To that end - I know one guy on here that bought NOS lenses (not attached to the tail light housing). I sent him a message to see if they are still boxed away, and if so, would he be interested in doing the running around to have the models made, and I'd compensate him for his time and the modeling fee. Fingers crossed.
DING DING DING Ladies and Gentlemen we have a WINNER!
YES indeed. A good set of OEM lenses can easily be either optically or laser scanned, or even manually (analog probe) scanned into 3D digital surface data that can then be utilized to construct the complete 3D parametric solid model.
No need at all for GM 2D drawings or tedious "converting" of information from 2D drawing into 3D model data.
Even a simple CMM will give a perfectly useable point data cloud to surface model the lenses
Sorry, this won't fly. A CMM will only gather surface point data, but it can't magically see "below" the surface and get the internal structure. This would be a better solution for the GT quarter windows and has been done already by someone else. In order to build a functioning mold, we need the geometry in 3D, whether you plan to use a CNC mill to machine the mold, or additive machining like laser sintering or 3D printing. A CMM or laser scanner is only useful to grab surface data- nothing more
Having used a machine very similar to the one Randye posted, it would be quite easy to draw a program to design new lenses dies. You simply disassemble the lenses, and measure them.
Sorry, this won't fly. A CMM will only gather surface point data, but it can't magically see "below" the surface and get the internal structure. This would be a better solution for the GT quarter windows and has been done already by someone else. In order to build a functioning mold, we need the geometry in 3D, whether you plan to use a CNC mill to machine the mold, or additive machining like laser sintering or 3D printing. A CMM or laser scanner is only useful to grab surface data- nothing more
That's where the drawings come into play. The question is what exactly is the end goal? If the goal is OE reproduction it becomes important to replicate the internal structure and construction. If the goal is to create something that fits and is more customizable the internal structure is unimportant so long as the external dimensions are correct for the new part to fit on the existing housing properly. I think a single piece is probably the better option as the manufacturing prou would be much simpler not having to worry about bonding the two pieces together properly.
That's where the drawings come into play. The question is what exactly is the end goal? If the goal is OE reproduction it becomes important to replicate the internal structure and construction. If the goal is to create something that fits and is more customizable the internal structure is unimportant so long as the external dimensions are correct for the new part to fit on the existing housing properly. I think a single piece is probably the better option as the manufacturing prou would be much simpler not having to worry about bonding the two pieces together properly.
And always remember that "perfect' is the enemy of 'good enough".
It strikes me that going the injection molding route is exactly trying for the perfect. Why not this: create a male vacuum forming buck using this stuff: http://www.smooth-on.com/gallery.php?galleryid=241 First mold creates a negative image (perhaps usable for 'blow-molding'....a second mold (made using the first) would create a positive image for vacuforming. Should be able to mount a pair of lenses, and with some work, create a single full width buck. Next take the old lenses and cut them down leaving an inch or so sticking up above the mounting clips (so the original mounting is unchanged), cut the new vacuformed lens to the appropriate depth, bond to the old part and you have it. All graphics would be external....mebbe printed vinyl wrap?....but that process is pretty well documented on the forum.
This would NOT result in an 'as new' part, but would be easily customizable. Shape would be identical. Not as many parts could be run as with a machined metal mold....but not all that many would be needed anyway....and the mold could be easily and cheaply duplicated.
Sorry, this won't fly. A CMM will only gather surface point data, but it can't magically see "below" the surface and get the internal structure. This would be a better solution for the GT quarter windows and has been done already by someone else. In order to build a functioning mold, we need the geometry in 3D, whether you plan to use a CNC mill to machine the mold, or additive machining like laser sintering or 3D printing. A CMM or laser scanner is only useful to grab surface data- nothing more
Sorry, YES, It does work. It has worked just fine the many dozens of times in my own experience that I have DONE IT.
You are correct , *only*, in that the CMM is capable of collecting surface point data.
