 There is certainly one UK pyro company who use a tablet press for stars. Link to comment Share on other sites More sharing options...
dave321 Posted March 23, 2012 Share Posted March 23, 2012 There is certainly one UK pyro company who use a tablet press for stars. arthur, i've worked for Pfizer for 31 years, mostly in the solid dosage area ie, tablets /capsules. rotary type tablet presses probably would expose the comp to more friction than single station presses like the old manesty f3 machines would you care to eleaborate on the name of the company using tablet pres for stars ? i would be intersted pm me if you prefer dave Link to comment Share on other sites More sharing options...
daniel22 Posted May 22, 2012 Share Posted May 22, 2012 With a tablet press, if you use MCNC in the Stars, you don't need a binder. That is fact. Yeah I always thought that was the case. Link to comment Share on other sites More sharing options...
warthog Posted May 22, 2012 Share Posted May 22, 2012 (edited) Have you ever actually seen a pill press in action? I worked at a company that used several pill presses to make hundreds of pounds of stars per day. They function only slightly differently than a rotating single star pump. They offer no real extra safety issues except for the relatively large amount of comp one must keep around if you have the slightest idea how to use them. They are hungry machines when it comes to using up composition. Said company was the one that developed the MCNC star by the way. They never really commercialized them, but I believe they do still use a bit of solvent in the mixture to aid in compaction. sorry, never did respond to this, yes I have and there are a number of different mechanisms that are all called tablet presses I guess from your description. The few I have seen in action were at a pharmaceutical company, Eli Lilly,and those didn't work the way you are saying. They took virtually dry powder and pressed them with extreme pressure into pills/tablets in sets of dies. There was a lot of shearing action involved with the ones I saw and extremely tight tolerances. I am not familiar with the ones you are talking about Mumbles so I suppose I should say no more on the subject. My mistake, Edited May 22, 2012 by warthog Link to comment Share on other sites More sharing options...
pyroboy1438 Posted May 31, 2012 Share Posted May 31, 2012 Harbor freight has 1 1/4 cubic feet cement mixers for 150.00 that are makiing very nice star rollers! Matt Link to comment Share on other sites More sharing options...
dbryceman Posted June 5, 2012 Share Posted June 5, 2012 Hello! I actually used an extruder to make dragon eggs this year. It worked very well. I have been considering various ways to make stars bound with NC Lacquer or Acetone/Parlon without cutting them and having a stringy mess. After cutting stars for a while, the consistency of the dough reminded me a bit of polymer clay, so I was reminded of my old play-dough extruder for making hair and spaghetti etc. I found several extruders on the internet for polymenr clay, but they are small. Extruders for pottery clay are much larger, but I am not sure they are ideal for solvents and such. I finally decided on this extruder as a test sample: http://www.polyclayplay.com/Products/Extruder/ProdClayGun.htm I ordered the green aluminum version for about $18 on Amazon. It is perfect for making small quantities of dragon eggs. A lesser extruder would not do. I must admit I cringed a little when I started extruding dragon eggs, but the composition flows pretty well. I was left with a durable 2mm spaghetti that broke easily into pellets. This extruder has a piston with an o-ring on it which cleans comp from the inside of the cylinder quite well. After a few batches of dragon eggs extruded throught the 2mm round die, there was only a flake of comp left on the piston, and it peeled right off the aluminum. The extruder piston is driven by a long threaded rod, which works a lot better than a trigger-style caulk gun. The dies that come with this are simple aluminum sheet cut-outs. So far it has worked well for dragon eggs with the 2mm die and parlon star composition with the ~1/4" die, but the capacity is small. I believe a larger capacity would work, since the composition doesn't really dry out very quickly inside the extruder. I intend to build a larger model of this type of extruder from aluminum. Initially I will probably try to make an aluminum caulk gun tube with a screw-on cap to hold the die in place. I think the piston with an o-ring may work for this as well. This would be reasonably cheap, except for making the piston or having one made. After fooling with this for a weekend, I'd recommend using the Makin extruder as a prototype since the piston is very good at cleaning the cylinder, and the threaded rod really seems to be the smoothest way to extrude a thick composition. A bigger model would be handy as well because the threaded rod on this extruder feels like it will snap off easily if you try to force it. I guess next I'll cover a boilie roller with adhesive aluminum sheet and see if that works. I like the idea of perfectly round spherical parlon stars, but I don't know how well it will work since the composition will be drying the whole time you are rolling the sausage and the boilies. Link to comment Share on other sites More sharing options...
