Yet another new simple project has reared its head and most importantly it will provide an opportunity to utilize the pantograph. This project is a simple puzzle consisting of six blocks of wood, with letters and numbers arranged to serve as month, day of the week, and day of the month. This idea came from Futility Closet. The picture below captures the completed puzzle.
The question that makes up the puzzling aspect of this set of cubes is what letters and numbers should be on the hidden faces of the cubes. The solution is shown below. Some letters and numbers need to serve multiple purposes to make this work: 6 inverted can serve as 9, n as u, p as d, and W as M.
Per the first photo, three different woods will be used for the six blocks. The blocks will be 1 1/4" cubes. The font will be something simple like Menlo Regular or maybe Gill Sans like this web page. The only real challenge will be spacing the letters and numbers appropriately on the block faces. The pantograph will need to be set at its highest to accomodate the cubes. The final consideration is how best to paint the numbers. A possibility for this is engraving the characters right through painters tape, paint, then remove the tape.
Glued up cutoffs of walnut and white oak separately in preparation for making the needed cubes. A scrap of pine may be used for the third wood, if I can't find something more interesting. The pine was switched for redwood. 1 1/4" cubes were cut from all three woods this fall morning and are seen below. They were briefly sanded by hand with 120 grit sandpaper.
The pantograph has been completed so it is time to cut the letters and numbers into the wooden blocks. A few extra blocks were made for learning how to use the pantograph to rout characters onto block faces. The font selected is Helvetica, size is 157, giving 1.5" high printed characters. The characters shown above were printed on three pages after creating a file in Pages, as TextEdit did not allow setting the margins leaving too few characters on a page.
The characters vary in line width from 3/16" to as narrow as 5/32", implying 3/32" widths on the block. The 1/16" bit will need two passes. My plan is to follow the characters with the stylus about 1/16" in from the outside and go all the way around both sides of lines to hopefully produce a properly proportioned product.
The first experiment in wood was undertaken this morning. The design was taped to a block of wood that was double sided taped to the wooden base. The test piece of wood had a 1.25" square traced onto its surface and was then taped to the aluminum base, ensuring the square was aligned appropriately with the stylus centered on the "0". The double sided carpet tape had a difficult time sticking to the aluminum even after wiping the aluminum down with acetone. The “0” was traced with the stylus after lowering the 0.072" router bit into the wood.
The resulting "0" was not perfect, partly due to challenges moving the stylus while keeping it 1/16" from the edges of the design and partly from the tool bit following the grain. The photo below shows the “0” after cutting and after a bit of sanding.
Paint was also experimented with. A black acrylic paint was used with a small brush. My painting skills are even worse than my skill at following the design with the stylus. Two things will be tried to improve the painting. First, the brush needs to be wet before use and shaped to a point. Second, the wood will be finished with shellac before cutting. This will ensure that any paint falling outside the character can be easily removed with a wet cloth.
Two coats of shellac were applied to the cherry scrap. After drying overnight another experiment was performed. The cutter was switched to 1/8" after a quick measurement of the previous attempt showed the character line width was very close to 1/8". The pantograph was readjusted and the “0” was cut again where shellac had been applied.The device slipped at one point as can easily be seen in the photo below. This may have been due to a cut depth that was too deep at 1/8". The fuzzies were removed with 220 grit sandpaper and the “0” was painted. Using the pointed wet brush and the shellac made for a much cleaner paint job and easy clean up for the minimal amount of paint that was outside the character.
The third attempt was a significant improvement. Two things were altered. First, the depth was set using the attached calipers to 1/16". Second, a small block plane replaced the sandpaper for cleaning off the fuzzies. The photo below shows the improvement. The final improvement that needs to be adopted is using a line instead of a character. Using the stylus to follow a real line rather than an imagined line in the center of the character will be much easier.
I could find no automated way to draw a line at the center of the characters, so did it the hard way. A screen capture of the text was imported into a paint program. A path was drawn in small increments through the center of the lines of each number, extremely tedious, but delivered a decent product. Not looking forward to repeating the process with all of the letters. The numbers were printed and then reprinted once the appropriate scaling factors were calculated. The photo below shows the printout.
A different approach will be tried for the letters as the work above was a pain in the a__. Tracing paper will be used and a line drawn through the center of each letter's lines. This should simplify things substantially.
In the meantime the blocks were all painted twice with shellac. The photo below shows the shellacked blocks alongside the pieces made at my recent MASW class on inlay as taught by Robbie O'Brien. Great teacher, great class!
The lighting does not do the inlays justice, especially the shell in the signature and the inlaid veneer flower. The flower made of three metals with a black mother of pearl center will be repeated on both sides of the dulcimer scroll. Stay tuned.
