New Seneca Dragonfly?

[splitbeing]

This is backtracking, but it's unclear to me whether you are using ballistol on the foam pad. I would expect dieseling potentially from that approach if not detonation. Maybe the oring and foam pad are silicone oiled?

When you repeat the process of opening up the passageways, would you take a few pictures of the steps, including also a step of increasing from 1 to 2 turns? The info here is so thorough, Don, that I suspect a guide with pictures would be a long lasting resource for the airgun pumping DF community!

[splitbeing]

Also backtracking, I am a little concerned about the pattern of fps increase vs pump number. There are a couple pumps that yield little increase followed by a pump yielding a large increase. This happens a couple times over the G test. I am not sure what is going on there and am concerned that the slow build to a huge push might stress and break something. Though again, I cannot explain what is going on there so it is speculation. While less powerful, the tests with a smoother curve of fps increase vs pump number seem safer to me.

[Nvreloader]

SB
I use Ballistol on all the pump rod joints and on each end of the pump rod,
I noticed there is some rubbing on the Black finish caused by the pressure during pumping.
The foam ring also has Ballistol on it, to reduce the friction/rubbing areas of the pump rod during it's operation.
I would believe that the "O" will keep the lubes separated during pumping action.

I use Silicone oil on the pump rod head "O" ring only, via this method,
I slowly open up the pump handle to just before the "O" gets to the air breathing hole in the pressure tube,
I put 1-2 drops of Silicone oil over the air hole, then open the pump handle to the fullest extent,
by opening the handle, the silicone oil is sucked inside the pressure tube, once the "O" ring passes by.

As for the increasing/decreasing of the pump rod head, I use a 17mm open end wrench in the slot of the pump rod,
just fits nicely, then use a 13mm open end wrench to loosen the lock nut under the pump rod head.
then I wrap the pump rod head w/"O" ring with a HD nylon strap, and use water pump pliers to grab the pump head
it appears to be locktited/sealed and loosen the head 1 full turn and check depth.

Note: Remove the "O" RING when checking the depth of the pump rod, it's easier to adjust etc.

Note: I have very lightly marked the pump rod shank with a needles point, right at the bottom of the "U" of the slot
cut into the pressure tube, just upstream from the air inlet hole.
Completely close the pump handle, then very carefully lift the pump handle until it is free moving,
BUT the pump rod is still LOCKED DOWN at it's maximum depth.
Mark the pump rod at this "U" point. There will be about 1/2" of space between the locked down pump rod
and free handle space.
This is the reference point for pump rod depth measurements, be as accurate as possible when marking.

Also note:
When pumping, the pressure from the pumped air will cause the pump rod to be pushed away from the
valve inlet flat face, by .020" - .030" by the retained pressure from pumping.
DO NOT ADJUST FOR THIS SLIGHT AMOUNT OF FREE SPACE,
leave it alone for safety on contacting the valve face.

As for the ODD Ball fps readings, there are some errors, and I could not correct them as the modify time ran out.......    
I went back and checked my log book, on the B test = 9 pumps should be 651 fps,
(fat finger mistake).

I also noticed some of these large fps jumps, the only thing I can think of is the INTERNAL Volume of the valve,
something has to be going on there, I have have checked all readings
and they are as shot/recorded etc.

I am very careful noting the number of pumps etc, and another item MIGHT be the Crosman ammo,
it is not the most uniform there is.....LOL  I will not waste good ammo for testing,
but will finish up with a good ammo comparison,  I hope.

I'll attempt photo's on the next tear down, BUT DON"T HOLD YOUR BREATH, photo's are my downfall here. 

Thanks,
Your thoughts and suggestions............
Don

[Back_Roads]

 Well I have learned alot, and have a.22 DF2 and 1 will not be until late fall I get the urge to turn a wrench for fun, so I avoid it now. But will follow the steps that count and do this mod on mine and get some nice photos to boot.

[Nvreloader]

I got bored, can't ride my bike, windy again.
 
So the DF II got hit again, with 1 change,
all air passageways got opened to .1562" and burrs cleaned up.
 
Note: This is the largest bbl hole diameter that can be used, as the distance between the "O" seals on the bbl, anything larger will require a bbl set back and new "O" ring grooves cut.
 
