Adjustable Bag Rider

This is project inspired by the ABR (Adjustable Bar Rider that is available for sale. The price of the bag rider is between 250 and 300$ which was way outside of my budget. 

I was able to take insperation from the existing product and make my own 3D Printable version of it. The total cost is around 40$.

Materials Required:
-Two, LM8UU Linear Bearings. (uxcell LM8UU Linear Ball Bearings 8mm Bore 15mm OD 24mm Length for CNC Machine 3D Printer 4pcs: Amazon.com: Industrial & Scientific)(This pack has 4)

-Two 8mm linear rods (ReliaBot 2PCs 8mm x 100mm (.315 x 3.94 inches) Case Hardened Chrome Plated Linear Motion Rod Shaft Guide - Metric h8 Tolerance: Amazon.com: Industrial & Scientific) (This pack also has two)

A height-adjustable rear bag rider for long range and PRS shooting. Turn the knob and the foot raises or lowers to dial in your rear support.

This project was inspired by the commercially available ABR (Adjustable Bag Rider), which sells for $250-300. That was way outside my budget, so I designed my own 3D printable version. Total cost is around $40.

Materials required

• 2x LM8UU linear bearings: uxcell LM8UU, 4-pack (you only need 2)

• 2x 8mm linear rods: ReliaBot 8mm x 100mm, 2-pack

• 1x 5/16"-18 threaded rod: 304 stainless, 2-pack (you only need 1)

• 1x 5/16"-18 nut: Zinc plated, 50-pack (cheap, and you’ll have plenty left over)

Mounting hardware (varies by rifle)
This part depends on your stock and how you want to attach it. I run a Christensen Arms MPR, so I used:

• 2x #10-32 x 1" flat head screws (from a local hardware store)

Printing

• Material: PETG

• Infill: 20% or higher (go higher for a heavier rifle or rider)

Assembly

1. Cut the linear rods and threaded rod to length. This depends on your rifle and the space above the rider. Mine are about 2.8" long.

2. Using a bench vise, press the linear bearings into the fixed housing until they’re flush with the side.

3. Press the nut into the knob, also with the vise.

4. Press the cut linear rods into the foot until they stick up the same amount.

5. Thread the threaded rod into the foot.

6. Attach the fixed portion to your rifle.

7. Slide the knob into the slot on the fixed part.

8. Slide the foot on, aligning the linear rods and the screw.

9. Turn the knob until it catches the screw and starts pulling the foot up.

That’s it. Now go send some lead downrange.

Picatinny version
For standard 21mm Picatinny/RIS rails, use the mount from Citruspers’ RIS/Picatinny mount.

• Uses metric hardware: an M3 nut and an M3x30mm (or longer) bolt

• Print in PETG for a stronger part

Files
An editable Fusion 360 project file is included, so you can adapt it to your own rifle.

Don’t see your rifle?
Message me and I’ll make you a custom version.

Questions? Message me, I’m happy to help.

Thanks to @IvanIlievski_1389752 for making the heavy duty version!

Happy shooting!