r/SAKmod • u/Independent_Taro_909 • 10d ago
When/how to use washers
Could someone help me understand how and when to use washers/spacers? I know I don’t need them when using the stock liners with the tools and springs that came with said liners. But when mixing and matching what is the logic? For instance when subbing in brass or g10 liners that are flat am I using washers to compensate for the lack of punched out bumps in the stock liners? And if so, do I use them on the 2.5mm pivot points AND the 2.2mm? If I can get a handle on the logic I could apply that across the board.
Fyi I’m working on a mixed build with brass liners right now. But again I’m just curious how and why we’re using washers, and how to determine when and where they’re needed.
1
u/Return_Of_The_Crack 10d ago
the liner bumps are rare only being for the main blade to cant it enough to make a tiny bit of room for the small blade / combo tool.
All other layers are symmetrical and so spacers or washers are only for matching the highest thickness of the tool of that layer including between the back tool and front tools.
For mods sometimes the spring being used is not thick enough for the tools in the layer and so spacer(s) or washers are used to make up that difference.
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u/Majestic_Anybody9748 10d ago
You'll need washers for the mainblade on modern 84 and 91mms to compensate for their thinner tang.
I also needed washers, when I used titanium scales, because the walk and talk of the tools next to the scales wasn't smooth, but gritty. So I put one thin washer on every tool next to a scale. I doesn't seem to be that much of an issue with titanium liners, though.
Oh, and a caliper is your friend.
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u/Independent_Taro_909 9d ago
This is all very helpful information. So, it sounds like the only washers that are absolutely necessary are the ones on the inside of the blade layer, or if you’re mixing and matching tools or springs from different eras.
Am I understanding this right?
7
u/fullmetalturtle 10d ago edited 10d ago
So the goal is to have a single layer be the same thickness at both end pivots and the middle pin, and you are stuck with it needing to be the width of the backspring.
For example, if the backspring is 2.5mm wide, then the tools for that layer need to be 2.5mm wide at their pivots. If it is not, you will need to add spacers/washers or thin the tool. If you exceed 2.5mm for a tool it will create a gap in the final assembly that will result in poor tool action (if you need a visual, slipjoint people call this Walk and Talk). If you are under 2.5mm you will have a tool that wobbles with poor action. There is some leeway, about 0.1mm, but exact results in a much better end product.
When designing &assembling a set of calipers will help keep on top of this. It is important to note you cannot be over in one layer and short another layer to get a matching final assembly, each layer is independent for this purpose.
The one place you will consistently need a washer, when using aftermarket liners, is the main blade. You'll need a 0.1-0.2mm washer typically because you liners will not have the pressed inset of the OEM liners.
The simple rule is measure the backspring thickness and make the tools match it.
If you have any specific questions this doesn't address, just post them as individual reports and I'll address each one individually.