3D Model Laser Scanning Multiple Times
Scanning a part multiple times can significantly increase the accuracy of the finished model.
A customer needed to reproduce some inserts for an automotive injection mold. Attempts to build them using their customer's CAD models failed because the inserts didn't match the models.
The inserts had advanced surfaces that had to match exactly with neighboring surfaces in the mold. This made the project ideal for laser scanning except that the accuracy required was about twice that of what my laser was typically capable of using a single scan. By scanning the inserts four times each and then averaging the scans, we were able to achieve the desired accuracy.
In a measuring system, if the measurement error is randomly distributed about zero, measurement uncertainty can be reduced as a function of the square root of the number of measurements made and averaged. In other words, if you measure something four times, the average of those measurements will have half of the uncertainty of any one measurement.
As part of Reverse Austin's monitoring of laser performance, I periodically scan and measure a CMM training standard. From the many measurements I've done, I can see that the measurement error is random and fairly well distributed about zero. If I chart the error from the averages of any four consecutive scans, I get errors that are a little less than half of the errors from individual scans.
If you've done your homework and you know the uncertainty of your scanning system, you can significantly improve accuracy (reduce uncertainty) by scanning multiple times and averaging the scan data.
Sunday, April 15, 2012
Saturday, March 17, 2012
3D Model Laser Scanning for Molding and Casting
3D Model Laser Scanning for Molding and Casting
Laser Scanning can have big payoffs for Molders, Mold Makers, Foundries and Pattern Makers.
1. Faster mold qualification with fewer development cycles, especially for overmolding.
2. Reuse of existing geometry from previous projects.
3. Precise capture of customers' prototype geometry.
4. Protection of legacy tooling.
Instead of relying on a few gauge points, laser scanning captures the entire part. By comparing the scan data to the nominal CAD model, the amounts and locations of all deviations can quickly be determined. When correcting overmold problems, the scan data can be used to create solid (CAD) models of the parts going into the overmold tooling. These models can be used to modify the overmold tooling to provide precise matches and/or crushes to eliminate shutoff failures.
When building new tooling to replace or supplement existing tooling, like going from single cavity to multi cavity, laser scanning can be used to create accurate CAD models of the existing tooling. The models can then be used to machine molds, electrodes or patterns. When the new tooling is complete, it can be scanned and the scan data compared to the original scan data to confirm that the new tooling precisely matches the old.
Customers don't always have complete CAD models for their products; they may only have hand made prototypes or they may have machined parts with hand made modifications. Laser scanning can be used to create accurate high quality CAD models that can be used to machine molds, electrodes or patterns. Before any tooling is built, the CAD models can be used for Additive Manufacturing (rapid prototyping) to produce models for customer approval.
Many shops have tooling that predates their current CAD system. Even if compatible CAD models exist, the models may not include all the "tweaks" that were done to make the tooling perform. Laser scanning can capture the existing geometry including any tweaks. The scan data can be stored as STL for later use or it can be used to develop compatible CAD models. In the case of a catastrophic event, tooling can be rebuilt.
Laser scanning can be a cost effective tool with large ROI. Contact me and let me explain how.
Laser Scanning can have big payoffs for Molders, Mold Makers, Foundries and Pattern Makers.
1. Faster mold qualification with fewer development cycles, especially for overmolding.
2. Reuse of existing geometry from previous projects.
3. Precise capture of customers' prototype geometry.
4. Protection of legacy tooling.
Instead of relying on a few gauge points, laser scanning captures the entire part. By comparing the scan data to the nominal CAD model, the amounts and locations of all deviations can quickly be determined. When correcting overmold problems, the scan data can be used to create solid (CAD) models of the parts going into the overmold tooling. These models can be used to modify the overmold tooling to provide precise matches and/or crushes to eliminate shutoff failures.
