Citrus airguns DE-PINGER for Benjamin Marauder

[Evan]

Good to know.  I am new to PCP's so wasn't sure if there was some maintenance that may eventually be required for the air tube that may necessitate removal of the designer. 

[RayK]

I'd love to order up a few... still no response from Mike on my shipping and disco questions... he must be awful busy!

Hi John.

I recommend you call Mike.  He is definitely a telephone guy, not an email guy.  1-352-418-2069  I've learned more from talking with him than by reading all the airgun forums - and I do read them all.  He is protective of his proprietary stuff sometimes because it is his business.  If he tells us how to do it all, after a while, we would all be doing it ourselves.

Ray

[RayK]

The "thump" is in the air tube...

Hi John.

Which caliber Marauder do you have?  If it is not 25, have you tried the BHB (Bstaley Hammer Buffer).  It is just some lubed o-rings against the valve that buffer the hammer, but it also quiets the hammer noise.  I did a write up about it a while back here https://docs.google.com/document/d/1wsnI6_GJHqhD13YGlihlBpQzb_X91qmCsdCxT4iQtMA/edit?usp=sharing
It works great on all the Marauders and P-rod except the 25 caliber gun.

Ray

[shultz]

Ray,

Thanks, I'll give him a call tomorrow... I'm ashamed to admit between family and work I've all but forgotten I do have a cell PHONE and land line... everything is text or email it seems these days

I have both .177 and .22 cal M-rod's, I'd add the .25 but it would hardly see any use... to much gun for backyard plinking(<25yds) and small pest control within the neighborhood.
I've tried the Bstaley mod several times... I get TERRIABLE hammer bounce for some strange reason I tried stiffer and softer duro O-rings, lube/no lube, full hammer spring tension and none... the ONLY thing that got rid of the bounce was running the hammer stroke out to about 5-6 CW turns taking the O-rings out of the picture...

I don't think the "thump" is hammer noise, I think its the pressure wave moving thru the air tube...it's worse on my .177 that's tuned for about 950fps, on my .22 I have it de-tuned to about 850fps and the thump is not near as noticeable... still, it's there.

I really don't care if the citrus de-pingers help with the thump, getting rid of the "ping" and not having to worry if/when the silicone tube may fail is good enough

John

Nearly forgot to say... the Bstaley mod works GREAT in my P-rod... a little T-port/valve work and disco spring along with the 4 orings gives me 2 good mags at 750fps with a third if I really needed it at a higher ES.

[shultz]

"I recommend you call Mike.  He is definitely a telephone guy, not an email guy."

Called Mike late this morning, my de-pingers are boxed up and ready to go out in the AM

I spoke with mike about the "thump", he thinks the gun is not tuned as well as it could be... may very well be the case. I'm waiting until the de-pingers show up before I go changing my tune. If the thump goes away or is at least diminished fine , if not, I'm following Mike's recommendation and tuning without a de-pinger so I can listen to the pitch of the ping as an indication of tune... of course I'll still use a chrony

[bnowlin]

I narrowed my thump down to the valve closing I think I put the A2A valve an stem in and the thump mostly went away.  I have 2 of Mike's depings coming Monday.  I will have to see if the small holes in the top of the depengs slows down the movement of air to the valve as I have everythin open and oversized.   Mike has It will not slow the movement of air as there will be enough air past it to get the same shots.  We'll see.
Bob

[shultz]

My depingers arrived today.

nicely machined but I noticed a little flash on the inside of a couple of the small holes, cleaned it up as I don't want a little sliver of delrin ending up in my valve...

So far I only have the one installed on my .177 M-rod, this is the gun that had the "thump". The thump seems to be greatly diminished...I didn't think to fire it a few times before installing the depinger... from what I remember of the noise it's not as pronounced, no ping that I can detect.

I probably would have installed another depinger or two by now...however, shortly after firing the test shots I noticed a hiss coming from my gauge! I did a soapy water test and found the leak was from the gauge block... great, full tear down time. I think it was pure coincidence that the leak popped up after the depinger install and has NOTHING to do with the depinger. The O-ring's on the gauge block were fairly flat, just degassing the gun and disturbing the O-rings is what caused the leak IMHO. Fresh O-rings all around, few test shots... no leaks

If your installing the depinger and your O-rings are nearly a year old like mine were might save some time and air and just do a full reseal since your nearly halfway there just installing the depinger


John

[RayK]

When I take the parts out of the air tube, I swap in new o-rings - unless they are almost new.  o-rings do take a set, so when you disassemble, then reassemble, things may not get back in the same position they were in before.

I use the trident divers lube for the silicone o-ring lube and it works great.  You can get it at divers supply stores or on-line.  Final assembly tip, as you push the parts into the air tube, put your lubed thumb over the gauge port hole to keep o-rings from popping out there and getting caught.  That can lead to a nick in your o-ring which will leak eventually.

