chuckufarley Posted January 8, 2017 Posted January 8, 2017 What thickness chipboard do you use? I have a hard time finding 1/8" board. Do you use thinner stuff and just laminate it to the desired thickness?
OldMarine Posted January 8, 2017 Posted January 8, 2017 I check the picture framing section regularly. They often have 1/8" matting and sometimes even have backing in that thickness. I got 2 sheets in a hideous flat pink today for $3 bucks. Apparently Pepto-Bismol isn't a popular color.
chuckufarley Posted January 8, 2017 Posted January 8, 2017 Reminds me of the color of an announcement on a certain fireworks forum that you loved so much a few months ago. I will check that out though, there's a hobby lobby not far away from me. A Michael's too.
MrB Posted January 8, 2017 Posted January 8, 2017 I had thought about using 1 to run a star roller as they are sealed, but it still concerns me because there is always that potential for something to go wrong. A good sealed motor shouldn't pose more risk then any other means of getting the roller to rotate. Given that it has an electric controller, you should be able to go with direct drive, and smile?Honestly tho, a ball mill is a lot more sensitive in this regard, the star roller isn't as much of a hazard, since the bulk of the composition in it's reach should be wet, or solid chunks that wont burn very fast anyway. Using a (toothed) belt drive isn't really an issue. Well, in my opinion. It's good to stay safe, but at what point are you going to go with belt drive over possible static buildup from the air powering the thing? B!
PIL Posted January 10, 2017 Posted January 10, 2017 Fotia, I will agree that cut stars don't burn as long as pressed ones. I recently did some testing on burn times, and found this to be true. For me, I build over 400 shells per year, and rolling is the most efficient way to make large amounts of stars. Also, the ability to make color changing stars is nice. Furthermore, for me it is easier to prime stars in the star roller, as opposed to priming pressed stars. And lastly, for ball shells, they stack better. Those are my reasons for rolling. I do press some stars, and I cut some too.. but 90% of my stars are rolled. Your TT to color shell looks great.Which method did you follow to roll charcoal stars ？ Did you add any alcohol to break the surface tension？
Nessalco Posted January 10, 2017 Posted January 10, 2017 Do you have a pic of the spring loaded ejector pump? http://www.amateurpyro.com/forums/topic/12003-my-homemade-comet-star-pumps/
Fotia Posted January 10, 2017 Author Posted January 10, 2017 Mr B quoteHonestly tho, a ball mill is a lot more sensitive in this regard, the star roller isn't as much of a hazard, since the bulk of the composition in it's reach should be wet, I disagree. The comp that you are sprinkling/throwing onto the rolling cores isn't wet and the whole batch is open/exposed to any spark/flame. Where as a ball mill is sealed. As far as static build up from the air flow, I can always place a ground on the hose. Same as I have on my ball mill.
LiamPyro Posted January 11, 2017 Posted January 11, 2017 If you're making smallish batches (50-500g?) I'd go with a star plate. I threw together one using some thick HDPE cutting board type material with 20 5/16 brass pins. There is considerable pin-hole clearance, as the board with the pins warped slightly and the holes aren't perfectly aligned. That being said, it works great and didn't seem to be bothered by willow diadem (containing unscreened titanium and ferro-titanium). For me, the process is smooth and quick, and I find it much more efficient/satisfactory than my few attempts at rolling. (It should be noted that I used small quantities (150g) in a barely functioning mess of 2x4s, a drill, a 5gal bucket and some steel bar weights, so I probably shouldn't be comparing the two techniques).
MrB Posted January 13, 2017 Posted January 13, 2017 I disagree. The comp that you are sprinkling/throwing onto the rolling cores isn't wet and the whole batch is open/exposed to any spark/flame. Where as a ball mill is sealed. It is indeed dry as you throw it on, but you more then compensate this with the fact that the star-compositions doesn't burn as violently, and you don't have as much new where ever it could take fire. If your actually storing the composition your adding to the stars next to the star roller, where it is viable that it could catch fire, then you are doing something wrong.B!
Mumbles Posted January 13, 2017 Posted January 13, 2017 Regardless, burns suck trust me. I'd rather spend a little more money and deal with less convenience and just get a sealed motor. I mean, you have to stand next to it while using, where as a ball mill can and should be run remotely.
Fotia Posted January 13, 2017 Author Posted January 13, 2017 And there is thermal heat from the motor casing. Not sure if it would be hot enough to ignite the powder but if I can figure a way to do it safer, I'm going to dig deep and spend more time & money even if it's just research & building. I could always encase the motor, but it needs open air or circulating air to keep from burning the motor up. Perhaps a screen mesh with filter elements & a fan on the inside against the filter to push/pull air. Even at that,it would have to be a sealed container and a fine filter. I work in a machine shop & that damned welding dust gets everywhere.
dynomike1 Posted January 13, 2017 Posted January 13, 2017 In the past 7 days I've ordered; 10 lbs of Indian Black aluminum, the Best of AFN, The Westech Manual,6 lbs of milled phenolic resin, 10 lbs of saran and some tubes.The pyro Dragon should belch some pretty fire after digesting all that green!Where did you find milled phenolic. I am not going to mill that stuff again if i dont have to. I think i had to give $9.00 a sheet for chipboard at Hobby Lobby, i'll have to look closer next time. My windshield wiper motor is a sealed motor. I would think you would pick up more static off of the plastic than the motor.