When building new tooling to replace or supplement existing tooling, like going from single cavity to multi cavity, laser scanning can be used to create accurate CAD models of the existing tooling. The models can then be used to machine molds, electrodes or patterns. When the new tooling is complete, it can be scanned and the scan data compared to the original scan data to confirm that the new tooling precisely matches the old.
Customers don't always have complete CAD models for their products; they may only have hand made prototypes or they may have machined parts with hand made modifications. Laser scanning can be used to create accurate high quality CAD models that can be used to machine molds, electrodes or patterns. Before any tooling is built, the CAD models can be used for Additive Manufacturing (rapid prototyping) to produce models for customer approval.
Many shops have tooling that predates their current CAD system. Even if compatible CAD models exist, the models may not include all the "tweaks" that were done to make the tooling perform. Laser scanning can capture the existing geometry including any tweaks. The scan data can be stored as STL for later use or it can be used to develop compatible CAD models. In the case of a catastrophic event, tooling can be rebuilt.
Laser scanning can be a cost effective tool with large ROI. Contact me and let me explain how.
Tuesday, March 13, 2012
3D Model Restless Legs and BPA
3D Model Restless Legs and BPA
Eliminating BPA from my diet appears to have made a significant improvement in my RLS symptoms.
Essentially all canned foods and beverages contain BPA as do foods and beverages stored in containers made of polycarbonate (recycle code 7). A recent Harvard study showed that eating canned soup five days in a row raised BPA levels in urine almost 1300%.
For years, I've suffered from RLS. Recently, the symptoms became so severe that they were affecting my ability to work. After reading about the Harvard study and, separately, about a possible link between BPA and RLS, I decided to eliminate BPA from my diet; no canned foods, no canned drinks, nothing stored in plastic containers with a recycle code of 7. Also, no restaurant foods that may have canned origins like tomato sauces.
The change in my RLS symptoms has been dramatic. While there is no scientific proof that eliminating BPA helps RLS, it's something that's easy to do. For me, it has been well worth the effort.
Eliminating BPA from my diet appears to have made a significant improvement in my RLS symptoms.
Essentially all canned foods and beverages contain BPA as do foods and beverages stored in containers made of polycarbonate (recycle code 7). A recent Harvard study showed that eating canned soup five days in a row raised BPA levels in urine almost 1300%.
For years, I've suffered from RLS. Recently, the symptoms became so severe that they were affecting my ability to work. After reading about the Harvard study and, separately, about a possible link between BPA and RLS, I decided to eliminate BPA from my diet; no canned foods, no canned drinks, nothing stored in plastic containers with a recycle code of 7. Also, no restaurant foods that may have canned origins like tomato sauces.
The change in my RLS symptoms has been dramatic. While there is no scientific proof that eliminating BPA helps RLS, it's something that's easy to do. For me, it has been well worth the effort.
Wednesday, February 29, 2012
3D Model Reverse Engineering for Reshoring
3D Model Reverse Engineering for Reshoring
Laser scanning based reverse engineering is a powerful tool for reshoring.
It's sad, but true that many products being manufactured overseas were at least partially engineered overseas. It's very common for molds and tooling for US products to be designed by and be owned by overseas manufacturers.
The overseas manufacturers often develop and build tooling at "no cost" which makes it easier to get started, but nearly impossible to leave. If a customer wants to move a manufacturing operation, he or she is often faced with having to redesign and rebuild all of the tooling. Laser scanning can help.
Often the tooling development process results in small tweaks to the part design. And often these tweaks go unnoticed and don't get incorporated into the official design. Trying to build new tooling doesn't just involve redesigning the tooling, but also redesigning the part. And that's where laser scanning based reverse engineering comes in.
3D laser scanning (or X-ray CT scanning) can collect enough measurement data to completely describe a part. The scan data can then be processed with advanced reverse engineering software, like Rapidform, to create high quality, dimensionally accurate CAD models. These models can be used for designing tooling, design documentation and quality control.
Think about laser scanning the next time you're involved in a reshoring effort.
Laser scanning based reverse engineering is a powerful tool for reshoring.
