Posted on January 11th, 2017
The day was young; my father left me a drawing on the table and demanded four of these brackets. Well he didn’t demand but he was paying me so that always helps. If you ever work on things and machine things, you have to maintain your machine and oil it and once and a while read it a bedtime story. Both my father and I have been neglecting our poor milling machine, it was making growling noises, bad fan bearings in the power supply for the computer. NO PROBLEM, psh I got this.
Oh dear god what have I done.... lol I’m kidding, but if you tinker enough like I do here’s one thing to think about. One day my dad said this awful statement "do you ever notice how many tools you use just for a simple task?". I wish he had never said that.... Just to change a dumb fan I needed a soldering iron, cutters, strippers, pillars, screw drivers, Allen wrenches... it just never ends. I turn around, there is just a pile of tools, and all I did was change a fan! The milling machine runs off a 486, and for you young whipper snappers out there this Intel 80486 has a whopping clock speed of 16MHz to 150MHz. This bad boy was first made in 1989, and made until 2007. A lot of CNC machines and commercial machinery made in the 90's used these things. I will tell you it is bulletproof and reliable. As I said, there is no simple task. All I had to do is open up the box and replace the fan, well about an hour later i managed to get it done.
This is the part in question. We don’t have any fancy CAM software so it all has to be programmed by hand and saved to a floppy disk, yea a floppy disk. It may sound outdated but it still works the same as a brand new unit. How many people do you know in your basement with a CNC Bridgeport, yea didn’t think you could think of many. Try not to hate on the technology, focus on the end product. This is a relatively simple part. They are little holders that go on the end of a telescope to hold a waterproof project box.
I am not great at programming stuff into the CNC but I do test cuts in wood first. You would think it’s kind of simple but sometimes I mess up tool left and tool right and clockwise and counter clockwise. No big deal just brute force through it and I got everything setup for a real run.
With some clever zeroing and planning it went pretty smooth, I had to mess with some of the Z-Axis settings and speeds and feeds but I cut on. Caution annoying noise below! Hold your eardrums or just turn it down, whatever floats your boat.
Things were going well for a change, I was whipping these puppies up in no time!
Another thing when you make parts, if you have a drawing thats 1:1 scale you can easily tell if you dun mucked it up or not. As you can tell my part is poifect.
Next the 10-33 tapped hole in the bottom. First a pilot hole must be made so that its in the correct spot. The drill that drills the hole is wibble wobbly and it needs to fine a home. So in order to make a little hole for it to go in you need a very short stiff drill or whats called a center drill.
Then you can drill the proper sized hole for a 10-32 tapped hole.
Wow none of these pictures are that great, there must have been some shmoo on the lens. Anyway next you have to tap the hole with, you guessed it a tap. Also some oil for lubrication, you do not want a broken tap in your part. But if you do break a tap, go upstairs get a beer then go sit at the mill mope for ten minutes then get a left hand drill and try to get it out.
Alas we are at an end. Many hours later and lots of sighs and we are done. All we have to do is debur the hole, because no one wants a sharp hole.