Editing Pivot System (section)

===Troubleshooting Bushings===

Here are some common issues, alsong with tips, tricks and solutions to help diagnoes and fix problems when your balisong doesn't behave as exprected.

====Adjustable Handle Gap====

If your handle gap shrinks when you press the handles together, for some balisongs, this is normal. However, if the change is excessive, it's likely that the [[#Inner Diameter]] of your bushing is too large.

====Handles Move Forwards And Backwards====

If your handles shift or "click" forward and backward (towards or away from the blade when your balisong is open), the [[#Outer Diameter]] of your bushing is likely too small.

====Unexpected Binding====

Binding that happens even though the balisong seems properly assembled can have several causes.

=====Wrong Sized Washer=====

It is important to use the correct washers for your balisong. Bushings aren't the only thing that will impact your tune.

======Wrong Thickness Of Washer======

Check the height of the washer that you currently have installed in your balisong. Some balisongs, like the [[Bladerunners_Systems_Replicant_V3|Replicant]] require thinner washers than most other balisongs.

======Different Outer Diameter Of Washer======

Some blades taper (become thinner) towards the bushing. Changing to washers with a different OD alters the clearence between the washer and blade: if you use new washers with a smaller OD than your previous washers, your balisongs tolerances might become a lot loser and on the flipside: if your new washers have a larger OD than your previous, your balisong might start binding.

=====Uneven Bushing=====

This is the most common cause for binding. A small amount of unevenness is usually acceptable, but the tighter your tune, the less tolerance there is before your balisong starts to bind. For example a difference of 0.030mm might not cause issues on a loose tune, but even a difference of 0.010mm can cause binding on a tight tune.

Stainless steel washers are especially problematic with uneven bushings because the hard washer will get forced into the blade, causing the edge of the washer to grind into the blade. This issue is far less severe with phosphor bronze washers, as the softer material will "glide" against the blade even if the bushing is not perfectly flat. 

Unfortunately currently there is no way to prevent uneven bushings, however you can minimize the chance of making your bushing uneven by buying slightly oversized bushings. This way, you will spend as little time as possible on the lapping surface, reducing the chances of introducing uneveness. However, this method comes with its own set of problems as this method is very unreliable and some bushing sellers, like [[TheTrueLink]] have been known to send out bushings that are shorter than advertised.

=====Fix Uneven Bushing=====

If you do not have a micrometer, there unfortunately is no precise way to confirm unevenness. 

Begin by taking measurements at multiple points around the flat face of the bushing and note each reading. The greater the difference between the smallest and biggest measurement, the more uneven your bushing is. Identify the area with the highest measurement, this is the part that needs to be sanded. 

======Fix Uneven Bushing By Hand======

Place the bushing on your lapping surface and apply only preassure on the side that had the highest measurement while grinding the bushing against the lapping surface. This will remove material from the entire side you are sanding, but significantly more from the are where you apply pressure, so if you tune was already very tight, this procedure will probably undersize the bushing.

======Fix Uneven Bushing With A Pivot Lap======

Assemble your pivot lap as described in [[Pivot_System#KnifeDogs_Pivot_Lap]] and apply lots of pressure to the puck and no pressure at all on the plunger. Do lots of passes, around 50-100 depending on how uneven your bushing is and how far away from the target thickness you are. The flat surface of the pivot lap and low pressure of the plunger which rests on top of the bushing will make sure that almost all of the pressure is only applied to the thicker side of the bushing.

=====Uneven Washers=====

Washers usually do not become uneven on their own, especially if they are stainless steel washers, but just like with uneven bushings, uneven washers can also cause binding. As with an [[#Uneven_Bushing]], you can try sanding the side of the washer that is thicker. However, removing too much material can lead to other issues, such as the chanwich seam on [[Squid_Industries_Tsunami|Tsunamis]] opening up. In most cases, you're better off simply replacing the washer.

=====Uneven Blade=====

To check if your blade is uneven, measure the area around the pivot hole, where the washer would normally contact the blade. If the thickness varies, the blade is uneven. Fixing this is extremely difficult. While sanding the thicker area, as described in [[#Uneven Bushings]] might seem like a solution, it is not practical as this method is not precise enough for a blade. Proper correction would require a surface grinder, which most people don't have access to. Your best option is to run the balisong with a looser tune. Some people try using stainless steel washers, hoping the harder material will gradually wear down the uneven blade, but this can cause other issues and is generally not recommended unless your bushings are perfectly even and you're okay with experimenting.

=====Used-Up Washer=====

This mostly affects phosphor bronze or brass washers, as stainless steel washers are too hard to get deformed significantly.

Phosphor bronze or brass Washers will wear down with time and they will develop a groove in the center due to the pressure from the bushing. When you reassemble your balisong, it's pretty much impossible to align the bushing perfectly with that groove again. As a result, one side of the washer will press harder against the blade than the other, which can lead to binding.

To fix this issue, you can lightly sand both sides of the washer with a high grit [[#Lapping_Surface]] until the wear marks are completely gone. This usually only takes a couple of circles or figure-eights per side, as phosphor bronze and brass is a lot softer than stainless steel. After that, you can [[Strop]] the surface of the washer. Do about 100 circles or figure-eights per side. Stropping removes almost no, if any material, but helps to refine the surface further. After stropping, your washers should have a reflective finish, though not quite necessarily a full mirror polish.

You can also try applying pressure to the pivot area as if you were trying to snap the handles off the blade. For a visual demonstration, watch this video: [https://youtu.be/tcGMmcxFaQM?feature=shared&t=1316 https://youtu.be/tcGMmcxFaQM?feature=shared&t=1316] and jump to the 21:56 mark.

At this point, reassemble your balisong and check the tune by [[#Feel]]. If the binding is still present, but reduced, you can repeat the process. Just be careful to not remove too much material, or you may end up with new problems which are described in [[#Uneven_Washers]].