BD's Mechanical Disk Recorder Build

[Bahndahn]

What material are you making the final "cone extensions" out of? Are those also going to be spun aluminum?

Hey Bryan,

I failed to mention the method I have come to to form the cylindrical members of these parts:

Basically I put down a soft pad and roll the pre-cut aluminium strips into a cylinder using two different brass rods. Today I realized that my paper cutter is the best tool for cutting the strips, so the next ones I make will benefit from some really nicely cut pieces for the cylinders.

Her is the setup for the 'roughing pass' roll– half-inch brass rod on a compressible pad:

Roll5.JPG

And here is the 'finishing pass' roll– quarter-inch brass rod on the same pad:

Roll4.JPG

My idea for the extension cylinder and the final cone-tip will be attempted this way too. I might have to work with some smaller rolling rods to get the correct diameter for the smaller cylinder, but all in all, this is very easy and highly effective so far!

As for the beverage can, the only beer I could find in a big can at my local Dépanneur was Colt45 , so I decided to go with Arizona Iced Tea to get as much aluminium as possible!!!

[recordboy]

This is such a wonderful thread to watch.

AZ icetea .99$ good deal for sure

I see some glue talk & even that wonderful aluminium rod stuff. both jb & that aluminium rod have been long time farm equipment & hot rod staples.

About 10 years ago a glue was released to the public, which I'm having a hard time finding now. either this new stuff marketed on tv is the same or a dumbed down version (like super glue is apposed to true Cyanoacrylate adhesives) ov what then was said to adhere ANYTHING to ANYTHING permanently once ultraviolet light was applied.

http://www.asseenontvwebstore.com/mobile/product.aspx?ProductCode=5%2Dsecond&404;http://www.asseenontvwebstore.com:80/5-second-fix-p/5-second.htm?gclid=CLCjwNmlzMoCFQIHaQod_y0ICA

Wondering if anybody's use that product or this new pen dispensed version.

Ive been waiting 10 years to know (when 1st released the smallest amount/kit was like 70$)

Jp weld is AWESOME tried & true

Yet pretty slow at drying (yet there lay its strength).

[Bahndahn]

I have engaged in a rather tangental project stemmed from my curiosity of record cutting, now I have a moment to update so here we go!

Somewhere along the way the questions arose: What the heck am I going to cut the sound onto? Well, plastic discs I guess. How do those who make the discs make the discs?

Turns out they have fancy machines called CNCs, which I guess stands for Catarrhinian Neuroscopic Cuttermachine.

All this looked like it was time to get a new piece of paper out and sharpen the pencil. Eventually I came up with my own Cuttermachien flavor.

8 months down the metallyfuzzy rabbit-hole and out the other side:

CNCinBasement.JPG

That clamp looks like its coming out of the router... I assure you it's not.

Mostly scratch built [except for the bearings, ballscrews, machinescrews, router holder casting] from some 300 pounds of cold rolled steel, aluminium, and stainless 416. Over 200 fasteners hold the chunks together.

The unloaded positioning accuracy retains ±0.0005" and so far my output tolerance sits within ±0.002" when cutting aluminium and softer.

This is good fun for milling PCBs apart from obvious cutting tasks. Here's one of my first PCB cuts:

Screen Shot 2016-08-21 at 1.18.42 AM.png

Alright alright, so this is some normal CNC stuff for those who are familiar.. However, I made one very exciting discovery when designing this machine, that I believe is 'original'. Who can spot it and explain it? Bryan, don't spill the beans..

[Bahndahn]

No guesses! Here it is:

The notable development in my design is the linear motion guide rails. I was faced with a number of parameters that needed to be fulfilled in order to efficiently build this machine; the rails needed to:

-precisely guild linear motion over the span of 30+ inches
-require as little machining as possible
-allow for mounting to a vertical surface [the frame of the CNC]
-cost as little as possible
-be easily maintainable and repairable
-allow for 'pre-loading'
-maintain high rigidity

These parameters put the fancy pre-made linear motion guides out of the question. Once those wear, they are done and need to be replaced – you can't regrind those.

After many hours of drafting, I came up with this configuration of two sizes of hexagons:

Screen Shot 2016-09-11 at 12.45.23 AM.png

Screen Shot 2016-09-11 at 12.55.02 AM.png

The hexagon that serves as the 'rail' has a vertical mounting surface that mounts, via a sort of stand-off, to the CNC frame. The hexagon that serves as the 'roller' is rotated 60º axially from the 'rail' hexagon forming 90º angles between surfaces on two sides. This allows for small bearings to contact the surfaces with great rigidity, especially when the system is doubled-up and made with preload adjustment ability. Note that the 'roller' hexagon is slightly smaller than the 'rail' hexagon to allow the bearings to be centred on the face of the larger.

This design can be produced such that the linear motion is highly precise. The surfaces can be re-ground, the rails can be rotated for fresh surfaces once the ones in use become worn, and all parts are easily replaceable, notably the bearings, which will likely be the first to reach their end of life.

This design is an excellent choice for those of you looking to produce your own linear motion guides for your lathe project. In the context of a lathe, the necessary linear motion is small enough to allow hand-lapping of parts on a surface plate – this means that one can produce a highly precise motion system by 'hand', as far as grinding/honing goes. Of course you can hand scrape these if you wanted as well.

I chose to make mine out of cold rolled stainless steel 416 which is 'free-machining' stainless. The stuff machines beautifully, is heat-treatable, and isn't very expensive.

More fun updates on the way soon!

[EpicenterBryan]

Bryan, don't spill the beans..

I've been a good boy Bennett.
I like it!

[Gridlock]

Bryan how are you posting at 1:05 pm when it is only 12:34 right now

[EpicenterBryan]

Bryan how are you posting at 1:05 pm when it is only 12:34 right now

I am a time traveler.

Bryan

[Bahndahn]

A few more CNC updates on their before returning to lathe discussion on this thread.

Here is a test cut of aluminium:

AlumCNC.JPG

Target external dimensions: 2"^2

The finish is really nice, it cuts aluminium smoothly with little trouble. The external dimensions are about 0.002" over sized consistently, and the inner bore is about 0.002" undersized.. The second face depth is within 0.001". What does this mean? Tool flex! When I first was learning machining from some engineers in university, I was shocked to learn that a 1" endmill on a large milling machine was flexing. It seemed bizarre that that was possible, and furthermore, the whole multi-thousand pound milling machine flexes! My 300lb machine definitely has some notable flex, so does the 1/4" endmill. This sort of thing can be compensated for by doing multiple finishing passes or programming a negative offset into the toolpath.

I am using Fusion360 to program for this machine, and it has some seriously slick algorithms for generating paths. I don't recommend CAD in it though, it's a joke compared to AutoCAD.