Intro: Gasket Centering Pin Tool
Recently I had to rebuild the intake of one of my cars. I found that a lot of the gaskets were toast and needed to be replaced. In some cases the previous "mechanic" did not even bother to install new ones.
So, I set to buy some... to my surprise, they were rather hard to find, expensive and of some rather poor quality in craftsmanship and material. On top of that, some arrived damaged in shipping and it already took weeks to get. On top of everything some gaskets were not available or only part of a "kit" that was ridiculously expensive and contained stuff I did not want or need.
So I decided to do something about it...
Most of the gaskets I decided to make were of symmetrical appearance (squares, circles, etc) but some were rather odd shaped. The throttle body was rather odd and give me fits, not to mention the water pump. I came with the solution below that establishes the exact center or all the mounting holes. Using that info and any program that can draw (Corel, Illustrator), I made complete sets of precise fitting gaskets cut on the laser, that were, well, Laser perfect. Here is my solution:
I made it at TechShop Chandler, techshop.ws.
Step 1: Get the Materials and Tools Together, Actual Machinig
A lathe is the best choice for this. You also need some screws that fit the holes of the part that the gasket goes to.
In my case, I went to the hardware store and got 4 Metric 10 screws that were short.
I chucked them one by one in the lathe and setting the height of the cutter lower than the center (see my other tutorial on lathes) I took a light facing cut.
If the cutter is set right you will get just a small nib sticking out of the back of the screw. They actually tend to be rather needle like and just right for the purpose.
If you mess up, and cut the nib off, no problem, reset the cutter and take another cut, you can compensate for the loss of material later by just screwing or unscrewing the bolt to match the height of the others.
I put some dye on my screws, it is easier to see that way, before and after the cut.
You should now have several screws enough to fill all your mounting holes.
Step 2: Setting the Screws Up
Go ahead and screw them all on. It works best if they are usually all the way down with the head against the actual part. Screw them only finger tight. Turn the part with the "legs" down on a flat solid surface and adjust the height so they are all the same, and the part is not rocking. That means that the "nibs" are even and in the same plane.
You are now ready.
Step 3: Make Your Mark
Get hold of a clean sheet of paper. Get to a worktable, or find a nice flat piece of scrap wood. Put the paper down on the surface and press the part with the sharp feet into it like you would a rubber stamp. After you pick it up you will notice the nice indentation right in the center of each hole. Don't do this on the nice dining table :)
It helps to take a marker and circle all of the markings it makes them to make the locations more visible.
Now take the calipers, and using the pointy tips you can measure the spacing between the indentations precisely. Also now, you can draw helping lines dimensions and additional geometry to aid with the final draft for the computer.
Step 4: Make Gaskets
Using this technique, I created images for hundreds of gaskets that are precise to half of a MM or less.
When cutting gaskets, use thick paper and make "proofs" in order to try them out, over the parts. Do not jump right into cutting your good gasket material, because you need some tweaking for sure.
See my other "gasket making" tutorial.
Hope this helps somebody, it helped me, and I saved hundreds of $$$ making my own gaskets