sskunky Posted June 27, 2014 Report Share Posted June 27, 2014 (edited) It's actually easier to pull the form off the mould whilst it's warm. The plastic will release easier.... Vern, it shouldn't warp as the ABS should have cooled enough by that stage. If you are not getting enough pull on the detailed parts then the plastic is probably cooling too fast and unable to pull in there..... You can use a heat gun to aid in these areas... just be careful not to over heat as it will blow a hole. You will find as the moulds heat up after a few pulls they will form better.... When you first pull the moulds are cool and that in turn will cool the ABS as it hits the mould. Edited June 27, 2014 by sskunky Quote Link to comment Share on other sites More sharing options...
sskunky Posted June 27, 2014 Report Share Posted June 27, 2014 Also if you are getting webbing at all.... Try strategically placing small blocks of wood around the mould.... It's all to do with the draw of plastic and small blocks change that and pull the plastic away from the offending area....hope this helps...... Quote Link to comment Share on other sites More sharing options...
walt[501st] Posted June 27, 2014 Report Share Posted June 27, 2014 That helps me!...i made a steel grate for the top of my oven, i put the next set of molds i am going to use up there to warm them before i use them Quote Link to comment Share on other sites More sharing options...
TK bondservnt[501st] Posted June 27, 2014 Report Share Posted June 27, 2014 it only makes sense to pre heat the molds, pre heat the plastic and keep the air in your work area a constant temp mark makes some good points there. I always see vac forming machines with the oven on top and usually people need to keep track of temps and air temps some machines actually blow hot air into the plastic from below to make an air bubble, which then allows the introduction of the mold from below then the vac is slowly introduced in short bursts until it's finally set fully. then even full pressure is gradual and slowly applied until it's the correct amount for the tool and size you're doing why dont you try adding the following features to your table 1 a lift below the forming area with the forming surface moving upwards from below the vac chamber 2 add a heat gun and a compressor to blow the plastic into a bubble 3 put the heater on top on rollers to allow the plastic to be heated from above right over the forming area with the lift in the lowered position. 4 when plastic is heated fully and saggging. blow a hot air bubble into it, lift the mold into the bubble and then pull slowly on the vac 5 cool the surface of the mold and press the plastic into the mold by applying a soft even blast of compressor air over the outside surface. 6 allow the mold to cure and partially cool and cut off the excess at the front of the faceplate and cut off the front of the helmet at the brow and cheek line 7 allow the molds to cool and blow air from inside to help pop them out of the form while prying with a small tool to help release making the lift area totally enclosed below the table surface would allow you to keep the pre heated mold box and forming surface an even temp by putting the oven plastic and forming tool lift in the same space and allowing your heater to roll over the top on rails and pushing away to the rear allows 2 things. you can pre heat the mold on the lift by simplly rolling the oven over the top. then when the mold has been pre heated the plastic sheet can be clamped into place and then the heater can be rolled over the top again. this keeps the mold box lift and plastic all heated. move the forming proces into a temp controlled spot. wear a respirator and after the process is complete ventilate the area. Quote Link to comment Share on other sites More sharing options...
usaeatt2 Posted June 27, 2014 Report Share Posted June 27, 2014 why dont you try adding the following features to your table 1 a lift below the forming area with the forming surface moving upwards from below the vac chamber 2 add a heat gun and a compressor to blow the plastic into a bubble 3 put the heater on top on rollers to allow the plastic to be heated from above right over the forming area with the lift in the lowered position. 4 when plastic is heated fully and saggging. blow a hot air bubble into it, lift the mold into the bubble and then pull slowly on the vac 5 cool the surface of the mold and press the plastic into the mold by applying a soft even blast of compressor air over the outside surface. 6 allow the mold to cure and partially cool and cut off the excess at the front of the faceplate and cut off the front of the helmet at the brow and cheek line 7 allow the molds to cool and blow air from inside to help pop them out of the form while prying with a small tool to help release <Head spinning> And then plan on selling several hundred sets of armor just to break even on your investment...didn't this whole thing start out as a simple art project? Quote Link to comment Share on other sites More sharing options...
walt[501st] Posted June 28, 2014 Report Share Posted June 28, 2014 Lol...yep Quote Link to comment Share on other sites More sharing options...
TK bondservnt[501st] Posted June 28, 2014 Report Share Posted June 28, 2014 I put that list of stuff out there. and I think how the first example pulls he did were actually pretty darn good! you should see the list of things you need to do pressure resin casting! the list is even larger! remember keep calm and have fun! Quote Link to comment Share on other sites More sharing options...
sskunky Posted June 28, 2014 Report Share Posted June 28, 2014 Vern, You sound like you've done a lot of Vacuum forming? What machines have you used? You should see the machines I have my armour made on. 8' x 4' big monster of a machine. I still haven't tired of watching it form half suits at a time. Quote Link to comment Share on other sites More sharing options...