USING that data to then construct a 3D parametric SURFACE, the surface model is then given specified *thickness* to create an *offset surface*, This results in a crude, but usable, 3D "shell" model. From there a competent CAD designer can finish the details of a complete solid model, measuring additional features as required.
ALTERNATELY:
You can gain even greater accuracy and mate, ("knit") TWO or more surface models together by simply FIXTURING the artifact you are gathering point data from and establishing a common X-Y-Z / 0-0-0 point origin for the initial data point for each surface. In this manner one can gather surface data from the *exterior* of the lens and then rotate or invert the sample and gather point data from the *interior* of the lens.
The exact SAME way I used to engineer complex aircraft engine turbine blades and vanes in R&D over 25 years ago.
This blade, like most, has a convex and concave side to it, (because it's an airfoil), as well as tapering thickness from root to tip *and* it twists about a chord centerline axis. A more complex surface than a Fiero taillight, but not too dissimilar. CMMs *routinely* even provide complete surface data of the entire base interlock (Christmas tree") of individual complex blades such as this.
New machines do it *optically* rather that utilize the physical probe to touch the surface.
See that little shiny "ball" in the photo above? It's called a "tooling ball" and it is being used here to do EXACTLY what I described earlier. It serves as the X-Y-Z 0 common origin for the artifact being scanned.
But then, what the hell do *I* know.......I've only been an engineer and successfully doing R&D in automotive, aerospace and biomed for over 30 years, managed both large and small groups of engineers and designers, served as Director of R&D for a global medical device corporation, hold 8 U.S. Patents and a few dozen foreign patents *and* now running my own successful consulting firm in "retirement".....
This also reminds me of teaching a "101 level" class in engineering technology at the local community college.....Yes, I've done that too.....
[This message has been edited by randye (edited 10-15-2015).]
And always remember that "perfect' is the enemy of 'good enough".
It strikes me that going the injection molding route is exactly trying for the perfect. Why not this: create a male vacuum forming buck using this stuff: http://www.smooth-on.com/gallery.php?galleryid=241 First mold creates a negative image (perhaps usable for 'blow-molding'....a second mold (made using the first) would create a positive image for vacuforming. Should be able to mount a pair of lenses, and with some work, create a single full width buck. Next take the old lenses and cut them down leaving an inch or so sticking up above the mounting clips (so the original mounting is unchanged), cut the new vacuformed lens to the appropriate depth, bond to the old part and you have it. All graphics would be external....mebbe printed vinyl wrap?....but that process is pretty well documented on the forum.
This would NOT result in an 'as new' part, but would be easily customizable. Shape would be identical. Not as many parts could be run as with a machined metal mold....but not all that many would be needed anyway....and the mold could be easily and cheaply duplicated.
What do you all think?
Larry
Since you asked....
Based on my own experience, if you are going to try thermoforming a polymer, (in this case most likely polycarbonate), and the end product needs to be optically clear and free of unreasonable distortion, then you are probably going to want to use a tool, (forming buck), that is capable of being *polished* to a suitable finish. That usually mandates *metal*, (aluminum or steel) for a suitably durable and polished tool.
For a good reference go look carefully at what "Pokey" produced for thermoforming the GT quarter windows.....
Sorry, this won't fly. A CMM will only gather surface point data, but it can't magically see "below" the surface and get the internal structure. This would be a better solution for the GT quarter windows and has been done already by someone else. In order to build a functioning mold, we need the geometry in 3D, whether you plan to use a CNC mill to machine the mold, or additive machining like laser sintering or 3D printing. A CMM or laser scanner is only useful to grab surface data- nothing more
There are scanners that will scan the entire surface in 3D. "Cheap" ones here: http://www.nextengine.com/
[This message has been edited by Mickey_Moose (edited 10-15-2015).]
There are scanners that will scan the entire surface in 3D. "Cheap" ones here: http://www.nextengine.com/
Nice. Good resolution too, (400 ppi) and accuracy, (.005 inch) $3k price is also very attractive.
