Introduction: Universal Cellphone Spidey-griper / Car Mount / Stand

I did this random hack about 9 months ago and have been living with it and using it constantly. I got to where I stopped noticing it and just used it. A friend reminded me to post it to instructables.

What is it? It's a thick vinyl strip secured to the cell phone that allows:
  • Single handed, yet secure touch usage
  • Quick car mount by sliding into an unused CD player slot
  • Prevents it from sliding off surfaces like dashboards
  • Makes it easy to fish out of pockets
  • Muffles the vibrating sound when placed on hard surfaces
  • Doubles as a night stand
I experimented with different materials like leather for the flap, but heavy vinyl worked best. It's soft, grippy, holds it's shape and is the right amount of rigid.

The hack is fairly easy. Attach a small strip of thick vinyl to the back of a cell phone cover. There might be multiple ways to do this, but here's my approach.

Warning: You must be able to remove the back panel to do this hack. NEVER expose cellphone batteries to heat. They tend to explode fiery acid. If you cannot remove the back panelfrom your phoneDO NOT ATTEMPT THISmodification.

Step 1: Materials


- Cellphone with a removable back panel

- Vinyl strip somewhere around 2.0 - 2.5mm thickness at least the size of the cell phone.
  My source: TAP Plastics 

- Polycaprolactone (PCL) plastic like InstaMorph, ShapeLock or Amaco's Friendly Plastic which comes in colors
  My source: Amazon  (black "Friendly Plastic")
  Used as "glue" to attach the vinyl to the back of the phone.


- Soldering Iron
  My Source: Radio Shack Digital Soldering Station (variable temperature)

- Heat gun
  My source: amazon, Milwaukee 8988-20 Variable Temperature Heat Gun is awesome


- Duct tape or the superior Gaffer tape (for prototyping before destroying your phone)

- Straight piece of thick wire. Like a snipped hanger (for finding center of cellphone)

- Razor or box knife (for scoring plastic)

Step 2: Prototype It First

Step 1 - Finding placement

With the back on the cellphone, you'll want to find the center of gravity or balancing point for the phone. You want to attach the vinyl slightly ABOVE this mid-line so the bottom is a little heavier. 

You can do this lots of ways. I used a wire hanger I had lying around to find it.

Step 2 - Test with tape first

Test the position by using some duct tape or gaffer tape. This isn't hard to figure out. Fold the tape over so it's not sticky everywhere except where it attaches to the phone. Cut it so it's a reasonable right width/height. Attach to the back of the phone.

The goal of this is to see if you really found the center-of-gravity and marked above it. If the top flips around then you'll know.

The tape comes off easily so be gentile.

Step 3 - Mark & clean

Mark where the mounting point should be on the back of the phone using something. I used a box cutter.

Clean off any sticky tape residue before going on.

Step 3: Hack the Phone

Step 4 - Cut the vinyl strip

Width: It doesn't have to be too wide. Around half or 3/4th the total width of the phone.
Length: Should be from the marked mount point to just shy of the bottom of the phone. 
Cut: The mount point should be cut at a steep angle. As steep and even as possible.

Bonus: use the heat gun to soften the edges and corners of the vinyl. This is as easy as just holding the vinyl with pliers and blowing heat over edges so they just start to melt. You'll see when it happens. Just stay clear of the tapered edge that attaches to the phone. You want that sharp.

Step 5 - Prep the cellphone back cover

This is where the soldering iron is used. In order for the Polycaprolactone plastic to join vinyl to the phone, it needs to have a good grip point on the cover. Simply scoring the cover isn't enough. I has to be melted a bit.

This cellphone has an antenna or something mounted to the inside of the back cover that I didn't want to damage. So, I used the solder iron to create a deep grove in the back cover, but do not melt all the way through.

WARNING AGAIN: take the back panel off the phone!!! You never want to get that battery hot!

On another phone that didn't have a back-panel antenna, I did melt all the way through and it was fine; however, it seemed to weaken the back panel a little.

The melt line on the back cover should be the same width as the vinyl and depending on your angled vinyl cut that tall.

The center line you marked is the lower bounds of the melt line. Melt and mount above it.

My soldering iron has a temperature control. I set it to 500° F and laid it down flat to draw the grove. If it starts smoking it might be too hot, but if you go quickly and don't press hard, it should be ok.

Step 6 Attach the PCL plastic

This plastic has a softening point of 150° - 170° F.

Gently heat the tapered edge of the vinyl and gently heat the back cover where you melted the plastic with the soldering iron.

150° isn't that hot. Don't overdo it.

Touch the Polycaprolactone plastic to the vinyl and it will stick. You won't need much.

Now press the Polycaprolactone overed vinyl to the back cover and let cool a few minute.

You can always clean up, reattempt or remove the hack by reheating to 150° F.

Step 4: Conclusion

That's it.

Don't put reattach the back cover until it's really cool. Remember:  Batteries + Heat = Exploding acid

Attached are photos from my first hacked phone I've been using for about a year.

Here's it in action:

Also, if you mess up or want to try a smaller/larger piece of vinyl, then gently heat the PCL plastic to 150° - 170° F. It pulls right off.
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