I finally got around to using my picatinny rail form cutters that I purchased on the bay. I had the steps all planned out in my head for a custom size rail for a Ruger 10/22. Totally overlooked the fact that the receiver on the Ruger had a 2.06" radius on top. I know it was 2.06 because I read it on the interweb so it has to be true right? It was a nicely drawn CAD file. I double checked other dimensions such as mounting screw placement and overall length, and they were correct. The radius had to be cut 7.5" long. I have a 4" Sandvik shell mill and a right angle attachment so I'm thinking MONEY!! This set up is perfect because the shell mill slightly exceeds the diameter of the right angle attachment which is necessary when traveling 7.5". The finish the Sandvik left was perfect. Im gonna need a beer because this was better than stealing!
Well............Not so fast knucklehead. The radius on the receiver was less than 2.06", far less. Now I am doing the math. The problem lies in the fact that there is so little of the radius to work with. My ciphering said it was closer to 1.375". Bummer since the right angle attachment has a radius of over 1.5" so I cant travel over the top of the piece. My only solution was a boring head and long boring bar. My little Criterion was 2" so it clears if I can find a boring bar to clear the side of if. This got ugly in a hurry, now I really need a beer. Here is what I ended up with. I knew it would not cut near as clean but I was only going to need to remove another .040 so I could take light passes.
The rest went very well. Lots of micro tramming, but I was able to hold .0005 across 7.5" everywhere.
The reason for 7.5" of rail and a more robust piece is because I am mounting a thermal scope. This devise was originally designed to sit in front of a day scope. In place of the day scope I am mounting a 3X optic. The white ring between the two pieces is a PVC bushing I made to eliminate stray light escaping between the two pieces.
Everything got a little long so the rail cantilevers out over the front and rear of the receiver. For that reason I "beefed up" the rail. The purpose of the Ruger is mostly to shoot rats at night out at the ranch.
The ebay cutter worked well. I have not tried the male counterpart cutter yet, but I will shortly as the 3X optic does not line up as well with the thermal as I had hoped. I did find it odd that the shank on the cutter was actually .6300 which fit a little snug in the 5/8" R8 collet. The only other complaint this whinny baby has is not having a .210" cutter for the recoil slots on the rail. I used a 3/16" cutter and made multiple passes on each slot.
Well............Not so fast knucklehead. The radius on the receiver was less than 2.06", far less. Now I am doing the math. The problem lies in the fact that there is so little of the radius to work with. My ciphering said it was closer to 1.375". Bummer since the right angle attachment has a radius of over 1.5" so I cant travel over the top of the piece. My only solution was a boring head and long boring bar. My little Criterion was 2" so it clears if I can find a boring bar to clear the side of if. This got ugly in a hurry, now I really need a beer. Here is what I ended up with. I knew it would not cut near as clean but I was only going to need to remove another .040 so I could take light passes.
The rest went very well. Lots of micro tramming, but I was able to hold .0005 across 7.5" everywhere.
The reason for 7.5" of rail and a more robust piece is because I am mounting a thermal scope. This devise was originally designed to sit in front of a day scope. In place of the day scope I am mounting a 3X optic. The white ring between the two pieces is a PVC bushing I made to eliminate stray light escaping between the two pieces.
Everything got a little long so the rail cantilevers out over the front and rear of the receiver. For that reason I "beefed up" the rail. The purpose of the Ruger is mostly to shoot rats at night out at the ranch.
The ebay cutter worked well. I have not tried the male counterpart cutter yet, but I will shortly as the 3X optic does not line up as well with the thermal as I had hoped. I did find it odd that the shank on the cutter was actually .6300 which fit a little snug in the 5/8" R8 collet. The only other complaint this whinny baby has is not having a .210" cutter for the recoil slots on the rail. I used a 3/16" cutter and made multiple passes on each slot.