Monday, January 15, 2018

One Small Step for Machine Kind

After having a metal lathe for a while, and really wanting to be able to mill some stuff (for no reason), and (after receiving a 25% off coupon at Horror Fright) I finally knuckled under.  I bought their mini mill.  I ordered it two weeks ago, and received it within 4 days of the order (uh, for freight, that's pretty good).  It shipped via FedEx, and it was boxed up pretty well :



I didn't have immediate time to do anything with it, so the crate sat in the garage for a week and a half.  Today, in order to celebrate diversity, I cracked white wood open to reveal a tool of many colors.  I have to say, it was packed to be protected, too.  Full of styrofoam, my sweet wife said I looked like I cussed a few times trying to get it out.  Ultimately, I dismantled the crate to get to the styrofoam, and then the styrofoam easily popped out.



After taking a quick inventory, I was wondering why I had another handle for the milling head wheel.  The paper said it was a "drawbar".  Someone in China probably didn't realize that a drawbar is a bit different, but hey, it appears like what it was intended for will work fine..


The chuck came mounted in the spindle (R8), and it definitely looks like it is not square (tipped sideways).  That is something easily remedied after tramming a drill press table.  Once I get the space for the mill, I'll clean it all the way up and tram it in.  Hearing that the thread pitch for the tables was not on the half inch, the second thing I did was check the wheel dials, and sure enough, the table is on 0.625" per full turn, while the headstock is 0.60 or 0.060" per rotation :




Well, that is definitely not a deal breaker.  For as cheap as this was, I think it will get my foot in the door on milling, and it will fit my current needs well.  Here is my list of to-do's :


  1. Belt Drive Upgrade (big difference in noise and reducing chattering of endmills from the plastic gears)
  2. Changing headstock spring and moving to a constant force piston
  3. Add a DRO
  4. Square vice or vice jaws
  5. Collets instead of the chuck (already done)
  6. Light on the work area
  7. Traverse endmills (better end mills than the cheap Chinese stuff)
  8. Plastic covers  for the tables/ways (so you have less to clean up)
  9. Depth gauge to work in tight areas (e.g. under the headstock)
  10. Leather wrapping the motor to reduce noise.
  11. Change lead screws from 0.625 pitch to 0.50 pitch)
  12. CnC changes

Sunday, January 14, 2018

No Supervision is a Bad Idea

An engineer should never be left alone in a room full of tools and materials with time on his hand.  As an example, here's the latest conversation.

Right Brain: Hey, I could use a laptop stand for my desk.

Left Brain (this is where the argument of NOT having a laptop stand should be) : You have brass.  Brass would look cool as a laptop stand.  Why not use brass to do it?

Right Brain : Great idea!  I have rubber sheets I used to make the brake bleeder jars, and I have some brass flats.  That means I have exactly what I need!  Shall we get started?

Left Brain : I'm not so sure about this... I mean, how could we bend those flats into a laptop stand?

Right Brain : Not a problem.  We have a press, too.  I'll figure that out, you just worry about making it look good enough that Honey Woman will let it stay inside on the desk.

Left Brain : Cool!

So, here's what happened next.  First, the idea went to an "official standards document", and marked into the material :


Then, starting to get things lined up for the bending of the flats.  First, I tried using machinist clamps to bend the bars at the same time.  But that failed to keep the bars lined up (parallel, yes, but they kept pivoting on me).  My next solution worked, and that was using some steel bar as a "clamp".  The brass was drilled and tapped, then the steel was match drilled to the screws and things were screwed tightly together :



Once that was complete and tested to ensure that there was the lack of movement if I twisted the steel, I headed out to the press and started to bend.  I don't have a fancy compact bender, so I had to use the shop press.  That was difficult to work around the tool without having dies, but it still worked out well :


The hardest part of those bends was actually the lip right on the end, with as short as it is.  I ended up starting it with the press to get it marked properly, and then finished the bend using a MAP torch and a hammer on a steel square tubing chunk.  I did some sanding (all of it by hand, actually, because I didn't want concave surfaces), and then coated it with lacquer to keep it from tarnishing :


Once those were complete, I parted off four hex rod pieces.  The length was the width of the flat bars I'd already painted (they'd sit on the bent flats).  I drilled and tapped them through the side and end-to-end.  I stood things up for a quick "fit" check :


Knowing it looked good, I threw the rods into the lathe and cut threads the length of both of them and rounded the ends.  This allowed me to simply thread the rods through the hex "nuts" that were attached to the brass flats, and bind it all together.  Next was a quick run to the basement to try it all out :



Worked out well, and only took me about a day!

Tuesday, January 2, 2018

New Years Boredom

What happens on New Years' day when you have 3D printer filament, a messy cupboard containing your shaving supplies, and you are full of boredom?  You make something to hold your razors on the cupboard door, that's what.  It's a nice test of the rapid prototyping techniques and tools.  Here's the details.

First, over the last little while, I kept thinking about trying to mount the razors against the inside of the cupboard door.  It keeps them easily accessible, and leaves the rest of the shelf open for other things like shaving gels and other "keep me in a state my wife is willing to be close to me" stuff.  Yeah, this is serious stuff.  I thought about using some robe-hangers found at the local orange-box-type of store, but didn't think it would work.  (Translation: I was too lazy to go buy one of those and try it.)  New Years' morning, I woke up early (it happens a lot, even if I was up late).  It only took me an hour before I needed to do something constructive (there is only so much screen time I guy can take before his engineering kicks in, you know?).  Then it hit me - why not build my razor hangers?  I have everything I need.

I headed out to the shop and grabbed the calipers (uh, just because I might need 0.005" of accuracy), and took a few measurements of the razors in the position I'd be hanging them.  This would simply give me the basic design of the holders.


Next, I opened OpenSCAD (seriously? Yup, I grew up with POV-Ray, so I am used to using code to set up the object.  It took me an hour to get everything the way I wanted it to look.


After the design and a quick STL export, I loaded it into the printer and hit "run".


My wife and I ran and played some racquetball, then came back to a failed print.  The filament got tangled up, and prevented it from being extruded.  [sigh].  I untangled it, got it set up again (with something to keep it spooling), and hit "run" again.


We ran to see "Star Wars".  Finally saw it.  If I actually cared about my "nerd credentials", I'd have been to see it sooner, but I'm willing to wait.  Visited an "adopted" couple of boys (cute, but bouncing-off-of-the-walls kinds of energy).  Then headed and grabbed dinner, came home, and found a successful print.  I did another one (I have two razors), just for that one.  We watched another movie while we ate dinner (Disney's The Sword in the Stone), and I had two prints ready to be cleaned up and installed in less than 24 hours.


This morning, I cleaned them up (breaking support structures out of the parts), and did some sanding on them with a Dremel to remove some of the hard edges.  They turned out nice, so I grabbed some machine screws and installed them.  I know I could have used some body filler to really smooth them out and painted them, but it just wasn't worth it to me.  My wife somewhat enjoys aesthetics.  To me, it has to have a good function. We are great together, because when our heads work together, we can do some amazing work.  So, they got installed as-is, and are fully functional.


Not a bad little bit of work!