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I've heard of a compound called "ReproRubber", but have never used it.
http://www.newmantools.com/flexbar/repl.htm
I CNC machine little metal plugs that fit into recesses in bodywork on boats.
Well, I have a customer who asked me to do a custom size - but it's not feasible for him to send the boat to me, obviously, so instead he took bondo and made an impression of the recess. So I have in my hand a piece of hard bondo that looks like a mushroom - the underside of the mushroom top would be the bodywork contour and the stem of the mushroom is the plug I need to make for the bodywork.
How would I "re create" the bodywork from this piece? I want to put some sort of mold release on it and use some material to make a negative of the part (which is itself a negative of the bodywork) - so I'll be left with an approximation of the original.
Whats the best material to use and how do I do it? I was thinking fiberglass but the only issue is it may not come out smooth when I am done. The Bondo is glass-smooth now and I want me negative-image of it to be smooth too. Also, what do I use to ensure it doesn't stick and I turn it into a solid mess
When I get the negative of this part, I will mount it in the CNC machine with a probe head to measure it, then I'll machine the plug and use the part I cast from his plug to ensure a correct fit.
Tolerances are huge because this fits into molded plastic pieces, which have sloppy tolerances, so I don't need to be within thousandths or anything.
Thanks for any tips!
I've heard of a compound called "ReproRubber", but have never used it.
http://www.newmantools.com/flexbar/repl.htm
First you get good, then you get fast. Then grouchiness sets in.
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)
I would digitize the negative image and generate the inverse with software.
Ken
Kenneth Lerman
55 Main Street
Newtown, CT 06470
BCC products in Franklin, Indiana has several products depending on your speed. I would pressure cast it at 150 psi. If your model has holes or small air bubbles it may colapse. Call me I have done many reverse engineering projects and cast rapid prototype parts. Can you send me a group of photos. gsilberberg@progressive-plastics.net I can probably either talk you through the process over the phone or do it myself. I have a small pressure pot at home..when I am not brewing beer in it (just kidding). Call me on my cell 317-408-2684. Indiana time now till 8:30 pm.
I know I could do that but without having the "other side" (positive image) its not easy to determine the flow of the surface (bear in mind part of the surface I will be milling is hidden by the interface between the stem and canopy of the mushroom shape. If I have the positive side, I can just measure off either one, then machine, fit and see how it looks.Originally Posted by lerman
That putty looks very promising Hu! Thanks, you earned your paycheck this weekYou know the parts we make for bikes - I have some interest from some boat guys but no way am I going to ask them to ship me body panels so I can measure, and I ain't into taking a Faro and laptop down to the marina and balancing them on a dingy while I measure
Thanks very much for your offer jetski! Unfortunately the model does have some small holes and cavities because it was sort of a quickly put together mold. I will try the putty that Hu linked to and it I don't have any luck I'll give you a shout. Thanks again for your very generous offer!
http://www.jmoritausa.com/perfectim_systems.asp
it creates very accurate negatives of the parent shape.
sets up to the consistancy of soft silicone rubber, quickly i might add.
1 to 2 minutes.
it is a dental molding compound. works awesome you will like it.
also if you need to check a feature that you can not put into a comparator
take a mold and slice a thin section of the material, and "walla" check it
under your optics.
probably real similar to the stuff hu mentioned.
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