Categories
ergonomics

VR Cover’s ‘Valve Index face gasket’ and ‘rear cover’ reviews

Originally posted by SkarredGhost, edited to correct my original spelling mistakes.


Introduction by Tony of SkarredGhost

The VR ergonomics expert Rob Cole of immersivecomputing.org has tried for us the VR Cover headset covers for the Valve Index, and had reviewed it for us. I’m very glad to host in this blog his professional impressions on this VR accessory, that it’s very informative for all the VR community. Considering that very soon there will be the launch of Half-Life: Alyx, all people owning a Valve Index are for sure interested in anything that can improve the comfort of their VR headset.”


VR Cover: Valve Index Interface & Foam Replacement Basic Set

valve index face gaskets
Playing with many different Valve Index face gaskets

The face gasket conundrum

Nine months after launch, replacement “face gaskets” for the Valve Index remain somewhat thin on the ground.

Valve’s official face gasket is often out of stock, and was only released in one width which may not be suitable for everyone.

Shipping Index with a single gasket was odd, considering Valve’s earlier collaboration with HTC which had seen the Vive shipping with both narrow and wide face gaskets in the box. 

Later I learned from Steam user BOLL that Index was originally listed in early April 2019 as coming with “2 Face Gaskets (narrow and wide)“.

By the end of April he had noticed the webpage had been edited to remove any mention of narrow and wide, leaving just “Face gasket”.

I’ve asked Steam support several times since launch about an official wide face gasket, but I always get the same reply

Steam support does not have any information on when or if a new gasket will be made available.

One of the moderators on the valve index subreddit said they had learned that the Index development kits had shipped to SteamVR developers with both width gaskets in the box, mirroring BOLL’s earlier findings. 

Physical evidence of a large Index face gasket recently emerged on Reddit after someone was mistakenly sent one of the “L” gaskets by Steam Support. As seen in the photo below, it has the old “clip in” pre-production mounting tabs, Valve then switching to magnets for the production gasket.

Perhaps this means some tooling or 3D printing files exist for this L model somewhere at Valve or their manufacturing partner in China, giving me hope that it could be released in the future!

The wide face gasket

As my previous article for SkarredGhost “Valve Index : A Good Fit?” mentioned, I couldn’t use my Index with the original Valve face gasket as it simply did not fit, it was too narrow for my face.

As a former Vive owner who always used the wide face gasket, this was puzzling as being a “sample-sized” person (medium everything and 63.5mm IPD). I am no huge-headed outlier requiring an oversized gasket, just a regular-sized person, if there is such a thing.

Perhaps it’s not well known that the wide Vive gasket was really a “regular” fit, with the narrow being for people with narrower faces; some Vive owners with larger heads had to build their own extra-large gaskets. This is why the wide gasket was fitted to the Vive headset in the factory and the narrow came as a spare inside the box. 

valve index out of the box
Valve Index, just taken out of the box

A temporary solution was provided for my Index gasket problem by 3D printing a stretched version of Valve’s plastic face gasket base design, that they had released as part of a big Index data dump into the public domain. Big thanks to Valve and to Anonymous Hermit for modifying the face gasket!

After receiving a 3D printed base from Ninja Prototype in China, I had stuck Velcro and magnets into place, using the Velcro to attach aftermarket Vive PU face cushions. As the Vive cushions were smaller than Index’s wider eye box I ended up cutting them to fit, to maximize the field of view. 

This was less than ideal as it had left several unsealed edges where the cushion was cut, which degraded over time from heat, moisture (sweat) and physical contact (abrasion) against the face from using and donning/doffing the headset.

It also caused mild skin irritation during longer or more active sessions with the PU cushions trapping heat and moisture against the skin; I experimented with some spare fabric from an Index face gasket I had stripped, which certainly added some skin comfort.

valve index wide face gasket
Adding some spare Index fabric onto the PU to increase the comfort

After going through a number of cut-up cushions since last year, I was excited to hear about the first commercially available Index Face Gasket from industry stalwarts “VR Cover”.

