Sewing Awl Hand Stitcher

A friend of mine needed to replace his old sewing Awal that had broken. Eager to demonstrate the benefits of 3D printing, I offered to make him one. It's a sewing tool that's usually used to stitch leather, canvas, and other similar hard materials where hand stitching is required.

Design & Printing

3D Software (Inventor/Fusion 360)

Cure Slicer

3D Printer

PLA Filament

Post Processing

Clippers

Sand Paper (Optional)

Spray Paint (Optional)

Use

Bobin

Awl Needle

Fabric

Scissors

I started with the basic shape and dimensions for the individual parts. Being a mostly circular tool the initial shapes were circles to which I then added fillets or chamfers as needed.

The Handle and Driver were extruded to the correct length and internal diameter to ensure a snug fit with a 0.3mm clearance.

The End Cap was drawn to 30mm to match the diameter of the handle and the outer edge filleted to a rounded edge.

Both Bolts were extruded to the necessary length with the threads and ribs to be added later.

The Fastener was drawn and extruded to a length of 12mm and a 1.8mm hole cut into the end to allow the needle to pass through. The outer surface was curved using the fillet tool from 2 varying diameter circles meeting.

The bolts had ribs added to the thump grip by creating a raised area on the outer surface then creating a circular pattern around the entire surface.

The End Cap had an 8mm inner section created which will later have threads added to it.

At this stage, the Driver and Driver Point are being created as one part to then be separated later. The hole for the Center Bolt is created and spacing for the bobbin is created using the extrude tool to remove material from the model. The driver point was also modeled with a hole to accommodate the needle.

A hole was cut in the Handle to allow for the bolt to secure the Driver and Handle together. The end of the Handle was then hollowed to create storage space for 2 additional bobbins and needles then the sharp angles were smoothened using the fillet tool.

Now that the parts are beginning to take shape, I added grip texture to the upper part of the Handle using a raised extrusion and the spiral tool which was then projected as a circular pattern around the entire outer surface of the Handle.

At this stage, the Driver is mostly complete and I created slite in the tip of the driver which will become the Driver Point. These slits are to allow the Driver Point to flex and hold on to the needle when the Fastener is tightened.

With the Driver complete, I cut the model into 2 separate parts and saved them individually. With the two parts created I made a hole at the end of the Driver to facilitate the Driver Point. I then added a section to the Driver Point to be threaded which will screw into the Driver.

The Fastener then had a rib added to the outer surface for grip when tightening. The ribbed sharp edges were smoothened using the fillet tool then repeated around the outer surface using the circular pattern tool.

With all the parts now created, the sections to be joined had right-hand threads added. All threads were then offset by -0.3mm to allow for various 3D printer tolerances. At 0.2mm layer height with a 0.4mm nozzle, these settings work great.

All 7 parts were printed on an Ender 3. Print time is around 6 hours and the parts including supports use around 35 grans of material.

Below are the settings and values used for printing:

Nozzle: 0.4mm

Layer height: 0.2mm

Infill: 20%

Wall Thickness: 0.8mm

Printing Temp: 210c

Bed Temp: 47c

Print Speed: 60mm/s

Cooling Fan: 100%

Support: Concentric at 5% Density

The gcode file with all parts at the above settings is attached to this step.

Using a pair of clippers or pliers, I remove the supports. Only 3 of the 7 printed parts require support, 2 of which are minimal.

Once the supports have been removed the parts are screwed in place. It will be a tight fit in some areas at first but once the threaded parts have been worked in and out a few times, it screws like ice on glass.

This step is completely optional as you can print the parts in any color you choose however, I only had black filament on hand and wanted to give some depth to the awl so I painted the driver and end cap in a matte gray.

I sanded the surface to allow for better paint adhesion. I then covered the exposed threads on the end cap to prevent the paint from attaching to it. Once I applied 2 coats of matte gray to both parts, I allowed 4 hours for the parts to completely dry.

Once dried, the parts were reassembled and ready for use.

Remove the end cap to store or retrieve extra bobbins and needles. The small center bolt is removed so the bobbin with the thread color of your choice can be inserted. Once inserted, the small center bolt is tightened to secure the bobbin. The fastener is then removed and the needle inserted into the driver point. With the needle inserted, the fastener is placed back onto the driver point and tightened, securing the needle in place.

Start by threading the needle and pull around 1-2 inches of thread through the eye of the needle. Drive the needle through the fabric for the first time. With the needle on the other side of the fabric, pull through a few inches more thread than is needed to complete your stitch.

Pull the needle back through the fabric and make the second stitch point (hole) in the fabric. At the second stitch, pull the needle halfway back out and it will create a loop in the thread. feed the length of thread you pull through earlier to complete the length of your stitch through the loop on the backside of the needle.

Repeat this process until your stitch is complete. At the end of your stitch, with the needle pushed all the way through the fabric, cut the thread at the back of the needle and tie the 2 ends of the thread together. Use scissors to trim the excess thread.

Once your stitch is complete, remove the needle and bobbin from the awl and store them in the handle by removing the endcap.