Build Your Own Needle Puller, Part One

[keithstout]

Build Your Own Needle Puller Part One

I cannot pull glass needles by hand. I simply don't have the dexterity and touch and can't learn it. I solved the problem by building my own needle puller. Perhaps it will help beginners pull needles. It might help hand pullers improve their needle quality. All my parts came from the same sub-assembly of an old sewing machine; any donor machine will serve. I will submit this presentation in two parts to avoid a data logjam.

I drilled a vertical hole in a 2X4. Into the new hole I placed a round shaft:

wood shaft.JPG (105.12 KiB) Viewed 1521 times

Starting at the top of the shaft, I have installed an adjustable spacer that now has a new job. On the back side of this spacer, out of view, are two set screws that hold the spacer firmly in place. It is never allowed to move. I cut into the spacer surface a slot with a hack saw blade. That slot must be perpendicular on the spacer, which makes it parallel the shaft:

puller top.JPG (87.2 KiB) Viewed 1521 times

I cut a rubber band to length and made a loop with the stapler. I slipped the band onto the top spacer. I'm ready to load the capillary tube. I slip a fine dental pick into the slot behind the band and gently pull the band out. I slip a capillary into the slot and gently release the band. I make sure the capillary seats straight in the slot:

top tube installed.JPG (91.91 KiB) Viewed 1521 times

In the overhead view, notice that the capillary sticks up out of the slot a little. This allows the band to grab it and hold it in place without crushing the glass. Care is taken to ensure the slot is not cut too wide or deep. Notice that the capillary parallels the shaft. This alignment means there will be no axial stress on the capillary during the needle pull. Axial stress will cause crooked needles:

top view, top tube installed.JPG (83.06 KiB) Viewed 1521 times

At the bottom of the shaft are two stacked components. The upper component is another spacer identical to the top spacer. This is the drop collar, as it is free to slide along the shaft, drop, and pull the needle. Below the drop collar is a gear with a new job: the drop stop. It limits the fall of the drop collar, and thus, the length of the needle pull. Using the setscrew, the drop stop can easily be slid into any shaft position and securely fastened. Then, the length of the needle pull is adjustable:

puller bottom.JPG (100.39 KiB) Viewed 1521 times

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End of Part One.