Computer controlled embroidery

The result

The hero shot above is the finished piece. It is my design sewn in thread onto woven cotton fabric, with filled areas and crisp text, all built up by the needle going through the cloth thousands of times. The rest of this page is the full workflow so anyone can reproduce it from the same files.

How this process is not covered in any other week

Every other week worked with cutting, milling, printing or casting, and all of those either remove material or add hard material. Computer controlled embroidery is a textiles process, and it is different in three clear ways.

• The material is thread and fabric. Computer controlled cutting cut sheet material, machining removed wood, and 3D printing added plastic. None of them joined thread to cloth, which is what embroidery does.
• The output is built from stitches, not a continuous tool path. A laser or mill follows one path to shape one object. Embroidery places thousands of separate needle penetrations, and the image only exists because those stitches sit next to each other.
• The new design skill is digitising. Cutting and printing take a vector or a model almost straight to the machine. Embroidery needs an extra conversion step where I decide the stitch type, the angle and the sewing order for every shape. That step has no equivalent in the other weeks.

So this week stands on its own as textiles and stitching, separate from the cutting, milling, printing and casting I did before.

Tools and materials I used

• Vector drawing software (Inkscape) to make the original artwork.
• Embroidery digitising software to convert the vector into a stitch file.
• A computer controlled embroidery machine with a hoop.
• Woven cotton fabric and a sheet of cut away backing stabiliser.
• Polyester embroidery thread in the colours my design uses, plus a bobbin thread.
• Small scissors for trimming jump threads.

Step 1: Drawing the artwork

I started by drawing my design as a clean vector. I kept the shapes simple and closed, because open or overlapping shapes confuse the next step. I made the smallest text large enough to read, since very small letters do not survive in thread. I saved this drawing as an SVG, and that SVG is the original design file in the files section below.

Step 2: Digitising the design into stitches

Digitising is the new step this week. It is where the drawing becomes a set of instructions the machine can sew. I opened my SVG in the embroidery software and set up each part of the design.

1. I imported the SVG and scaled it to the final size I wanted on the fabric, well inside the hoop area.
2. I picked a stitch type for each shape. Large areas got a fill stitch, and thin lines and small text got a satin stitch so the edges stay sharp.
3. I set the stitch direction for each filled area so the thread catches the light the way I wanted.
4. I set the sewing order so the machine sews the background colours first and the detail colours last, which keeps the top layers clean.
5. I assigned a thread colour to each section and named the colour stops in the order I would change thread.
6. I ran the software preview to watch the whole sew simulated stitch by stitch, then exported the stitch file. I exported it as a machine readable stitch file, and that file is in the files section below.

Step 3: Hooping the fabric

Hooping holds the fabric flat and tight so it does not move or pucker while the needle works. This step decides whether the result is clean, so I took my time with it.

1. I laid a sheet of cut away stabiliser under the fabric to support the stitches.
2. I loosened the outer hoop ring, laid the fabric and stabiliser over the inner ring, and pressed the outer ring down over both.
3. I pulled the fabric gently from the edges until it was drum tight, with the weave straight and no wrinkles, then tightened the hoop screw.
4. I checked that the fabric did not sag when I pressed the centre. If it moved, I rehooped it tighter.

Step 4: Threading and loading the file

1. I wound a bobbin with bobbin thread and dropped it into the bobbin case.
2. I threaded the top thread through the guides, the tension discs and the needle, following the path printed on the machine.
3. I mounted the hoop onto the machine arm and made sure it clicked in firmly.
4. I loaded my stitch file onto the machine and set the thread colours in the order the file expects.
5. I moved the needle to trace the outer edge of the design so I could confirm it stayed inside the hoop for the whole pattern before sewing.

Step 5: Stitching

I started the machine and stayed next to it the whole time. The image appears slowly as the needle builds it up stitch by stitch. When the machine reached a colour change it stopped and asked me to swap the thread, so I changed to the next colour and let it carry on. I trimmed the jump threads between sections as they appeared so they did not get sewn over.

Problems I hit and how I fixed them

• The fabric puckered on my first try. The hoop was not tight enough, so the fabric shifted under the needle. I rehooped it drum tight and added the stabiliser sheet, and the surface stayed flat after that.
• The top thread broke once. The top tension was set a little high. I lowered the top tension by a small amount, rethreaded the top thread fully, and restarted from where it stopped. It ran to the end with no more breaks.
• Small text came out rough and lumpy. I had digitised the small letters as a fill stitch, which is too dense for thin shapes. I changed those letters to a satin stitch and re exported the file, and the letters came out crisp.
• A few loose jump threads were left between colours. I did not trim them early enough. On the next colour I trimmed each jump as soon as it formed, and on the finished piece I clipped the rest by hand.

This week meets the wildcard requirements:

• I documented the full workflow step by step, covering digitising, hooping, threading and stitching.
• I explained how computer controlled embroidery is a textiles process not covered by the cutting, milling, printing or casting weeks.
• I described the problems I hit, with puckering, thread breaks, rough text and loose jumps, and how I fixed each one.
• I included the original design file and the stitch file so the result can be reproduced.
• I included a hero shot of the finished embroidered piece at the top of the page.

What I learned

The new idea this week was digitising, the step that turns a picture into stitches. The same drawing can look great or messy depending on the stitch type, the direction and the sewing order, so most of the skill sits in that conversion rather than in the drawing. Hooping the fabric drum tight turned out to matter just as much as the design, because a loose hoop ruins even a perfect stitch file.

Files and requirements met

Everything needed to reproduce this embroidery is here: the original vector artwork and the stitch file exported from the digitising software.