VR Cover to the rescue

VR Cover has been making face gaskets, face cushions and other facially related parts since the first consumer headsets launched in 2016. Tony @ SkarredGhost put me in touch with the nice people at VR Cover who sent a sample I could test (thanks Sharon!)

vr cover valve index
Box sent by VR Cover

The package arrived in a very neat plastic container, consisting of:

  • 1 x Facial Interface (plastic gasket base)
  • 1 x PU Leather Memory Foam Replacement (Standard) i.e. thin
  • 1 x PU Leather Memory Foam Replacement (Comfort) i.e. thick
  • 2 x side wedges
vr cover cushions
Cushions provided by VR Cover

This was an impressive set of parts, well finished especially the plastic base with its own Velcro facing and magnets.

The first thing I did, of course, was to compare the VR Cover plastic base with my own 3D printed wide base and an original Valve gasket, and this is where I noticed a key difference; the VR Cover plastic base was identical in radius to the original Valve face gasket.

valve index 3 face gaskets
Top to bottom: valve Index face gasket, 3D printed custom wide face gasket, VR Cover Valve Index face gasket

Looking closely, I realized VR Cover had created two fitting options on a single width plastic base by supplying thin and thick versions of their PU cushions.

Using the “thick” cushion gave me an identical fit to the original Valve face gasket, albeit with a different material. I tried installing this option but as with the Valve original, I had a noticeable gap between my forehead and the cushion which prevented me getting my face forward enough to fit the headset correctly.

I also tried the side wedges but could not get my face anywhere close to the front of the face cushion!

VR cover side wedge
Trying with side wedges, but with no luck

Using the “thin” cushion gave a wider fit than the original Valve face gasket, but still not as wide a fit, as my 3D printed setup.

Width is better talked of as radius, or circumference, in my case a 59cm head which is the upper end of “medium” in a bicycle helmet or baseball cap – the thin cushion and VR Cover plastic base wasn’t an ideal match, but certainly closer to my measurements than the Valve original face gasket. 

Unfortunately, I soon found that using the “thin” cushion led to physical discomfort and red marks on my forehead, as I could clearly feel the plastic base pressing though the thin cushion which after 30-45 minutes of use left my face feeling a little sore.

This was not unique to the VR Cover’s thin cushion by any means, Index is a relatively heavy headset which means extra cushioning in the face gasket helps to spread the headset weight and headset clamping force across the available areas of the head and face. To confirm, last year I had experimented with using thin aftermarket Vive cushions with my 3D printed base but had soon switched back to slightly thicker cushions to increase session comfort

Of course, there was nothing stopping me from trying VR Cover’s face cushions in my 3D printed wide base, these fit well and let me experiment with the thin and thick cushions.

The thick cushion worked well at first, providing extra comfort to isolate my face from the headset weight and clamping force.

Installing the VR Cover inside the 3D-printed plastic gasket base

The thin cushion also worked to bring my face as far forward into the display as possible. However, despite the increased radius of my 3D printed base, the physical weight of the Index headset soon made its presence known through the thin cushion, again leaving me feeling a little sore after an hour of use.

Using VR Cover’s thick cushion with my 3D printed base gave a more positive outcome than using their thin cushion with the VR Cover plastic base, so I carried on using the thick cushion for a while.

However, after perhaps two weeks of regular use, I started to notice the weight of the Index headset again and realized the foam inside the thick face cushion was slowly flattening out (thinning) reducing my comfort. After another two weeks, my thick cushion did not look much thicker than the thin cushion (which I had hardly used) and I found it a little uncomfortable apart from short sessions with less movement.

The PU issue

Something else that has to be mentioned, and it’s not specific to VR Cover’s Index face cushion, is the biological incompatibility of PU as a facial interface material when you consider the skin’s requirement to breathe (release heat and sweat).

There is little evidence that the PU material itself causes a reaction as fully reacted polyurethane polymer is chemically inert.

From the PU Manufacturers Association: “Skin contact with some polyurethane products may result in skin sensitization”, but also “There are no applicable exposure limits for cured polyurethane materials”

There is very little information on the use of PU as a skin contact layer, I found this from the US National libracy of medicine, which concluded that PU was more effective than silicone for scar treatment:

Efficacy of a polyurethane dressing versus a soft silicone sheet on hypertrophic scars.

The polyurethane dressing demonstrated a significantly more pronounced reduction in severity of these clinical signs after four and eight weeks of treatment and was better tolerated than the silicone sheet.

So whilst PU itself is generally not an irritant, it can act as a “dam” to prevent the skin from breathing in areas directly in contact with the gasket – think of it as being a waterproof layer between your skin and the outside world, this then stops the skin functioning properly in that area.

