oops. I never looked at the photo. I was so focused on describing the process(es) of creating non round holes, I just rambled on. What can I say; I’m old!
@TwinTurbo, thanks for the correction. Broaching is what I was thinking of. It’s been almost 30 years since I worked in the compressor shop that used broaches to machine rectangular holes in the cylinder heads.
My understanding is that welding would embrittle and create stress concentrations that would eventually result in structutal failure. Remember the triple hydraulic failure in Iowa (UA 232)? Caused by a included flaw about the size of a grain of sand. Took over 1,000 hours to stress-propogate to the point of failure.
No problem @jtsanders! I can tell you a lot has changed in 30 years. We still use most of the old school tools for various manual operations but primarily computer controlled where the designer directly downloads the CAD files to it.
We have some castings where the shape has been called “organic” by some designers. No human could detail the dimensioning or fabricate it economically. But computer software can create these complex features and curves easily and the machine can make them as easily as any rudimentary geometric shape. The casting eliminates a lot of machining time so the mill only has to remove the final amount to achieve the finished dimensions.
The purpose is to create precise movement in the oil filled cavity to promote thermal equilibrium by natural convection and conduction. The internal features are designed and modeled by software that is quite accurate in projecting performance.
These parts drive the QA people nuts since they have to AQL 1 out of 10 on a computerized comparator and it takes about an hour.
There was a recent article in the WSJ about how automakers are using computer simulation of how the parts work to speed up the CAD CAM process.
“New technology and computing power allow vehicle makers to conceive and test designs much more quickly—and cheaply. That’s allowing more innovation to improve performance and fuel efficiency.”
There was a recent article in the WSJ about how automakers are using computer simulation of how the parts work to speed up the CAD CAM process.
That has been going on for years. Nothing new. It’s just getting more sophisticated.
Absolutely, but the speed increases combined with improved computational methods (especially fluid flow and combustion simulation) has shrunk what took weeks a few years ago to day/hours. Unfortunately I can’t link to the actual story, it requires a subscription.
What I took from it was a ‘uh-oh, won’t need so many engineers now’. Kind of like what lawyers are going through with the AI-assisted document review. What used to take tens of hours for beginner lawyers is now done by a scanner and computer. Result: huge drop in lawyer hiring.
What I took from it was a 'uh-oh, won't need so many engineers now'.
New technology has been displacing jobs for decades. But with engineering the field is also growing…so not as many jobs are being displaced. In software with the tools and IDE’s the amount of man-hours to write a program 15 years ago can now be done in 1/3 that time. Doesn’t mean they are hiring fewer engineers though. What is happening the field has been expanding so much that we still need more engineers (with the right skill sets) then we did 15 years ago. And it’s getting worse (or better - depends on your point of view). The software engineering field is growing faster then people entering the field. They expect a major shortfall by within the next 10 years. Great for engineers looking for work…lousy for me who’s trying to find them.
Engineers may be able to come up with new designs faster than ever, but in the end, it still takes a skilled craftsman to make the molds for those intricate shapes that go into the core blowing machine. These are usually made by hand, or at least the final machining is done by hand.
When you are only making 20 or so molds for a years worth of production, CNC is not cost effective.
Mike, I was referring to the automotive engineers, not software/computer engineers. If the process of designing an engine can be done in 1/10th the time, then I would think fewer engineers would be needed.
Mike, I was referring to the automotive engineers, not software/computer engineers.
Automotive engineers are just a defined mechanical engineer. While the automotive industry has downsized here in the US…other area’s for mechanical engineers are opening up. Pretty much all of engineering jobs are on the rise world wide. It depends on the company if they plan on hiring here in the US or outsourcing that job overseas. I have two relatives that were automotive engineers for Chryco. They are now both working in the Aerospace field as mechanical engineers. Many of their skills transferred easily.
Mike from New Hampshire writes
The software engineering field is growing faster then people entering the field. They expect a major shortfall by within the next 10 years. Great for engineers looking for work..lousy for me who's trying to find them.
Maybe things are different in NH. But I ran into a group of high school students in the bookstore, they were all looking at the books how to apply for college. 5 or 6 of them sitting on the floor with scores of college entrance books laying around them, you know how high school students act in bookstores. Anyway happened to be passing that aisle, so I asked them what they wanted to major in in college. The answers for their desired college majors I got back were one lawyer, two physicians, one finance major, one hotel management, one MBA.
Being here in Silicon Valley, I was surprised nobody in this group of what appeared to be bright high school seniors mentioned their goal for a college education would be a STEM field. But not one said Science or Engineering. I asked why. Most effected a “I don’t want to explain” look. But one of the group spoke up, said his dad was an Engineer, and had been layed-off twice in the past 10 years, and now had been out of work 3 years straight.
