Abbott Analytical Products

Reference:

• LinuxCNC knowledge base library.
• FreeCAD user manual and its Path Workbench.
• OpenSCAD user manual, CheatSheet, and highly useful insight.

Note: ** Some browsers do not allow links to these sites from their anchors.

Through-Wire Wooden Fishing Lure:

Brief Summary of Project:

This project, 021_fishlure, employed previously gained FreeCAD knowledge, experimentation with FreeCAD Parts.Revolve workbench.tool, incorporation of four flute endmills, and cable wrapping loops. The results, lure style 021.4, is a stronger, realistically shaped crank style lure. Fish actually took an interest in this prototype.

Pond testing, lure confirmed the need for a lip. Various lip designs were attempted using materials such as plexiglass and thin sheet metal. Finally a potential, feasible 3D printer design was discovered. However, that design was determined to be too difficult to insert/mate with the 021.4 style lure body. A modification of that 3D printer design and of the 021.4 style lure was employed. A discussion of the modifications to the lip's 3D design can be found as a "make" of the original lip design. The FreeCAD project 021 was modified to include a pocket cut on the bottom of the lure to support mating with the lip with a modest negative three degree drop. The documents for the 3D printer lip and the pocket cut are provided further below in this section.

Field Testing The 021.4 style lure was successfully "pond tested". The addition of the luminescent plastic lip greatly improved the dive and play characteristics. It may have also improved the over-bouyant behavior. A second test session proved to be exciting with ,Fishing lure+lip 21.4.2. After a couple of lazy casts, a "bass" struck. The fish was played to a point where a rocky culvert empties into the pond. The fish could not be netted and was lost. Later during that second test session, Fishing lure 21.4.2, almost survived a severe collision with a metal fence during casting. The lip was destroyed and lost one treble hook. But the body survived. A new lip was installed, new treble hook was installed, and epoxy sealant was applied as needed to seal the lip and body.

Discussion of Process Flow
The FreeCAD project files, resulting gcode, and salient LinuxCNC support files for the Sherline Next Generation 8580 with Rotary Table/Right Angle are given below in seven part compressed file rar format. A high level view of contents of the compressed files is given directly below. Links in the next section lead to the downloadable seven compressed files.

1. A file called dirlist which provides a working manifest of the zip file.
2. Folder containing a more detailed a working checklist for moving through the milling process.
3. FreeCAD project files for Lure and Finish Operations.
4. The full collection of gcode for milling the lure objects.
5. A folder containing supporting program modules with images which require loading to the LinuxCNC machine folders.
6. The Cura 3D printer design project and gcode are available from the lucca82 Make Project at Thingiverse. That site also contains a discussion directly related to the 3D Printer aspect of the lip for the lure.

Download Actifcats

1. Part1
2. Part2
3. Part3
4. Part4
5. Part5
6. Part6
7. Part7

Tool Table Entries

• T21 P21 Z1.273 D0.045 ;dremel scribe engraver added 20190502
• T22 P22 Z4.013 D0.0625 ;dremel 1/16 drill
• T23 P22 Z4.013 D0.0725 ;dremel 3/32 drill
• T24 P24 Z2.264 D0.1275 ;1/8 x 3/8 4flute
• T25 P25 Z0.0 D0.25; 1/4 x 38 2 Flute End Mill Hand Powered

"stepper.var" Entries

Discussion of Design Process Flow

See the earlier crank lure and realistic lure for a discussion of the maturing steps in crank lure design. Instead of using a Side-1 and Side-2 (Right Half and Left Half) the perspective was changed to Dorsal {Top} Half and Belly {Bottom} Half. This change allows the compartmentalization of the design. The Dorsal Half has both eye buds and the primary shape of the lure. The Belly (Bottom} Half features include the Through Wire, the Belly Hook Loop Wire, and Alignment Pins Holes.