Away from medical trials, back in the VR world, the PU cushions were doing what they’ve always done for me which was the causing localized skin irritation, leaving my forehead sore after a session with a big red mark, combined with the weight of the headset pressing through the cushion. Longer-term there is a tendency for these marks to develop into spots or blemishes where the skin is repeatedly irritated.

vr headsets red mark face
Red marks left on the face of the user

PU has its advantages for VR facial interfaces, as it doesn’t absorb moisture, so it’s easy to clean which makes it ideal for sharing headsets or use at public events where hygiene is critical and users are only doing short sessions (i.e. VR demo at a shopping mall). 

It also has an adhesive property in that it sticks to the skin when wet, making the headset “stick” in place better at the expense of making it difficult to reposition. One practical example of this is if you snag the tether and yank the headset out of position, it’s then much harder to reposition on the face with a damp PU cushion.

For a solo user at home, wearing a device like the Valve Index which is designed for long term comfort, the PU cushion started irritating my skin making my Index less comfortable, negating the possibility of longer sessions with adequate comfort.

The materials that Valve used on the Index face gasket were specifically used to increase user comfort to support long sessions, and this was my realization after months of using different PU cushions and fabric covers.

Of course, before receiving the VR Cover sample, I was using PU cushions in my modified 3D printed base, but these had a perforated surface, and had been cut into three pieces providing some extra breathability. The VR Cover PU cushions were fully sealed, with no surface relief, effectively trapping whatever local heat and sweat my head produced.

Once again I must stress the issues of PU cushions are not unique to this VR Cover product, depending on how active your session is, your fitness level, room temperature and so on….will all have an effect on how much of an issue using PU is?

Solution to the PU issue?

I’ve given some feedback to the team at VR Cover, to see if there is an alternative material – this is not an easy task as the material needs to be biologically compatible whilst being durable and easy to clean! 

As many Valve Index owners found out with the original Index Face Gasket, it soaks up sweat very quickly, becoming moisture-laden with a tendency for bacteria to build up inside the foam core leading to a less than pleasant experience.  Whilst it was possible to wash under cold water and air dry, this didn’t deep cleanse the cushion and repeated washing started to create ripples in the fabric surface.

Another aspect of PU that has to be mentioned, as it was commonly cited an issue on the HTC Vive when used with aftermarket PU cushions, is the build-up of heat and moisture inside the headset.

One function provided by the fabric cushions on the Vive and Index is to wick away moisture from the face and store it inside the cushion, effectively protecting the electronics inside the headset. I noticed very quickly when using PU cushions that my headset got wet inside, at the top where the lens assembly is located.

valve index sweat pu
Valve Index with sweat caused by PU cushions

In the short term, this meant more frequent removal of the headset and cleaning of the lenses as they become covered in sweat smearing the surface and reducing clarity.

In the long term, this may cause problems, as some Vive owners found when using aftermarket face cushions leading to corrosion damage to the PCB inside the headset, something that rarely affected people using the original fabric faced cushions.

Whether this can damage the Valve Index is unknown, the Vive reportedly lacked any internal waterproofing; I’ve seen some “tear down” shots of the Index where its PCB appears to have a waterproof coating but I can’t confirm this.

The ripple effect

Another big improvement could be a “pre-curved” cushion to eliminate the ripples that are created by fitting a flat-cut cushion to a curved plastic base. This is caused by the inside face (plastic base side) and outside face (face side) being the same distance/length.

As the cushion is fitted into the plastic base the inside face is stretched whilst the outside face is compressed causing the ripples seen in my image. These ripples can be felt across the forehead and may be partly responsible for the discomfort felt during longer sessions.

Ripples cushion valve index vr cover
Ripples on the VR Cover cushion

Once again, this is not unique to VR Cover, and is seen in many other VR face cushions. The big advantage of a pre-curved face cushion is the absence of ripples or material bunching up as the pre-curve naturally matches the radius of the plastic base on both front and rear cushion faces. 

The original Valve Index face cushion and Oculus Rift CV1 face cushion are both pre-curved designs with no ripples appearing in the surface until well worn.

Conclusion?

Overall the VR Cover set has a good design concept as I like the modular approach, and of course bringing an alternative Face Gasket for the Valve Index to the market is very welcome.

For people who want a same width replacement for the Valve Index Face Gasket and cannot buy one from Valve due to stock levels, it will solve that problem. 

