What is scatter winding?
When wire is wound into coils on a pickup, the most basic definition of scatter-wound means “non-uniform.”
Imagine a spool of thread that doesn’t have thread on it yet that you’re going to wrap thread around.
If you were to wrap that thread in a uniform way, you would start the wrap on one side, with each consecutive wrap following the other until you reach the other side, then start wrapping in the other direction and crisscross until you were finished.
If you were to wrap the same thread in a non-uniform way where you wrap a few times on one side, then go straight to the other side and get a few wraps there, then to the middle and “fill” the spool in a non-uniform way, that’s a scatter-wind.
Does scatter winding have a “standard?”
No. Scatter-winding is particular to manufacturer. Seymour Duncan will scatter-wind differently than Lindy Fralin and differently than other pickup makers and so on. In addition, there are also pickup makers who scatter-wind by hand, and still others who will use a machine. There is no single “right way” to scatter-wind.
What pickup makers do is experiment with different scatter-wind techniques until they find one they think works well, and go with that.
So how do we scatter wind with the coil winding machine
There are two ways of doing Scatter Winding on our machines.
First one is to manually winding the pickup by guiding the wire by hand and varying the speed of the bobbin motor.
In the software use the Manual tab where you can set the maximum speed and amount of turns required.
Once activated you will then use the dial on the controller box to vary the speed and sit there building up your scatter pattern by guiding the wire with your hand.
The second way is to emulate the scatter winding by creating a bunch of saved pickups that each have a different Turn Per Layer (TPL) and different amounts of winds.
Once these pickups are all saved, you can then setup the Standard Scripting Engine in the software to execute each of these mixed TPL bobbins one after the other.
Some people still use the old Mixed TPL Mode built into the software for running pre-saved bobbins, but we now recommend using the Standard Scripting Engine instead as you are restricted to only running and cannot use the extra commands the Scripting Engine offers. The reason we have still left the Mixed TPL Mode in the software and manual is for people still using it.
Lets do a quick run down on how you would do this in the software.
The pickup we are going to wind has a height of 6.2mm and we want to wind a total wind count of 7170 windings using 0.05mm wire.
Step 1 Create your bobbins/pickup sets
For this example we are going to create just three different sets, but you could have as many as you wanted as all with different configurations.
Set1 will have the configuration of 31 TPL and we want it to do this for 10 layers which will take 310 windings.
**Originally I was trying 33 TPL and will explain below why I changed it to 31**
Set2 will have the configuration of 40 TPL and we want it to do this for 20 layers which will take 800 windings.
Set3 will have the configuration of 80 TPL and we want it to do this for 16 layers which will take 1280 windings.
To make this easier we have a TPL Calculator in the software.
So I set my required TPL to 33 and clicked Calculate and then Populate Results.
Now as you can see the calculator will take the resolution of the machine and divide down the width of the pickup by the calculated wire size(pitch) of 33 winds.
For us to to do 33 TPL it would reduce the winding area down from 6.2mm to 6.1875 which is not a huge problem as it is scatter winding after all, but lets try and keep it to the actual height to 6.2mm for this example.
Picture above shows the calculation based on 33 TPL but pickup height has been reduced and not 6.2mm that we require, so lets change the TPL to 31.
Now as we can see by changing the TPL to 31 we now have a calculated pitch of 0.2mm which then changes the height of the pickup nicely to 6.2mm.
When we have finished calculating our pickup, we can click on the Close button and next save the pickup.
To Save the pickup, click on the top Save button and enter a name you would to save it as and then click the Save button below the description.
As you can see now your saved pickup will appear in the drop down list at the top.
Now repeat this for Set2 and Set3 and save them. They should now all appear in the pickup drop down list.
Now we have our 3 sets created, the next step is to add each of them to the Standard Script Engine.
Click on the ADD Extra Scripting Commands button.
Next choose the first set that you saved and call Mixed TPL1.
Click the Add Pickup to Script
Also add Mixed TPL2 and Mixed TPL3.
When you have finished adding your three sets, then click the Close button.
Now with all 3 sets adding to the Script, you can click the Start button and the machine will start winding the three sets one after the other until all the sets are complete.
You will end up with 2390 windings completed, so we could either run this script again or repeat it again 3 times to get out target winds of 7170.
Note that the bobbin motor will ramp up and ramp down between each set.
To copy a section of the script you can simply highlight the lines you which to copy and right click anywhere in the Script window and choose Copy from the menu.
Next right click again in the window and choose Paste from the menu.
As you can see we have pasted the sets twice.
Another way we could of done this was to add a loop instead of repeating the commands.
Click on the ADD Extra Scripting Commands button.
Place the cursor in front of the first command and press the return key.
Tick the Add Start Loop with count and put the number 3 in the box.
Now click on the Add Command button.
You will see the Start Loop command has been added to the script.
Place the cursor at the end of the last command and press the return key.
Tick the Add Finish Loop box.
Now click on the Add Command button.
You will see the Finish Loop command has been added to the script.
Click the Close button.
Now when you click the Start button it will loop through and run each set three times.
So far all our sets we create had a even number of layers and after finishing each set the wire feeder always ended up at the zero position. If you create sets that has an uneven layer count you can add a Move Feeder to Zero command as shown below so the wire guide is in the correct position before starting to wind the next bobbin.
Ticking the Move Feeder to Zero and then clicking Add Command button will add to the script.
You can also insert movement commands if you want to start your saved set away from the zero feeder position by adding in movement commands.
For example if you had created set2 with a TPL that was set to 4.2mm height and wanted to start set2 at feeder position 2.5mm then you would add a movement command before the command.
The Script would now run the first set and then move from zero to 2.5mm before winding the second set.
Above was an example of how to do emulated Scatter winding using pre-saved bobbins but of course you could just add and use individual winding commands for each layer, but you would end up with a lot of commands also you would have the bobbin motor ramping up and down between each command that could drive you mad after a while!
Of course you could convert all those single commands to a Absolute Script that would get rid of the need of the ramping between commands, but that is a whole different article that I would need to write.
**Update** A new article on the Absolute Scripting Engine is available, Click Here
There are a number of commands that can also be added and executed in the Standard Scripting Engine which allows you to create some crazy winding patterns and have a lot of fun!