Tag: Gardening

Putting the entire fixture layout onto a tool layer produces a template to align the text on the sticks:

The rectangles mark where you put cut layer rectangles around the text in each stick. The sticks are 18 mm wide, so a 10 mm cutout leaves what should be enough wood along the edges. The rectangle length is a serving suggestion, as you must adjust the cut rectangle to fit the text.

Group everything except the four targets into a single object so you won’t inadvertently move only a part of it. The targets must remain separate to work with the Print-and-Cut alignment. With that set up, Lock the position of the entire layout to prevent you from moving any part of it.

Starting with a blank tag in the template:

Draw a rectangle in a cut layer to match the template, which is easy if you have Object Snap set up properly:

Add your text in a chunky font like Fira Sans Condensed Heavy, set to 15 mm tall with 5 mm horizontal spacing:

LightBurn aggressively snaps a new text cursor to the nearest pre-existing text, so you may be forced to click far away from where you want to place the text, type the text, then move the finished string. LightBurn will also snap the text to the display grid as you drag it around, so hold the Ctrl key down to disable snapping while you eyeball the proper alignment with the rectangle. Leave about 2 mm between the left edge of the rectangle and the first letter to make an easily visible space.

Although you can use lowercase letters, uppercase letters have the compelling advantage of being attached both top and bottom, so retype the text if you forgot about the Caps Lock key:

The 15 mm font height I’m using seems to be the overall maximum from the top of the tallest letter to the bottom of the lowest descender, not the height of any specific capital letter, all of which extend beyond the cut rectangle by about half a millimeter. That’s crucial to make this thing work, so tune the font and its height appropriately.

Select the text string when you have it properly aligned:

Hit Ctrl-D to duplicate the text, tap the ↑ (Up) arrow key to move the copy out of the way, and set it to the fill layer.

Now the magic happens.

Select the rectangle, Shift-select the text, and Boolean Subtract (Alt minus) the text from the rectangle:

Realize that you have screwed up by not shortening the right side of the rectangle to leave about 2 mm of open space. Bang on Ctrl-Z to undo the last step, shorten the rectangle, Shift-select the text again, then subtract the text from the rectangle:

Select the filled copy and whack the ↓ (Down) arrow key to move it back over the cut layer:

Now the filled layer will toast the characters to a nice brown and the cut layer will remove the background rectangle.

After finishing the text dance for all the markers, the template should look something like this:

The cheerful circles come from LightBurn’s Print-and-Cut Wizard aligning the template with the fixture holding the craft sticks on the laser platform, about which more tomorrow.

Converting craft sticks into plant markers should be a mass-production process, which means a fixture is in order:

Admittedly, making ten markers at once barely qualifies as “mass production”, but you (well, I) can think of it a proof of concept.

The basic shape comes from a 0.25 mm outset around the measured size of a craft stick (150×18 mm), plus an alignment target:

A good rule of thumb says never do any more work than absolutely necessary, so the rest of the fixture comes from linear arrays replicating the stick slots and targets:

The two strips over on the left (with a common cut down the middle) get glued to the underside of the fixture:

They’re exactly 5 mm apart to bracket one of the knife-edge bars supporting the fixture. The bar is upside-down to put its flat side upward:

Yes, the fixture is made of chipboard, mostly because it’s about the same thickness as a craft stick and it’s cheap & readily available. Each target gets an ink blot to make it more conspicuous; there is also a tiny hole burned through the chipboard at the center to mark the other side for the strips.

Two knife-edge bars (sharp side up) support the sticks near their ends, well out of the cutting path, to prevent scorch marks:

It’s worth noting the knife-edge bars are 5 mm wide and the platform spaces them on 3/8 inch = 9.525 mm centers. Not 10 mm, not 9.5 mm, exactly 3/8 inch. Kinda like the platform leadscrews: a 4 mm lead thread driven by a belt with 0.2 inch pitch. Only in America.

This doodle captures the key dimensions down there in the corner to work out where the strips should go:

Now, to convert names from a garden map into plant markers …