Air Machinegun Forum

General Air Machinegun Discussion Category => Drozd and Blackbird Discussion => Topic started by: DU-BB on October 26, 2015, 05:36:33 AM

Title: TBK, do you know what thread size the inlet is?
Post by: DU-BB on October 26, 2015, 05:36:33 AM
Maybe we should start a thread size sticky. I'm going to go ahead and start with o-rings, I have those down pretty well.
Title: Re: TBK, do you know what thread size the inlet is?
Post by: TBK on October 27, 2015, 12:19:59 AM
I need to find a drawing so the thread sizes can also be listed by part number.

The Blackbird air inlet thread for the HPA adapter is 12mm x 1mm pitch.

The back of the Drozd and Blackbird valve body is a very fine thread at 10mm diameter x .5mm pitch.

The bottom of the valve body where the expansion chamber or inlet attaches the valve to the mag body is ...

The breach end of the Drozd and Blackbird barrels are both 8mm diameter by .75mm pitch.  That is obviously the thread for the barrel nut as well.

The Drozd barrel muzzle end is ... Need to double check and will update this...

The solenoid nose thread is 8mm diameter x .75mm pitch just like the barrel nut.


Title: Re: TBK, do you know what thread size the inlet is?
Post by: DU-BB on October 27, 2015, 04:13:51 AM
Check this out:
http://www.ebay.com/itm/ATM2266-Auto-Meter-2266-Metric-1-8-NPT-Female-to-12mm-x-1-Male-Adapters-/361170089627?hash=item54176a369b:g:kCkAAOSw14xWGVtZ&vxp=mtr

Now this looks useful, could be what I was searching for. It looks like it is. The question, now, is if it is long enough to seal.

I just ordered one, so I guess we'll find out now. This will be very useful if it works.
Title: Re: TBK, do you know what thread size the inlet is?
Post by: TBK on October 30, 2015, 07:46:06 PM
Good find.  Let me know how that works.
Title: Re: TBK, do you know what thread size the inlet is?
Post by: DU-BB on October 31, 2015, 01:25:41 PM
Just got the fitting, and I can tell without even trying it that it's not going to work without some work. It's 2mm shorter, and that means that it's not going to engage the oring down in the inlet unless I plane 2mm off the inlet block, which I just might do. As-is, it's going to leak out the set screw hole just about no matter what. This fitting came with a crush ring to seal it on the other end of the threads, between the end of the inlet block, and the nut part of the fitting, which will leave the set screw leaking. I might solder a couple of washers on the end of it, to make it longer, but planing the inlet block is probably easier, and won't cause anything else not to seal, since the inlet block seal is down inside the hole. In fact, looking at the Drozd fittings I have around, they have 3 or 4mm of space between the threads and the rest of the fitting, so it wouldn't even cause it to engage less threads.

Update: Okay, I milled 2mm off the inlet block, and it works fine. That really wasn't a big deal to me, it's well enough within the limits of my tools and skill set, but it did take some modding, and 5 or 10 minutes. You can see the advantage in the direction the hose goes, now. I like it now, it will suffice for my purposes.

(http://i1234.photobucket.com/albums/ff412/ClayStation2/PICT0131_zpsbxt6zqig.jpg)
Title: Re: TBK, do you know what thread size the inlet is?
Post by: Administrator on October 31, 2015, 04:27:57 PM
Nice.  How big was the hole through it?

TBK
Title: Re: TBK, do you know what thread size the inlet is?
Post by: camracer on November 02, 2015, 12:34:59 PM
That works.

Be nice to have a swivel fitting, eh?