I'll have to check the valve seats and "O" rings, as I was having funny pumps results until I finished about 10 shots, then everything settled down and progressed OK.

Low fps results with the valve opened up, don't know why?  But, better shot curve results,
seems to be very uniform? Even thou I forgot to lube everything before shooting. 

                (H)
1 pump = 252 fps
2 pumps= 305 fps
3 pumps= 383 fps
4 pumps= 416 fps
5 pumps= 449 fps
6 pumps= 524 fps
7 pumps= 567 fps
8 pumps= 600 fps
9 pumps= 633 fps
10 pumps= 690 fps
11 pumps= 711 fps
12 pumps= 754 fps
13 pumps= 801 fps
14/15 pumps = 801fps
H test
Same pump tests as all the others, only item changed was,
All air passageways opened up to .1562" Dia (reamed).

Summary of all the tests
     Test       A     B    C    D     E    E-1   F     G     H
1 pump = 265-288-262-255-259-269-269-262--252
2 pumps= 288-321-380-383-383------393-377--305
3 pumps= 322-354-462-465-465------452-390--383
4 pumps= 465-361-524-528-521------479-436--416
5 pumps= 515-597-574-570-567-574-538-488--449
6 pumps= 567-610-620-600-600------623-498--524
7 pumps= 600-616-643-626-623------646-639--567
8 pumps= 633-620-672-649-643------652-754--600
9 pumps= 652-651-688-659-662------708-810--633
10 pumps= 666-688-698-672-679-692-728-833-690
11 pumps= 678-----------688-683------744-833-711
12 pumps= 679-----------702-712------770-833-754
13 pumps= 681-----------712-718------770-833-801
14 pumps= 680----------------721------770-833-801
15 pumps= 679----------------728-741-770-833-801
There was no extra air left after any pump test, for any shot.

(A Test)
Here is the  full 15 shot+ pumps test, 3 pumps per the number,
pumps were a complete cycle, open then closed arm pump arm, per each pump stroke.
with the OEM 18/19# spring, full length,14 gr Crosman ammo
 
(B Test)
1 complete turn on pump rod, nothing else changed. A 11# Flat wire spring, 5" long,
.415" O/S Dia, .252" I/S dia, 35 coils, .023" thick Flat wire, coil bound at less than 1.030"

(C Test)
I just finished the 1 >10 pumps x 3 each per pump,
pumps were a complete cycle, open then closed arm pump arm, per each pump stroke.
2 complete turns on pump rod head, nothing else changed, with a 11# Flat wire spring,
5" long, .415" O/S Dia, .252" I/S dia, 35 coils, .023" thick Flat wire, coil bound at less than 1.030"

(D Test)
I just finished the 1 >15 pumps x 3 tests per pump number,
pumps were a complete cycle, open then closed arm pump arm, per each pump stroke.
2 complete turns on pump rod head, with a 11# Flat wire spring, 5" long, .415" O/S Dia,
.252" I/S Dia, 35 coils, .023" thick Flat wire, coil bound less than 1.030",14 gr Crosman.
All air passageways opened up to .145" Dia (reamed), removed air filter at valve inlet.

(E Test)
Same test as all the previous tests, the only item changed was the hammer spring.
Using a OEM 6/7# Storm Rider Round wire spring, 3.360" long, .384" O/S Dia,
.300" I/S dia, 25 coils, .035" thick round wire, coil bound at 1.020", 14 gr Crosman ammo.
All air passageways opened up to .145" Dia (reamed), removed air filter at valve inlet.

(E-1 Test)
Here is something I found out that is very interesting with this DF II, 22cal rifle
I lubed all pivot points, and the oil wiper seal and shot these Oiled 3 pump tests.

(F Test)
Same test as all the previous tests, the only item changed was the hammer weight to 533 gr
and Hammer spring weight of 9-10#'s.
Using a Flat wire spring, 2.500" long, .415" O/S Dia, .265" I/S Dia,.022" thick Flat wire,
25 coils, 14 gr Crosman ammo. 2 complete turns on pump rod head.
All air passageways opened up to .145" Dia (reamed), removed air filter at valve inlet.

