CT-17 Block Plane; The Back-story…
Monday, April 19th, 2010As promised last week, here are further specs on the CT-17 Dual Angle Block Plane;

Weight: 748 grams/1.65 lbs
Overall Height in Use: 61.2 mm/2.41 inches
Sole Length: 162.5 mm/6.4 inches
Sole Width: 48.75 mm/1.92 inches
Iron Width: 34.92 mm/1.375 inches
Iron Finish: Back, Optical Lap < 4 RMS
Iron Thickness: 4 mm/.16 inch
Iron Material; A2 Tool Steel, Rc 60-62, Cryo treated
Iron Bevels: Low Angle: 30 Degrees (25 primary +5 deg. micro bevel), Regular: 35 Degrees (30 primary +5 deg. micro bevel)
Iron Tension: Adjustable
Depth of Cut, Change per Revolution: .025mm/.001 inch
Throat Opening Range: 0 – 4 mm/.15 inches
Maximum Blade Cant : 2.5 Degrees
Sides to Sole Squareness: plus/minus .05mm/.002 inch
Materials: 304 Stainless, Steel Pivots
Blade Guard: Anodized Aluminum, Resides in Plane during use, attaches to back edge of iron for sharpening (affixed via 2 rare earth magnets)
Finish: Interior of body & components; glass bead finish, sides abrasively grained, pivots black oxide. Cap is polished. There is no black chrome on this piece.
Traditionally, most metal block planes use a cross-pin to anchor the chip breaker/cap to the body which holds the iron in place. By eliminating this pin, we were able to address the ergonomics of the tool with new light. The pic below, utilizes one of the stereo lithography models to illustrate the hand position where the index finger rests directly behind and above the cutting edge in a contoured pocket–this I am excited about because it feels great;

The design of the body is “circle centric” as circles were the predominate theme in the tool–they are everywhere and accentuated when possible to reinforce the theme. As illustrated below, the main holes in the body make grasping the tool securely easy and without much effort–it feels like it belongs in the hand…


The pic below illustrates the most traditional hand position using a block plane;

Although not illustrated here, the front “tote” pivots for two hand use and the inclination can be adjusted to suit your tastes.
For the past couple of years I have been wallowing in the money pit of radio controlled helicopters–while on my work retreat I realized they have had quite a subtle influence in my work over the past year or so. With the CT-17, I consciously used the influence as a design criteria as you can see below…

Regarding the clues in this totally awesome and worthless blog;
Clue # 1 was a close-up/abstract of the “tail pipe” depth adjuster.
Clue # 2 involved the making of the video. The blade lock mechanism is not linear and at thirty frames per second, I needed to know the exact location of the clamp arm, cap and link throughout the range of motion when opening and closing. This involved a sequence of 12 individual frames to open and 12 to close–the animation software we use is not constraint or interference based so I had to do it manually. This illustration below should bring clarity…

The rest of the clues should make sense now.
Regarding the video, it was put together by Michael who also wrote the music beat. Editing by yours truly, hosted by YouTube. You are probably thinking, I would love to see that again! Here ya go;
For those of you curious about the software we used in this project (not in any particular order); Cobalt, SharkFX, HyperShot, HyperMove, Premier Pro, PhotoShop, Excel and FantaMorph.
On a personal note, I have been deeply troubled by the story of Phoebe Prince (the Massachusetts high school freshman who took her own life after relentless bullying by classmates). Why, we as a culture allow this kind of thing to happen is beyond my ability to comprehend. I was once told that bad people exist because good people do nothing.
So, on a much less serious scale–completely insignificant in comparison–but nevertheless related, we here at Bridge City deeply appreciate those of you who take the time to correct some of the inaccuracies and mean spirited posts circulating on the internet regarding this tool. It is a huge step in making the internet a much more useful tool.
More questions regarding the CT-17? You know where to find me.
Thanks to all for making this project so much fun. For those of you who earned a $50 Gift Certificate, you can expect an email sometime in the next 10 days–Natasha, aka. “The Gift Certificate Queen” is on vacation this week.
–John


REAL LIFE EXAMPLE #1: You are making drawers with veneered ply bottoms. Plywood is like snowflakes–no two sheets are the same thickness. So you cut your bottoms and it is time to cut the grooves in the four drawer pieces. Depending on your drawer, you will likely use a router, router table, table saw or–our HP-6 hand plane. Either case, our new secret weapon will work wonders. Here’s how.

















