HTC Vive HMD Helmet Adapter

thingiverse

An adaptation of http://www.thingiverse.com/thing:1620362 adapter. Basically a rework of it, but credit given for the idea and clip design. This adapter is designed specifically for the http://www.northerntool.com/shop/tools/product_200659536_200659536 welding helmet liner from Northern Tool, which is currently under $10. It may work fine for other liners as well, but results are not guaranteed. Print two of the brackets. I used a new to me PLA filament called BAMtack!, which prints really well on my printer. The front strap needs to be removed from the helmet liner. Remove the cushion piece, it just velcros on and can be attached to the top welding strap. Note that the top welding strap is adjustable for length. You may need to adjust it to get it to sit higher or lower on your head as needed. Unscrew the side knobs on the liner. Remove the flat spacer and discard from each one. Remove the other thicker spacers and reserve them. Add the brackets to the screw post so that the slot on the end is closer to the inside of the liner. Add the fat spacers back and put the nut back on. Between the slot in the brackets and the slot in the welding liner where the screw holds everything together, you should have plenty of range of adjustment to move the HMD forward or backward to fit the smallest or fattest heads. Slide the two elastic side straps out of the D-rings holding them to the HMD. Just angle the rubber piece on each end of the straps a little and with just a little pressure, you can slide them out at an angle. Snap the 3D printed bracket onto the D-ring on the HMD using the slot at the front. Now take four M3x10 screws and screw them into the four holes on the brackets, making sure the D-ring is fully seated. These bolts should go through the D-ring and secure the HMD to the brackets. No nuts are needed; the screws will bite into the print and hold it secure. Do not overtighten! Take your two side straps from the HMD and you can wrap them around the strap on the helmet liner, securing them to themselves quite nicely and providing more strappage to keep the helmet secure. Unlike in the picture here, you may want to unsnap the top strap of the helmet liner and run the top strap of the HMD under it instead of over it like in the picture. Press down on the back knob and twist it to open the liner strap all the way. Drop the whole contraption onto your head and press down and twist the knob on the back to tighten things back up. In playing with it, I've found that the HMD is now rock-solid on my big melon; I can look up and down without any shifting at all. Super vigorous activity may cause some bouncing, but until we have a socket in the back of our skulls feeding directly into the brain, I'm not sure it's possible to comfortably eliminate all possible movement of a device strapped to your face. I'm marking this as a WIP because I want to design and print another pair of brackets to allow the use of another elastic strap that would sit below the 'hump' in the back of the head to add even more support, getting more weight off the face. Print Settings: Printer: MendelMax 3 Rafts: No Supports: Yes Resolution: 0.25 or whatever you like Infill: 10% or whatever you like Notes: I printed mine at 10%, with three layers and two perimeters. The brackets seem strong enough, but YMMV; if you're concerned, then up the perims to three and the infil to 30%. Supports may or may not be necessary depending on your printer; I find them useful because they make sure the slot in the bracket is nice and clean and are easy to pry out with a pick.