Magnetic Needle Guide + Injector assist for insulin / GLP-1

Injecting myself makes me anxious.  This device takes away most of the stress by giving me an ergonomic grip on the syringe and automating the injection motion with magnets.

After adding the syringe, push up the sled until the embedded magnets snap it into place.  While holding the guide against your skin, push down gently on the knob and the sled will smoothly jump to the lower set of magnets while inserting the needle.  The syringe plunger will be within easy reach without adjusting your grip.

Compatibility:

Pick a shell based on needle length:

• Compatible with 6mm, 8mm, or 12.7mm / ½" needles in the standard shells.  
• “Tall” shell supports longer needles up to 1" or 25mm
• “X-Tall” shell supports needles up to 1.5" or 38mm

Syringe adapters available so far for:

• 0.3ml (30 unit) U-100 syringes
• 0.5ml U-100 syringes
• 1ml U-100 syringes
• 1ml Luer Lock syringes
• 2ml BD Emerald Luer Slip syringes
• 3ml Luer Lock syringes
• Somavert 1ml dose
• Inhixa 0.4ml dose
• Inhixa 0.8ml dose

I'll add more as I'm able to find and measure them.  Feel free to let me know what you need in the comments and I'll try to track it down if I can.

These are the specific U-100 syringes I modeled this on: https://a.co/d/9yr9vVx 

and these 1ml Luer Lock: https://a.co/d/67SUaba 

Common uses are Insulin, GLP-1 (Semaglutide / Tirzepatide), TRT (testosterone / hormone replacement therapy), or B-12 injections.

Options:

• Shells available with open view of the needle or covered
• Enclosed shell option provides the most coverage and the best grip but you will likely need to load syringes by lifting the sled out first.

Printing and assembly:

Total assembly takes less than 5 minutes.  All magnets are press-fit and shouldn't need any glue

1. Print all parts as oriented in the files.  No supports are needed.
2. Grabber: Print the grabber for the syringe type you need
3. Sled:
   1. Press in 3 magnets.  2 on the rear and 1 on the bottom. (take care that both rear magnets are facing the same direction)
   2. Align PTFE with the slots on the side and press in.  You can insert it while long and then cut flush with the top after.
   3. Attach the grabber using 2 M3x6mm screws
4. Shell:
   1. Press in 3 magnets.  The polarity should be aligned so all three are attracted to corresponding magnets on the sled
   2. Optional: Add a strip of scotch tape to the inside/rear wall of the shell running vertically over the magnets.  It makes for a very low-friction surface for the sled.
   3. Insert the sled from the top.  It should slide smoothly with no interference.  If your magnets are oriented correctly, you'll feel it stop when the sled is flush with the top of the shell.  Pushing it further, it should snap smoothly to the bottom position.
5. Pusher knob: attach the knob to the top of the sled using the M3x20mm screw.

You're done!

Tips: 

1. If the sliding motion feels stiff, check the the PTFE tube is fully pressed into the sled from the sides.  Try pressing the side of the sled/tubes against a table to ensure that it's not bulging out.
2. Stiffer / thicker wall PTFE tube seems to have a more reliable shape and make for a more frictionless slide.  I used 2mm ID, 4mm OD tube and it worked well.  I have some thin 3mm ID tube that didn't work reliably at all.
3. You can fine-tune the sled by trimming/rounding off the bottom lip /  cut edge ff the PTFE after it's inserted into the sled

BOM / You will need:

• 2  X  M3x6mm button head screws 
• 1  X  M3x20mm screw (Or M3x30mm for “Tall” option)
• 6  X  6x3mm magnets ( https://a.co/d/8aIsi1P )
• about 4" / 100mm of 2mm ID / 4mm OD PTFE Teflon tube ( https://a.co/d/3ThyJNc )