Making a mold, and casting a reversed/opposite version?

[tubachris85x]

I am just curious..is there any cheap/effective method for taking, for this case a helmet, and doing this?

I've heard of it being done before, where trying to get almost perfect symetry, they will take one side/half of the helmet, mold it, and end up with a reveresed version of it, so that they can put the two together, and mold it as one single piece.

I am sculpting my own helmet, and I am having some issues of symetry..I mean I can get it close to matching the finnished side, but I am just curious if this is possible without the aid of computer operated machinery.

Perfect example, is that on Bobmaker's site, he showed how he made a reversed jango chest armor piece, but I think that would be simpler, because of the lack of details..

Thanks!

 

[00MrNotWrong00]

I find this very interesting. Making sure everything looks perfect no matter how some one looks at my work has always been a HUGE pain in the but. I always wondered if you could set up a carving duplicator to do something like this. If anyone knows how you could do something like that I'd love to heard all about it, but I don't think there is such a process. I think you just have to trust your calipers and develop your eye.

 

[Tim Allen]

I have seen it molded and flipped to copy the other side but I know they do that with the CNC machines for the new vader helmet

 

[00MrNotWrong00]

This is the copy carver web page http://www.copycarver.com/index.htm If you look at what it does and how it does it, you can kinda put together in your head how it wouldn't be that hard to set it up to run backwards (move the styles right and the cutter goes left). Although I have never heard of anyone doing that. Sill I am very interested in this thread and I hope someone gets on here soon and shows me something that just blows my mind.

 

[tubachris85x]

This is the copy carver web page http://www.copycarver.com/index.htm If you look at what it does and how it does it, you can kinda put together in your head how it wouldn't be that hard to set it up to run backwards (move the styles right and the cutter goes left). Although I have never heard of anyone doing that. Sill I am very interested in this thread and I hope someone gets on here soon and shows me something that just blows my mind.

Yea, I've seen something like this before. I know that the national mint uses something similar when making their coin engravings. I guess, you'd just have to figure out how to make it sculpt in reverse?

 

[00MrNotWrong00]

I don't think anyone has ever done this before. I have to be wrong because it seems very easy, but then why wouldn't everyone that makes stuff just make half and then copy the other half in reverse ? This is the most interesting fabrication question I think I've seen here and I hope very much that some one that knows more about this will chime in very soon.

 

[tubachris85x]

I don't think anyone has ever done this before. I have to be wrong because it seems very easy, but then why wouldn't everyone that makes stuff just make half and then copy the other half in reverse ? This is the most interesting fabrication question I think I've seen here and I hope very much that some one that knows more about this will chime in very soon.

Yea. I mean, I can't really personally concieve any other way of doing this without the aid of a mechanical device and or computer.

 

[GrenadeKing]

To my knowledge there is no way to make something in reverse through molding. If you molded up one half, and cast it, you'd end up with a cast of the same half. You have to physically create the other side. That's the only way I know of. :confused

 

[t_bone9600]

This may be way out there... but... Would it be possible to make a silicone mold, turn it inside out, fill the backside with something for support, then use fiberglass to copy the inverted mold and go from there? Just a thought the question really got my gears spinning.

 

[Mike Rush]

I've seen sculptors work with a mirror beside the piece. You look at one side of your sculpture and compare it with the reflection of the other side. If your work is symmetrical, it should look like two identical sculptures side by side. If not, you can see where the differences are and correct them.

It's still judging by eye, but it's a lot easier than having to mentally flip things round and guess.

 

[tubachris85x]

This may be way out there... but... Would it be possible to make a silicone mold, turn it inside out, fill the backside with something for support, then use fiberglass to copy the inverted mold and go from there? Just a thought the question really got my gears spinning.

I honestly dont think so...I mean, the only way do to that, would be to make the layer of silicone incredibly thin, to that it retains the details on BOTH sides...but I doubt something like that can be done successfully

 

[asoncsm101]

To my knowledge there is no way to make something in reverse through molding. If you molded up one half, and cast it, you'd end up with a cast of the same half. You have to physically create the other side. That's the only way I know of. :confused

I totally agree. I'm glad you posted that reply as that's how I read the original post on this subject.
Getting something perfectly symmetrical is not that easy. Mainly because the human eye/brain is so amazing in it's perception of dimensions & our brains being "hard" wired for symmetry. It only needs to be a few points of a millimeter out & it WILL register as being incorrect. But! Having said all that, I have worked on many prototypes where every single dimension was spot on & well within tolerances & it still looked wrong?! This is where the atristic eye comes in. It would take me forever to go into all the different ways to do this & much of it is determined by materials & use of the object to be made. My best advice is to go to your local library & see if they have any books on Patternmaking or Patternmakers We are a dying breed.

 

[00MrNotWrong00]

Hay whoa why isn't this at the top ? Don't let this one die until more people have chimed in and given their two cents. Some one else has to have figured this out. I'd like to have as many people looking into this as possible.

I believe this can be done without a laser scanner or a CNC machine.

 

[defstartrooper]

Hay whoa why isn't this at the top ? Don't let this one die until more people have chimed in and given their two cents. Some one else has to have figured this out. I'd like to have as many people looking into this as possible.

I believe this can be done without a laser scanner or a CNC machine.

Of course it can it wouldn't be that difficult to reverse a 3d file of one half im sure and join it with the original half then machine or create a master with a rapid prototyper.
Not cheap but not difficult.

 

[Jarvis B]

To get as close as possible to being symetrical I have allways made paper or card stock templates ahead of time for only one side of the project and try to match as best I can all the parts by flipping the templates as the sculpt progresses.
Hope this idea helps.

 

[hydin]

I am kinda stumped on this too..

I have a superman shield from one of the water guns that I wanted to "flip" and turn into a bizarro symbol, but I can't figure out how.

Chris

 

[00MrNotWrong00]

OK does anyone know who on this forum has been making crap the longest ?

If we can find someone that has been making junk for like 40 years, and he says he has never heard of such a process. Then I will build a copy carver that makes reverse copies of items. But I want to be sure no one has ever done this before.

So lets find a really old guy and ask him.

 

[micdavis]

Can't be done. Short of some of the digital solutions already suggested. That's where the skilled part comes in here.

I've been building models and props for 36 years. And was trained by guys that had been doing it for 50. One guy had a model of the Spirit of St. Louis built from cut offs of Spirit of St.Louis. HIS dad was building the plane at Ryan and would bring home cut offs and his son would build the same pieces. Wing spars, made from cutoffs of the REAL wing spars. Wild.

 

[asoncsm101]

Can we clarify what the actual question is? Cos if it's what I'm thinking this is not rocket science. You cannot make one side of a pattern then mould it to give you the other side.All you will get is a copy of what you have just done. IF you are "carving" it out using some sort of CNC programmed router or what ever then yes you can make both sides.Infact you can even "carve" it in reverse to give you a mould. Hope this helps.

 

[micdavis]

The tracing device coin makers use is called a Pantagraph. It allows you to make smaller carving using large patterns. It basically traces using a series of arms and levers that reduces the size. But I have never seen one that will flip it.