Apr 23, 2012
The mouth lip was modified for better clearance and the center cavity was removed to help speed up the machining process and the logo were modified to reflect the coarser resolution of electrochemical etching. The height was also reduce to better fit the raw stock height.
Apr 23, 2012
The shallow mouth opening has too steep of an angle and tends to peal the cap back. The mouth opening was elongated to give better leverage to lift the cap.
Apr 13, 2012
| Electro-Chemical Etcher - McMaster | |
| Starter Kit 2amp Hand Marker | $73.80 |
| 16oz Stainless Steel Electrolyte | $10.77 |
Raw Stock, Machined, Deburred Burnished & Etched
Apr 13, 2012
The mouth of the bottle opener was based off the dimensions of the can opener tool on a Leatherman Sideclip. A few laser cut acrylic prototypes were made to test the mouth geometry for bottle cap engagement.
The bottle opener in the foreground was the very first prototype drawn with a commercial 3d cad before switching over to FreeCAD.
Op1 and Op2 Completed
Op3 Completed after numerous unsuccessful attempts in the background.
Apr 07, 2012
| Bottle Opener Speed and Feed Calculation | ||||||
| Tool | SFM | Diameter | RPM | Feed per Tooth | # of Flute | Feed (ipm) |
| Maritool .250” 4F TiAlN | 315 | 0.250 | 4813 | 0.0014 | 4 | 27 |
| Maritool .125” 4F TiAlN | 315 | 0.125 | 9626 | 0.0005 | 4 | 19.3 |
| Maritool 2.48 Shell Mill - ACK300 Inserts | 300 | 2.480 | 463 | 0.0060 | 5 | 13.9 |
| Fixture Machining | ||||||
| Tool | SFM | Diameter | RPM | Feed per Tooth | # of Flute | Feed (ipm) |
| Kennemetal .500” 3F HPF37 | 800 | 0.500 | 6112 | 0.0040 | 3 | 73.3 |
| Kennemetal 2.5 Shell Mill - K110M Inserts | 3000 | 2.500 | 4584 | 0.0060 | 3 | 82.5 |
| Maritool .375” Drill Mill 4F | 300 | 0.150 | 7640 | 0.0005 | 4 | 15.3 |
| SFM | Diameter | RPM | Feed per Rev | Feed (ipm) | ||
| Iwrin #36 Drill | 200 | 0.1065 | 7174 | 0.0040 | 28.7 | |
| Irwin #25 Drill | 200 | 0.1495 | 5110 | 0.0060 | 30.7 | |
Apr 06, 2012
Modify radius and location of head and tail holes for fixturing with socket screw during op3, machining of the profile.
Apr 04, 2012
Before the g-code can be written, the machining tool path needs to be determined. A total of 3 cutting tools will be used. A shell mill to smooth both the top and bottom, a .25" end mill will perform most of the rough profiling, and a .125" end mill will perform the final profiling pass.
Each cutting tools has a specified cutting parameter. For both the .25" and .125" end mill the recommended radial cutting depth is 20% of tool diameter. Base on this information, LibreCAD was was to draw out the tool path.
In g-code, the tool path is represented by a series of linear and circular moves. Each transition point, ie where straight line meets a curve or where curves of different radius meets, on the tool path needs to be specified in terms of its X-axis and Y-axis coordinate. If the the next move is a circular move, the radius will also need to be specified. The process of dimensioning the transition points can be quite tedious.
Apr 03, 2012
| Stock - Metal Express | |
| 304ss flats, 4” x 0.5” x .125”, 100pc @ ~1.865 | $86.00 |
| Tooling - Martitool | |
| .125 Double End 4F Carbide End Mill TiAlN, 2 @ 8.51 | $17.02 |
| .250 Double End 4F Carbide End Mill TiAlN, 1 @ 14.82 | $14.82 |
| 45 deg Shell Mill Insert, ACK300 grade, 5 @ 10.70 | $53.50 |
| Fixture – HomeDepot | |
| 6-32 Hex Socket Screw | $0.65 |
| 10-24 Hex Socket Screw | $0.86 |
| 6-32 Irwin Drill/Tap Kit | $4.97 |
| 10-24 Irwin Drill/Tap Kit | $5.47 |
| Tooling – Martitool, 2nd Batch | |
| .125 Double End 4F Carbide End Mill TiAlN, 4 @ 8.51 | $34.02 |
| .250 Double End 4F Carbide End Mill TiAlN, 2 @ 14.82 | $29.63 |
| .125 4F Carbide Drill Mill 120Deg 1 @ 8.44 | $8.44 |
| 3.3mm .1299” Cobalt 130deb Screw Length Drill TiAlN 2 @ 7.58 | $15.16 |
| USPS Priority Mail | $12.45 |
Apr 03, 2012
Two Fixtures:
- Step Soft Jaws for:
- Op 1 - Side A Facing
- Op 2 - Side B Facing, Hole & Pocket Machining
- Profiling Fixture for:
- Op3 - Profile Machining
Apr 03, 2012
While waiting for the cutting tools to arrive. The effect of hollowing out the bottle opener was explored with Z88, an open source FEA software. Z88 is available in Debian, but Z88Auora the newer gui version of Z88 is only available as a Ubuntu package. Luckily, the Z88 was able to install under Debian.
After many hours of bumbling around, some sort of an answer was derived. The accuracy of the answer is unknown, but the picture look pretty. The skeletonized bottle opener does deflect more, but not that much more than the solid body version.
The ascii mesh was created using FreeCAD and imported into Z88. After reading through documentation, it appears that while Z88 is an open source software, Z88Auora is a binary only distribution.