TK bondservnt[501st] Posted June 28, 2014 Report Share Posted June 28, 2014 thanks mark, I'm sure that members watching this thread would love to see your table in action! take a video and photos so we can all marvel at the process of making things. I've had lot's of good teachers over the years and I've studied a lot. but I was planning to get into forming before I realized how many scores of people are doing it. like paul, you, AP and so many others... it's too hard to count! I decided not to enter the forming stages of the hobby but I am still obsessed with knowing and meeting people who are interested in that part of the hobby. my main passion is to study casting and molding. which I'm in the process of obtaining the correct tools and methods. my goal is to make resin blasters of the highest quality. it's been about 3 years of research and testing. and soon I'll start the process of molding. I need to purchase more original parts, and the whole rebel gun situation is getting pretty interesting. the goal is to have every small arm that I'm interested in. the e-11 the snowtrooper, the han solo versions, and imperial variants the MGC and a demilled sterling are in the shop, I'm just studying right now. I even have the sterling inner barrel and want to make replicas that have as many of the working parts as I can do. keep up the good work jeffery.. we're all proud of you here! Quote Link to comment Share on other sites More sharing options...
Tolo[TK] Posted June 28, 2014 Report Share Posted June 28, 2014 Vern, You sound like you've done a lot of Vacuum forming? What machines have you used? You should see the machines I have my armour made on. 8' x 4' big monster of a machine. I still haven't tired of watching it form half suits at a time. 8 x 4 😮 Sent from my iPhone 5 using Tapatalk Quote Link to comment Share on other sites More sharing options...
Elumusic[TK] Posted June 30, 2014 Author Report Share Posted June 30, 2014 Good tips guys...I especially like the wood blocking idea. But as much as I agree with the heater on top, I am definitely not re-working my table at this time. That would have required a complete re-design of the table and the vacuum frame. Although the more I do this, the more I am thinking about that...ugh...errrrrr....... Ok so that being said, here is what I did to modify the heater. This worked wonderful and I got really great plastic sag. About 6 minutes of bake time on the plastic and then whipped the arm of the table over quickly to keep air into the sagging HIPS. It hit perfectly and I got no bad webbing. The face part came out great. Comes off the mold no problem. Great lines. But the helmet....guys I need help with this. I can't get the plastic off the helmet no matter if I blow air into the mold or not. I need to know how to get this off without destroying it. Here are the pictures. The oven is now 9" deep. I can get a really deep sag on the plastic without burning it. The face....a little webbing at the corner of the head but that was my fault. I didn't move quick enough and I let the plastic get a little too soft. The helmet...webbing only in the front where it gets cut off anyway.. No big deal here. The detail is great...but I can't get the damn thing off the mold. Disaster! Quote Link to comment Share on other sites More sharing options...
walt[501st] Posted June 30, 2014 Report Share Posted June 30, 2014 webbing easy fix...build a slope out the front from the brow line Quote Link to comment Share on other sites More sharing options...
Elumusic[TK] Posted June 30, 2014 Author Report Share Posted June 30, 2014 webbing easy fix...build a slope out the front from the brow line But how do I get it off the mold? puhlease help!!! Quote Link to comment Share on other sites More sharing options...
sskunky Posted June 30, 2014 Report Share Posted June 30, 2014 But how do I get it off the mold? puhlease help!!! There is no easy way with a solid mould... The undercut on the back tube stops it from coming off.... Cut around the front and sides and cut as much of the back as poss, then with a pair of gloves on try get your fingers under the front of the cap and pull up and back pivoting on the rear tube..... Does that make sense? Otherwise you need a mould that collapses or a hydraulic plattern to pull the mould out of the plastic..... It's the hardest part of vacuum forming.... Especially these helmets.... It's the undercut..... You could try tilting the mould forward a bit so the undercut is more vertical..... Quote Link to comment Share on other sites More sharing options...
sskunky Posted June 30, 2014 Report Share Posted June 30, 2014 Just a thought.... are you using talc on the mould? sprinkle talc on the moulds before you form them,....... it does aid the release a bit... That and a good blast of compressed air. Quote Link to comment Share on other sites More sharing options...