Fotia Posted January 13, 2017 Author Posted January 13, 2017 Yes, plastic can create static as well as air passing through a rubber hose, but I have been thinking of having a grounding station with different cables/attachments at the work bench with some way of attaching what ever I'm working on with a ground cable attached to a grounding rod driven into the ground.
MrB Posted January 13, 2017 Posted January 13, 2017 Regardless, burns suck trust me. I'd rather spend a little more money and deal with less convenience and just get a sealed motor. I mean, you have to stand next to it while using, where as a ball mill can and should be run remotely. But that is the point... the alternative was already a sealed unit. It's not like i recommend standing next to a washer motor with worn coals sending sparks everywhere...B!
Mumbles Posted January 13, 2017 Posted January 13, 2017 I must have mis-read or confused some things. With the wide spread, and stupid, use of drills as motors I can never drive this point home enough.
Fotia Posted January 13, 2017 Author Posted January 13, 2017 I WAS regarding a sealed motor. You still have the potential thermal temp of the casing, the possibility of arc jump between connections; & I don't know if this has ever happened to you, but it did me; there was a loose connection inside a running motor on a fan & as I went to move it a litle, it bit me. Not sure where people get there sealed motors from, but I bet most are from ebay/china or H.F. Not trying to knock them, but we all know the quality is not so great from them. I guess my whole point is I believe a pneumatic operated roller would be less likely to be a concern. Not that anything couldn't happen.
Fotia Posted January 18, 2017 Author Posted January 18, 2017 Well I finished milling a 6 fin impeller instead of the four I first made for the pneumatic roller. I actually got a little more weight in it before it slowed down as I continually added lead balls to it. As I started disassembling it the dummy bell went off in my head. The shaft for the impeller is 1/4" so I grabbed the angle die grinder and tightened the collet on the shaft. Got it going and started adding lead balls to see how much weight it would run. I got to 1lb & 10oz before it started slowing down with the air pressure wide open. I know it's not great, but at least I could use it to roll cores or small stars for small shells. The bowl is only an 8qt so it should be fine for that. Looks like I'll have to build one with a sealed motor in an enclosure.
OldMarine Posted January 18, 2017 Posted January 18, 2017 I guess I'm going to pull the trigger on a HD mixer as several have recommended. It needs minimal modification and running it outdoors means the danger is minimized.Fotia, have you considered a hydraulic motor? It seems that would be both more powerful and controllable in my opinion.
Fotia Posted January 18, 2017 Author Posted January 18, 2017 Do you mean a hydraulic pump? If so it would still be run by an electric motor, but could be done remotely. Hmm.....
OldMarine Posted January 18, 2017 Posted January 18, 2017 (edited) Do you mean a hydraulic pump? If so it would still be run by an electric motor, but could be done remotely. Hmm.....Yup, your pump/motor could be remotely located same as a compressor and hoses run to the roller. This would also operate more quietly and with a more even speed and torque not affected by additions of comp or your hand stirring the contents. Edit: Just had another thought... a 12 volt pump would make this roller portable and a decent pump could also run a press with the proper setup. Edited January 18, 2017 by OldMarine
Fotia Posted January 18, 2017 Author Posted January 18, 2017 So if someone already had a hydraulic press that used an motor & hydraulic pump, all they would need is a hydraulic motor & a couple of valves to switch devices & control flow. Or buy the pump with the intent of building both. I like it, but that means $$$
thepyrotextbook Posted February 9, 2017 Posted February 9, 2017 Personally, pumped and cut stars are a great starting place for newer hobbyists, but these stars (like mentioned many times across this thread) lack the ability to be able to be made into color changing stars. For small batches, pumping is the way to go, for medium sized batches, cutting is the way to go, and for any large batch or for color changing, rolling is the way to go. The only downside to cutting stars is that they tend to burn a bit faster than pressed or rolled. Just my opinions though.
dynomike1 Posted February 9, 2017 Posted February 9, 2017 Personally, pumped and cut stars are a great starting place for newer hobbyists, but these stars (like mentioned many times across this thread) lack the ability to be able to be made into color changing stars. For small batches, pumping is the way to go, for medium sized batches, cutting is the way to go, and for any large batch or for color changing, rolling is the way to go. The only downside to cutting stars is that they tend to burn a bit faster than pressed or rolled. Just my opinions though. I agree.
lloyd Posted February 9, 2017 Posted February 9, 2017 (edited) "...but these stars (like mentioned many times across this thread) lack the ability to be able to be made into color changing stars."------------ That's not true, at all, about pumped stars. They CAN be made to be color-changing, by mating different-colored "half high" stars/comets, then pasting-in, so they burn only from one end. It requires careful choice of burn-rates, but that doesn't rule out it's being done. Only cut stars cannot be color-changing in normal practice. Oh... and keep in mind that 'pasting in' doesn't necessarily require paper-and-paste. Color-changing cylindrical stars can also be had by dipping the mated comets/stars into a molten or (otherwise) liquid 'inhibitor' substance -- like white glue. BTDT over thousands of such stars for commercial production. I might add that I've seen it done with cut stars, also. They were cut with a 'grid', like a fluorescent lamp grid, rather than with a knife. The method was to press-down a patty half-high, place the grid on the mass, then place round stars in the middle of each square, pressing each down to half-high. Then another layer of the outer composition was 'pattied-down' on top, and the whole mass cut with the grid. I don't think it was worth the trouble, but it did work. <shrug> Lloyd Edited February 9, 2017 by lloyd
Boophoenix Posted February 10, 2017 Posted February 10, 2017 This isn't my handy work, but might add some food for thought to the thread. This is some of TR's work.
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