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Hi guys;
Here's a picture of the coil winder that I designed and built about two years ago. I use it to make all of the pickups in my Scroll Basses. The coils are all custom sizes and geometry of my own design.
I call this machine semi-automatic, because it has a fully synchronized feed mechanism to do the layering. However, it just has a manual counter, and I start it, stop it, and control the speed with my hand on the motor controller knob. Most of my coils I wind at about 1500 rpm.
Yes, this machine can be a little confusing in a picture. Here, it's running at speed. Those are toothed timing belts and sprockets. The whole assembly of the large aluminum plate moves side to side, carrying the black feed pulley which feeds the wire onto the coil bobbin. The aluminum plate is supported at three points by black Delrin blocks, all of which are riding on spinning shafts as they slide side to side. The block at the right is the second point, and the third is fastened to the back of the plate at the top, riding on the main shaft.
The third shaft down is the feed shaft, which is driven at a 1:16 ratio from the main shaft. Those are left hand threads on one end and right hand threads on the other, cut at 20tpi. The aluminum bar under the feed shaft is a rocker, pivoting in the center, with Delrin blocks on the ends that have partial matching threads cut in them. Engaging either one of the Delrin blocks causes the mechanism to feed accurately in relation to the main spindle's rotation. Clicking the rocker the other way causes the feed to reverse directions in a fraction of a second. A solenoid moves the rocker against spring tension. A pair of limit switches at the bottom sets the limits of feed travel, by contacting the two adjustable screws.
The black cylindrical part is just machined out of black Delrin; there's no additional bearing inside. It's multi-purpose. The feed shaft spins inside it, while it also serves as the sliding bearing for the whole aluminum plate assembly to move side to side. And, a slot on the bottom of it retains and guides the rocker bar.
The second shaft down is clamped to the aluminum plate, and it has the Delrin pulley on the end which is the actual guide for the wire. The pulley spins freely and is cut with a very narrow V-groove that the wire rides in. Running the wire around the pulley and up onto the bobbin like that seemed like the best way to feed the wire through all kinds of angles without dragging or jamming. As you can see, the bar that the pulley is on can be adjusted vertically and horizontally to handle a wide range of pickup sizes.
The end of the main (top) shaft has a steel flange with two dowel pins and a tapped hole in the center. It's made so I can easily swap the aluminum disks, which are made up to fit each of the size coils that I make up. In the photo, I'm winding one of the round P-pickup coils, which is set up on a single 2 1/2" disk. For oval coils, the bobbin is clamped between two disks. The "footprint" of the bobbin is machined into the surface of each disk to the depth of the flange, so the wire can't catch on the edges of the flanges. The largest set of disks I've made up so far are 6" diameter, for some special single-coil 7-string bass pickups.
I machined up all of the shafts and parts to my own design. The pulley size that I needed on the main shaft for the toothed belt drive was small enough that I just machined it right into the shaft, with a small slotting cutter and a spin-index fixture. Those are standard 1/3" pitch XL belts. The plastic pulleys are right out of McMaster's.
The machine is running at around 1500 rpm in the picture. At that speed, the wire is whipping around quite a bit coming off the spool. My wire guide/tensioner assembly is about 6" from the face of the spool to keep the whipping from getting out of control. At speed, you can barely see the wire. It's just a photographic fluke that it appears between the pulley and the bobbin here. There usually isn't much whipping right there, but there is a slower side-to side walking of the wire as it layers up, even though the feed rate is mechanically correct.
The motor is a Bodine 1/8 HP DC unit with a Bodine controller. I picked them up on ebay for $50. They're smooth and reliable with a fine speed adjustment.
Yes, I have a fairly complete machine shop in addition to my woodworking shop. My hobby is collecting and restoring antique metalworking machinery. I am indeed a mechanical wacko.
Here's a picture of the coil winder that I designed and built about two years ago. I use it to make all of the pickups in my Scroll Basses. The coils are all custom sizes and geometry of my own design.
I call this machine semi-automatic, because it has a fully synchronized feed mechanism to do the layering. However, it just has a manual counter, and I start it, stop it, and control the speed with my hand on the motor controller knob. Most of my coils I wind at about 1500 rpm.
Yes, this machine can be a little confusing in a picture. Here, it's running at speed. Those are toothed timing belts and sprockets. The whole assembly of the large aluminum plate moves side to side, carrying the black feed pulley which feeds the wire onto the coil bobbin. The aluminum plate is supported at three points by black Delrin blocks, all of which are riding on spinning shafts as they slide side to side. The block at the right is the second point, and the third is fastened to the back of the plate at the top, riding on the main shaft.
The third shaft down is the feed shaft, which is driven at a 1:16 ratio from the main shaft. Those are left hand threads on one end and right hand threads on the other, cut at 20tpi. The aluminum bar under the feed shaft is a rocker, pivoting in the center, with Delrin blocks on the ends that have partial matching threads cut in them. Engaging either one of the Delrin blocks causes the mechanism to feed accurately in relation to the main spindle's rotation. Clicking the rocker the other way causes the feed to reverse directions in a fraction of a second. A solenoid moves the rocker against spring tension. A pair of limit switches at the bottom sets the limits of feed travel, by contacting the two adjustable screws.
The black cylindrical part is just machined out of black Delrin; there's no additional bearing inside. It's multi-purpose. The feed shaft spins inside it, while it also serves as the sliding bearing for the whole aluminum plate assembly to move side to side. And, a slot on the bottom of it retains and guides the rocker bar.
The second shaft down is clamped to the aluminum plate, and it has the Delrin pulley on the end which is the actual guide for the wire. The pulley spins freely and is cut with a very narrow V-groove that the wire rides in. Running the wire around the pulley and up onto the bobbin like that seemed like the best way to feed the wire through all kinds of angles without dragging or jamming. As you can see, the bar that the pulley is on can be adjusted vertically and horizontally to handle a wide range of pickup sizes.
The end of the main (top) shaft has a steel flange with two dowel pins and a tapped hole in the center. It's made so I can easily swap the aluminum disks, which are made up to fit each of the size coils that I make up. In the photo, I'm winding one of the round P-pickup coils, which is set up on a single 2 1/2" disk. For oval coils, the bobbin is clamped between two disks. The "footprint" of the bobbin is machined into the surface of each disk to the depth of the flange, so the wire can't catch on the edges of the flanges. The largest set of disks I've made up so far are 6" diameter, for some special single-coil 7-string bass pickups.
I machined up all of the shafts and parts to my own design. The pulley size that I needed on the main shaft for the toothed belt drive was small enough that I just machined it right into the shaft, with a small slotting cutter and a spin-index fixture. Those are standard 1/3" pitch XL belts. The plastic pulleys are right out of McMaster's.
The machine is running at around 1500 rpm in the picture. At that speed, the wire is whipping around quite a bit coming off the spool. My wire guide/tensioner assembly is about 6" from the face of the spool to keep the whipping from getting out of control. At speed, you can barely see the wire. It's just a photographic fluke that it appears between the pulley and the bobbin here. There usually isn't much whipping right there, but there is a slower side-to side walking of the wire as it layers up, even though the feed rate is mechanically correct.
The motor is a Bodine 1/8 HP DC unit with a Bodine controller. I picked them up on ebay for $50. They're smooth and reliable with a fine speed adjustment.
Yes, I have a fairly complete machine shop in addition to my woodworking shop. My hobby is collecting and restoring antique metalworking machinery. I am indeed a mechanical wacko.
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