Specs for a foster fitting?

[oldpro]

 does anyone have specs for the male foster fitting?

[subscriber]

For standard 8 mm diameter Foster fitting.  Don't know why they leave that 8 mm dimension out of the drawing, below.  Female fitting spec at second link below:



https://airmega.en.made-in-china.com/product/nsHmAjrbbqce/China-OEM-CNC-Manufacturer-of-Quick-Disconnector-Coupling-Filling-Foster-Plug-for-Air-Rifle-High-Pressure-Charging.html

https://airmega.en.made-in-china.com/productimage/oylJYwrdyMcF-2f1j00qrSRpfZgvLbG/China-Manufacturer-of-Female-Foster-Quick-Connector-to-Male-1-8-BSPP-Fitting-Plug.html



Size - 8 X 8mm, 8mm male to male connector, quick disconnect adaptor:
www.amazon.com/Foster-Paintball-Airsoft-Disconnect-Adaptor/dp/B08952KVN7

[steveoh]

There are no specs because they are all different from whoever you buy them from.

Read this and weep.

https://airgunguild.com/airgun-tanks-compressors-and-filling/foster-parker-air-venturi-and-various-chinese-fittings/

I write companies asking for specs, and begging them to please come up with specs that all companies use if only for safety’s sake. I usually get no response.

The behavior of all the Airgun companies, HPA fitting makers, that make and use Foster type fittings etc are criminal as far as I can see.

I’ve had a brass / stainless “Foster” fitting fail at 4,000 psi and I’m lucky I didn’t get hurt and that the 4500 psi tank didn’t get damaged. The pressures we use are no joke.

Fascinating to me is that you Travis, a fellow who has actually been in the business of manufacturing high end airguns at two different companies is asking us for Foster Fitting Specifications. Since Wicked Air Rifles, and Jefferson State Raptors used “Foster Fittings”, shouldn’t you have already had the answer to your question?

If I were an Attorney I’d file class action suit against them all, because of the implied compatibility between connectors that are often NOT at all compatible.

Take an 8mm Chinese paintball female connector and mate it to a “Foster”, or “Parker”, or “Quackenbush” , or “FX”, or “Benjamin” etc connector and you have a situation where there’s a good chance that 8mm connector will fail at high pressure and send your fill whip flying at incredible speed that is enough to lose an eye or maybe even cause death.

The industry needs their collective peepees whacked.

[nervoustrigger]

Summary:   There are no specs.  Also, you should be ashamed for not knowing the specs because you once used ostensibly standard off-the-shelf Foster fittings.

Pfffft.

[USAFANG6799]

Right or wrong I’ve been sanding the male fittings to fit.
Not saying follow my lead but it’s works for me.

[USAFANG6799]

By bringing up the question it brings out how broken the lack of standards are and a reminder for buyers to beware beginners as well as Old Pros. 

[steveoh]

Summary:   There are no specs.  Also, you should be ashamed for not knowing the specs because you once used ostensibly standard off-the-shelf Foster fittings.

Pfffft.

The truth is rather painful isn’t it?

“standard off-the-shelf Foster fittings” is an Oxymoron. Part of the problem is using the brand name “Foster” and applying it to quick connect fittings from myriad other brands even though they are not compatible.

Pardon my bluntness but the truth and reality is essential.

ASTM.org is perhaps an organization that can shed some light.

[nervoustrigger]

From the horse’s mouth:
https://www.zsi-foster.com/mm5/graphics/profile/FOSTER-12MP-PROFILE.pdf

Not a fully dimensioned drawing but it establishes the OD as 0.31” nominal with a 0.005” tolerance.

[oldpro]

 This is exactly why I asked the question! What got me going was Manny just got a new AEA gun and the foster wouldn’t seal to the female. So I started measuring a bunch of Fosters and they are all over the place. This is sad to say the least. Thank you Steven for your reply it basically backs up what I found. I’ll bring this up in the meeting at ASTM.

[sb327]

There are no specs because they are all different from whoever you buy them from.

Read this and weep.

https://airgunguild.com/airgun-tanks-compressors-and-filling/foster-parker-air-venturi-and-various-chinese-fittings/

I write companies asking for specs, and begging them to please come up with specs that all companies use if only for safety’s sake. I usually get no response.

The behavior of all the Airgun companies, HPA fitting makers, that make and use Foster type fittings etc are criminal as far as I can see.

I’ve had a brass / stainless “Foster” fitting fail at 4,000 psi and I’m lucky I didn’t get hurt and that the 4500 psi tank didn’t get damaged. The pressures we use are no joke.