Rifles use four 118 o-rings and P-rods use four 113 o-rings for the air tube.  There is one on the valve body, one on the fill assembly, and two on the gauge block. P-rods also have one size 111 o-ring inside the valve.

Ray

[Finchlake]

Has anyone one else noticed that you have more air left in the tube after a couple of mags after installing these depingers ? It seems that after two(2)mags (16 shoots) in my .25 Mrod I have more air pressure left than I use to, before I  installing the depingers. I go ahead and put in a third mag and shoot a few more shoots. This may just be my imagination. I did not do any test on the before and after installing the depingers, so I'm not willing to say for sure this is happening.

This was not something I expected to happen. Anyone else notice this ?

[FuzzyGrub]

Still waiting for the ones I ordered.  If you are saving air, did the velocity drop? 

[Finchlake]

If you are saving air, did the velocity drop?

Not that I can tell, I do not have a crony. Both of my MRods (.22 & .25) are still shooting good. I'm wondering if the two small holes in the de-pinger are acting as a sort of regulator ? My velocity could be down but not enough to affect POI. 

The effect seems to be most noticeable on my .25. Maybe I should not have even brought this up since I do not have anything to test with.

It would be a good experiment, for someone to test before and after installing the de-pinger.

[FuzzyGrub]

You may be correct.  I just installed one on a .25 cal Mrod last night and here is the before/after:

Before depinger: Gun was at 3Kpsi, and didn't feel like pumping it back to 3150, so ran a 16 shot string to finish it off.

848
856
850
848
851
848
849
844
844
842
837
831
831
821
816
811


Installed the depinger without any modifications, or touching any of the adjustments, and pumped back to 3.3K. which is too high, but wanted to see the complete front end:  (depinger has the small holes facing fill probe and was installed all the way into the airtube,against the gauge block.)



792
794
800
796
805
800
804
804
817
815
821
824
827
827
822
830
833
827
833
831
830
833
830
828
826
824
825
821
815
811
804
798
End 2.2Kpsi

Pellets = JSB Kings

It appears that it is limiting it somewhat, but getting much better efficiency. BTW, ping is all gone. Comments?

Tonight, I plan to do a 3Kpsi fill string to directly compare to the before. Also, another 3.3K fill but record psi every 4 shots. Not far from a respectable 4 mag string.

[Gertrude]

Fuzzy,
Interesting numbers there.

 In the first string your first 7 shots hold fairly close to the same FPS, beginning at 3Kpsi. (do we know what the ending pressure was ?)
 In the 2nd string you got 16 shots before the FPS peaked, beginning at 3.3Kpsi.
 It will be interesting to see what tonight's actual side by side beginning pressure comparison will be, with beginning and ending pressures being the same.

(depinger has the small holes facing fill probe and was installed all the way into the airtube,against the gauge block.)
It appears that it is limiting it somewhat, but getting much better efficiency.

^^^ This ^^^ also raises another couple of questions to me.
 First,
 Is there a Specific Instruction from Citrus,... on the orientation (direction) to install the Depinger ? ... I.E.- with the small holes forward, and the hollow "cavity" side aft ?

and Second,
 Is there also a Specific Instruction from Citrus,... to install the depinger all the way into the airtube, against the gauge block?


If So,...
 then it does stand to reason that the depinger is ALSO acting as a quasi-regulator,....
 ....but unless I am missing something,... It does NOT explain why your 2nd string got 16 shots before maxing out on the FPS.

The only thing I can think of with this, is that possibly,.... MAYBE,... you are seeing some valve lock in the first 16 shots of your second string, due to the extra .3Kpsi at start of the string ?
 But that just dosen't seem to make sense either.

again,... I think it will be very interesting to see the side by side comparisons with equal pressures.

I also think it would be very interesting to do a equal pressures,... shot strings comparison,... first with no Citrus Depinger installed,... then followed by another (equal starting pressure) shot string with the Citrus Depinger installed only half way down the airtube,... then again followed by a third shot string (equal starting pressure) with the Citrus Depinger installed all the way down against the valve block.

 I think this might lend some indication as to whether the Citrus Depinger is acting somewhat as a regulator... with it being oriented holes forward, cavity/hollow aft.

 If this hypothesis is correct,... then it would also stand to reason that the overall length of the Citrus Depinger could be altered, (longer or shorter) to provide yet another means for "fine tuning" to the best efficiency. yes ? no?  comments ?
or
 If this hypothesis is incorrect,... then I just did a whole lot of 2 fingered typing for nothing !  hahaha ! 

btw- now here's the sticker, (or STINKER as it may be)...
 I am now on my 10th day waiting for my 2 Citrus Depingers to arrive for both mine and my daughters .22 Mrods. I expect that it will arrive ANY DAY now,... and I do not own a chrony !
 I would LOVE to test this hypothesis. It would also be interesting to see if the original intent of "depinging" changes with the two different positions within the airtube.
 HMmmmm,..... if I ONLY knew someone semi-local,... who has a chrony,.... who would enjoy and assist in this test ,... 
 

