Spline slot cut into the bottom rail

Novena Heirloom – LCD panel/bottom rail alignment

The LCD panel on the Novena Heirloom is made up of a wood composite panel of my own design with solid wood rails and stiles forming a slot around the panel to receive the LCD. As discussed in a previous posting, an aluminum hinge plate has tenons machined into it to fit into the slots at either side of the assembly.

The hinge plate transfers the torsional forces from movement of the LCD panel to a pair of torque hinges specially manufactured for the Heirloom.  A wooden lower rail attached to the hinge plate assembly meets the bottom edge of the composite panel as the two slide together to capture the LCD. The place where these two meet required a special solution to maintain alignment after screwing the hinge plate to the composite LCD panel.

I looked at a sample assembly with a set of of screws across the front face of the hinge plate, but the effect was a bit heavy on the hardware look. After exploring several alternative ideas, I decided to use the CNC mill to cut a slot into both surfaces into which an aluminum spline would fit. This allows the panel and hinge plate to be pulled apart in the future for either LCD or hinge replacement. Then only two screws are needed – just above the hinges.

Space between bottom rail and LCD panel
A woodruff cutter moves in this gap to cut opposing slots

The simplest way to accomplish this while maintaining proper alignment between the bottom rail and the composite panel turned out to be running the job on the CNC mill with a small Woodruff cutter. A bit of manual g-coding produced the desired result.

The last step will be to fabricate the aluminum splines to fit the matching slots.

Novena Heirloom – hinge plate construction


Veneered hinge plate sliding into LCD panel
Veneered hinge plate sliding into LCD panel

The Novena Heirloom design incorporates an aluminum hinge plate designed to transfer torque-hinge torsional loads to the LCD panel housing. The housing itself is made from a combination of a wood composite material developed for the project and a set of matching solid-wood stiles and a rail along the sides and top respectively. These L-shaped solid members form a slot that receives the LCD when slid into the assembly from the bottom. The hinge plate then follows to form the fourth capturing channel for the LCD. It also incorporates the bottom wood rail.

hinge mount
Mounted hinges on the aluminum hinge plate with lower wood rail.

The custom hinges designed for the Heirloom computer mount to a CNC-milled recess on the inside of the hinge plate. The hinge leaf location is hidden by the LCD enclosure panel during assembly. A mortise for the hinge knuckle is cut into the lower wood rail to provide clearance with a clean appearance. The edges of the aluminum hinge plate form tenons that slide into the slot formed by the wood stiles at the sides of the LCD enclosure.

hinge and reveals

Along with the two hinge locations, the CNC milling operation for the hinge plates includes clearance channels that reduce the mass of the plate assembly and provide room for the LCD cable routing. The back face of the channeled hinge plate meets the inner surface of the composite LCD enclosure panel where a pair of screws attach the two and complete assembly of the LCD enclosure.

tapping hinge holes
Freshly tapped hinge mount holes.

Another reason for the aluminum plate design is the significant overhang at the bottom channel for the LCD. The LCD PCB occupies the lower inch or so of the panel, a space which must be blanked out to reveal just the visible area of the LCD when the unit is assembled. I initially considered using the aluminum plate in its raw state but experimentation led me to choose a veneered assembly to more effectively match the visual appearance of the Heirloom interior.

Veneering the hinge plate.
Veneering the hinge plate.

As is often the case with visually simple design, this assembly proved to be quite challenging to pull off. Matching tolerances between CNC milled aluminum plates veneered with 0.027″ of material and the solid wood and composite enclosure assembly required that the hinge plates be individually trimmed to thickness and face width on the CNC mill. I wrote a set of g-code files with a range of parameters to cover the variability within the enclosure assemblies and then carefully matched each hinge plate to its corresponding hinge plate.

The net result of all this work is a set of beautiful LCD panels with a clean and simple appearance true to the character of the overall design and a sturdy mechanical system for hinging the panels to the bottom half of the Heirloom enclosure. After final shaping of the top and bottom rails and trimming at the stiles, the LCD enclosures will receive finish in preparation for final assembly of the computers.

Novena Heirloom – lid capture magnets

The Heirloom is essentially a clamshell style laptop computer enclosure. But it has a removable keyboard and supporting rear panel section to facilitate access to the interior of the computer. Typical laptop hinge systems require magnets to fully close the LCD panel. In the Heirloom, these rare earth magnets are embedded during the construction process.

The stiles, or vertical members, have a recess cut on the CNC milling machine for each of the magnets. They are marked so that they get installed in the proper orientation. Ask my how I know to do that!

One of my favorite shop-made mallets and a simple installation tool made from a wood dowel are used to install the magnets. A rubber-toughened cyanoacrylate glue is used for the install.