Fascinating to me is that you Travis, a fellow who has actually been in the business of manufacturing high end airguns at two different companies is asking us for Foster Fitting Specifications. Since Wicked Air Rifles, and Jefferson State Raptors used “Foster Fittings”, shouldn’t you have already had the answer to your question?

If I were an Attorney I’d file class action suit against them all, because of the implied compatibility between connectors that are often NOT at all compatible.

Take an 8mm Chinese paintball female connector and mate it to a “Foster”, or “Parker”, or “Quackenbush” , or “FX”, or “Benjamin” etc connector and you have a situation where there’s a good chance that 8mm connector will fail at high pressure and send your fill whip flying at incredible speed that is enough to lose an eye or maybe even cause death.

The industry needs their collective peepees whacked.

What failed on the one you mentioned?

The bore is a critical dimension as well as material. It would be nice to know what these things ‘should’ be but we also should take some responsibility ourselves. We are the ones buying the cheap knockoff brands.

The male interface is only half of what needs to be correct as well.

Dave

[Privateer]

Manny has my AEA. I started making a new fill probe from a Stainless Steel Evanix probe by turning it down.
Plenty of meat on those probes!
When it got to cutting the o-ring grooves deeper my lathe suffered a broken part that I haven't replaced yet.
The probe is the thread on to a male foster adapter to avoid the problem of a bad male end from AEA.
When I tested the Evanix cut down it would blow the o-ring since I need to cut it deeper for the o-rings.
And probably cut it to small in the dimensional as that was when I found my lathe was going bad.

[steveoh]

There are no specs because they are all different from whoever you buy them from.

Read this and weep.

https://airgunguild.com/airgun-tanks-compressors-and-filling/foster-parker-air-venturi-and-various-chinese-fittings/

I write companies asking for specs, and begging them to please come up with specs that all companies use if only for safety’s sake. I usually get no response.

The behavior of all the Airgun companies, HPA fitting makers, that make and use Foster type fittings etc are criminal as far as I can see.

I’ve had a brass / stainless “Foster” fitting fail at 4,000 psi and I’m lucky I didn’t get hurt and that the 4500 psi tank didn’t get damaged. The pressures we use are no joke.

Fascinating to me is that you Travis, a fellow who has actually been in the business of manufacturing high end airguns at two different companies is asking us for Foster Fitting Specifications. Since Wicked Air Rifles, and Jefferson State Raptors used “Foster Fittings”, shouldn’t you have already had the answer to your question?

If I were an Attorney I’d file class action suit against them all, because of the implied compatibility between connectors that are often NOT at all compatible.

Take an 8mm Chinese paintball female connector and mate it to a “Foster”, or “Parker”, or “Quackenbush” , or “FX”, or “Benjamin” etc connector and you have a situation where there’s a good chance that 8mm connector will fail at high pressure and send your fill whip flying at incredible speed that is enough to lose an eye or maybe even cause death.

The industry needs their collective peepees whacked.

What failed on the one you mentioned?

The bore is a critical dimension as well as material. It would be nice to know what these things ‘should’ be but we also should take some responsibility ourselves. We are the ones buying the cheap knockoff brands.

The male interface is only half of what needs to be correct as well.

Dave

The brass portion of the female fitting separated from the stainless portion, sending parts flying. I was standing right next to it when it happened. I almost crapped myself.

This is a fitting that came with my Yong Heng compressor that fills 4500 psi tanks, bottles, and Airguns. They are 8mm fittings.

I’ve also noted that the female fittings come with varying numbers of ball bearings.

Also I’ve noted that I have replaced a number of male fittings than suffer from deformation. They will show ball bearing impressions in the steel.

First order of business is that fittings need to be compatible and have measurement standards on both male and female fittings.

Some companies like FX have oddball long fittings required for the female end as they connect inside of the Airgun. So this means outside measurements need to be standardized also.

Second order of business is the actual pressure rating. I’m willing to bet that many of us are running on the ragged edge of failure, since some of these fittings are Not rated on the fitting or in their packaging if they come in packaging.

If we are filling to 4500 psi, what do you think hoses, and fittings should be rated for? I would think 6,000 psi would be minimum.  But perhaps 9,000 psi is more like it. I bet a number of the fittings we all run are rated at 3,000 psi.

I’m very surprised we haven’t seen hundreds of failures and scores of injuries from using underrated and incompatible fittings.

Like I said, the industry is criminal in it’s behavior.

