Creating a Pimax-DAS Adapter


#1

I am 8k Backer / Lurker around 485s (not my exact value) and waiting eagerly for my Pimax emails and shipping confirmations…

I am also a Programmer, Designer and a Tinkerer… and impatient, liking taking a cracks at a problem, looking for solutions.

I had also previously designed a rudamentary Headgear mod for My Vive prior to waiting DAS (Deluxe Audio Strap) prices to dip.

Now I am in a similar situation where I want to use my DAS (the prices never dipped, thats 99 € just for the damn headgear and some slighly better than average audio, so I want to reuse it) on the Pimax, but

I dont want to glue or tape velcro onto the DAS, like shown with the “Frankenpimax” method that was show by @mixedrealityTV. Instead I like to make a more utiliterian solution which you can swap the same headgear between headsets, without having to mess around with cables much.


Update

First Prototype Release, With full Assembly Instructions



Historical post:

Already have some progress regarding the mounting joinery for the DAS and have it figured out the dimensions and mounting methods to get them working just fine:

Now I just need the other measurements and I can basically create an adapter for the Pimax

Taking account printing directions and toughness, this should be atleast as tough as the connection point it self, with the right printer tolerances (0.1 mm layer height ±50μm dimension tolerance) and materials. In this case my recommended material is PETG (not PET), which is a very good material for the subject, this works well with friction based joineries, due

A. Flexes more than ABS as a softer plastic.
B. Its a weaker than ABS, but its stronger than (regular, non enchanced) PLA, so probably avoids damaging to the headset over prolonged use.
C. Its much simpler to print than ABS as its less toxic to print

Update

Thanks to @UnholyBeardedOne I now have all the information to continue :slight_smile:
Will use this thread as a log.


So to go forward with the project and have more accurate info I am looking for the following measurements

Once Done and tested, will release the print files under CC Attribution Non-commercial license which you can send to a local 3d printing service for a few dozen bucks if you dont have a printer of your own.

This should also allow for modifications for other headsets from pimax, or others in the future. Ofcourse, the caveat for all would be “use at your own risk” :slight_smile:
CC: @SweViver


Pimax 5k+ received! Setup experience (Spamenigma)
#2

I got a printer that is perfectly dialed in but I suck at 3D programs. :slight_smile:
Please give the needed information to the man. :stuck_out_tongue:


#3

Paging @UnholyBeardedOne

Would you be so kind as to please provide OP with the required measurements?

The entire Pimax forum would be incredibly thankful!


#4

Hi Menithal.

I have taken the measurements for you as follows…

Diameter (blue) is 2mm

Side (purple) is 4mm

Bottom (green) is 2.5mm

Length (red) is 31mm

Hole measurements as follows…

Dimension of holes (purple) 5mm, (red) 16.5mm, (blue) 8mm, (green) 33mm.

The distance the hole is from the inner edge down the centre line is 8mm.

Neil.


#5

Awesome! Very many thanks, ill continue on the prototype once I get home from work

One thing I forgot to ask for was the clearance below the top hole, could you get that value as well?

The entire thing will be limited hanging on 2 mm thick 3d print though so going to be very tight to get the print connected to the side joints. some room has to be left in the thickness to allow for the print to “cup” the rod. was hoping for 4 mm, but will have to deal with that :smiley:

Hopefully my tests can atleast lift at min 40 Newtons (around 4 kilos total, or 20 newtons / 2 kilo per unit) with that, then i will be happy using it wihtout any worries.

Fortunately we have 30mm play room with the height, so the surface area can be used to distribute the stresses.

Will need to do some tests and simulations!


#6

Ace @UnholyBeardedOne !!

Thank you!


#7

I can’t decipher your cryptic writing!

What is a DAS?

At least I know that ABS would be acrylonitrile butadiene styrene and PLA would be polylactic acid while PETG would be a glycol-modified polyethylene terephthalate which explains what PET stands for.

But what the heck is a DAS that you wanna hook up to a HMD with those materials?

