Announcement: Welcome to TRB-CNC Routing

My name is Tom. I recently purchased and built a medium sized CNC routing table. I’ve now discovered I can easily share the wonders of CNC routing with a few of the masses. If you’re one of those masses, put on your creative thinking cap and keep reading.Gantry and table front view

Below is a short introduction to CNC and my specific machine. The picture to the right shows the basic table with X, Y and Z axes. The router bit is inside the black brush thing. In the photo you can see the top of the router motor sticking out from the “Dust Shoe”, the thing with the black brushes on the bottom. The dust shoe has a long hose to clean up cuttings as they are cut. This is important so they do not interfere with the action of the bit. Too much waste material can hinder cutting action and result in inaccurate cuts. Behind the router on the back side of the Z axis bar is the “lead screw”. Continue reading

New Years Update for 2016

Well this site is getting to be a little bare. I’ve not been working much during the last year so It’s time to get to work and make some more cool things. I lost the keys to my room downstairs and had some other social issues come up, most of which are now dealt-with. So, onwards and forwards…

New Year Sub Woofer Enclosure

Latest 3 CF sub enclosure with "adequate" internal bracing.

Latest 3 CF sub enclosure with more than adequate internal bracing.

Today I finished yet another speaker project. This one I designed myself and customized for a client. This project is a large, tall, sealed, 33 ft, 12″ sub woofer enclosure with more than adequate bracing. This is the most heavily braced enclosure I’ve made to date featuring an inverse arc, U shaped rear panel brace and two side panel H shaped braces to provide the stiffest possible enclosure without going to thicker materials. As I gain more experience I’m learning how to design enclosures with smaller effective panel segments and braces that break up the panel to raise resonance. All three braces are glued and screwed down the center as well at at the outer attachments. The brace below is designed with an “inverse arc” along the rear panel. This shape provides the thickest part of the brace centered on the largest, weakest part of the back panel. The holes are cut in the arc to reduce its overall volume impact on the enclosure. Center and front braces are customized to fit the TC LMS 12″ driver magnet as well as provide full length top to bottom bracing in two places along the sides, front to back. The internal bracing reduces panel resonance equal to a 6″ wide panel assuring its resonant characteristics will occur well above its operating range. Continue reading


December also yielded work. These small pine shells are used as packaging for something mysterious.

IMG_20131211_120439_275 Each “box” is first roughed out with a 1/2″ bit to relief the inside. Next the corner radius is set using a 1/4″, extra long 4 flute run down each inside edge. Next an index is cut around the perimeter of each cutout to align two pieces as a shell and lastly they are cut free using a very long Super-O single flute 1/4″ bit. See Gabriel Matthews Design or click on lower image for more information.


Packaging shells cut from 6/4 Pine.


December is not over yet so check back soon for updates.


Alphabet BoardNovember was also a busy month. The machine, being still new, was upgraded and carefully examined to be sure all is working well. This included the replacement of the router which began to chatter from worn bearings. The first project came in for form of an alphabet board. This board is apparently used to teach special education students how to form alphabet letters using dexterous feedback in addition to visual. Both UPPER and lower case letters were cut on the same plywood board. One on each side.IMG_20131009_092123_792 Alphabet BoardThese were cut using two bits. First I removed most of the material with a 3/16 end mill. This cuts the grooves that make the letters. Next I duplicate the path using a 3/8 “T” bit to under cut around each line. This makes it possible to place a bolt or large screw into the line and slide it around. The careful placement of openings allow removal only at specific points while tracing the letter.


September – October Projects

I’ve been busy, so busy I haven’t had a chance to add my latest designs. Over the summer I worked on a project for Bamberg Audio. Phil Bamberg adds new designs regularly and for this one I was right in the middle.

Original Series 3 Design The initial Series 3 was designed with a “facetet” baffle to reduce baffle diffraction and enhance dispersion.

This design was picked up by several other people and used in other projects as well as a few pre-ordered, early design Series 3 systems. However, this design was dropped in favor of a newer A frame design.

A frame baffle design The new design uses an A shaped monitor atop the same woofer module. A new oval grille (not pictured) completes the new monitor.Unfinished assembled Above is the unfinished, assembled enclosure.Below is the crate I built to ship the parts. FedEx was very helpful in making sure the crates (there are two of them) got where they needed to go without incident.


Initial assembly shows braces and port openings for woofer enclosure. Phil was quite busy on his end as well. He cut the lock miter joints for all corners seams.

1380403_578550825573263_1372136252_n 1491273_607184429376569_100356897_o

Click image for more information on this design.

July 2013 Newest Project

African Paduk

African Paduk

This version of the baffle was a test baffle. Since I’ve discovered better materials and made use of them. This African Paduk machines up very nicely in a stellar looking baffle. With the box painted black they are ready for the test bench to install drivers and design the crossover.


This new baffle has a 3D machined round over edge. I can now offer this edge as an option on any flat pack as a custom option. Flush mounting in also a custom option.

Basic Arrangement Continue reading

New Sub Enclosure 1.5 Cu Ft

Working sub before finishing.Today I added a new sub woofer enclosure to my flat pack designs. This enclosure is 1.6 cu. ft. nominal, about 1.5 with 12″ driver, damping material and wiring and is suitable for a woofer from 8″ to 12″ in diameter either ported or sealed.

Basic Enclosure

Construction makes assembly simple and foolproof with dado joints on back, front (optional) and sides. Top and bottom panels fit into dado cuts on front, back and sides so all joints are tight sealing double edge dado joints. Standard material is 3/4″ MDF unless you want 3/4″ plywood at a little more cost.Drawing

Enclosure Construction

The enclosure features a dado set U brace around the sides and back to stiffen the enclosure which, when properly glued and attached, helps make that “tight” sounding sub woofer you’ve always wanted. An additional full wrap brace can also be ordered providing bracing in two dimensions (left and right plus top and bottom and back) rather than just one dimension. If the sub is placed on the floor with the brace oriented horizontally and spikes are used on the bottom, the extra bracing is unnecessary.

Continue reading

NaO Note II RS Custom Baffle Project Completed

Drawing Rear viewThis latest project is another Dipole. These are baffles cut for an NaO Note II RS dipole speaker system. These are complex specialty baffles featuring front and rear routing and custom roundovers for both drivers and outside edges. Drawing Front viewThe initial drawing was separated into front and rear view then toolpaths assigned to each side independently. I then had a choice to either chuck up a regular piloted roundover bit, hang it off the Z axis and use it like an upside down router table to cut the various roundovers, or to realign the baffles and use a CNC program to cut them. Continue reading