Dorsal Half/Belly Half:

The initial steps in the design differed from the earlier crank lure of Project 016. The Dorsal or Top Side was based upon an ellipse 2D shape. Using this shape as the outline, a continuous multipoint DraftWire 2D line was drafted from the left most point touching the x-axis to its right most point touching the x-axis. Using the Draft bench-revolve, the 3D Dorsal Half was created. With the Dorsal Half defined, it was then copied/pasted as the Belly Half. With the Belly Half shape now available, the Belly Half was modified from within the Draft workbench to generate the "desired" shape.

From that point forward the Dorsal Half and Belly Half were available for creation of Jobs and the associated *.ngc code. The Through Wire Processing was originally attempted as a separate CAD/CAM CNC gcode process. But common sense that it was better to create the Through Wire grooves, drill Belly Holes, Alignment Holes, "custom fit" craving of gaps for wire wraps manually, and adding a pocket cut to provide mating surfaces with the plastic lip. NOTE: For this early prototyping of the 021.4 style lure, the pocket cut was executed post-bandsaw separation because the need for the lip had not been confirmed. The difficulty in the alignment curved body lures presented with this deferred pocket cutting of the prototype strongly suggested that this pocket needs to be cut prior to the waterline surfacing while the centerline and factory edges of the woodstock can be employed.

A bandsaw was employed to separate the Dorsal Half and Belly Half from the workstock. The Dorsal Half and the Belly Half were then placed in a vise (with sacrifice wooden bumpers) to allow the drilling of the two alignment holes. The original centerlines (now significantly shortened) of the Dorsal Half were used for the drill operation setup.

Once the Alignment Pin Holes had been completed the two halfs were separated and then re-assembled. During the re-assembly, the Belly Half was now placed above the Dorsal Half such that the Alignment Pins could be inserted to allow exposure of the Belly Half's split face matching surface. With the Belly Half's matching surface exposed its centerline could be roughly verified between the head and tail points along the x-axis. The lures Through Wire groove was then scribe to a sufficient depth to allow the wire to just reach the top of the surface. The Belly Hook hole and its associated wrap "bore" hole were drilled. The accompanying "howto zip package" will provide a more detail set of steps as well as the pocket cut gcode and additional files to support this new operation.

The two lure halves were removed from the vise. The Through Wire Loops and Belly Hook Loops were created, assembled, and installed. Clearance "bore" holes were identified and created as needed to allow a "good" fit between the two halvs. This required a couple of assembly attempts using the Alignment Pins and then gently separating. During separation the both halves were examined to locate any points of conflict that might require additional "boring/cutting".

Once a "good" fit was achieved with the two halves and alignment pins were epoxied bonded. The excess lengths of the alignment pins were allowed to protrude from the Belly Half while being tangent with the Dorsal Half's surface. Painting coats were added as each dried. Avoid placing paint on the lip mating surface of the lure. Once the lure has dried the lip is ready to be epoxied into place. After that mating joint has cured a slanted slightly off-centerline pre-drill hole should be made such that the lip is pulled toward the mating surfaces of the lure. A small wood screw should then be fully inserted and then sealed. The body of the lure, immediate mating of the lip, and the lip's screw should then be receive sealant coat. The lure hardware was added after a "full" sealant cure in a solar oven.

Dorsal Half

Begin with the Part Workbench

Import Lip STL model from Thingverse Crankbait with lip

Convert Lip STL model to a Mesh model.

Convert Lip STL Mesh model to a Solid.

Create a rendering of the Belly Half with "cut" For Lip.

Use the Previously create belly bottom

Create a Cutting Tool Composed of a Cone and Rectangle

From the Draft Workbench

Create the Actual Cut Pocket Model

Create a closed four corner projection of the cone cutting tool.

Z should be set at a negative value of the height

of the lip's matching surface.

Rotate the projection three degrees such that the

bow is higher than the stern part of the lip.

From the Part Workbench

Continue development of the Actual Pocket Cut Model

Create a extrusion of this projection with the height equivalent

to the lip's mating surface height.