It's sad, but true that many products being manufactured overseas were at least partially engineered overseas. It's very common for molds and tooling for US products to be designed by and be owned by overseas manufacturers.
The overseas manufacturers often develop and build tooling at "no cost" which makes it easier to get started, but nearly impossible to leave. If a customer wants to move a manufacturing operation, he or she is often faced with having to redesign and rebuild all of the tooling. Laser scanning can help.
Often the tooling development process results in small tweaks to the part design. And often these tweaks go unnoticed and don't get incorporated into the official design. Trying to build new tooling doesn't just involve redesigning the tooling, but also redesigning the part. And that's where laser scanning based reverse engineering comes in.
3D laser scanning (or X-ray CT scanning) can collect enough measurement data to completely describe a part. The scan data can then be processed with advanced reverse engineering software, like Rapidform, to create high quality, dimensionally accurate CAD models. These models can be used for designing tooling, design documentation and quality control.
Think about laser scanning the next time you're involved in a reshoring effort.
Saturday, February 11, 2012
3D Model Texas Medical Device Alliance and STL
3D Model Texas Medical Device Alliance and STL
I attended my second TMDA meeting on February 9, 2012. The presentation by David K. Leigh was especially interesting.
David spoke on the evolution of design and manufacturing and the role of additive manufacturing in the evolution. He also spoke of the need of and ongoing efforts to develop formal specifications for additive manufacturing processes.
Later, via email, David pointed me towards information on the ongoing development of a replacement for STL. Originally dubbed STL 2.0, it's now named AMF. The format promises to significantly increase resolution while simultaneously reducing file size. Additionally, there are discussions on adding the ability to include voxel data (3D bit-maps) commonly used by medical imaging equipment and industrial CT scanners.
David K. Leigh is the president of Harvest Technologies in Belton, Texas.
I attended my second TMDA meeting on February 9, 2012. The presentation by David K. Leigh was especially interesting.
David spoke on the evolution of design and manufacturing and the role of additive manufacturing in the evolution. He also spoke of the need of and ongoing efforts to develop formal specifications for additive manufacturing processes.
Later, via email, David pointed me towards information on the ongoing development of a replacement for STL. Originally dubbed STL 2.0, it's now named AMF. The format promises to significantly increase resolution while simultaneously reducing file size. Additionally, there are discussions on adding the ability to include voxel data (3D bit-maps) commonly used by medical imaging equipment and industrial CT scanners.
David K. Leigh is the president of Harvest Technologies in Belton, Texas.
Wednesday, January 11, 2012
3D Model Reshoring with Laser Scanning
3D Model Reshoring with Laser Scanning
Laser scanning can be a vital tool in bringing manufacturing back to the US.
A customer of one of my clients wanted to reshore a line of fishing lures. Production was continuing overseas so the molds were not available. Also, due to the high level of rework required on the lures, it was felt that the overseas molds would not be adequate for US production. My client's customer chose to have new molds built here.
My client, an injection molding company, had already begun production of one lure in the series. Reverse engineering the first molds using conventional methods was very time consuming and required several mold revisions to achieve an acceptable product. Repeating the process on the other lures in the series was going to be prohibitively expensive so Reverse Austin was contacted to see if the process could be expedited using laser scanning.
My client had had less than satisfactory experience with laser scanning performed by a previous vendor. The CAD models produced were comprised of many small surface patches that included small imperfections and which were difficult to tool path.
To show my client that not all laser scanning is created equal, I grabbed an old lure from my tackle box and scanned and modeled it. Based on the results, my client agreed to have me scan and model two of the remaining lures in their customers line.
My client had SLA rapid prototypes made from the Reverse Austin CAD models
Laser scanning can be a vital tool in bringing manufacturing back to the US.
A customer of one of my clients wanted to reshore a line of fishing lures. Production was continuing overseas so the molds were not available. Also, due to the high level of rework required on the lures, it was felt that the overseas molds would not be adequate for US production. My client's customer chose to have new molds built here.
