The D-ROC Bass Guitar, 2½ Axis
Sheldon Dingwall and Dingwall Guitars (Saskatoon, SK Canada) is one of the pioneers in the development of today’s multi-scale fan fret electric bass guitar. Sheldon was a player from a very young age, first learning the piano at age 5, drums and then guitar at age 12! But Sheldon didn’t stop there. He decided to build his own guitar in his uncle’s cabinet shop where he learned the critical woodworking skills from a master craftsman.
The VisualCAM Project
The VisualCAD/CAM project chosen for this case study is the CNC machined body of the Dingwall D-ROC electric bass guitar in its standard configuration. This is one of three ready-to-play guitar models from the Dingwall line. See more electric bass guitars in the Dingwall line further on in this article.
What sets this VisualCAD/CAM part file apart from other 3 Axis machining jobs is that only one 3D surface is required. Both the top and back are 3D contoured. It is used to define the sculpted top face of the D-ROC body. The remaining geometry are 2D and 3D curves. These curves are used to drive each of the 2½ Axis and 3 Axis toolpaths used to complete the machining job. The VisualCAD/CAM part file is shown below. The 3D contour surface is colored in deep violet. The remaining geometry curves are black and the stock definition is shown transparent.
The Machining Job & Setup
The VisualCAM Machining Job for the Dingwall D-ROC body consists of one 3 Axis setup output to the Fadal 88Hs post processor. The Stock is defined as an extrusion of the outer perimeter curve, defined as “Regions Stock” in the Machining Job tree. The actual stock material for this project is Khaya, also known as African Mahogany. The setup consists of 5 MOpSets (Machining Operation Sets). Each set contains multiple machining operations grouped by tool definition and other factors.
The first MOpSet contains 3 Axis rough and finish MOps (Machining Operations) for the upper contoured face of the Dingwall D-ROC body. The remaining MOpSets contain operations for the 2½ Axis roughing, pre-finishing and finishing toolpaths used to complete the machining job. The Machining Job tree, stock and completed cut material simulations are shown below.
|The Dingwall D-ROC body from stock (upper) to completed Machining Job (lower)||The Dingwall D-ROC body in the VisualCAM Machining Job containing 5 MOpSets of toolpath operations.|
The second MOpSet in the Machining Job contains three 2½ Axis Pocketing operations to rough out the Neck, Bridge, and Pickup pockets using a 25.4mm diameter flat end mill, an offset cut pattern, climb cut direction, and 50% stepover, leaving 2mm of stock allowance on the part. One cut level at a depth of 6mm is used with a ramp entry and linear retract motions. Cut Arc Fitting is enabled for this operation with a Fitting Tolerance (t) of 0.1mm.
|(Left) The Machining Job MOpSet for the 2½ Axis Pocket roughing for the Neck, Bridge, and Pickup pockets. (Right) Cut material simulation showing the toolpaths for all three operations.|
The third MOpSet in the Machining Job contains five operations to pre-finish the Neck, Bridge, and Pickup pockets all using a 9.5mm flat end mill. The Neck uses two 2½ Axis Engraving and Profiling operations that follow the exact location and direction of the 2D geometry curves. Engraving is a versatile operation used when you want exact positioning control of the cutter at all times. The Pickup pocket is pre-finished with a 2½ Axis Profiling operation and the Bridge pocket uses a second Pocketing operation, each leaving 0.5mm of stock on the vertical side walls of the part.
|(Left) The Machining Job MOpSet for the 2½ Axis Engraving, Pocketing & Profiling operations for pre-finishing the Neck, Bridge, and Pickup pockets. (Right) Cut material simulations showing the toolpaths for all five operations.|
The fourth MOpSet in the Machining Job contains three 2½ Axis Profiling operations to finish the Neck, Bridge, and Pickup pocket side walls each using a ⅛” (3.175mm) diameter flat end mill using a 10-degree ramp entry. These finishing passes cut to a depth of 3mm leaving zero stock allowance for the exact assembly fit required for the Neck, Bridge, and Pickup components.
|(Left) The Machining Job MOpSet for the 2½ Axis Profiling operations for finishing the Neck, Bridge, and Pickup pockets. (Right) Cut material simulations showing the toolpaths for all three operations.|
Final Slots & Holes
To wrap up the D-ROC body machining setup, the final MOpSet includes the mounting and accessories using 2½ Axis Engraving, Pocketing and Drilling operations. The first two are Deep Drilling for the Bridge (1.984mm diameter) using a 3mm step increment and Standard Drilling for the Pickup (4.76mm diameter). These are followed by Engraving operations for the truss rod slot and bridge ground slot and finally a Pocketing operation for the three 9.50mm diameter control knob accesses.
|(Left) The Machining Job MOpSet for the Bridge/Control Slot & Holes. (Right) Cut material simulations showing the toolpaths for the 2½ Axis Engraving, Drilling and Hole Pocketing operations.|
We hope you enjoyed reading about this cool project as much we did writing it! We also want to extend a very special thanks to Sheldon Dingwall and his team at Dingwall Guitars for allowing us to share their phenomenal success story! Sheldon Dingwall is the winner of the 2018 SABEX Entrepreneur of the Year, Dinwall Guitars also received the 2017 SABEX Business of the Year and Exported of the Year! Congratulations to Sheldon and his great team at Dingwall Guitars!
Cool project Sheldon!
We couldn’t let you go before proudly showing off more D-ROC electric basses from Dingwall Guitars. Here are just a few pics and reviews. Be sure to visit Dingwall Guitars at the social media links provided below! D-ROC Enjoy!
More Shop Pics from Dingwall Guitars!
Dingwall Guitars has now manufactured over 20,000 electric bass guitars each a work of art, craftsmanship and companionship! Here are some additional pics from the shop at Dingwall Guitars.