(G Test)
Same test as the above test, only item changed was lengthen the pump rod head
to maximum distance, to not block the air inlet hole, and oiled the wiper seal oiler.
Using a Flat wire spring, 2.500" long, weight = 8-9#'s, .415" O/S Dia, .265" I/S Dia,
.022" thick Flat wire, 25 coils, Alum Hammer weight at 533grains. 14 gr Crosman ammo.
All air passageways opened up to .145" Dia (reamed), removed air filter at valve inlet.

(H Test)
Same test as the above test, only item changed was lengthen the pump rod head
to maximum distance, to not block the air inlet hole, and oiled the wiper seal oiler.
Using a Flat wire spring, 2.500" long, weight = 8-9#'s, .415" O/S Dia, .265" I/S Dia,
.022" thick Flat wire, 25 coils, Alum Hammer weight at 533grains. 14 gr Crosman ammo.
All air passageways opened up to .1562" Dia (reamed), removed air filter at valve inlet.


Your thoughts and or suggestions................
Tia,
Don

[splitbeing]

This just keeps getting more curious! The lower fps with a nicer shot curve are additional clues to consider. Its as if at certain pump numbers, not all the pressure is released and then subsequent pump numbers do get that air out. Hmmm... might not be right... still waking up. Wondering if relubing will boost those numbers back up. Guessing the gun is happier with that new shot curve. [chuckling] Imagining the gun has less indigestion and better breathing now.  So impressive.


Thanks for the instructions on the pump head adjustment and lubing. Most helpful!

[Nvreloader]

SB
I swear this pumper is haunted, there is no rime and reason, IMHO why it changes from
the low end to the high end (fps wise), with such little changes etc.

I also open the up  the air inlet valve end to .1562" along with all the other air passages.
Maybe I went too far? If the air inlet makes that much difference,
I have to use a set screw and bush the .1562" hole back to .100" dia,
one thing about using a set screw, as I can change them to whatever dia I want/need.

I'll check the seat and make sure it it perfect with no burrs etc.

I like the lower end fps steps, but it is missing on the high end fps somewhat.

I really liked the G test results, but I am not above testing to see other results.
Thanks,
Your thoughts or suggestions,
Don

[nervoustrigger]

Hi Don,

Regarding Trial H where the velocity dropped despite having enlarged the porting, a few possibilities and questions come to mind:

1.  In the venerable Crosman 13xx platform, one observation is that increasing the porting helps the .22 cal but hurts the .177 cal.  The difference is believed to be related to the early part of the firing cycle when the pressure pulse first hits the back of the pellet...that the larger porting represents a larger volume to be pressurized between the valve seat and the pellet, thus the initial pressure hitting the skirt is somewhat diminished.  A pumper's valve volume being rather small, after all.  Now I realize your Dragonfly is a .22 cal so this theory may not apply.  Or it may indeed apply given other differences between the platforms.

The biggest clue is that Trial G topped out at only 10 pumps.  After you enlarged the porting, the velocity didn't top out until 13 pumps.  And of course it was slower at 13 pumps than it had previously been at 9 pumps...which suggests maybe you were having to bring the valve up to a higher pressure in order to compensate for an otherwise diminished initial pressure slapping the pellet in the behind.  Or it could mean that something happened which made pumping less effective, something completely unrelated to having changed the porting.

2.  Does "all air passageways opened to 0.156" include the valve throat?  Moving up from 0.145in to 0.156" represents an area increase of almost 16%, meaning the valve is now nontrivially harder to knock open.  Perhaps even more if your 0.156" figure is an adjusted figure that represents the equivalent cross-section after accounting for the area occupied by the stem.  The valve is soaking up more of the hammer's energy to unseat the poppet, generating less lift, and therefore delivering less of an early kick in the pants to the pellet to get it moving.  Granted I do notice you have confirmed the valve is not retaining air which means there is definitely plenty of dwell, but the velocity loss may have less to do with dwell than it does lift.

3.  This last idea / possibility is more mundane than the first two.  Maybe something subtle changed in the course of reassembling after enlarging the porting.  The usual suspect would be a slightly different alignment of the valve exhaust port and the barrel port.  Maybe a transfer port seal compressing differently and slightly modifying the effective cross-sectional area for airflow.  But it could be almost anything.  The preferred approach to check would be to step back to Trial G and make sure its results are repeatable, then re-do Trial H.  Of course it's not particularly feasible to put metal back so second best would be to simply tear down and go through the motions of reassembling very carefully and retest Trial H to see if you get a different result.

