I've always wondered how they paint on the colored stripes. I put "how do they paint the stripes on resistors" on google, but all I got was links explaining how to READ color codes.
Has anyone ever heard anything about this process?
They get the christmas elves in the off season to paint them on with their toy decorating brushes.
No, but after an hour or so hunting through my father's random box of hundreds of resistors looking for the value I wanted, I got a powerful urge to take any old one and paint on the right colours... (Never did, though!)
Mike.
Isn't it obvious? Early resistors were hand painted, then they developed machines for the job.
-- Never piss off an Engineer! They don't get mad. They don't get even. They go for over unity! ;-)
how did they paint the machines?
Angelfish caps (Mullard) were dipped in paint to different depths to form the stripes.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
Carefully.
It's a no brainer they use a machine. My question goes much deeper. How does the machine do it? Are the paints applied by a paint brush, or something like a felt tip marker, or maybe some sort of spray method? Once the correct colors are chosen for that batch of (whatever value), how do they rotate them so the paint is not smeared. I can only assume they are picked up by their leads, not the body, and somehow rotated by their leads too.
I do believe the early resistors, especially those ceramic types that had colored dots on them, were probably hand painted. I have also noted that the old bumble bee caps often had irregular stripes, where the paint was thicker in spots, thinner in others, and the edges were not always precise.
There is a series on tv, which is usually only shown on Saturday mornings, during the kids shows, that show how an item is made. The ones I remember are making candy, and making lightbulbs (incandescent). They show the entire process, start to finish, and show each step both in the machines and how workers are involved. I cant recall the name of them programs, and have not seen any in a long time, but they are quite interesting. That lightbulb one was extremely interesting. Each bulb is tested in a machine and workers watch ot make sure they light up. Seeing this, (on tv or youtube), for resistors would be interesting. Too bad they dont have more stuff like that on tv, rather than the usual garbage that is mostly on the channels these days.
One thing I do know, is that most small electronic parts with wire leads, leave the factory in the form of ladders. Meaning that 100 or
1000, or any other number of them are one long strip being held together by 2 strips of paper around the leads, to form what looks like a ladder.So, if you worked at Zenith assembling radios, there would be rolls of those ladders for every value of resistor, capacitor, etc, needed, at each work station.
By the way, there is a good documentary video on youtube that shows radios being made at Zenith. It was filmed in (If I recall correctly), the 1950s. Worth watching!
I remember when computers used core memory the manufacturers employed oriental women to string the cores because of their small, nimble hands. This may be much the same kind of thing.
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Not any more. They now have to use a proportional share of big, hairy, burly men. They throw those misprinted resistors out. Haven't you noticed the price increases?
They waited until they were completely built, you silly rabbit!
-- Never piss off an Engineer! They don't get mad. They don't get even. They go for over unity! ;-)
Then you don't know anything.
The proceed is called Tape + Reel, or Ammo Pac, but they are for automated manufacturing. Leaded components are becoming rare, in manufacturing, since Surface mount far exceeds leaded components, and have for decades. Hand assembly doesn't use taped components, since it takes time to remove the tape before a component is installed. Zenith used odd tube sockets and terminal strips that often used the full length of the component's leads. The tape's adhesive would cause cold solder joints.
-- Never piss off an Engineer! They don't get mad. They don't get even. They go for over unity! ;-)
snipped-for-privacy@tubes.com wrote on 9/9/2017 2:14 PM:
Don't know about resistors being hand painted as that sounds expensive. But I know mica caps used look hand painted and in searching I found one style that is clearly hand painted.
-- Rick C Viewed the eclipse at Wintercrest Farms, on the centerline of totality since 1998
Resistors are made from a clay-like material containing carbon or other conductor in various amounts. Colourants are added, and the material is rolled and layered into large 'pats', so for example a 4k7 resistor pat might have cream, yellow, cream, violet, cream, red, cream, gold, cream coloured layers. This is rolled to the correct thickness corresponding to the final resistor length, then hollow punches form the resistor bodies, usually several thousand from one pat. The better quality ones are rolled for smoothness and low noise. The wire ends are fitted, the resistors are baked and often varnished. For high accuracy resistors, the depth of one wire end is adjusted on test before the baking stage.
Cheers
-- Clive
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