FrankRizzo Posted June 9, 2012 Share Posted June 9, 2012 (edited) How about this neat machine? I would guess that the price is ~$2,000-3,000. http://www.youtube.com/watch?v=MwEmxH0xB_I Edited June 9, 2012 by FrankRizzo Link to comment Share on other sites More sharing options...
dbryceman Posted June 11, 2012 Share Posted June 11, 2012 Howdy! Some folks have had success building their own boilie (carp bait) rollers like the one posted by FrankRizzo. I have seen the machines for sell in the UK for about 1000 Euros, but they sell mated sets of rollers only for under 500 Euros. (I'm in the USA) Textile scrolling rollers could be a substitute for these rollers, as they have a similar fluting pattern and they come in aluminum and nylon flavors. I'm planning to try a cheaper hand roller just to see if it works. The only problem with the hand rollers is they are all plastic (I think polystyrene?) so I am pretty sure acetone is going to have its way with it. I have adhesive foil which could protect it for a test but a permanent set of plates would likely need to be made from a better material. As long as the dough stays damp long enough it should work in theory! Now I just have to find a supplier selling them in the USA. It seems that home-made boilies are far more popular in the UK. One hobbyist posted this .pdf explaining how he built a machine like the one in the Youtube video above. http://www.atc-carpfishing.be/ATC-Carpfishing/Projects_files/My%20Boilie%20Machine.pdf I'm confident that design would work for parlon stars. I am partial to aluminum because the dough generally doesn't stick to it, but it may do just fine on nylon rollers. If I can ever get a portable 'field' boilie roller shipped to me I'll build the poor guy's version and let you know. The worst case is I learn something and pay $20. My hope is that the two plates in the roller do not actually make contact except on their mated surfaces for sliding. If the individual ribs in the plate are rubbing, I am concerned about the friction. Here's what a field model or hand-roller looks like: http://progressive-baiting.de/shop/en/Bait-Making-Equipment/Mammut-Hand-Rolling-Board/Mammut-Boilie-Roller-10mm?source=2&refertype=1&referid=49 A set of plates or rollers is required for each size you would make - so I am more interested in the manual boilie rollers at the moment. I have watched people make boilies on plates and they go really fast. There are two methods I am aware of - extrude a sausage of dough using an air powered extruder and then lay the sausage perpendicular to the grooves in the roller. Place the lid on, slide the top back and forth a few times, and drop out your finished spheres. The diameter of the sausage is critical, so most handheld boilie plates have a flat back designed to roll the right sized sausage on a flat surface instead of extruding. This would be the second method. Oldguy - You might be interested in these air driven extruders. I didn't like them for pyro, but they will fire super-slime at kids in the next neighborhood with little pressure. Since my post regarding the aluminum polymer clay extruder, I have seen several extruders out there with large capacity and metal bodies, but they are all trigger driven like a typical caulk gun. If I go with an extruder, I imagine I will beg someone with metal-working skills to build an aluminum caulk tube with a brass or aluminum plunger, grooved for an o-ring. Any caulk gun would do fine for my purposes... but I still really like the threaded-rod-driven plunger used by the tiny extruder I bought to play with. If I have any success with a plastic plate, I will have a set of alumimum plates manufactured for this purpose just so I have a trophy. Best of Luck! Link to comment Share on other sites More sharing options...
LehighValleyPyro Posted July 13, 2012 Share Posted July 13, 2012 (edited) I worked on tablet presses for about 5 years. They absolutely do work for stars. I know of at least one fireworks manufacturing company that uses tablet presses daily to make stars. Can't say who. One company I visited, I won't say who, was making flammable tablets for airbags with tablet presses. They had the presses behind a blast wall. Another application I haven't seen considered - star cores! I've seen tablet press punches as small as 1.5mm. You won't see that on a piece of junk Manesty though Edited July 13, 2012 by LehighValleyPyro Link to comment Share on other sites More sharing options...
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