Elumusic[TK] Posted June 30, 2014 Author Report Share Posted June 30, 2014 I wonder if a glass workers suction cup would work? The front of the cap is the worst part. It is stuck down like glue. I'll try the talc powder. Everything is working perfectly and I am totally bummed out about not being able to pull the helmet off the mold. Talcum powder is next. Quote Link to comment Share on other sites More sharing options...
sskunky Posted June 30, 2014 Report Share Posted June 30, 2014 are the moulds feeling tacky when they are hot? some fillers and resins will soften when hot.... Also did you paint the moulds with anything? if you did the paint can stick to the plastic too.... Quote Link to comment Share on other sites More sharing options...
Elumusic[TK] Posted June 30, 2014 Author Report Share Posted June 30, 2014 They don't feel tacky at all. And no paint on the surfaces. I ordered a dent pulling suction cup 4.5" diameter, 110 lbs to get a grip on the top of the helmet. I don't know if it will work or not. But between that the talc I hope for the best. I just hope the top of the helmet is smooth enough to get a good grip with the suction cup. Quote Link to comment Share on other sites More sharing options...
sskunky Posted June 30, 2014 Report Share Posted June 30, 2014 I'll be interested to see if the cup works. Have you got the vac moulds secured to a base board? Quote Link to comment Share on other sites More sharing options...
walt[501st] Posted June 30, 2014 Report Share Posted June 30, 2014 And compressed air...and marks suggestions about power...it helps..and just an fyi...the helmet is the hardest to remove...just keep trying different things Quote Link to comment Share on other sites More sharing options...
Elumusic[TK] Posted July 1, 2014 Author Report Share Posted July 1, 2014 Nothing is attached to the board. The molds just sit on top of the vacuum table. Someone told me to add a ridge line across the front of the helmet that can be cut away and used as a gripping point. I'll try that with the talc next and also the suction cup. Quote Link to comment Share on other sites More sharing options...
sskunky Posted July 1, 2014 Report Share Posted July 1, 2014 Mount them to a piece of Marine ply. It's much easier to demould with the helmet moulds on board. It gives you something to grab hold of. You can add a X section to the inside of the moulds and secure it in then screw the board to that...... Add filler to make the seam smooth and good. Once it's mounted just drill some holes on the bottom so the vacuum can work. Quote Link to comment Share on other sites More sharing options...
Elumusic[TK] Posted July 1, 2014 Author Report Share Posted July 1, 2014 (edited) Mount them to a piece of Marine ply. It's much easier to demould with the helmet moulds on board. It gives you something to grab hold of. You can add a X section to the inside of the moulds and secure it in then screw the board to that...... Add filler to make the seam smooth and good. Once it's mounted just drill some holes on the bottom so the vacuum can work. Great plan...I will get the molds cross braced and screwed to the table. I'm also wondering if I am heating the plastic too long? and what thickness of plastic should I be using on the helmet? I am using .093 currently. In the next couple of days I will make another attempt after the modifications and then also try the heat gun for the face detail. And I am going to modify the vacuum lines to incorporate few valves to shut down the vacuum and allow compressed air to blow air back into the mold after the vacuum goes off. Should be fairly simple. Edited July 1, 2014 by Elumusic Quote Link to comment Share on other sites More sharing options...
Elumusic[TK] Posted July 7, 2014 Author Report Share Posted July 7, 2014 Ok...Success!!! I want to thank every one of you guys for your support and guidance on this. So here is what I did this weekend. I created a way to attache the molds to the table via long screws and bracing in the molds. I also modified the vacuum system to include a compressed air connection to blow air back into the mold to help release it. And it worked. I still had to wrestle the helmet off the mold with constant air pressure, but what I got was perfect. I also started molding the eyes. I purchased some smoke colored acrylic and as soon as I finish the eye molds I will get these done next. Here are the bolts and cross bracing. I used the same holes in the table for both molds. The holes go all the way through and tighten with a wing nut underneath. When not in use I pull the bolts and use some duct tape below to seal the holes underneath. This is my modification to the vacuum lines and compressed air system. I used pvc valves to control the different systems. A little bit of webbing but nothing inside the usable areas. Face off the mold.....The detail is excellent. Ready for assembly. And last but not least...Here is the beginning of the eye molds to be done in smoked acrylic. I poured some sculpt-able plaster into the eye socket of the finished pull. Cooking spray to keep it from bonding to the plastic. I pulled the plaster when it was done and created a base out of plaster that was contoured like the back of the eye. I will still need to dremel the eye portion to make is smooth like a bubble and take into account that the thickness of the acrylic will need to fit into the eye socket. Quote Link to comment Share on other sites More sharing options...
Tolo[TK] Posted July 7, 2014 Report Share Posted July 7, 2014 Wow, this is the 1st Pepakura helmet that comes out great! Sent from my iPhone 5 using Tapatalk Quote Link to comment Share on other sites More sharing options...
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