AICS Cheekpiece Limit Collars

A simple collar to limit the depth of the cheekpiece on an Accuracy International Chassis System (AICS) 1.5 or 2.0 rifle chassis. These collars allow you to easily remove your cheekpiece and then return it to the exact position you had it prior to removal. You won't lose your cheekpiece position when it becomes necessary to remove it (as is the case for cleaning on the 1.5 (fixed) version of the AICS.

The front collar has a flat on one side to allow it to clear the scales/covers at the front of the cheekpiece recess. While it's possible to only use the rear collar, using both the front and rear collars is recommended for the most accurate return-to-position of the cheekpiece.

Important Note: These collars have been designed with minimal clearance, so ensure your printer is capable of printing with tight tolerance before attempting to print and use these collars. For this reason, it is only recommended to print these collars with a 0.4mm nozzle. Printing with a 0.6mm nozzle (or larger) will result in improper fit. Printing with a 0.25mm nozzle is possible, however, I had issues with the collars splitting along the layer lines when threading in the grub screw.

Necessary Hardware:

• 2x – M3x4mm grub screw (or 1x if you opt to only use the rear collar).

Printing Instructions:

• 0.4mm nozzle required.
• 0.1mm layer height strongly recommended; no more than 0.2mm layer height.
• 3 perimeters.
• 100% rectilinear infill.

Assembly & Use:

1. Prior to installing the collar on the cheekpiece, it is necessary to tap the hole for the grub screw by threading a grub screw in each collar all the way until the grub screw protrudes about halfway into the center of each collar and then backing it all the way out to clean any debris from the grub screw threads. Reinstall the grub screw and position it so that it is just shy of protruding into the center of the collar.

2. Set your cheekpiece to an appropriate height for your body/shooting position and rifle setup. Mark the current position on the mounting rods of the cheekpiece with a pencil.

3. Slide the collars onto the mounting rods of the cheekpiece until the bottom of the collar sits on/aligns with the pencil mark.

— See optional step below. —

4. Secure the position of the collars by tightening the grub screw in each collar. Be careful not to over-tighten the grub screw as it will strip the threads out of the collar and you will have to print them again. Use only two fingers on your driver with a light grip and gently tighten the grub screws only until your fingers slip. Try to pull the collars out of position with a small amount of force; if they don't move, you're good to go.

5. Reinstall the cheekpiece in your AICS.

Optional Step: If you are anal-retentive (like me), you can optionally choose to level your rifle longitudinally and then make slight adjustments to the collar positions (after step 3, before step 4) in order to get the cheekpiece to sit perfectly level when limited by the collars. Once you are happy with its position and level-ness (if that bubble is not perfectly centered between the lines, you're not trying hard enough)…

…continue on to step 4.