That's all I've got!  Frankly I'm not particularly optimistic that the solution is contained within one of these three items but maybe we'll get lucky or at least help give rise to some other ideas.

[Nvreloader]

Ok Guys
I re shot this H test again, and these are the results,
                H-1
1 pump = 236 fps
2 pumps= 367fps
3 pumps= 449 fps
4 pumps= 495fps
5 pumps= 511fps
6 pumps= 574fps
7 pumps= 597fps
8 pumps= 613fps
9 pumps= 757fps
10 pumps= 813fps
11 pumps= 856fps
12 pumps= 869fps
13/14/15 pumps = 869fps or less
H - 1 test
Same pump tests as all the others, only item changed was,
Oiled the pump rod and head, this was pumped to 10 pumps and left over night,
shot this and recorded 705 fps, may have a leak?.
All air passageways opened up to .1562" Dia (reamed).

Summary of all the tests
     Test       A     B    C    D     E    E-1   F     G     H    H-1
1 pump = 265-288-262-255-259-269-269-262--252-236
2 pumps= 288-321-380-383-383------393-377--305-367
3 pumps= 322-354-462-465-465------452-390--383-449
4 pumps= 465-361-524-528-521------479-436--416-495
5 pumps= 515-597-574-570-567-574-538-488--449-511
6 pumps= 567-610-620-600-600------623-498--524-574
7 pumps= 600-616-643-626-623------646-639--567-597
8 pumps= 633-620-672-649-643------652-754--600-613
9 pumps= 652-651-688-659-662------708-810--633-757
10 pumps= 666-688-698-672-679-692-728-833-690-813
11 pumps= 678-----------688-683------744-833-711-856
12 pumps= 679-----------702-712------770-833-754-869
13 pumps= 681-----------712-718------770-833-801
14 pumps= 680----------------721------770-833-801
15 pumps= 679----------------728-741-770-833-801
There was no extra air left after any pump test, for any shot.

(A Test)
Here is the  full 15 shot+ pumps test, 3 pumps per the number,
pumps were a complete cycle, open then closed arm pump arm, per each pump stroke.
with the OEM 18/19# spring, full length,14 gr Crosman ammo
 
(B Test)
1 complete turn on pump rod, nothing else changed. A 11# Flat wire spring, 5" long,
.415" O/S Dia, .252" I/S dia, 35 coils, .023" thick Flat wire, coil bound at less than 1.030"

(C Test)
I just finished the 1 >10 pumps x 3 each per pump,
pumps were a complete cycle, open then closed arm pump arm, per each pump stroke.
2 complete turns on pump rod head, nothing else changed, with a 11# Flat wire spring,
5" long, .415" O/S Dia, .252" I/S dia, 35 coils, .023" thick Flat wire, coil bound at less than 1.030"

(D Test)
I just finished the 1 >15 pumps x 3 tests per pump number,
pumps were a complete cycle, open then closed arm pump arm, per each pump stroke.
2 complete turns on pump rod head, with a 11# Flat wire spring, 5" long, .415" O/S Dia,
.252" I/S Dia, 35 coils, .023" thick Flat wire, coil bound less than 1.030",14 gr Crosman.
All air passageways opened up to .145" Dia (reamed), removed air filter at valve inlet.

(E Test)
Same test as all the previous tests, the only item changed was the hammer spring.
Using a OEM 6/7# Storm Rider Round wire spring, 3.360" long, .384" O/S Dia,
.300" I/S dia, 25 coils, .035" thick round wire, coil bound at 1.020", 14 gr Crosman ammo.
All air passageways opened up to .145" Dia (reamed), removed air filter at valve inlet.

(E-1 Test)
Here is something I found out that is very interesting with this DF II, 22cal rifle
I lubed all pivot points, and the oil wiper seal and shot these Oiled 3 pump tests.

(F Test)
Same test as all the previous tests, the only item changed was the hammer weight to 533 gr
and Hammer spring weight of 9-10#'s.
Using a Flat wire spring, 2.500" long, .415" O/S Dia, .265" I/S Dia,.022" thick Flat wire,
25 coils, 14 gr Crosman ammo. 2 complete turns on pump rod head.
All air passageways opened up to .145" Dia (reamed), removed air filter at valve inlet.

