R-Engineering
Plastic
- Joined
- Mar 14, 2018
I have been using 3d printed lapping bits to improve the rugosity and visual appearance of the bore in Airsoft Barrels. Improvements in accuracy can be dramatic . Below is a picture of Steel barrels before and after lapping:
Left is an unmodified Steel barrel, Center is Steel & lapped a few thousand passes using a 3d printed lap, Right was lapped by a Taiwanese company using unknown methods. All Steel barrels appear similar to the barrel pictured left before being lapped. The unmodified barrel is able to reflect the camera flash back to the lens and you can see the shadow of the leading ridge. On the lapped barrels no light is reflected back to the camera and the shadow of the leading edge is not visible. This is because all light entering the bore is reflected down the bore as a mirror would, the sign of a very fine surface finish.
I decided to produce a hand driven rig to speed up the process. After completing the device I found that the 3d printed bits are less than ideal. I decided to seek out metal adjustable laps and found the Acro brand. They produce Brass Laps. Unfortunately they do not provide the same effect. Instead the surface finish has been made worse & I do not know why:
Lapping steel Before & After
Lapping brass Before & After
Using 3d printed laps we can achieve a visually improved surface finish. However the brass Acro lap has worsened the appearance of the surface. I read online that the lap must be made of a softer material than the surface that is being lapped & this could explain why the Brass Acro lap with a Brass barrel did not work. However it does not explain the Steel barrel having the same effect. I realize now I don't fully understand the lapping process. Can anyone explain why this happened?
Brass Acro lap next to a 3d printed lap coated in lapping paste and cut metal.
Left is an unmodified Steel barrel, Center is Steel & lapped a few thousand passes using a 3d printed lap, Right was lapped by a Taiwanese company using unknown methods. All Steel barrels appear similar to the barrel pictured left before being lapped. The unmodified barrel is able to reflect the camera flash back to the lens and you can see the shadow of the leading ridge. On the lapped barrels no light is reflected back to the camera and the shadow of the leading edge is not visible. This is because all light entering the bore is reflected down the bore as a mirror would, the sign of a very fine surface finish.
I decided to produce a hand driven rig to speed up the process. After completing the device I found that the 3d printed bits are less than ideal. I decided to seek out metal adjustable laps and found the Acro brand. They produce Brass Laps. Unfortunately they do not provide the same effect. Instead the surface finish has been made worse & I do not know why:
Lapping steel Before & After
Lapping brass Before & After
Using 3d printed laps we can achieve a visually improved surface finish. However the brass Acro lap has worsened the appearance of the surface. I read online that the lap must be made of a softer material than the surface that is being lapped & this could explain why the Brass Acro lap with a Brass barrel did not work. However it does not explain the Steel barrel having the same effect. I realize now I don't fully understand the lapping process. Can anyone explain why this happened?
Brass Acro lap next to a 3d printed lap coated in lapping paste and cut metal.