The student, he said he had an interest in the STEM fields, enjoyed and did well in his math and science classes in high school, and he asked his dad if it was a good idea to study Science, Math, and Engineering in college. He explained his dad said “No, it was good for me, but that is no longer a good path for college students who wish to work in the USA.” Outsourcing and H1B insourcing is so rampant in high-tech, that his dad recommended another path, a field that isn’t so easy to outsource or insource the job. That was the kid who decided to study hotel management.
When I asked the other kids there what they thought, they said uniformly “yeah, this is well known street smarts, everybody knows this is a problem. Why spend tens of thousands of dollars, rack up a huge student debt, when the job situation is so uncertain in high-tech. The game is rigged. The gov’t is competing against STEM students for the available jobs”.
It’s NOT just in NH or Boston. Although this area is one of the big hot–spots for software development.
http://money.cnn.com/magazines/moneymag/best-jobs/2011/fast-growing-jobs/1.html
http://www.wantedanalytics.com/insight/tag/computer-software-engineers/
http://software.intel.com/en-us/blogs/2013/06/05/high-demand-the-occupational-outlook-for-developers
And other engineering jobs across the country/world…
http://www.engineersguideusa.com/Careers/engineer_career_outlook.htm
Of all those jobs those High-School kids said…I’d be telling my kids to stay away from. Service jobs are a dime a dozen. Lower then average pay and not much potential for growth since a lot of people are majoring in those fields. Engineering has been and will be the employment growth sector for at least 10-20 years.
Maybe those kids aren’t representative. Some objective data would be helpful I suppose. If there aren’t enough US citizens to fill available USA-based STEM jobs, wages should be going up significantly more than other sectors, and universities should be producing and granting more STEM degrees to US citizen students, b/c students would be naturally drawn to these fields due to job demand. I wonder what the data says? Data like wage growth over the past 10 years, yearly growth in the number of PhD-Engineering degrees granted to US citizens over the past 10 years, etc.
“Automotive engineers are just a defined mechanical engineer.”
Every single engineering discipline is now involved in “automotive” engineering. Mechanical, electrical, software, optical…
Speaking of displacement- ever seen those pictures of a giant room filled with a 100 drafters from the 50s and 60s? (Some here may have been in that room). Like people making buggy whips, they faded away and were replaced by fewer, more skilled craftsmen.
“When you are only making 20 or so molds for a years worth of production, CNC is not cost effective.”
Labor is always more expensive than machine time. The time it takes to download the program and set up the mill is a fraction of time it takes to do the machining by hand. The machine does not belong to a union or get paid benefits…
TwinTurbo, I worked in a foundry that made cylinder heads for all three US manufacturers and one Asian manufacturer. The molds were made by hand. A million dollar CNC machine will pay for a lot of manhours. You don’t invest in that kind of machinery that will only be used a couple days a year, and you still have to pay a machinist to operate it.
By hand made, the old way was to make a positive out of wax in about 1" layers, the positive is coated with a glorified mud and autoclaved to harden the mud into a ceramic and melt out the wax, then the core mold is cast and final machining done by hand.
I haven’t been in this business for some time now, but I would suspect that the positives are now made with a 3D printer instead of by hand, but still finished by hand. The rest of the process would still be the same.
I also worked at a joint manufacturer, running the knee department. The 3D printers were just becoming available and were very small, which was OK for knee joints. We used CNC to make the high volume joint parts that used Titanium or polyethylene and to finish machine parts that were cast from CoCr. All casting was investment casting, the wax molds were made by hand out of aluminum. Custom joints were made with the 3D printer. That was state of the art in the mid 90’s.
Back then, a small 3D printer cost over $100k.
I believe that the holes mentioned in the OP resulted from the need to separate the mold making up the water jacket void from the deck. The hole was where a spacing pad set the thickness of the deck.
I’m an engineer, and I can tell you that the field is lacking good talent. When I started with my current company, they were spending tens of thousands of dollars per year recruiting talent overseas due to a lack of good STEM graduates here. Half the time they got burned by prospects using the company to get into the US and get green cards, then bailing out for other opportunities. To this day, our company is working with student groups to try and boost interest in STEM at universities across the country.
Since 2008, tho, we’ve almost had a hiring freeze due to lack of work, but the company is making big moves overseas to tap into the desire for the oil-rich nations that are booming right now to use Western engineers for their construction design and project management experience.
How are wages in your sector of engineering BK? Going up as fast as other businesses like consumer goods, finance, medical care? At least keeping up w/inflation I hope.
Rod, if it is an aluminum block, the permanent mold (PM) only forms the outside of the block. Sand cores make up the water jackets. The PM pulls away and when the casting has cooled, the block is put in a “shaker” where the sand core is broken up and shaken out. The sand does exit through those holes as well as through the “freeze plug” holes.
On a cast iron block, both the interior and exterior of the block are all sand. The sand has a small amount of epoxy resin in it to hold it together. The sand goes through a giant furnace to burn off the resin and then back to the core machine for reuse.