P-rod quad o-ring size for bstaley tune

[TF89]

I have looked around and don't see what the part number is for the McMaster-Carr quad o-ring.  I've seen lots of reference to the 113 o-ring, just not for the quad.

Does anyone have that information?

Thank you,

Dave

[Tucobenedicto]

External diameter of 113 is 0.666" nominal,just search a quad the same diameter (a bit more can be even better for a tight fit in the tube) and about 0.1" of thickness.

[Bentong]

I have seen others use garden hose gasket.
Try here >> https://www.theoringstore.com/index.php?main_page=product_info&cPath=367_2205_829_831&products_id=35140&zenid=d94a8edd9edcb6d8663efee4ef11f46c

http://www.oringsandmore.com/x-rings-size-113-price-for-10-pcs/

[Tucobenedicto]

I have seen others use garden hose gasket.
Try here >> https://www.theoringstore.com/index.php?main_page=product_info&cPath=367_2205_829_831&products_id=35140&zenid=d94a8edd9edcb6d8663efee4ef11f46c

http://www.oringsandmore.com/x-rings-size-113-price-for-10-pcs/

My bad,nominal external diameter is actually 3/4,not sure if an x ring can respond well in a Bstaley tune,can't be too soft?

[TF89]

That is why I was hoping for a part number that people have actually used.  I looked on the site and I see a number of variables with the quad ring and I really don't want to re-discover when others have gone before .

[Tucobenedicto]

That is why I was hoping for a part number that people have actually used.  I looked on the site and I see a number of variables with the quad ring and I really don't want to re-discover when others have gone before .

I hear you  better to wait someone else jump in.

[mobilehomer]

Look no further. Exactly what you want.
http://www.jsairrifles.com/Marauder-Pistol-P-Rod-O-Ring-Hammer-Buffer_p_46.html

[TF89]

Thanks Ken.  I did see those, however I was looking for little more quantity than just the 3 in a pack.

Now that I know what the various names are for the quad/x-ring/Quattro o-ring I found these.  Thanks to Bentong for leading me in what I think is the right direction.

Chemical-Resistant Viton® Fluoroelastomer O-Ring
https://www.mcmaster.com/#6540k137/=1ea8tpp


x-Profile Oil-Resistant Buna-N O-Ring
https://www.mcmaster.com/#90025k228/=1ea8uao

Not sure which one would be better?


I made an edit as I messed up on the names.  Sorry to all concerned.

[Tucobenedicto]

I vote for the quad ring,i think can last longer.

[nervoustrigger]

This is a very low stress application for O-rings.  Why would an X profile last longer?

[ray1377]

Don't hold me to it, but I remember reading just a few days ago about a fellow having good luck with square profile o-rings instead of the usual round ones.
https://www.mcmaster.com/#square-o-rings/=1eadx1z

Thanks
Ray

[moorepower]

I will try to look tomorrow. I just got a bag of 3/4” OD square orings from McMaster Carr. I think 70 durometer. That’s what I use and am happy with them.

[Tucobenedicto]

This is a very low stress application for O-rings.  Why would an X profile last longer?

Not the X,i think the square profile can last longer in the hammer contact zone,but is just a thinkering.

[FuzzyGrub]

I have been using a combination of X and O, and thin spacer.


Hammer   XOX||   Valve

[screwwork]

Dr Fuzzy is in the house.

[Back_Roads]

I have been using a combination of X and O, and thin spacer.


Hammer   XOX||   Valve

That reminds me of a regulator washer stack ... hmm 

[TF89]

I have been using a combination of X and O, and thin spacer.


Hammer   XOX||   Valve

Hi John,

Can you go into a little more detail on how you did it?  I'm about to order some square o-rings and it would be nice to get it right the first order.

Thank you,

Dave

[pecor]

When I strip her down next time, I'm Going to give garden hose washers a try,

[FuzzyGrub]

I have been using a combination of X and O, and thin spacer.


Hammer   XOX||   Valve

Hi John,

Can you go into a little more detail on how you did it?  I'm about to order some square o-rings and it would be nice to get it right the first order.

Thank you,

Dave

I've used BunaN, 70D,  x-ring and o-ring are 113.  The main advantage to x-ring is they hold their position better in the airtube. Square O-rings work too, just the whole stack needs to be all square.   I also use a little moly grease to help hold them in place.

I can't say I have any proof the XOX works better than square, but it gives the BSB a little more mystique.   

The shim needs to be from 1/2 - 2/3rds the thickness of the 113 o-ring.  I have sourced these from local H/W stores.  You can use thin ss fender washers, but will need to grind off some of the outer edge to fit in the airtube.  Neoprene washers of the right thickness are easier to install.  Some moly on the back side to keep it next to valve. 

The shim keeps the throw adjustment within 1 turn of full CCW for a 16 FPE tune.  I use a 0.110" TP and a 0.3" OD X 1.5" X 0.042" Music Wire hammer spring.  If your power goal is 12FPE or less, go with 4 O-rings, no shim.  If 20FPE +, go with just the 3 O-rings. 

[TF89]

Thank you very much John!!!  If you don't mind my asking, where did you buy your spring from?  Also at 16fpe, what is your fill and shot count.

Again,

Thank you,

Dave