Just know that there are numerous commercial SERVICES all over the U.S. that will perform the work for you a lower cost than purchasing the equipment, but if the prices on these optical / laser instruments keeps coming down the paradigm will change soon.
Based on my own experience, if you are going to try thermoforming a polymer, (in this case most likely polycarbonate), and the end product needs to be optically clear and free of unreasonable distortion, then you are probably going to want to use a tool, (forming buck), that is capable of being *polished* to a suitable finish. That usually mandates *metal*, (aluminum or steel) for a suitably durable and polished tool.
For a good reference go look carefully at what "Pokey" produced for thermoforming the GT quarter windows.....
Randye,
Thank you. But I do not understand something that you might be able to explain: You say the forming buck needs to be polished. In this case, the buck casting material is a resin which is not granular, except perhaps at a fine scale....would this not pick up the same surface finish as the original form....in this case an original lens? Since my expertise is aerospace and nuclear engineering....and now long since obsolete....I would defer to your knowledge....but it seems this might be a fairly low cost process to prototype unless there is something seriously wrong with the concept.
Thanks again for your information and opinion and back to you!
Just know that there are numerous commercial SERVICES all over the U.S. that will perform the work for you a lower cost than purchasing the equipment, but if the prices on these optical / laser instruments keeps coming down the paradigm will change soon.
Exactly
Hence the reason I do not understand the amount of effort that is being put into trying to obtain the original drawings/specs/whatever from GM. Sure having the original molds would be nice, but those are long gone and I don't see a point to trying to remake them using the same 80's technology. But that is just me...
Thank you. But I do not understand something that you might be able to explain: You say the forming buck needs to be polished. In this case, the buck casting material is a resin which is not granular, except perhaps at a fine scale....would this not pick up the same surface finish as the original form....in this case an original lens? Since my expertise is aerospace and nuclear engineering....and now long since obsolete....I would defer to your knowledge....but it seems this might be a fairly low cost process to prototype unless there is something seriously wrong with the concept.
Thanks again for your information and opinion and back to you!
Larry
In cases where thermoforming tooling for thinner, lower trans-T temperature materials are being used, the urethane or epoxy cast tooling approach might be fine, however to manufacture a *durable* and environmentally stable product such as the Fiero taillight lens, my personal first choice of material would be polycarbonate, (impact resistance, UV stability, structural strength, temperature cycling capability, etc.) Neither ABS or acrylic would be my first choices for a good product, for the reasons already cited. From what I know of the Fiero lenses I have, and have worked with, it will minimally require approx. .125 inch thick sheet material, (allowing for corner and curve thinning during forming).
As you can see above, just the mold surface temps for thermoforming Polycarbonate is within 20 degrees F of the MAX operating temperature of the material you referenced, (and that's a fairly standard temp capability for most all tooling epoxies).
Far too narrow of a delta to be considered safe for series production in my opinion. The *PROCESSING* temps for polycarbonate, (335F - 400F) are already above the maximum temp. capability of the cast epoxy tooling, so obviously, damage to the tool is very likely.
Lets look at some data from "Makrolon" brand, one of the largest current producers of sheet polycarbonate:
HEATING CYCLE Heating MAKROLON® Polycarbonate Sheet for vacuum forming requires heat penetration to achieve a 350°F to 360°F. The heat required will be higher for more complex shapes. When MAKROLON Polycarbonate Sheet reaches forming temperature, uniform “sag” occurs. The amount of sag depends on the size and thickness of the sheet. A 12˝ x 12˝ x .060˝ sheet will sag approximately 1˝. A 36˝ x 36˝ x .177˝ sheet may sag 4˝- 6˝ at the center. Once uniform temperature has been achieved, timers can accurately reproduce the condition, and part-to-part consistency can be maintained.
PROCEDURE:
O Sheet thicknesses up to .177˝ gauge can be heated from one side. Above .177˝ gauge, two-sided heating is normally required to significantly enhance productivity.
