DesertFoxRomel Posted April 13, 2008 Report Share Posted April 13, 2008 I got an idea, how about carving a small metal plate and mold it into the pu to reinforce it? It might be worth a try. Otherwise, great work Link to post Share on other sites
mprojekt Posted April 13, 2008 Report Share Posted April 13, 2008 I got an idea, how about carving a small metal plate and mold it into the pu to reinforce it? It might be worth a try. Otherwise, great work oro? omfg. <rummages in my structural wire bin> Fox, that was awesome. I completely forgot about using an armature! Link to post Share on other sites
mprojekt Posted April 16, 2008 Report Share Posted April 16, 2008 The first half of the mold box is almost done! I just need to stop getting distracted by Space Rangers 2 and I'll have a mold ready no later than this Friday. I am following DesertFoxRomel's suggestion and the new mold will support a wire armature. Link to post Share on other sites
xlizer Posted April 17, 2008 Author Report Share Posted April 17, 2008 The first half of the mold box is almost done! I just need to stop getting distracted by Space Rangers 2 and I'll have a mold ready no later than this Friday. I am following DesertFoxRomel's suggestion and the new mold will support a wire armature. That is good to hear. I'm just letting you know that people are still checking in on this. Link to post Share on other sites
mprojekt Posted April 17, 2008 Report Share Posted April 17, 2008 First half of the improved mold is poured and cured. 2nd half is getting poured after work and the mold should be ready for resin casting by Friday night. I'll post a couple of pictures of the new mold tonite. I'm going to cast an ultra crappy test piece using glass-filled epoxy using the old one-piece mold tonite as well. Link to post Share on other sites
mprojekt Posted April 18, 2008 Report Share Posted April 18, 2008 First half of the improved mold is poured and cured. 2nd half is getting poured after work and the mold should be ready for resin casting by Friday night. I'll post a couple of pictures of the new mold tonite. I'm going to cast an ultra crappy test piece using glass-filled epoxy using the old one-piece mold tonite as well. Pictures taken but didn't have time to post before I had to go to work. I did get the epoxy mixed and into the old mold. I'm still waiting for it to harden. Pot life for this formulation is 15 minutes but it's going to stay flexible for up to 6 hours after it gels. MEH. Not very useful when I'm looking for fast turn-around times! I am using the wire armature suggested by desertfoxromel (again, thanks!) but it's back to poly-urethane for the resin. Even though epoxy is stronger than the current PU resin that I have, it's not as versatile as Dascar RP-40 or Alumilite Regular. So here's the plan: The first few castings that dont have air bubbles will be available as free samples, starting with xlizer and his gal. I can say that the part is "strong enough" for use, fill your screen with fancy words and show off pretty pictures - that doesn't mean that it will stand up to the rigors that potential customers will subject it to. Basically, I want to get these into wild for normal installation and testing by people other than me. If the armature reinforced, TAP poly urethane resin prototype works out for yall, then I'll be happy with the concept and start production for retail sale using engineering PUR. "Dear Santa, I would like a small CNC mill..." Link to post Share on other sites
xsboredom Posted April 19, 2008 Report Share Posted April 19, 2008 Pictures taken but didn't have time to post before I had to go to work. I did get the epoxy mixed and into the old mold. I'm still waiting for it to harden. Pot life for this formulation is 15 minutes but it's going to stay flexible for up to 6 hours after it gels. MEH. Not very useful when I'm looking for fast turn-around times! I am using the wire armature suggested by desertfoxromel (again, thanks!) but it's back to poly-urethane for the resin. Even though epoxy is stronger than the current PU resin that I have, it's not as versatile as Dascar RP-40 or Alumilite Regular. So here's the plan: The first few castings that dont have air bubbles will be available as free samples, starting with xlizer and his gal. I can say that the part is "strong enough" for use, fill your screen with fancy words and show off pretty pictures - that doesn't mean that it will stand up to the rigors that potential customers will subject it to. Basically, I want to get these into wild for normal installation and testing by people other than me. If the armature reinforced, TAP poly urethane resin prototype works out for yall, then I'll be happy with the concept and start production for retail sale using engineering PUR. "Dear Santa, I would like a small CNC mill..." Great work!! If you dont mind can i be second for the tests . Hopefully the final product can withstand my 32 rps setup :[. Link to post Share on other sites
xlizer Posted April 23, 2008 Author Report Share Posted April 23, 2008 It has been a while; I would love to hear any updates if there are any. Link to post Share on other sites