Gluing up the rails with magnets pre-installed
Gluing up the rails with magnets pre-installed

Once the magnets have been installed, the stiles get glued up to the wood composite panel assembly. Side clamps underneath bring the rails in towards the center. Rows of spring clamps clamp the stiles down into full contact with the overlapping veneer on the back side of the composite panel. Plastic spacers keep the stiles in alignment without adhering to the glue

LCD composite panels ready for stile attachment
LCD composite panels ready for stile attachment

A rabbet cut along the edges of the LCD panels receives the stile members with just the top veneer layer overlapping the stile. These panels exhibit the veneer/glass/cork/glass/veneer construction.

A simple test demonstates the effect of the magnets as the panel nears the opposing magnet set.

Magnetic attraction at the opposing side is accomplished by a pair of magnets installed into a CNC-milled recess on the inside of the aluminum side plates.



Novena Heirloom – re-cutting hinge countersinks

A day like any other . . . get the shop “fore-bird” settled into his supervisory perch, turn on the compressor and lights and settle in to check with Azendoo to figure out what lies ahead. It occurred to me that I should check out the countersinks on the otherwise nicely made custom hinges I had fabricated in Taiwan for the Heirloom laptop case. As will be covered in another post, these hinges had been a significant challenge to overcome. After months of querying and cajoling, specifying and maybe swearing, I had finally managed to get one of the handful of torque hinge manufacturers to consent to making a minimum order of thirty sets of hinges suitable to the task.

The final custom hinge design for the Novena Heirloom laptop computer
Custom hinge design for the Novena Heirloom laptop computer

I was still flashing back on the inexplicable hesitation expressed by at least two of the suppliers to add a countersunk hole to the design. Since I routinely manage a decent countersink without much trouble, it was puzzling why this simple task would cause any consternation. The hinges are hardened after fabrication, so presumably this job would be handled before that step when the softer steel would readily accept the cutting action of the tool. But when the supplied hinges had a odd look about the holes. There was certainly no compelling need to add to the still lengthy list of tasks, but on further inspection, it was clear there would be an issue. A flush screw head fit is required in both mounting locations and unfortunately, this was not what I had.

Aluminum soft jaws hold the hinges in position for the CNC countersinking operation.
Aluminum soft jaws hold the hinges in position

I worried that the hardened steel would present a challenge in correcting this issue. But a quick test indicated that a carbide countersink (two of them as it turned out) would be up to the task. But I also noticed the holes were slight off target in some instances, so add re-centering to the challenge! I decided to set up some aluminum soft jaws in a vice on the CNC mill to enlarge and center the extant countersinks in one operation. A simple bit of g-code finished off the preparations which included milling a recess in the jaws to accept and register a pair of hinges.


A bag of goodies
A bag of goodies


Novena Heirloom – a Laptop Computer

Novena Heirloom Design

I was approached by friend and collaborator Joshua Lifton of Crowd Supply to consider working on a design for a new laptop computer case. It took me a moment to realize he was talking not about a carry case but the actual housing for a computer system. Since we were already working on a specialized keyboard project, it seemed like a natural fit. The only catch – I had about three months to get it ready to photograph!

He provided the URLs for details on the hardware and as soon as I began reading I was hooked. Renowned hardware designer Bunnie Huang was creating an open-source computer with amazing specs and had already received much interest and positive feedback on the project.

I had been designing bespoke cameras for the better part of 25 years and was looking for a new outlet for my skills and design philosophy. As an Apple computer fan and an even bigger fan of Apple design precursor Dieter Rams, I was game for a challenge in the electronic hardware realm.

Right side open view - photo:Scott Torburg/Crowd Supply
Right side open view – photo:Scott Torburg/Crowd Supply

I jumped in and began work with excellent feedback from Josh and his partner Scott. The original concept more closely resembled a tablet without a touch screen – it was strongly hinted that the target audience was not in the touch screen camp! Before long I began working more closely with Bunnie on the project and the concept morphed in the laptop direction with a twist – the keyboard would be removable. Bunnie’s hardware is a hacker’s dream and easy access to the inner workings was a given.

Cables! – photo Scott Torburg/Crowd Supply

I considered a variety of approaches and finally settled on very familiar territory – the combination of metal and wood. My camera designs utilize this classic combination but with a more modern design character than the more common rectilinear forms. They often incorporate a fabrication technique similar to that developed for the British Mosquito bombers of WW2 and carried forth by the Eames design duo in their classic furniture designs. It is an effective means of producing the curved forms I admire.

I began a series of experiments with material combinations. It soon became clear that an alternative to my usual “cross-banded” wood veneer lamination might be useful in this instance. Leaning on my camera design experience once again, this time looking to the composite fabrication techniques used for some of my panoramic camera designs, I pushed harder on the experimentation and finally landed on a combination that worked. A hybrid not unfamiliar to contemporary surfboard makers, the Novena composite consists of outer layers of paper backed wood veneer over a high-density cork core with intervening layers of 5.5 ounce fiberglass cloth all assembled with a high modulus epoxy resin. The result is a very stiff and light weight material perfectly adapted to the vacuum-lamination process used to assemble them.

