doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Screw Slotting

I guess I have been wrong in using a jewlers screw slotting file all these years.
bill

Nothing wrong with a jewelers saw or screw slotting file. But if I'm in a machine shop having just made a screw and there's a milling machine in front of me, I'll cut the slot in the mill. It takes me less time and I do it better in a mill than I can with a saw or file. That's just me...I came from machine shops.

I've always marveled at what a real machinest can do.
I can't and will admit it. I get by with my small lathe and mill for the things I need to do. But I retreat back to manual skills to do alot of tasks,, some that surely could be done on them with the right know how.
I am comfortable doing them this way.

What ever way gets the job done and done correctly.
There is no 'right way' IMHO,,just different ways.

"I've always marveled at what a real machinest can do."

I was always facinated with machinery, and after graduation from high school back in 1964 and after a little hiatius, my dad got me a job in the plant where he worked. I went to the machine shop, actually it was a model-prototype shop and handed out tools to the machinists. I had done some lathe work and the foreman used to give me some lathe and small milling jobs to do. Each person had his own bench with a granite surface plate, height gage, and all the micrometers and dial vernier calipers, and tooling you needed. All the machines were set up in metric, along with the mics and the prints were also in metric with the decimal equivilent also.

Everything made went to the inspection department, and everything was measured using an optical comparator, if hardened, was tested on a RC scale. All the technicians in the climate controlled room wore cotton gloves, so as not to change the temperature of the piece/s. Some of the tolorences were as low as .0005 most were within +/-.002.

Because I was no threat to them, they would let me see some of the work in progress, and it was amazing to see a block of steel 8"x8"x8" cut in half and hollowed out with a mirror finish. The part was formed into it and was used in a plastic injection machine, incredible work.

Later in life I worked in a power plant and many times made parts on lathes, milling machines, shapers. In our one nuclear plant there was a lathe there that could held one of the generator rotors, you rode the carriage form one end to the other.

Now afer retiring, I have a small lathe and make screws, firing pins, bore gages., etc.

So when I see something that was made 80-100+ years ago, I always marvel at the way it was made and can respect those that did the work.

David,
Going back just to the 60's and 50's, some of the aerospace machining I've seen, made with only manual controlled machines, was simply astounding. Complex cuts, angles and radii, transitions, etc., all done manually. Some of that stuff took a long time to make. Lots of setups.

About 20 yrs ago, I took a mfg engrg curriculum at UCLA, one instructor stated that CNC had not changed overall mfg capabilities much if at all. I think there's some truth to that in most areas. It has changed how long some operations take, especially for short runs or single items. But nearly all items produced today could be produced on manual machinery.

Chuck, you are right, anything that can be done on a CNC, was first done manually. Like you said, it makes single parts faster.

Thinking back to then, we had a retired WW II Army Sargent that did most of our hardenig, he carried a pocket file in his apron and when a part that he hardened was done and drawn back, he would take that file to it and say it is 60 RC. Take that part to the inspectors, he would maybe be l point off.

I made an adjustable sine plate, had it hardened, re-ground it and went and had an inspector I knew look at it on the optical comparator. I don't know why, I didn't know triginometry, but had the book.
It was .0004 off at 5.000 between centers and my mentor said make another pin. I didn't, still have it wrapped in an oil cloth. Make a hardened 3" machinist vise and many sets of parallels all of which I still have. It was fun and a great learning experience.

Chuck;
When I started into model making we were doing everything manually. We made wing conturs by what we refered to as straight lining which meant a set up for every cut. I started on the first NC mill that was put in th shop, ran a punched tape. Later we went to CNC. Actuallly these machines are in effect still straight lining, but you can run a whole contoured surface with one set-up.

I just grind the slot in with a surface grinder at the job.
Cleans up those buggered ones.

Miller,
I recall running some paper tape machines as late as the late 70s. All those thumb wheels on the console for "offsets" from the programmed cutter path. Those were NC lathes. I ended up in a nuc R&D shop that had all manual machines which suited me. Everything was short run or one off.

Miller, Chuck, back in the past, the plant also had a production department and they used a tape that was set up to drill and tap holes in a masonite boad, quite a few of them in different sizes. It was always interesting to watch the first run after it was set up to see the tap come down on a blind hole and make it's own. Most of the time the set-up man and someone from R&D were there on this first run, both would shake their heads and say back to the drawing board.