mprojekt Posted April 23, 2008 Report Share Posted April 23, 2008 It has been a while; I would love to hear any updates if there are any. The good news: wire armatures work inside my new mold and improve the strength of the casting. The bad news: TAP polyurethane still sucks (it's too weak even with the wire) and TAP 1:1 epoxy is too thick to shoot into the mold without air bubbles until we get a pressure pot. Better news: Ordered a 1-quart kit of Dascar RP-40 engineering polyurethane - if this does what I hope it will, then I'm ordering even more. Will be ordering a 2-gallon pressure pot from Harbor Freight. * * * * * * * Thoughts: The neat thing about this project is the interest it's generated both here and locally. We've even got the guys at Airsoft Extreme in Santa Clara asking us about our casting projects. I've got at least two teammates who are thinking about picking up P90's based on the success of this project. Link to post Share on other sites
xlizer Posted April 23, 2008 Author Report Share Posted April 23, 2008 The good news: wire armatures work inside my new mold and improve the strength of the casting. The bad news: TAP polyurethane still sucks (it's too weak even with the wire) and TAP 1:1 epoxy is too thick to shoot into the mold without air bubbles until we get a pressure pot. Better news: Ordered a 1-quart kit of Dascar RP-40 engineering polyurethane - if this does what I hope it will, then I'm ordering even more. Will be ordering a 2-gallon pressure pot from Harbor Freight. * * * * * * * Thoughts: The neat thing about this project is the interest it's generated both here and locally. We've even got the guys at Airsoft Extreme in Santa Clara asking us about our casting projects. I've got at least two teammates who are thinking about picking up P90's based on the success of this project. Well that's just downright impressive. I hope your tests go well, and thanks for the update Link to post Share on other sites
zentaurus Posted April 24, 2008 Report Share Posted April 24, 2008 just got my TM p90 RD and considering the CA sportsline version as well. put me in for a few pieces, mprojekt. and kudos for the effforts. might there be a few other small pieces in the works too? Link to post Share on other sites
talon_0315 Posted April 24, 2008 Report Share Posted April 24, 2008 Better news: Ordered a 1-quart kit of Dascar RP-40 engineering polyurethane - if this does what I hope it will, then I'm ordering even more. Will be ordering a 2-gallon pressure pot from Harbor Freight. Speaking of which, someone needs to send me a link. -cough,grin- Link to post Share on other sites
mprojekt Posted April 24, 2008 Report Share Posted April 24, 2008 just got my TM p90 RD and considering the CA sportsline version as well. put me in for a few pieces, mprojekt. and kudos for the effforts. might there be a few other small pieces in the works too? For the P90? Actually, yes. I've started sculpting a block to install in P90 high caps to improve feeding. Since it's a simple shape, casting is going to be a breeze and I can even use crappy TAP Plastics polyurethane since the part isn't loadbearing. I'm also working on a little comestic piece for my SL9SD that goes immediately behind the brass deflector, G36 trigger shoes, and anything else Talon and I can think of. Link to post Share on other sites
zentaurus Posted April 25, 2008 Report Share Posted April 25, 2008 AUG mag well caps to stop bbs from getting into the receiver? 5.56>>9mm mag adaptors? a better cap for tm-compatible AK fire selector screw? p90 butt end extender to allow bigger size batts? same thing for the AUG? just a few suggestions off the top of my head Link to post Share on other sites
mprojekt Posted April 30, 2008 Report Share Posted April 30, 2008 <<waiting for Dascar Plastics resin to arrive>> Sheesh. You'd think UPS was worried that this was a binary explosive or something. It is shipping by ground though and they've got 2 more days to get it here before it's late. Link to post Share on other sites
Stealthbomber Posted April 30, 2008 Report Share Posted April 30, 2008 Quit spamming. Link to post Share on other sites
xsboredom Posted May 8, 2008 Report Share Posted May 8, 2008 Uhhh any update on the piece? >__< Link to post Share on other sites
mprojekt Posted May 12, 2008 Report Share Posted May 12, 2008 Uhhh any update on the piece? >__< More good news/bad news as of 12 May 2008: ***Good news: Dascar RP40 resin is stronger than the TAP Plastics stuff, especially when filled 50% with milled e-glass fibers. The cut-off lever stood up to bending with a 10 pound weight before snapping outright. The epoxy lever I cast handled 15 pounds. Dascar RP40 polyurethane with a hard steel wire armature was good to 20 pounds before failing. Epoxy was the same. (tests were performed by hanging a weight from the middle of the lever - primitive, I know). Additional polyurethane and epoxy samples took compressive forces pretty well but eventually failed with repeated blows from a 5 pound ball-peen hammer. Results with an armature are good enough for me to run a batch using a pressure vessel and send them out for testing. ***Bad news: Both set of tests seem to show us that polyurethane and epoxy are not -quite- strong enough to be used safely as a cut-off lever without an armature. If I could find a source of