With this new material option in hand, I went to work on curves. Perhaps due in part to my background in luthery (guitar building) and my father’s career with Porsche, I have a great fondness for curves. And of course, a great advantage of curves is their inherent stiffness – expressed in its purest form in monocoque structures. In the case for the Novena, the structure relies on additional elements, perhaps qualifying it for the moniker “semi-monocoque”.

The final configuration of the Novena case relies upon this wood-cork composite material for the flat LCD bezel, the bent-laminated lower housing and an additional feature – a removable panel behind the lift-off keyboard that, with the keyboard removed, provides for full access to the interior of the system. A key feature of the design is the wavy pattern across the bottom of the case intended to improve rigidity and cooling from the bottom of the case while providing a unique visual element in the design.

Wavy bottom curves – photo:Scott Torburg/Crowd Supply

Completing the structure are machined side panels in 6061 aluminum with a simple facet at the top and bottom to emphasize the port array and articulate the overall form. The sides fit flush with the top components and transition around the front and back to extend beneath the curved wooden case at the bottom to protect the wood finish.

Left side with ports - photo: Scott Torborg
Left side with ports – photo: Scott Torborg/Crowd Supply

The design considers the ergonomics of the bluetooth ThinkPad keypad in continuing the keyboards’s subtle front curve down the front edge of the case to provide a comfortable palm rest. A simple cutaway at the center of the palm rest allows for the removal of the keyboard.

Removable bluetooth keyboard – photo: Scott Torborg

In an attempt to carry through a simple, artisinal quality in the design, I opted to show the friction hinges in a fashion reminiscent of lidded wooden boxes. A straightforward mounting arrangement will allow for a low-impact replacement procedure in the event of a very active user!

Novena-1010 section
Hinge and speaker/cooling port – photo:Scott Torburg/Crowd Supply

I chose rift-sawn white oak for the prototype but have an eye on options for the final version. An unobtrusive, hand applied finish will compliment the bead-blast-and-anodize finish on the aluminum sides.

I will be posting further updates on the design both here and at the Crowd Supply site during the campaign.

Kurt Mottweiler
Portland, Oregon

Pinhole Photography – Lensless in Portland

pinhole photography exhibit

Pinhole Photography

First Friday event at ADX in Portland
November 1, 6-9 pm
417 SE 11th Avenue, Portland, OR 97214


Thanks to all those who came out for the opening evening for our pinhole photography event. It was a pleasure to work with these three friends on the event.
Remember that the show’s pinhole images will remain on display through the month of November. Unfortunately, the cameras were only on display for the opening event.
Be sure to check it out and have a look at the ADX facilities if you haven’t been there.

Phase two: Project Petzval

Petzval lens in its new mount
Petzval lens in its new mount

The next lens in the vintage lens / 5D Mk3 project is this nice vintage Petzval. we had an available bellows mount that just happened to fit the second EOS body adapter I had on hand. I fabricated an adapter to mount the lens to the front standard and bored a slight clearance in the rear standard to just reach infinity. The extant bellow sitting behind the rig is too small on the inside dimension to accommodate the lens so I will make a bag bellows to fit between the standards. It seemed not worth the effort to fab and fold up a new bellows.

Meanwhile the first project with a Tessar has been through some testing with revision to be made. I’ll post the revised version when it’s ready to rip.

In the interval, I’ll give a shout out to my favorite captain of industry – Elon Musk – and this amazing video of the Model S production facility. I do love Tesla . . .

Portland bike views and moving metal

I took my rascally Klein franken-bike and rode over to Rocky Butte for modest workout and some great views over the city. Zane (my African Grey parrot) is becoming increasingly proficient at bike rides. He told me to snap an iPod view of the Hood from on top.

Hacking a press brake
Hacking a press brake
I needed to use my pneumatically-enhanced Bonny Doone clone to bend some 1/4 SS so I welded up a shop made press brake attachment. The little beast did the job with ease.

“Air bending” is an interesting process. The gap between the two bending points determines the radius of bend.

I found that a piece of thin gauge sacrificial metal under the part took the scraping and preserved the surface on the part. Now I can make all sorts of 90 degree-ish things!


Archicam multi-pinhole lensboard


I recently made a pair of these pinholes cameras at the request of a friend who does architectural photography. The idea had been to do a shift camera but my friend Darius finally came to me with the idea of using multiple pinholes instead. So I built this very simple 4 by 5 camera with short focal length that can either be shot as a shift camera or with multiple pinholes open at once. A steel lens board allow simple magnets to be used for shutters.

front view of Archicam
Magnetic pinhole covers
Archicam top removed
Removable top and lens board
bubble level in top panel
Bubble level
4 by 5 holder system
Simplified holder system