Since I have the surface grinder working now, I can sharpen my own blades for my chipper shredder. But to sharpen them I heeded to build a jig to hold the blade at a 45°angle while it is being sharpened.
The blade is 4.250" long and approximately 1.250" wide. The three countersunk holes are for 1/4" - 20TPI countersunk socket head capscrews. The capscrews are then secured with a nylock nuts on the inside of the chipper wheel.
The edge was pretty much blasted away from years of use. I am going to make four new blades to have on hand so I can just change the blade when it gets dull. Then I can sharpen three of them at once instead of having to sharpen it every time.
The angle of the blade is 45° an easy angle to duplicate. The blades thickness is a little less then 0.250"
I dug out a piece of angle to use as the jig. I cleaned up the cut ends and then ground the surface I wanted to use to mount the blade on. I then set it up in my mill and located the one corner, and started to drill the matching bolt pattern into the jig. Once I had drilled the holes I tapped then to 1/4 - 20, and the jig was ready for the blade.
I then mounted the blade using three socket head capscrews, and placed the jig on the magnetic chuck. I blocked the jig on both ends with my 1-2-3 blocks, to prevent it from get thrown across the shop by the grinding wheel.
I then rough ground the blade to hog off the worn surface. After dressing the wheel again I sparked off and then took another 0.001 off of the edge in several steps and sparked out.
The finished face of the blade.
I did clean up the back of the blade to help remove the dings in the edge, I took about 0.003" off that surface and it made a great difference in the quality of the edge.
I have to make a decision on what material to make the blades from, I need to study up on them determine what grade of tool steel would be the best for these.