Recently I acquired the old hammer shown in the pictures. The rubber grip on the handle was very loose, and worn out and grody. Solution : Print a new grip in TPU (flex).

For reference, the hammer has an elliptical section (ellipse 9s 14mm x 19mm) about 132mm long where the grip is meant to be fitted. Of course this grip is only going to fit this particular hammer, but it may serve as a useful example for designing and printing similar grips.

Print Instructions

Print in TPU (flex) as follows :

• 0.3mm layer height
• 30% rectilinear infill
• 2 perimeters
• seam position (nearest) - I find this helps to reduce stringing

Note : 30% infill provides for a very slight “cushion grip” - reduce the infill for a softer cushion, or increase for a harder grip. The particular brand of TPU is  also a variable here, but I estimate that rectilinear infill in the 20% - 40% range should work.

CAD

The OnShape 3D CAD files for this are here :

https://cad.onshape.com/documents/ca2609cc3a885010130cd92d/w/64ce02015b9f95f5a5bd09ce/e/a6cbcaa0efe4fc5f38bb7cd3?renderMode=0&uiState=63c1aefd39bce04144de9588