View Full Version : Non-removal technology?
04-24-2002, 09:17 AM
Just about every machining operations that I can think of fashions metal by removing parts of it. Is there a technology that allow adding of metal selectively and accurately?
04-24-2002, 10:41 AM
A laser is used to convert a 3-D image from
the computer into a solid rendering. The
laser "builds" of liquid polymer one layer upon another. Imagine a plastice toy like
a large GI Joe figure. The company will make
a model using stereo lith (for short) to
prove the look of the doll. Industry uses the same idea by laying down thin layers of
copper actually "building" edm electrodes.
I'm sure Thrud will add to this I'm sure
he is better at the particulars. Stereo lith
is also used for prototypes whether made of
metal or plastic. It is very interesting to
Another process that shapes metal without
removing it is forging and casting.
04-24-2002, 01:21 PM
I figured, as John said, that some welding processes would fit the bill. Unfortunately mine is rarely SELECTIVE or ACCURATE!... but wildly random. (Do other occasional welders with middle age vision deterioration also find welding more difficult because of glare on their glasses?)
04-24-2002, 01:22 PM
How about Nano-mechanics/fabrication. Where they construct on a atomic level.
I read a article once (someone please tell me if you know where I can find it again) about a universities research department covering this very topic, fabricated what was thought to be the smallest NUT/BOLT combo. To mock their competing university they sent their microscopic nut/bolt combo to them (I guess one could fit some absurd number of these on the head of a pin!)
The competing university in response; drilled, tapped the end of their bolt and fabricated a bolt for the hole and sent it back.
04-24-2002, 04:25 PM
There are also the various metal suspended epoxies. Obviously they are not very structural but for making a prototype or part that won't see a lot of stress I hear they work pretty good.
Once cured they can be milled, drilled, tapped, cut, etc... Micro-Mark carries one called Lab-Metal with aluminum powder. $17.95 for a 3/4 lb can.
They're supposed to work good on a pitted metal surface. Spread it on like putty, wait 12 hours and mill, file or scrap to smooth.
Suggest the "Metal Spray" process. Plasma torch with metal powder. Used to redo bearing surfaces etc. Required grinding afterward
04-24-2002, 06:26 PM
LYNNL: I reduced the frustration factor while welding by buying a pair of safety glasses ground to my perscription but in a focal length that makes everything sharp and clear from a distance 4" to 30" and getting a self darkening welding helmet. Now when I make my ugly welds I can't blame my poor vision. They are just as ugly as before but at least I am not surprised when I raise my hood. ;-) WALT ARREN
04-24-2002, 09:43 PM
Rapid prototyping with lasers and UV sensitve goop, then investment casting. Standard fare in the automotive OEM arena and aerospace. I seen a process where Nokia phone coverplates were made by actually freeform spraying the molten thermoplastic on a flat foam bed. The company was from Ontario and I have their card somewhere if you want the number.
IBM has used Tunneling Electron Microscope technology to move singe atoms. For more info check out the Oxford Series In optical and Imaging Sciences "Introduction to Scanning Tunneling Microscopy" by C. Julian Chen ISBN:0-19-507150-6 Very interesting.
As far as direct metal application we have plating, plasma spray welding, submerged arc welding, thermite, laser fusion of applied pastes and powders, and the various forms of soldering. AMD also has a "Silicon on Insulator" technology but I do not know how it is applied to the wafers.
[This message has been edited by Thrud (edited 04-25-2002).]
04-25-2002, 05:41 AM
You can also drill and tap and screw something to something else.
04-26-2002, 11:07 AM
Regarding the auto-darkening welding lenses Walt mentioned above: How permanent is that feature in welding helmets?
I've thought of getting one, but someone once led me to believe they started losing their effectiveness after awhile. Welding salesman I talked to were kinda vague in answering that question.
04-26-2002, 04:09 PM
Metal spray on a plasma tourch style rig. Used in our shop to spray heat sheilds on jet engine nozzles and afterburners. We Spray a Carbide compound on hardened metal surfaces because airflow is so high will cut the Steel like it was butter. Have to finish material with a diamond grinding wheel that is sooo fun to dress. Most impossible material to remove if part is to be overhauled, use one carbide insert to remove hardcoat off a nozzle .500 dia and about .345 long. After Hardcoat is removed insert looks like swiss cheese. Bean counters have fits when they look at tooling expenses.
Electro plating. Chrome on a bumper and Al plating are a few others.
04-26-2002, 08:54 PM
A quality helmet is around $500 (Can) $300 (US). When the battery, if so equipt dies - it does ultra-dark (15). The better ones are self-propelled with a solar cell and a large (around 1 Farad) capacitor as a storage battery. You still need to buy lexan covers for the autoshades to protect the LCD from damage.
They rock - if you can swing the bucks for one and weld lots they are well worth it. If you have trouble seeing where you are starting these helmuts are for you - they are like sunglasses until a arc is struck then they blacken to the desired setting. They block IR/UV as good as the Gold lenses so your eyes feel "unbaked" after a hard day's welding. Just don't run over it, leave it lying around, or lend it to anyone - they won't want to return it!
04-26-2002, 10:06 PM
Lynnl: Thrud be speakin d truth. I bought mine 5 years ago and the one that my buddy has is about 7 years old. His works as well as mine. After using his I begged the wife to buy me one. With the auto darkening helmet and the single focal length in my glasses I don't have anywhere near the problems with welding that I wsed to have. WALT
lynnl, ditto on auto-darkening helmet-they are nice to have. I've been using one for about six years and have had no problems with it. Last time I looked you could pick up a no frills Speedglas for something like $169.00 US.