(maybe some kind of Digital Aperture System like this one :smiley:…)


#8

Also sometimes in the future (I hope very soon) we will be provided an exact 3D file of the headset for modding purposes as said by @xunshu .

Need 3D model and measurements of Pimax HMD


#9

DAS = Deluxe Audio Strap when searched in the context of the Vive. you could also have checked the frankenpimax post thats pinned.


#10

About 11mm direct centre of the hole measured from underneath hole to base. If measured from top ot the hole add 2mm which is the thickness of the plastic.

On the outer edges of the hole where the blue and red line are in you pic it dips to roughly (9mm) measured from underneath, as it tapers down from the centre line and you loose some depth.

Neil.


#11

Thanks, thats all the measurements I need to go ahead.


#12

Small status;

To even test the feasability of creating an easy mount joint with the dimensions I was provided, I made a 2.3mm thick model with the intent to connect to 2mm diameter rod to simulate the Pimax 8/5k+ hinge, with the joinery DAS connection prototype I made earlier. I didnt have a steel rod but instead found a old mini screwdriver I had laying around which had its tip broken, but a 2mm thick body, so to decided to use that instead.

Unfortunately the print did fail to print properly (it ended up in halfs), but was still usable as a test print to test weight baring possibilities

I ziptied some weights and hanged them off the joint where the DAS would connect to… The results were suprising, for with a “cut in half print”.

Went all the way lifting upto 4 kilo weights on a single hinge with everything focused on the joint that would connect the DAS to the Pimax. At that point, its most likely the DAS will loosen than anything, as its also just plastic holding your hmd to the headgear. This is double my own minimum requirement for this.

I did not think to trying any large weights, the 2 mm thick steel mini screwdriver was also flexing at that point significantly, so I have to say, I dont think anyone will put strap their headset with that much force on their face (8+ kg overall over the surface area where the mask touches the face).

This now points to the direction that this is absolutely doable!

Those who have the pimax, how do the hinges feel? Are they steady and are they all metal? I know the top seems to be just plastic.


#13

This is great work! Really looking forward to your final results.

I was also thinking of reusing my DAS but was sceptical about the frankenpimax. Your solution seems to be a (by far) better approach.

:grinning:


#14

May take a while :smiley: I dont have a Pimax yet, and it may take till end of november at this rate


#15

@Menithal are you in Thingiverse?


#16

No not yet, but ill be creating one and uploading a few of my designs I’ve had for a good while now.


#17

Playing around with a concept for the top strap mounting point.

I noticed that quite a bit of the Pimax concepts for the solid headstrap basically put all the force on this; unfortunately the DAS puts it to the sides instead to distribute it elsewhere from the forehead. So its probably safe to say this is more solid than the hinges.

Taking that account, it should be something that doesnt damage the headset, and should distribute as much force as possible, as one could still tighted the straps quite a bit on the top. Will still need to have to play with it and see if I can damage the top accidentally with this since its not filling the entire space.


The Yellow part is printed flat surface, while the Red part is printed on its so that its profile has the outer walls. its width is enough to slide the DAS strap in and out. Pushing the entire unit forward would loosen the parts enough to be slid out (needs to be tuned, but when pulling force is applied, it should remain tight.)

Measurements are a bit fast and loose (0.5mm tolerance), but I wont have precise version until I have my pimax, but I think this should actually work fine as is.

Will print out a prototype with that after I fix my extruder on my printer.


#18

Nice work, I can try with ABS if you up the files.


#19

Just a heads up, you want to create your Thingiverse account early. They don’t let you share your design until a minimum 24 hours later.


#20

Thanks for the heads up,

fortunately I do have an thingiverse account but its just not active. :slight_smile: Should have the print files for others to print test available by Sunday.

@TrevorVR
ABS may be tricky due to shrinkage, you may need to adjust the models accordingly once I get them up, but the tolerances are quite tight for some parts (Especially the hinges) ill try to take some of this to account when finishing up the version that will go on Thingiverse though.