For those who cannot 3D print a plastic base, or don’t feel confident building their own, VR Cover’s plastic base provides an instant solution with two cushions to choose from.   

For people requiring the wider face gasket (without 3D printing) it can offer a solution but your fit and comfort will depend on your craniofacial shape, and whether you can tolerate the “thin” cushion which I had to use to make it wider. 

However, it’s still not as wide fitting as the 3D printed option and I did find it uncomfortable for longer with the PU material causing a skin irritation; as said before, not unique to VR Cover but just the use of PU as a skin contact layer.

My final conclusion is that choice is always good so VR Cover needs to be congratulated for bringing this to market. I’m sure with further developments by the VR Cover team this product can offer more fitting and comfort options for Index owners. 

In an ideal world I’d like to see VR Cover offer 2 versions of their Index kit:

  • Regular plastic base (as tested here)
  • Wider plastic base

Each base could be supplied with 2 pre-curved face cushions (1 for use, 1 for spare)

I’d recommend using a medium thickness cushion of a higher densitybreathable foam core and skin-compatible surface material.

Valve Index Head Strap Cover

Later on, I received VR Cover’s new “Valve Index head strap cover”.

VR Cover valve index rear cushion
Valve Index Head Strap Cover

In their own words:

Experience a fresher, cleaner headset when you add our hygienic 100% cotton cover to your Valve Index. Our absorbent cotton accessory wraps onto the strap and quickly soaks up sweat from the back of your head to leave you feeling more comfortable.

The set includes:

  • 2 x Valve Index Head Strap Cover

A concern for a number of Index covers was the non-removable rear cushion inside the headset harness. Despite using the same anti-microbial fabric as the original Valve index face gaskets, it was obvious that over time this could become dirty, stained or unhygienic.

Valve Index rear cushion
Valve Index rear cushion

Of course, I’ve tried to remove the head strap’s rear cushion on my Index months ago in an attempt to drill a hole through the headband plastic to modify the tether cable routing, but had stopped after finding it was retained using what looked like one-time “snap fit” plastic clips.

After levering an area of the cushion’s plastic backing with a flat blade screwdriver it felt like the clips might snap, so I left it in place. This presented a problem as there was no way to replace the fabric facing of the rear pad; over time this could take on moisture, bacteria, dirt and become worn or compressed from regular use. Replacing the rear harness was not possible at a consumer level, even if spares were available. 

Upon opening VR Cover’s Index Head strap cover kit, I was a little confused by the instructions until I realized both covers were inside out. Turning them the right way around helped, but the instructions still proved a little confusing so I tried fitting it myself to figure out exactly where the straps and Velcro were supposed to go. It’s great that they supplied two, so you have a spare for yourself, or can run two so you have a spare for guests to use (this works well combined with a spare face gasket). 

valve index rear covers
Valve Index rear covers plus instructions

Eventually, I got the cover fitted to my Index, and placed it on my head. Immediately I noticed the harness was now a little too tight as adding the cover had slightly reduced the circumference so I backed off the rear knob adjuster 3 clicks.

Valve Index rear cover fitted
Rear cover fitted to the headset

The most interesting aspect was discovering that the fabric cover firmly gripped the rear of my head (mainly the occipital bone). This added a welcome degree of stability to the head strap, reducing front end (eye block) movement of the VR headset. Not something I was expecting but a very welcome surprise.

It also felt a little softer and more comfortable across the rear of the head strap / harness, I didn’t notice any difference in heat or sweat compared to using the “naked” Index head strap, despite energetic sessions in Beat Saber and Pistol Whip.

valve index rear cushion cover
Rob Cole wearing the headset with the rear cushion cover

As I’ve only been using it a few months, I cannot comment on long term durability except to say it’s not showing any wear, and if it does wear then it’s done in job in protecting your Index. It’s also great value, coming with two covers, perhaps fitting the cover on day one of your Index ownership will help your Index maintain its own value rather than degrading as many VR headset tend to over time.

The only improvement I could think of was to the instructions, it might have been me not understanding them but that in itself is the “acid test”: can they be understood very quickly and easily? The VR Cover head strap cover itself thankfully suffers no such problem, it’s highly recommended by me!

Thanks to VR Cover for the test samples and of course thanks to Tony @ SkarredGhost for the hookup.

And thanks to you for reading!

By immersivecomputing.org

Human exploration of the immersive computing interface

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