Trim the excess displayed above the level Z=0.0 using a cutting block.

Encase the cut model in a workstock block suitable to reflect

the lure's Belly workstock to obtain a model object of the pocket cut.

From the Job Workbench

Create a Job using the Pocket Cut Model as the Job's model

Under Operations Select 3D Pockets

From Pocket 3D select the bottom face of the Pocket Cut Model.

For Depths Start Depth select default and set

later. Set Finish and Step Down to suit.

For Heights and Operation select select the best for your equipment.

From the Combo View select the 3D Pocket operation

Set the Finish Depth to suit the negative value of the Lip height.

Once entered FreeCAD will begin a round of calculations

Verify the results display a number of toolpaths.

Post Process Lures

Post Process Lure

Generate Dorsal Half gcode

Generate Belly Half gcode

Generate Belly Outline gcode

From a text editor import a copy of the Belly Half gcode

Delete all Dressup and Surface gcode except for the last waterfall loop.

For the identified last waterfall loop perform a global Z

replacement such that Z now has a minimal depth

cut. For example Z=-0.01 in.

Save this document as the Belly Outline gcode.

Generate Lip Pocket Cut gcode

Adjust both ngc files as needed

Preamble

Post-amble

Extraneous Paths_1

Extraneous Paths_2

Extraneous Paths_2

Move To Mill

Customize gCode

Add custom version control/history

Add custom content

Simulate Milling Operation

Practice Flip and Reset

Set Y Axis Touchoff

Simulate Dorsal Half Waterline and Contour/Dressup

Simulate Belly Half Waterline and Contour/Dressup

Simulate Belly Outline and Lip Pocket Cut

Make Saw Dust

Design to gCode Process Flow With a collection of nine gcode files the project was moved to the mill. The Probe file was replaced with a level and a "scribe" point engraver to verify centerline on top. Then the work stock was flipped and the bottom centerline was verified. Verifcation of both top and bottom centerlines involved moving in the X axis along the centerline and "touching at several points. The combination of the 4-jaw chuck, right angle, level, centerline, and engraver/probe produced excellent results.

For a detailed, stepwise description of "how-to" create the lure from the CNC Mill to painting/coating and lip assembly view the process steps"how-to" document.

Project Photo Gallery:

Click Item to Expand

Shop Setup	Operating	Results	Description
New Points Used: y touch-off setting for P1 G54 to sync with centerline. Used: vise alignment for drilling and scribing. Points From Prior Projects Chuck, Shims, Mill, Keypad, Rotary Table, Right Angle Chuck, Shim, Centerline Stock Centerline SideB Ready for Milling Milling Side-1 Flip To 180 Side-2 Ready for Milling Simple Scribe Scribe-Mill End Holder Centerline	Dorsal/Belly Separation Bandsaw Blade View Blade Cut Width Twisted Loops 3 Locations 20GA GS Steel Wire Twisted Loop 5/64 Drill Hole Length to Match Belly Side Plus Loop Dia to Suit A/B Part Epoxy Sealant "How-To" Create Loops Video Other Helpful Videos 3D Printer Lip Creation Presentation Repair Field Damaged Lure Repair 21.4.2	New Features Four Flute Milling Glossy Eye Buds Wrapped Loops Dive Lip Pond Testing Largest: 21 Inch Bass NC. First documented catch. Pleasant day.	021 Lure Style: Crank Length: Lure: 2.522 in. Lure+Lip: 3.393 in. Width: .796 in Height: .911 in Weight: Lure: .343 oz Lure+Lip: .446 oz Painting 1> Body 1.1> Kiln Primer 1.2> Acrylic. Green, Yellow, Orange 2> EyeBuds: Black on Yellow 3. A/B Part Epoxy Sealant Hardware Twisted Loops Split Rings #0 Treble Hooks #8 Wood Screw #4 Stainless Steel

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Please send comments or questions using e-mail, voice telephone at 919-846-7705. (Last update: Nov 25, 2019 tar)