Up next on my list is myriad fill port probe connectors coming from different manufacturers. There is no good reason why these can’t be standardized, with sizes, ratings, and even o-ring sizes.

Why do we put up with $2,000+ Airguns that don’t have have standardized fittings?

Further down my list is the fact we have a variety of threaded hose / fitting connections. 1/4 BSP, 1/4 NSP, Metric, tapered, straight threads, etc. I am gobsmacked at complete lack of standards here.

[Back_Roads]

 Another possible issue with AEA guns is they have a small hole for the HPA exit or the intake on the gun, they are slow to take air in, may also be an issue with trying to use a hand pump. Though slow filling is best IMO.
 My AEA Challenger 24" probe is in spec., way better than the China hand pump female connections I have encountered in the past.

[steveoh]

Right or wrong I’ve been sanding the male fittings to fit.
Not saying follow my lead but it’s works for me.

As an experiment I chucked up two make 8mm fittings in my drill press and “machined” them down to fit genuine Foster and Parker female fittings. (Hint, they are different). I was successful with one, and I mangled the second. But because the other dimensions also varied, I threw both in the garbage because I value my fingers, eyes and equipment.

I think it’s a bad idea to sand or file down these fittings.

[sb327]

Another possible issue with AEA guns is they have a small hole for the HPA exit or the intake on the gun, they are slow to take air in, may also be an issue with trying to use a hand pump. Though slow filling is best IMO.
 My AEA Challenger 24" probe is in spec., way better than the China hand pump female connections I have encountered in the past.

AEA’s slow fill issue is the internal check valve design. It’s terrible. A taper head screw with an oring. That threads into place. The best I can tell, the air has to push through the screw threads.

Dave

[Nomadic Pirate]

Over the years I had way more problems with Fosters then I even had with probes.

[mobilehomer]

From the horse’s mouth:
https://www.zsi-foster.com/mm5/graphics/profile/FOSTER-12MP-PROFILE.pdf

Not a fully dimensioned drawing but it establishes the OD as 0.31” nominal with a 0.005” tolerance.

i just looked at the "print" It is terrible. Three decimal places is a .005" tolerance. .31" is a .010" tolerance when not called.

[oldpro]

Over the years I had way more problems with Fosters then I even had with probes.

The problem with probes is there are 20+ different probes used across the industry. This needs to be standardized also IMHO

[subscriber]

Having a Foster fitting blow out is inexcusable.  At 4500 PSI it would cause a degree of permanent hearing damage for anyone in the room.  The fright alone for anyone nearby could cause such a start that they could hurt themselves from sudden body movement.

The fitting that comes flying out has the potential to do damage.  The question is how much energy does it carry?  A quick calculation suggest that at 4500 PSI a Foster fitting blow-out carries about 9 FPE.   This based on an effective "piston" diameter of 5/16", that travels 1/4" under full pressure before venting.

The foster fitting is much heavier than a .177 pellet at that energy level, so would be travelling much slower - not likely to go as deep into flesh as a fast moving pellet.  Below, I attempt to quantify the fitting's velocity. 

I downloaded the compressed air coupling 3D model shown below from McMaster, at the link provided.  The fitting is similar to a Foster fitting and might help ballpark a Foster fitting's mass.    Yes, I could design a Foster fitting from the wonky specs posted, but this is a shortcut to a ballpark answer.

After designating the fitting's material as "alloy steel" in Solidworks,  SW reports the weight as 0.0344 lb, or 225  Grains.

So, a 225 grain projectile carrying 9 FPE would be travelling at 135 FPS; or 92 MPH.  Fast enough to break the skin, should there be bone directly underneath, such as the skull, fingers or shins.   The potential for a broken finger or damaged joint would be of concern.  That said, if the fitting hit a person in the eye, the risk of permanent blindness would be very significant.   Not something I want to be hit by for sure; but nothing like a .45 caliber airgun slug launched from a 34" barrel.


www.mcmaster.com/53445K117/





What also annoys me is PCP airguns that require an odd fitting to mate with a Foster ended pump, where the odd fitting is not included with the airgun, and that fact is not made obvious when you look at the product page.   So, added cost and frustration; resulting from a possibly a deliberate omission, because it reduces the apparent price when the purchase decision is made...

[Nomadic Pirate]

Over the years I had way more problems with Fosters then I even had with probes.

The problem with probes is there are 20+ different probes used across the industry. This needs to be standardized also IMHO

Been saying that for years now,......that would make a huge difference.