[chinsettawong]

Hi David,
 
I'm sorry to hear about your accident.  Wishing you a speedy recovery.
 
I always like to see what people build.  So, when you have a chance, please show me your work.  
 
Oh, I have no doubt at all that your DIY headphones sounding good.  I always compare mine against Stax SR007 and SR009.  After comparison, they are back in their boxes as I feel that my headphones sound just as good, if not better.  
 
Wachara C.

 

[OnyxOcelot]

Well, from the looks of things, you seem to have figured it out!  But, for reference, I use the "Tiny G" post-processor.  Synthetos -- the company which made the Arduino G-Shield for GRBL -- also made Tiny G, and they support similar sets of G-Code.
 
https://github.com/synthetos/TinyG/wiki/What-is-TinyG
https://www.synthetos.com/topics/vectric-aspire-post-processor-for-use-with-tinyg/
 
 
Quote:

Hello,

I use an arduino with GRBL.
Find the righ post processor is my current problem...

 

[-JFK-]

Thank you a lot, I will check that.
Currently for 2.5D no problem but for 3D I still have error in G-Code...
I think that I will have time tomorrow.
Now, I building the hardware for tensioning the mylar.
I will not use scale on the mylar but the frequency fondamental of the membrane to get something more accurate and repeatable.
I will post pictures once done.
Tx!

 

[OnyxOcelot]

Here is my new Mylar stretching rig, in case anyone is interested!  
 
Some design details:
-- Dowels run through the corners, with springs around the dowels pushing the frame apart.  
-- Turnbuckles allow me to tension or loosen the frame evenly.  
-- Each piece of frame that touches Mylar has rubber on it to prevent tearing at edges.
-- I use spring clamps to hold the frame top and bottom together.
 
Happy to answer any questions is someone wants to build a similar device!
 
 

 

[chinsettawong]

Interesting stretcher.  Have you already made some diaphragms out of it? 

 

[OnyxOcelot]

Yes, I've made one pair of diaphragms with it.  It is VERY easy to use and seems to work relatively well.  I don't have a good way of comparing / measuring diaphragm tension, so can't speak to its effectiveness, but I can get the mylar drum tight (so that it has a clear note when tapped) relatively easily.  Next time, I will try using heat (a hair dryer) to allow the mylar to stretch further.
 
One note, I suspect it stretches furthest at the corners, so maybe having more corners (making a similar design but using an 8-sided shape) would spread this tension out and allow one to stretch the diaphragm material even tighter without ripping.
 
Quick question: I have had some difficulty finding the best way to make a housing for my headphone drivers.  Does anyone have any suggestions on this?  I'd like as simple a solution as possible for the housing and strap.  Currently, I use a pair of gutted out old headphones, but nothing fits quite right.  I have tried on my mini-mill but it is a bit weak to work with wood.  Or perhaps oak is too hard of a wood...  maybe I could find a much softer wood...
 
Quote:

  Interesting stretcher.  Have you already made some diaphragms out of it? 

 

[chinsettawong]

If your stretcher can do a good job making the diaphragm, you really don't need to do further heat treatment. In fact, if you do it, the diaphragm tension will not get any better. In my experience, it even makes it worse. You can try it.

As for me, I prefer to make the stretcher big enough to make a pair of diaphragms in one go. By that way, you get a matched pair everytime.

 

[-JFK-]

Hello,

This is my first attempt for the membrane tension!
Material:
-20" bicycle wheel.
-16" bicycle air chamber.
-Medicine pump
-mylar, double side tape, tube...

The air chamber diameter is too big so I have choose to fold it one time.



Why a medicine pump?
-Because it's easy to release pressure!
Don't forget to remove the air chamber valve

Then, simply put the tensioner on the mylar and tape it.
Reverse all and:
Without tension:

With tension:


Last step:
A little kick on the membrane and check the frequency resonance.
Adjuste the frequency with more or less pressure in the air chamber then glue the stators (my next step!)

Any remarks are welcome!
Regards

 

[lauren312]

Thanks to this topic, I have learnt a lot of new interesting ideas to do it myself. I’ll follow the guidelines to make my own one. Hope to be successful at the first time I try.

 

[MuZo2]

 

Great idea. Looking forward to the finished result.

 

[chinsettawong]

I like your hand pump.

 

[-JFK-]

Hello,

I don't know why, but from the beginning, something tells me that "double sided coating" is the way that I should go...

So I just bought graphite powder and want to mix it in contact cement glue (French word is "colle contact neoprene").

After some digging over Internet, I will try 50/50, glue/graphite mix.
If needed, I will add some "white gaz" (French : "essence C") to smooth it.
If anyone of you have skills in glue, just let me know if I'm on the right way!

Then, I just fix a broken megaOhm meter and like to know if someone know how to measure the diaphragm conductivity and values.

Any information on how to apply the coating is welcome too

See you next step... Thanks!

 

[chinsettawong]

Hi JFK,
 
You should try to read the thread.  The discussion on diaphragm coating has always been brought up again and again.  If you want to use graphite powder, don't mix too much with the glue.  You really don't want the diaphragm to be very conductive.  I've tried the mixture of graphite powder, PVA glue, and water.  While it works, the glue tends to absorb too much moisture from the air and eventually fails.  I really don't recommend it.  But if you just want to try it for fun,  then just go ahead.  Putting the glue on the diaphragm also adds a lot of weight to the diaphragm, and that isn't good.
 
Double sided coating isn't necessary.  I doubt if you will hear any difference.
 
Wachara C.

 

[-JFK-]

Hi JFK,

You should try to read the thread.  The discussion on diaphragm coating has always been brought up again and again.  If you want to use graphite powder, don't mix too much with the glue.  You really don't want the diaphragm to be very conductive.  I've tried the mixture of graphite powder, PVA glue, and water.  While it works, the glue tends to absorb too much moisture from the air and eventually fails.  I really don't recommend it.  But if you just want to try it for fun,  then just go ahead.  Putting the glue on the diaphragm also adds a lot of weight to the diaphragm, and that isn't good.

Double sided coating isn't necessary.  I doubt if you will hear any difference.

Wachara C.

Sorry,

I was not clear.
I will coat the diaphragm with "staticontrol" solution.
The mix glue/graphite is to glue (and electrically connect) the diaphragm to the cooper side pcb spacer.

 

[Julez]

Coating one side or two does not make any difference in sound. I first could not belive it but I tried it on one headphone.
I coated one driver on both sides and the other only on one side. There is absolutly no difference between the two sides!
I think the advantage of coating only one side is that it is faster and you can expect less trouble with dust. If you coat both
sides I don't know if there is any advantage. But Stax does coat both sides. So at least they must think it is better to coat
both sides. I will stick now to only coating one side. That works very well even on repaired Stax headphones wich had both
sides coated before my repair. And compard to the same headphone in original condition there is no difference in volume.