Cánh Tay Vẽ

This is a drafting arm that I made a to make technical drawings. the main bearings I used was F688 bearings that I got from Creality printer tensioner bearings, but F625 bearings from the V-wheels from Creality printers also work. There's 2 per wheel so you would need at least 4 wheels total for the joint. The rods can be as long or as short as you want but I made it with 250mm and does a good job of getting everywhere you want on a paper about 12 x 9in. I had problems of joints rubbing on my desk, so I made casters to roll around intend of drag around

Drafting Arm CAD

BOM

• 8 x 250mm Harden Steal Rods 

• 8 x 40mm Harden Steal Rods                                             (for Ruler Holder V1)

• 8 x F625 Flanged Bearing or 8 x F688 Flanged Bearing (for joint)

• 2 x MR104 Bearing                                                               (for caster wheels)

• 4 x F696 Flanged Bearing                                                   (for caster wheels)

• 12 x M3 x 10mm                                                                    (to hold the rods in the joints)

• 2 x M3 x 35mm                                                                     (for Ruler Holder V3)

• 2 x M4 x 20mm                                                                     (for caster wheels)

• 2 x M4 x 6mm                                                                       (for Desk Mount M4 Screws)

• 2 x M4 Nut                                                                             (for Desk Mount M4 Screws)

• 8 x M5 x 25mm                                                                     (to hold the joints to each part)

• 2 x M5 x 20mm                                                                     (for caster wheels)

Updates

11/19/25

• Made the CAD link a public document in Onshape  

• Added a new option for a ruler holder so you don't need the 40mm harden rods and just need 2 x M3 x 35mm screws

• Added a right and left ruler holder

11/20/25

• Added new desk mount with a printed screw that fits a wide variety of desks

• Organized the files 

11/29/25

• updated the descriptions and the BOM to match the parts better