O Heat source is removed and heated sheet is forced over or into mold where vacuum is applied.
Obviously, the epoxy mold surface is going to see initial material temps. in excess of 350F........(not "ideal")
Yes, most true epoxies DO pyrolize to carbon without a fluid transition stage, so you don't expect them to "melt" like thermoplastics, however warping, embrittlement & cracking and surface pitting or flaking as well as out-gassing onto the product material are all reasonable concerns when routinely exceeding the operating temperature of these "quick-tooling" epoxy and urethane materials.
All of THAT is why *I* wouldn't use any of the "quick tooling" materials to produce anything that might be used for this application.
*Your* thoughts?
[This message has been edited by randye (edited 10-15-2015).]
The above is why program managers are willing to pay the price to have program/project engineers!
Thank you.
Next week I hope to speak to the engineers at the forming concern in NJ. I will be forearmed with your analysis and my own, admittedly, uneducated opinions. Since I am much more concerned with satisfying my own needs rather than producing lenses it may well prove to still be the best approach for onsey-tuesy production.
Hmmm...sudden thought....perhaps chrome plating of the surface would solve some of the thermal issues (no knowledge whatsoever of the difficulties or costs involved with plating plastic surfaces).
Damn but I do miss the days where I could simply roll some of this kind of cost into a DoD contract!
Nice. Good resolution too, (400 ppi) and accuracy, (.005 inch) $3k price is also very attractive.
Just know that there are numerous commercial SERVICES all over the U.S. that will perform the work for you a lower cost than purchasing the equipment, but if the prices on these optical / laser instruments keeps coming down the paradigm will change soon.
You are right Randeye. It's not like I am a moldmaker by trade who has built tail lens and headlight molds. Oh wait!! I have.. Magna Autosystems, Tycos, Decoma..
Please go right ahead and use a CMM to recreate the tail light molds. Getting the surface data is easy- nothing complicated about that. It is getting the interior components, building adequate mold cooling, inserts, and ejection that won't hurt the optics that is the challenge. Turbine blades and vanes are simple to reverse engineer with laser- there is no internal structure.
But you know better, so please feel free to build a working prototype mold with CMM data. Lots of dreamers on PFF that would love to jump on a new bandwagon. Time to start a new thread. Lets' call it... Reproduction TAIL LIGHTS coming soon! And yes, you are bang on that polycarbonate is the only way to go, which is the reason the other forming methods being discussed will not work.
[This message has been edited by cam-a-lot (edited 10-15-2015).]
Damn but I do miss the days where I could simply roll some of this kind of cost into a DoD contract!
Larry
You and me both!
Those old "salad days" of the DoD - CPFF contracts sure were great times and we did some amazing engineering. I was at UTC, Pratt & Whitney, Government Engine Business, R&D when we had over 8,000 scientists, engineers and technicians on the WPB, Florida campus. We will probably never see those kinds of collections of knowledge, talent and ability all in one place ever again
Turbine blades and vanes are simple to reverse engineer with laser- there is no internal structure.
REALLY? Please tell me all about turbine blades and vanes. I want to read this.
..............Actually please DON'T
I *could* allow you to continue looking foolish and you trying to provoke an argument with me, however there is absolutely no need to prolong this with you.
...and finally, lets hope that the Von Mesis diagrams shown over the INTERNAL STRUCTURES of these fairly typical turbine vanes don't confuse you:
Lets make "deal" here shall we? I won't tell you how to machine something, (even though I could), and you won't tell me all about *engineering*, which you clearly can't.
YOU are PRECISELY why I try to avoid getting involved in crap like this, and why I don't make products for Fieros. I have better and much more profitable ways to apply my knowledge and time than arguing on the damn *internet* about my own PROFESSION with contrarians.
..and by the way, just exactly WHAT "internal structures" on the FIERO CLEAR POLYMER TAILLIGHT COVER / LENS are you so blasted concerned about ?
