CrutchAttach - Assistive Magnetic Forearm Crutch Holder, Open Sourced.

CrutchAttach is a magnetic holder for forearm (elbow) crutches. It allows users to snap their crutches together, freeing up one hand for everyday tasks — like holding a stair rail or grabbing a coffee. Born from a personal challenge, it was developed over 3 years and 26 iterations in collaboration with real users. Now, it's available to anyone, anywhere, as an open-source, 3D-printable tool.

Born from a simple, personal need — solving one problem, for one person — CrutchAttach was first envisioned in response to a real challenge shared by Anton, a wounded friend who needed a way to manage both crutches while keeping one hand free.

That seed grew into a versatile, global solution.

1. Intuitive – Use it with a snap. The magnets connect the crutches instantly and securely.
2. Universal – Designed for both short-term recovery and long-term mobility needs.
3. Retrofittable – Fits almost any elbow crutch with no modifications.
4. 3D Printable – Engineered for easy FDM printing at home or in any lab.
5. Simple to Assemble – Uses off-the-shelf magnets and inserts.
6. User-Tested – Developed with and for real users through over 26 iterations, across 3 years.

There are solutions out there, CrutchAttach is the first open source, for the benefit of all needed.

Creating and installing the CrutchAttach is divided in general into 3 steps:

1. 3D printing the parts
2. Installing inserts and magnets
3. Assembly onto the crutches.

Lets Make!

Tools:

1. FDM Printer, plate size 180*180 und up (yes the A1 mini is totally capable for it:).
2. Cutter.
3. Scissors.
4. Ruler.
5. Solder (for placing the brass heat inserts).
6. Allen Key / Hexagonal Wrench.
7. Marking Pen.

Materials:

1. FDM Filament, PLA / ABS / PETG - About 50 m / 140 gr.
2. Masking Tape for marking.
3. Screws - M4 8mm Steel Hex Drive Flat Head Screw - 4 Units.
4. Brass heat inserts, - M4 Heat-Set Inserts for Plastic, 6 mm - 4 Units.
5. Disc Magnets with countersunk hole , Diameter 20 mm, thickness 4mm, 4 units.
6. Zip tie, 5 mm wide, 20 cm length - 4 Units.
7. Double sided foam tape 1/2" / 15 mm width, about 20 Cm.

Purchasing links:

1. Screws - Amazon Link / Ali Express
2. Brass heat inserts - Amazon link / Amazon Complete kit with solder / AliExpress Kit
3. Disc Magnets With Countersunk Hole - Amazon link

⚠️ Important: Make sure you buy alternating polarity magnet pairs. Some vendors ship uniform poles, which won't work with the design. The units are connected using magnets on each side with opposing south-north polarity in order to have a strong connection between the units.

1. Zip tie - Amazon Link / AliExpress Link
2. Double sided foam tape 1/2" / 15 mm width - Amazon Link / Ali Express link

While using Elbow / Forearm Canadian crutches, usually there will somewhat of a-symmetry in their usage, usually as one leg is more functional from the other or one hand is dominant over the other. Usually the right hand is the one that we would like to keep functional and our design address it.

So in our design you will find us addressing it in the production, assembly and placement under "Static" and "Dynamic".

1. Dynamic, refers to the crutch which is being place on and off from the active hand, usually for right handed people it will be placed the right crutch.
2. Static - refers to the crutch stays on the arm constantly, respectively it's usually the left one for right handed people.

Note: For most right-handed users, the right crutch is the 'Dynamic' (on/off) one, and the left is the 'Static' (always worn) one. You can flip this setup for left-handed use and mirror the 3d files on the slicer.

Included 3D printing files 3 files which need to be printed by the following qty.:

1. 20250513 CrutchAttach - Cover.3MF - 2 Units, this part is symmetrical and match both sides.
2. 20250513 CrutchAttach - Dynamic.3MF - 1 Unit, this part is goes to the crutch which is being place on and off from the active hand, usually for right handed people it will be placed the right crutch.
3. 20250513 CrutchAttach - Static.3MF - 1 Unit, this part goes to the crutch that stays on the arm constantly, respectively it's usually the left one for right-handed people.

Alternatively, you can use the 20250513 CrutchAttach - Set.3MF to print a complete set in one go.

Filament - we've used PLA with most of our produced units (over 100..:) which provide fair strength and durability, yet to achieve max strength PETG or ABS can be used but a bit more work is required to remove support.

Infill - 20% gave us durable units, more robust parts can be achieved if tweaking a bit and applying variable infill up to 100% on the edges to reach max strength.

Support - only the Dynamic should be printed with supports and "On Build plate only" should be applied as well. in the covers we do not use supports as it might clog the zip ties housing. If you choose to print in PETG, make sure that the supports are not sticking too hard to the units or clog the zip ties housings (they are circular cavities) and we had issues when using certain PETG filaments where kits were trashed as we couldn't separate the supports without damaging the integrity of the unit. We use default settings - 30 degrees with tree supports in our prints.

It's important to print the Static unit positioned vertically while other units can be printed any way. The Static's part has "lips" that surround the magnets in the Dynamic unit and we want to print it with orthogonal printing lines to the forces applied when using CrutchAttach.

Parts Assembly:

1. Heat inserts - Using a solder insert the 4 brass inserts, if you're new to the subject, check this video.
2. Screw the Disk Magnets using LN Key / Hexagonal Wrench to both Static and Dynamic units. Ensure that polarity of the magnets ensure correct polarity between Static and Dynamic.
3. Ensure proper attachment of the Static to the Dynamic part.
4. Double Sided Adhesive Foam Tape Placement, cut 8 pieces of the tape, each about 30 mm length.
5. Place the pieces into the recess at the covers and the Static and Dynamic, 2 pieces at each unit.
6. Zip Tie lacing - Lace the zip tie from left to right, first through the cover units.
7. Then through the Static or Dynamic units, then back to the Cover to close the circle.
8. Repeat for the Static or Dynamic unit.
9. Ensure all units snap.

At this stage we will place the CrutchAttach over the cutches, adjust it and fix it.

The attachment is not permanent — it can be adjusted or removed anytime, we're not changing a thing at the crutches, just making them more useable :)

1. Marking, at the Static Crutch, mark with a ruler 10 Cm using a pen or making tape, at the Dynamic crutch, mark 15 cm.
2. Preparing for instalment, remove the liner from the adhesive foam from both units Static and Dynamic, from all printed parts, covers and all.
3. Initial Placement, Static - place the static (the bigger one) on the static crutch, (the 10 cm mark), facing outward of the body and tighten a bit the zip ties. It looks like it is a bit protruding outside but this is how it needs to be.
4. Initial Placement, Dynamic - place the Dynamic (the smaller one) on the dynamic crutch, (the 15 cm mark), facing inwards of the body and tighten a bit the zip ties.
5. Checking - Snap the two crutches together using CrutchAttach! you will notice the gap between the two crutches, the dynamic is a bit in the air, that is what it's suppose to be so it can go over stairs and other obstacles...
6. Final set - this done with the user, fine tune the location of the Static and Dynamic and tighten the zip ties as possible, cut with a cutter the remain as close as possible to the connecting point.

You're now set with CrutchAttach, the best crutches hack.

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PS

1. Our Instagram page can be found here 🤩🤩