 

[FuzzyGrub]

Ron,

First off, you jumped on the idea I was thinking about, another possible tuning mechanism.     

No installation instructions, but believe I read that (on a forum) is how it is suppose to be installed.  If you install it further up the tube, I think it will creep toward the gauge block with use. 

I don't think I wrote down the ending pressure of the before.  Unlikely that I'll remove or slide it further down.  The small hole(s) and long thin wire that would need to snare it in the hole, would more than test my patience.  Would have to remove gauge and valve and push everything back thru. 

If I recall correctly, both of your Mrods are .22, so you might not see the same effect.  Might have to reduce the length of the cup? 

I waited over 3 weeks before contacting Mike.  Apparently, he thought it shipped or shipped and never arrived.  He quickly sent them out and I received in a few days.

PS: You are a long way from my chrony!      Probably close to 3K miles.   But, you are welcome to stop by. 

[Gertrude]

Ron,

First off, you jumped on the idea I was thinking about, another possible tuning mechanism.     

No installation instructions, but believe I read that (on a forum) is how it is suppose to be installed.

Well it makes the most logical sense to install it with the "cup" aft. that way, if it does creep aft towards the gauge block, it cant completely block the air flow.

PS: You are a long way from my chrony!      Probably close to 3K miles.   But, you are welcome to stop by. 

Haha,... Actually I was hoping to "cattle-prod" Rayk into a responce for us to hook up sometime and do some shooting. i know he is semi- local to me, and before my backyard range got shut down, he was wanting to come by and shoot.
 Now I'm working on another range permission, (my 4H thing), and it's looking pretty good so far. We have a scheduled Meet 'n' Greet this coming Saturday morning. keeping fingers crossed


 I'd also love to hear from a few other more experienced members here on the GTA, about the hypothesis and questions we have raised here.

How about it ?
Can we hear from a few of the "master tuners" crowd...  Ribbonstone, rsterne, Motorhead, PakProtector, CDT, Lloyd, DEz,.... what say you guys

[Finchlake]

Thanks FuzzyGrub for doing the testing, I had wrote the whole thing off as my imagination. I  have my depingers installed with the cup  pointing aft, positioned half way down the air tube.

[FuzzyGrub]

Ron,

I did record the ending pressure as 2.2K for the before.

Here is a 24 shot string, starting at 3.0Kpsi, with approx gauge readings every 4 shots:

823   3000
825   
824   
827   2800+
825   
831   
832   
833   2700
828   
827   
830   
834   2500+
832   
830   
831   
828   2400+
826   
822   
820   
814   2300
810   
807   
801   
797   2200


Don't know if I'll get time to do a 3.3K fill string this evening.  After that, will check what the settings have been at for all of these strings.

[Finchlake]

It does look like velocity was reduced some. I do not see the 848 to 851that you had in the first string. One the other hand it looks like your consistency between shots is much closer on the last string. I would think this would be good for accuracy.

Thanks for doing the testing and reporting.

[rsterne]

I don't have an MRod, but I understand the idea of a depinger.... I think you are creating a plenum that is too small for the FPE level your gun is tuned to.... I assume the hole in the depinger is quite small, let's say 1/8", and it is installed right against the gauge block.... I further assume that the hole in the gauge block in an MRod is larger than 1/8", hopefully more like the 1/4" hole in the front of the valve?.... Without the depinger, if you have a 1/4" hole through the gauge block and valve front, which is larger than the exhaust ports, air can get into the valve faster than it can get out, so all of the air in the reservoir is available to keep the pressure at the valve seat at reservoir pressure, or very nearly so.... Once you put in a restriction that is smaller than the exhaust porting just in front of the gauge block, the pressure at the valve seat DURING the shot will drop.... The gun will shoot as if the pressure is lower, ie generally it will have less power and more shots....

There are two solutions to this issue.... One would be to enlarge the passages in the depinger (which may make it work less efficiently) so that more air can pass through it than out of the valve during a shot.... for an MRod a 1/4" hole should work.... The other would be to put the depinger in further from the valve.... I have seen depingers where there is a metal rod spacing it forward in the air tube to provide a large plenum to avoid this power loss.... Just placing it forward of the gauge block will likely not work, as the pressure difference across it when you shoot will make it slide back until it stops against the gauge block....

Bob

[Gertrude]

Thanks Bob,

In case you had not seen this particular part, here is a couple of pics