The last practice “0” was cut this morning. A flat bottomed end mill was used, 1/8", set to 0.06" deep. The new line drawing was utilized and it was easy to follow. The result was still not as good as hoped. I believe the culprit is that the end mill wants to follow the grain. The “0” was cleaned up first with a plane and then improved with a small chisel. The result is seen below. Didn't bother to paint the “0”. It is time to tackle the blocks.
I guess I could inlay the letters … nah, way too much work for this project.
Two oak blocks were selected for the numbers. The 1/8" bit was set 0.06" deep and milling began. There was significant resistance, but I pressed on only for the bit to break and fling the block across the shop! Expanding the photo below shows the bit embedded in the block before breaking. The milling was then attempted at 1/32" depth on a different face of the damaged block and proceeded easily.
Getting the blocks centered and squared needs to be addressed before proceeding. A block was placed under the end mill centered, while the stylus was centered on the “0”. Lines were drawn on the aluminum base around three sides of the block. To cut the numbers the blocks were taped in place, the end mill set on the top of the block, the end mill moved off the block and lowered by 0.03", the stop set, and the end mill raised. The stylus was set at the beginning of a number and the end mill lowered to the stop after turning the Dremel on. Cutting proceeded and the Dremel was stopped. Most of the numbers turned out well, though controlling depth is difficult. While cutting the “7”, the end mill dug in as seen in the photo below. This was repaired with a wood insert.
One of the depth controlling challenges is the set screws often come loose due to vibration. There is also enough up and down play in the pantograph to confuse depth setting.
The remainder of the numerals were cut and then all were painted. Painting is painstaking! In the end both blocks look okay. On to letters!
A slight change in the process saved a significant amount of time. The line letters were made using tracing paper. The tracing paper cutouts were then used to guide the stylus. The first three weekdays went well as seen in the shot of "Tuesday", but while cutting the fourth the end mill somehow dug deeply into the block, flinging it across the room. The gouge is shown in the second photo and the plug, made quickly from the same redwood, glued in place in the third.
The other error on the “S” was from raising the stylus, not enough, and moving it to the top of the “u”. It and the plug will be sanded and reshellacked before finishing the “u”.
It is not clear how the end mill dug into the block, dropping an additional 1/16". All of the set screws are tight. The end mill feels tight in the collet, but will be checked prior to proceeding. The same problem happened on the “F” also necessitating a repair. All of the set screws were tight and the collet had been tightened, convincing me that there is sufficient flex in the pantograph that the end mill is capable of pulling itself down into the work.
Most of the excess plug was removed with a small plane and routing the “u” was finished. The entire face of the block was sanded and two coats of shellac were applied. The photo shows the repaired “Su”. The “F” was cut also giving problems and requiring repair. Oy!
The days of the week were painted this morning after repairing the “F”. Painting was very troublesome as the shellac is still difficult to clean of the excess paint. Some areas seemed to have less shellac and the paint did not come off at all. So an experiment was conducted. The “F” was cut into a spare block after putting blue painter's tape on the face. The tape and the wood produced a lot of fuzzies that had to be removed with an Xacto knife using a new sharp blade. The block after fuzzy removal is shown below. The second photo shows the letter after a quick painting. So much simpler, though knife cleanup of a more complex letter will be time consuming.
After three days spent sitting the grandsons a morning was spent cutting the letters for the months. This was done on three walnut cubes. The traced letter was taped in place. One face of the cube was covered with painter's tape and the opposite face was taped with double sided tape. The cube was put in place centered when the stylus was centered. The height was set, the stylus was moved to a beginning point on the letter, and the end mill was lowered into the cube. After tracing the letter the letter had its fuzzies removed with the Xacto knife. The first letter is seen below before and after fuzzy removal.
This was repeated with all three cubes, putting three letters on each. The double sided tape won't work over the painter's tape, so only three faces could be done at once. After a bit more work adding painter's tape to key spots, the letters were painted as seen in the photo below. The end mill dug in a bit on the second of the nine letters, so three pieces of double sided tape were put on the cubes instead of the two, which didn't quite cover the face. There were no more dig ins after making this simple change. The second photo below, taken after spending two days with the new grandson, shows the nine completed letters.
The last of the letters were taped, cut and painted this morning. This completes all of the cubes. The last item to make is a set of shelves for the cubes. These will be made from three 1" wide aluminum strips with slots cut for interlocking the strips. That plan assumes there is some appropriate aluminum available in inventory.
Aluminum was available and was cut to length, a 1" X 3.75" piece and two 3/4" X 2" pieces, all 1/8" thick. A 3/8" deep 1/8" wide slot was cut on center through the two shorter pieces. Two 1/2" deep 1/8" wide slots were cut into the longer piece of aluminum with 1 5/16" between them. After cleaning up all three pieces they were quickly assembled as shown in the first photo below. The stand with the blocks in place is shown last and completes this project. A good way to learn the strengths and weaknesses of the pantograph when cutting wood.