My client, an injection molding company, had already begun production of one lure in the series. Reverse engineering the first molds using conventional methods was very time consuming and required several mold revisions to achieve an acceptable product. Repeating the process on the other lures in the series was going to be prohibitively expensive so Reverse Austin was contacted to see if the process could be expedited using laser scanning.
My client had had less than satisfactory experience with laser scanning performed by a previous vendor. The CAD models produced were comprised of many small surface patches that included small imperfections and which were difficult to tool path.
To show my client that not all laser scanning is created equal, I grabbed an old lure from my tackle box and scanned and modeled it. Based on the results, my client agreed to have me scan and model two of the remaining lures in their customers line.
My client had SLA rapid prototypes made from the Reverse Austin CAD models
Thursday, December 8, 2011
3D Model Laser and X-ray CT Scanning Projects
3D Model Laser and X-ray CT Scanning Projects
I'm often asked "What is scanning used for?".
I use 3D laser scanners and X-ray CT scanners to create dimensionally accurate CAD models of physical objects (parts) and to perform dimensional analysis and non destructive testing (NDT). The parts generally fall into one of two categories; old stuff and new stuff. The old stuff usually involves CAD modeling and the new stuff dimensional analysis and/or NDT. The following are a few examples:
A foundry making investment cast fire sprinkler heads needed to increase production on an older model head. The foundry wanted a multi cavity mold that would produce wax patterns that were identical to the ones produced with the old single cavity mold. During the development of the original head, the single cavity mold had been modified based on customer requirements and the parts coming out of the mold were significantly different from the old drawings. I was able to laser scan one of the wax patterns and create a solid CAD model that replicated the pattern precisely. The customer then scaled the model for shrinkage and cut a new multi cavity mold. According to the customer, "The parts from the new mold are indistinguishable from the old".
A contract manufacturer specializing in aircraft structural components needed to machine a replacement for a 4' long section of cracked longeron from a commercial airplane. The standard procedure was to use a profile mill to machine a replacement by tracing the profile of the old longeron. The manufacturer had gotten rid of the ancient profile mill in favor of new CNC equipment and had no way to machine a new longeron without a CAD model. I was able to laser scan the cracked longeron and a plaster cast of part of the longeron still in the aircraft and then create a solid CAD model of the replacement with an integral doubler (splice). The customer machined the replacement part and "it dropped right in".
A contract manufacturer machining a family of parts for a long time customer damaged a functional gage for one of the parts. A new gage fabricated to print produced parts that weren't functional. Investigation found that many of the other functional gages weren't made to print even though parts made to them were functionally acceptable. I was able to scan and model the gages to enable the shop's drafting department to produce accurate drawings and to aid machining of new ones in the event of another mishap.
A firearms manufacturer cracked a set of forming dies used on one of its most popular pistol magazines. The dies had been tweaked to provide parts that functioned reliably and did not exactly match the CAD models originally used to make them. Prior to the accident, the manufacturer had already had me scan and model a magazine in preparation for designing new and improved dies. Unfortunately, the accident accelerated the project and necessitated a more direct approach. I was able to scan and model the old dies so that new ones could be machined immediately.
As part of a reshoring effort, an injection molding company needed to design and fabricate molds for a sporting goods item. The original molds were made to match hand carved prototypes and no drawings or models were available. I was able to laser scan and model one of the parts produced overseas so that new molds could be produced here.
A manufacturer of high end kitchen utensils was having problems with unacceptable overmolding on one of its product handles. The problem was caused by mismatch between the parts coming out of the primary molds and the overmold tooling. I was able to laser scan and model some parts from the primary molds. The CAD models included the shrinkage and warping found on the parts. The models were used to re machine the overmold tooling to precisely match the parts. This has since become the manufacturer's de facto method for debugging overmold problems.
