Advice on extreme IPD mod?

Im seriously considering do the extreme IPD mod. The distance between my pupils is 64mm. The smallest distance between the 8kx lenses is 70mm. So my vision is blurry no matter how i adjust the headset, unless i move it left to right, to put one eye in the sweet spot. This mod brings id down to 64mm. I had a few questions. Does anyone have advice on doing this mod that are not listed on the tree different reddit posts? Is there a tool kit that is advised to use, specifically for taking apart the 8kx without damaging it? My biggest concern is the sensor that reads the distance between the lenses has to be disabled in the mod. How will that effect how the headset displays the image? Because when I manually change the ipd, i notice the headset adjusts the screen image to compensate for the adjustment. How will it know how to compensate sync the image after the mod? If it can compensate, how should i do the mod, so that it is in correct sync? Thanks
Here is a link to the mod

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I did the mod. I had to or the headset would have been useless to me. I made some pry bars out of plastic for splitting the cases. As far as the slider goes, you dont have to disable it, you can meticulously drill a small hole through actuator that the slider “pin” will go into. Just take your time, dont get in a hurry, document with pics.

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Wow interesting. Can you elaborate on that slider mod more? How does it affect the software in the headset when you adjust the headset to the below and above the factory limit? I mean the ipd number displayed on the screens. Do you have a link to your mod documented on this forum?

It is detailed on Reddit though not sure if @stixvr was the originator or not.

My ipd is 67.1. The mod was iirc originally done for someone around or less than 60mm.

Use this search term as shown in r/pimax on reddit.

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I am very confused - 70 mm is the maximum hardware IPD, not the minimum. 64 mm is well inside the hardware IPD range and should theoretically not require this mod, although for some people setting an IPD much lower (~4 mm I hear) than their physical IPD does give them better clarity. As for the questions, I expect it will stop reducing the software IPD below the limit, but you should just be able to further compensate using the software IPD setting in Pitool.

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Man its been over a year since I did the mod so I dont remember much about it :roll_eyes:. Sooo that being said if you look at the 2nd pic , just below the left lens, you can see the slider under the square plastic actuator(has a round hole to the left of a square hole which was the old hole the square gray slider pin protrudes through, hope that makes sense. I dont have a tutorial or documented mod, I just shot pics of everything. If you send me your email address I can send the pics, I took them in incremental order. The pics might just make the whole process confusing, lol. But it can be done.

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The OP’s IPD of 64 “might” not need the mod?? My IPD is 62, while the HMD will display my correct IPD in the headset, the spot in the lens where my eyes look at is a blurry image, the lenses needed to come closer together for the non blurry spot in the lenses to come into view, then I had to go back and adjust the actual “image” IPD to match the new lens IPD.

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Ok… Before you do anything drastic, I suggest you read this: Clarifying Near IPD x Distant IPD confusion

There is a perfectly good reason the lens c-c spacing is greater than your IPD, and if applies equally well to other headsets with canted lenses - most certainly the Valve Index, and your first course of action should be to try modifying the thickness of the face interface padding, so that the eye relief is right for getting your pupils intersected by the lens axes. Your 64mm IPD is (or at least close to) the median among people, around which the adjustment range of almost all HMDs, including the p8k/5k series, is centered.

I’ve done the mod, and it didn’t help me, predictably - not only because my IPD is only 59-60mm, and not only because with these lenses, at least my particular eyes give me only a tiny pinprick of sharp imagery in the very centre, even when perfectly positioned (this is the real problem), but also because the whole notion of trying to get the lens spacing down to one’s IPD is misconstrued to begin with, and comes with a host of detrimental consequences.

My unit had a millimetre or so to go on the potentiometer’s medial end, so as long as I didn’t file down more than that on either side, I didn’t need to do anything to the coupling between the lens shuttle and the potentiometer; If you do move the hole, you’ll just need to apply the corresponing offset in PiTool settings, to get the reading correct.

EDIT: It is probably worth mentioning, and keeping in mind, that by opening my p8kX up, and modifying it, I have of course made it ineligible for the trade-in upgrade offer, to the upcoming p12k… (EDIT2: …as well as voiding any outstanding warranty.)

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Ok thanks. I will DM you my email with you would be so generous as to send those pics. How was your experience with the headset after the mod? how was the image, FOV, and distortion, ect?

An IPD of 64 is pretty average and should not need the IPD mod. As mentioned above, you should try changing the distance between eyes and lenses and see if this improves the image for you. Like switching between thick and thin cushion, pushing and pulling the headset a little. From my personal experience, 1 mm more or less can make a huge difference.

In my case, I noticed that the ideal distance for me is right between thick and thin cushion. I ordered some velcro tape from Amazon and applied it to the back of the thin cushion. Using that, I get a clear image. Optimal IPD setting also aligns with my actual IPD (65 mm)

There are also some third party cushions you could give a try:

If that doesn’t work, you could try fiddling with the IPD offset and screen vertical offset settings in Pitool.

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The only thing it did for me was clear up the blurriness. Fov seemed unchanged, I never really saw much distortion to begin with unless Im looking for it when I turn my head.

The other issue I had with the 8KX and the 8K and 5K+ was “eye strain”. I had to sell all of my Pimax headsets for this reason. I tried to find the link to a post on this forum I made regarding the eye strain, I think Pimax deleted it, LOL. It had like over 500 replies! If your not having that issue, the Extreme Mod might be a viable upgrade for you. Bierbaron mentioned trying some face cushion mods first. I would suggest that also. Didnt work for me but I would be willing to try ANYTHING before doing the Extrem IPD Mod, it was quite the undertaking and you can easily ruin the headset. I Effed up a couple things while performing the mod, I tore a ribbon cable and something else, cant quite remember, so I had to repair my damage all along still performing the mod.

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Thanks. I have tried all of that for a week now. No position worked other than moving the headset to the sied to put my one in the sweet spot. When i adjust the ipd through pitool, it makes it a little less blurry, but makes my eyes cross eyed, and causes major eye strain. Im using my oculus quest 2 as a reference. In my quest 2, the image is much more clearer. Id like to avoid the mod if it was possible. Does not look fun to do.

I think this maybe the post you might be looking for.

In search use @username keyword
“:mag_right: @stixvr eye strain”

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I saw that one Helio. I searched for eye strain and eyestrain in the topic and under my user name. I couldnt find it. Maybe I used different words in the topic… There was like 500 replys. Lots of folks with that issue trying to find a fix

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I tried most of the fixes but none worked for me regarding the blurriness, the extreme mod made the image crystal clear but just didnt help with the eye strain like I hoped. I did the mod knowing that it might not fix the eye strain… uuuh

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Do you recall if you were the Op?

Well that was quite a while ago and I was thinking that I did start the thread, maybe I didnt??

I think I found it. The Op was the one whom had tons of accounts on here.

@Jasonkane this guide may help.

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Thats the one, remember PimaxUSA saying the 800 replys was like just a dozen of the same posters, lol. And that this was anecdotally…

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Do you by any chance wear, or need reading glasses?

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