[This message has been edited by randye (edited 10-15-2015).]
The above is why program managers are willing to pay the price to have program/project engineers!
Thank you.
Next week I hope to speak to the engineers at the forming concern in NJ. I will be forearmed with your analysis and my own, admittedly, uneducated opinions. Since I am much more concerned with satisfying my own needs rather than producing lenses it may well prove to still be the best approach for onsey-tuesy production.
Hmmm...sudden thought....perhaps chrome plating of the surface would solve some of the thermal issues (no knowledge whatsoever of the difficulties or costs involved with plating plastic surfaces).
Damn but I do miss the days where I could simply roll some of this kind of cost into a DoD contract!
Larry
Almost forgot to say Thank You for the compliment Larry....it's appreciated
If you are ONLY seeking to pop *one* or *two* sets of thermoformed lenses off some epoxy quick-tooling, you might get away with it.
My "analysis" was obviously directed toward series production tooling, (even if it is "short run").
There are copper filled epoxy materials that could possibly provide the conductive substrate that might allow metal plating over the surface. I would have to investigate that IF I have time. For the cost and effort involved in that approach though, it may be more economical and simpler to just machine aluminum, polish it and go.
[This message has been edited by randye (edited 10-15-2015).]
The $3000 they referred to is for the scanner itself, they also said just a scan could be done by a company with a scanner for less
quote
Originally posted by randye:
..and by the way, just exactly WHAT "internal structures" on the FIERO CLEAR POLYMER TAILLIGHT COVER / LENS are you so blasted concerned about ?
As Silvertown and I have found out, (and I'm sure others) the internal structure is the black part inside, it is much more than just the "PON TIAC" part, it extends over most of the lens. So to make a 'set' it would take 4 pieces being made and then bonded/sonic welded together.
With a scanner one could scan the inside and the outside, then minus the thickness of the outside clear to get the model of the inside.
Your earlier post shows blades with no internal structure, which is obviously what I was referring to. But you can pat yourself on the back by finding blades on Google that do have internal structure (therefore cannot be reverse engineered by using surface scanning methods)
Either way. When are you going to start making tail light lenses? It is easy to rent or borrow a CMM or laser scanner for a day in any North American city. I wish you the best of luck with your endeavor, as many on PFF would love to see new tail light lenses, and you clearly have all the answers, experience and superior intelligence to make this happen! We eagerly await the 3D scanned data that will allow for tooling to be built to replicate the lenses.
[This message has been edited by cam-a-lot (edited 10-16-2015).]
Why is this thread devolving AGAIN into a pissing match over who's the smartest guy in the room??? How about instead of focusing on whose idea won't work we come up with a plan that will
Originally posted by Napoleon_Tanerite: Why is this thread devolving AGAIN into a pissing match over who's the smartest guy in the room??? How about instead of focusing on whose idea won't work we come up with a plan that will
I have a plan that would work. However, just having a plan isn't enough. One also needs the resources to enact said plan.
But I don't go around making threads about bringing a product to market that I don't currently have the resources to create. But when I try to provide helpful information in the threads where people do that, or ask questions, I'm all of a sudden "the bad guy" because I'm not making the product, though I've done enough research to know what it will take to get it done.
Why is this thread devolving AGAIN into a pissing match over who's the smartest guy in the room??? How about instead of focusing on whose idea won't work we come up with a plan that will
quote
Originally posted by randye:
YOU are PRECISELY THIS is why I try to avoid getting involved in crap like this, and why I don't make products for Fieros. I have better and much more profitable ways to apply my knowledge and time than arguing on the damn *internet* about my own PROFESSION with contrarians.
[This message has been edited by randye (edited 10-16-2015).]
Why is this thread devolving AGAIN into a pissing match over who's the smartest guy in the room??? How about instead of focusing on whose idea won't work we come up with a plan that will
The same thing happens in meetings between engineers and production. But the end result gets things done. There are several members you included who desire to see this happen and that is 50 percent of getting it done.
