Umarex Gauntlet Cheek Riser Adjustment Assembly Installation Instructions
- Remove the sling swivel at the bottom of the butt stock by turning it counterclockwise. This is used to lock the adjustment wheel in position or release it to adjust the cheek riser height.
- Remove the rubber buttpad. There are 2 phillips head screws holding the buttpad on. Carefully remove these 2 screws with a phillips head screw driver.
- Under the buttpad there is a plastic plate held on by 2 phillips head screws, the screws are at the top and are side by side. Remove these 2 screws and identify the orientation of the plate, both sides look the same (place a mark with a silver sharpie to avoid confusion in re-assembly).
- With one hand rotate the cheek riser adjustment wheel clockwise, raising the cheek riser, and with the other hand gently pull up on the cheek riser. You may need to slightly wiggle the cheek riser to prevent it catching on the internals of the butt stock. Continue to do this until the cheek riser is freed from the butt stock.
- Look into the cavity of the buttstock where the cheek riser resided. You will see a small screw on top of the aluminum ‘pinion gear’. Remove this screw with a small phillips head screw driver.
- Before removing any additional parts go back to the rear of the buttstock. Underneath the 2 screws which held on the plastic plate is a cavity. Within this cavity is a spring plunger which functions as a detent. This should be backed out before proceeding, back it out 5 or 6 turns.
- Look into the cavity where the cheek riser resided. You will see a threaded hole in the aluminum pinion gear. Take the cheek riser and thread it back into this hole, 3 or 4 turns is all that is needed. Now using the cheek riser lift out the pinion gear.
- Now slide the steel adjuster wheel out of the slot on the side of the butt stock.
- With the 2 original metal parts removed you can proceed to install the lightweight 3D printed versions.
- Slide the 3D printed adjuster wheel through the slot on the side of the butt stock making sure the raised gear shaped portion is facing down.
- Now drop in the 3D printed ‘pinion gear’ through the top of the buttstock and make sure the small hole is oriented to align with the small hole in the adjuster wheel. Check the length of the supplied flat head phillips screw against the stock screw. If they differ in length use the supplied screw. Install the flat head screw through the pinion gear and tighten it carefully. DO NOT OVERTIGHTEN! As you tighten this screw check the movement of the adjuster wheel, if it begins to bind the small screw is too tight, back it out until the adjuster wheel rotates freely. You should feel the detent as you turn the adjuster wheel.
- It is necessary to adjust the spring plunger, this is the spring plunger accessed through the back of the stock referenced earlier. If it is too tight it will wear a groove in the 3D printed part and fail to operate properly. You should feel the spring plunger drop into the detent of the pinion gear with very little resistance in between turns of the adjustment wheel.
- Now thread the cheek riser into the pinion gear, via the brass threaded insert in the 3D printed part. Align the cheek riser with the buttstock and rotate the adjuster wheel counterclockwise. Turn the adjuster wheel counter clockwise until it is at its lowest position. This is a hard stop. Do not continue to rotate after it had hit its lowest point as you can damage the parts.
- Once the cheek riser is at its lowest point you can fine tune the detent. Again, you should feel the spring plunger drop into the detent, but it should not give resistance to turning the adjuster wheel.
- Re-install the plastic plate, insert the 2 screws, the ones which are side by side near the top and tighten carefully. These thread into plastic within the buttstock and can be stripped.
- Install the buttpad using the 2 screws you removed in step 1. Again, tighten them carefully as they thread into plastic and can be easily stripped.
- You are now ready to set your cheek riser height. Keep in mind that attempting to exceed the maximum range of the cheek riser can damage the stock and or the 3D printed parts. When the wheel hits a point of difficulty turning it has reached its maximum range. Turing it further will only damage the stock or the 3D printed parts and will not increase the Cheek risers’ range of motion.
Replace the sling swivel in the bottom of the stock by rotating it clockwise. IMPORTANT: As you tighten the sling swivel wiggle the adjustment wheel back and forth, don’t turn it just wiggle it, and continue turning the sling swivel. Once you feel the wheel will not wiggle anymore turn the sling swivel until it is appropriately aligned. If you over tighten this it will punch through the 3D printed part damaging it.