A medical device manufacturer wanted to shorten the development time on a new delivery system. The system was an assembly of ultra precision injected molded parts with extremely small features. Previously, similar systems had required many iterations of mold tooling designs to achieve the desired product quality. Using X-ray CT scanning I was able to create very precise, ultra high resolution CAD models of the as-molded assembly components. I then 'assembled' the components in CAD and used fly throughs, sections and interference checks to determine the required modifications and eliminate many mold iterations.
The above are only a few of my scanning projects, but perhaps they give some idea as to "What is scanning used for?". For more details.
I'm often asked "What is scanning used for?".
I use 3D laser scanners and X-ray CT scanners to create dimensionally accurate CAD models of physical objects (parts) and to perform dimensional analysis and non destructive testing (NDT). The parts generally fall into one of two categories; old stuff and new stuff. The old stuff usually involves CAD modeling and the new stuff dimensional analysis and/or NDT. The following are a few examples:
A foundry making investment cast fire sprinkler heads needed to increase production on an older model head. The foundry wanted a multi cavity mold that would produce wax patterns that were identical to the ones produced with the old single cavity mold. During the development of the original head, the single cavity mold had been modified based on customer requirements and the parts coming out of the mold were significantly different from the old drawings. I was able to laser scan one of the wax patterns and create a solid CAD model that replicated the pattern precisely. The customer then scaled the model for shrinkage and cut a new multi cavity mold. According to the customer, "The parts from the new mold are indistinguishable from the old".
A contract manufacturer specializing in aircraft structural components needed to machine a replacement for a 4' long section of cracked longeron from a commercial airplane. The standard procedure was to use a profile mill to machine a replacement by tracing the profile of the old longeron. The manufacturer had gotten rid of the ancient profile mill in favor of new CNC equipment and had no way to machine a new longeron without a CAD model. I was able to laser scan the cracked longeron and a plaster cast of part of the longeron still in the aircraft and then create a solid CAD model of the replacement with an integral doubler (splice). The customer machined the replacement part and "it dropped right in".
A contract manufacturer machining a family of parts for a long time customer damaged a functional gage for one of the parts. A new gage fabricated to print produced parts that weren't functional. Investigation found that many of the other functional gages weren't made to print even though parts made to them were functionally acceptable. I was able to scan and model the gages to enable the shop's drafting department to produce accurate drawings and to aid machining of new ones in the event of another mishap.
A firearms manufacturer cracked a set of forming dies used on one of its most popular pistol magazines. The dies had been tweaked to provide parts that functioned reliably and did not exactly match the CAD models originally used to make them. Prior to the accident, the manufacturer had already had me scan and model a magazine in preparation for designing new and improved dies. Unfortunately, the accident accelerated the project and necessitated a more direct approach. I was able to scan and model the old dies so that new ones could be machined immediately.
As part of a reshoring effort, an injection molding company needed to design and fabricate molds for a sporting goods item. The original molds were made to match hand carved prototypes and no drawings or models were available. I was able to laser scan and model one of the parts produced overseas so that new molds could be produced here.
A manufacturer of high end kitchen utensils was having problems with unacceptable overmolding on one of its product handles. The problem was caused by mismatch between the parts coming out of the primary molds and the overmold tooling. I was able to laser scan and model some parts from the primary molds. The CAD models included the shrinkage and warping found on the parts. The models were used to re machine the overmold tooling to precisely match the parts. This has since become the manufacturer's de facto method for debugging overmold problems.
A medical device manufacturer wanted to shorten the development time on a new delivery system. The system was an assembly of ultra precision injected molded parts with extremely small features. Previously, similar systems had required many iterations of mold tooling designs to achieve the desired product quality. Using X-ray CT scanning I was able to create very precise, ultra high resolution CAD models of the as-molded assembly components. I then 'assembled' the components in CAD and used fly throughs, sections and interference checks to determine the required modifications and eliminate many mold iterations.
The above are only a few of my scanning projects, but perhaps they give some idea as to "What is scanning used for?". For more details.
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