As Silvertown and I have found out, (and I'm sure others) the internal structure is the black part inside, it is much more than just the "PON TIAC" part, it extends over most of the lens. So to make a 'set' it would take 4 pieces being made and then bonded/sonic welded together.
With a scanner one could scan the inside and the outside, then minus the thickness of the outside clear to get the model of the inside.
Please note that I was very specific in reference to ONLY the CLEAR POLYMER LENS / COVER
Yes, I am fully aware that the black colored portion *inside* the OEM CLEAR LENS / COVER is allegedly a SEPARATE *DECORATIVE* PART that is supposedly *bonded* to the clear part. (*Delamination* ring a bell?)
(I still believe that the lens covers may be an early *2 shot* injection molded part, but not having seen the molds or having other confirmation I can only go on my own suspicions and seeing what appear to be the gate remnants of the black portion inside OEM lenses. Make your own determination, It really doesn't matter for purposes of replicating parts now when injection mold tooling is cost prohibitive. That black inner portion was only intended to *function* as an opaque decorative mask anyway... )
[This message has been edited by randye (edited 10-16-2015).]
The same thing happens in meetings between engineers and production. But the end result gets things done. There are several members you included who desire to see this happen and that is 50 percent of getting it done.
That's why we need someone who can talk to the engineers so the customers don't have to. We need someone with people skills... A PEOPLE PERSON!
With a solid game plan I am all for putting money behind something.
Also, if the clear lenses can be made, I was thinking the "black part" (with the pontiac cutout) could be a vinyl inlay that could be secured in place with something - maybe epoxy or a thin coating that can be applied evenly?
Also, if the clear lenses can be made, I was thinking the "black part" (with the pontiac cutout) could be a vinyl inlay that could be secured in place with something - maybe epoxy or a thin coating that can be applied evenly?
Some options to consider would be the inner black piece is a separate insert not welded to the outer clear lens. Maybe vacuum formed? Or just clear lenses and make a paint mask and mask the outside and paint the outside black. Although not exactly like OEM it would be reasonably close to OEM.
------------------ Rodney Dickman
Fiero Parts And Acc's Web Page: All new web page!:www.rodneydickman.com Rodney Dickman's Fiero accessories 7604 Treeview Drive Caledonia, WI 53108 Phone/Fax (262) 835-9575
... Or just clear lenses and make a paint mask and mask the outside and paint the outside black. ...
I want to be able to paint the inside of the lenses. Much like an RC model body. Let the plastic take the abuse, and leave the paint scratchless behind it's protective cover.
I want to be able to paint the inside of the lenses. Much like an RC model body. Let the plastic take the abuse, and leave the paint scratchless behind it's protective cover.
Wow, Imagine that. Doing whatever YOU want with a simple clear lens cover.
[This message has been edited by randye (edited 10-17-2015).]
Your response seemed a bit aggressive given that I have not argued with you or detracted from your contributions.
I wasn't being "aggressive" with you, so relax. I was being "rhetorically blunt" and a wee bit *terse*. (Think: John Houseman in "The Paper Chase" https://www.youtube.com/watch?v=cZJEhlIefxA )
Next time I'll plaster smiley faces on it if that's what you require Mister Hart.
Between my JOB engineering things that actually make MONEY for me, I try to find a little time to post to stuff like this, (that don't), so I'm frequently "rushed" .
Additionally, anyone that experiences continual problems with paint running and cannot achieve crisp, clean masked edges is doing it WRONG.
[This message has been edited by randye (edited 10-18-2015).]
Additionally, anyone that experiences continual problems with paint running and cannot achieve crisp, clean masked edges is doing it WRONG.
Thanks for clarifying that you weren't be aggressive, and explaining why you were being a little blunt and terse.
To the quoted point -- that's exactly why I'd rather find another solution other than paint. I know it's not something I do well, and like you, would rather dedicate my time to other ventures that have more meaning (in this case, instead of getting better at masking/painting).