long-strand glass fibers, then it's entirely possible that cast-able polyurethane and epoxy would be strong enough without any other reinforcement. Without an armature, this grade of polyurethane resin with or without 70 micron glass fibers has to be 3 to 5 times as thick. Epoxy is in the same boat. BUT once that thickness is achieved, the casting is much stronger. Epoxy takes a few hours to set up enough for demolding and absolutely requires the use of a pressure vessel to reduce or eliminate air bubbles. The samples are going to be a little while. ***Moving forward: We have an 80 PSI pressure vessel now for epoxy and long pot duration polyurethanes. I want to do something weird: basically, separate the casting into 3 pieces that have hard steel wire armatures and assembled with epoxy or rubberized cyano-acrylate. Again, if any of you need a P90 cut-off lever ASAP - waiting for me and Talon is not a good idea. Although we have regular jobs and a few other more commercially important airsoft projects, the cut-off lever is important enough to us that we are dedicating whatever time we can to it. The issue is that we don't have a lot of time to spare so this is slow-going. That said, I hope to have the armature-reinforced samples ready to go "soon". ***Thoughts: As mentioned previously, I've cast larger pieces for props and other things. Even though few of these were designed to put up with a lot of mechanical stress, they were thick enough that I never had problems with durability. The new techniques I've learned from this project are going end up improving any medium or large casting projects I do in the future. For me, this has certainly been a good learning experience in small-scale casting of mechanical parts and worth the time and money. If there was anything I could wish for, it would be a fuse deposition modeler that prints in ABS+, polycarbonate, or PPSF. Link to post Share on other sites
Harmless Posted May 12, 2008 Report Share Posted May 12, 2008 Is anyone still interested in this piece? and does it matter if the metal is stronger than the stuff the gear box is made of? I was thinking of cobalt chromium. I may be able to get this made but I'll have check with my technician and its likely to be expensive. Link to post Share on other sites
xsboredom Posted May 12, 2008 Report Share Posted May 12, 2008 I am still very interested in this piece as right now my p90 is a full auto saw . I am in no rush at all for this item so please take your time. Link to post Share on other sites
mprojekt Posted May 12, 2008 Report Share Posted May 12, 2008 Is anyone still interested in this piece? and does it matter if the metal is stronger than the stuff the gear box is made of? I was thinking of cobalt chromium. I may be able to get this made but I'll have check with my technician and its likely to be expensive. Any chance you're talking about Stellite's Denertia casting alloy or something like Talonite? I can definitely see either route being pretty expensive for a short run of parts or excessively expensive for just one. If I had access to a desktop CNC mill, I would probably be trying to do this with 2024 or 6061 aluminum since both Talon and I live less than 15 to 30 minutes drive to more than a few metal suppliers that carry these and other alloys on the cheap. Link to post Share on other sites
Harmless Posted May 12, 2008 Report Share Posted May 12, 2008 I'm a dentist and I have technician who I could ask if he could copy it and cast in a dental alloy. It might be possible. If it is you, want it gold? Link to post Share on other sites
mprojekt Posted May 12, 2008 Report Share Posted May 12, 2008 I'm a dentist and I have technician who I could ask if he could copy it and cast in a dental alloy. It might be possible. If it is you, want it gold? haha nooo. Not for me. I'll stick to my resin experiment for now. Xsboredom might be more interested in a CoCr alloy part but he would probably want to know how much it would cost first before committing. I could call Stellite myself today and get a quote for just the casting ingots but ehhh... unlike you, I don't have a technician to go to nor do I have a melting furnace or other hot metal casting equipment. Link to post Share on other sites
xlizer Posted May 12, 2008 Author Report Share Posted May 12, 2008 haha nooo. Not for me. I'll stick to my resin experiment for now. Xsboredom might be more interested in a CoCr alloy part but he would probably want to know how much it would cost first before committing. I could call Stellite myself today and get a quote for just the casting ingots but ehhh... unlike you, I don't have a technician to go to nor do I have a melting furnace or other hot metal casting equipment. We are still waiting for a solution, but are in no real rush. Sure sooner rather than later would be preferable, but it doesn't really matter, and I am interested in how this turns out. Link to post Share on other sites
zentaurus Posted May 13, 2008 Report Share Posted May 13, 2008 me too -- verryy. would definitely like something in reserve for my P90s. sooner than later preferred too. but something forthcoming is better than nothing at all Link to post Share on other sites
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