(G Test)
Same test as the above test, only item changed was lengthen the pump rod head
to maximum distance, to not block the air inlet hole, and oiled the wiper seal oiler.
Using a Flat wire spring, 2.500" long, weight = 8-9#'s, .415" O/S Dia, .265" I/S Dia,
.022" thick Flat wire, 25 coils, Alum Hammer weight at 533grains. 14 gr Crosman ammo.
All air passageways opened up to .145" Dia (reamed), removed air filter at valve inlet.

(H Test)
Same test as the above test, only item changed was lengthen the pump rod head
to maximum distance, to not block the air inlet hole, and oiled the wiper seal oiler.
Using a Flat wire spring, 2.500" long, weight = 8-9#'s, .415" O/S Dia, .265" I/S Dia,
.022" thick Flat wire, 25 coils, Alum Hammer weight at 533grains. 14 gr Crosman ammo.
All air passageways opened up to .1562" Dia (reamed), removed air filter at valve inlet.

(H - 1 test)
Same pump tests as all the others, only item changed was,
Oiled the pump rod and head, also was pumped to 10 pumps and left over night,
shot this and recorded 705 fps, may have a leak. 14gr Crosman ammo.
Note: No "O" rings have been changed, all OEM thru all these tests.......
All air passageways opened up to .1562" Dia (reamed).

Your thoughts and or suggestions................
Tia,
Don

[nervoustrigger]

Very good, sounds like you found the source. 

When I said:
“ Or it could mean that something happened which made pumping less effective, something completely unrelated to having changed the porting. ”

If I make enough guesses, one of them is bound to hit.  Kinda like the strategy of psychics and clairvoyants.

[splitbeing]

Woohoo, Don! 869? Did you think it possible?!  Are you also interested in repeat tests as it settles in? Curious how those bumps in fps increase will or won't smooth out as a curve (fps increase vs # pumps).

[Nvreloader]

Hi Jason
Thank you, LOL....................

I can't believe that oiling/lubing these parts make that much difference, JDLR..........?

This 22 caliber valve internal dimensions are approximately = .390" I/S Dia x 2.120" long,
inlet hole .102" Dia, plus the tapered ends for the top/bottom seal/poppet seats, 2.50 CI.

The total volume of these valve parts is approx 1.04 CI, not including the spring,
so there is not much air volume inside this valve, if I have figured it right.
See this photo of this part,
Go to page #17, post #332, and there is a photo of the valve and parts etc.
https://ibb.co/8b8nZD7

Another item I don't like,  is the tapered seats at the top inlet valve hole and the poppet
also has tapered seats.  This can't be helping the efficiency of this valve.

Since I have a new valve coming, I'll see if I can make flat faced valve seats for both ends,
should be easier opening and sealing etc.

When I opened all air passage ways, only these parts were opened up,
bbl hole,
action hole,
brass TP hole,
valve tp hole.
I did not touch any thing else.
 
I turn a brass rod the exactly fit the hole of every part,
then use these rods to make sure that the part is clamped in the proper relationship
to the reamer angle etc.

Would bushing the air inlet valve hole on the pump side back to .102" and valve TP hole to
.136" be a good start?

And I can also set the bbl back and make a new chamber etc,
as the OEM "O" ring spacing limits the transfer hole to .1562" max in this 22 cal bbl,
without cutting into the hole etc.

All these OEM "O" rings are well used and probably has minor nicks etc after 10+ tear downs,
all new "O" rings will be installed on the final build.

Thank you for your time and trouble, Jason.
It is greatly appreciated.

Your thoughts and suggestions..........
Don

[Nvreloader]

SB
I had a faint Idea that a little more could possibly be obtained.
I am happy thou, BUT curiosity grabbed me and won't let go.............LOL.

There will be more follow up tests, this lubing and fps increases JDLR, in mho.
I think this OEM valve is the major hiccup??

Jason is a lot smarter on this stuff than I am, I am still learning, I hope.

With good new "O" rings, I am hoping it will settle down to a good average.
I'll take 800 fps all day long, and I can change to a lower level if needed,
via pumping, which I can't do with my PCP's as easily.

On to some heavier weight pellets, I can't wait to try out the NOE WC -vs- Sage bunnies.

Tia,
Don

[Spacebus]

I wonder if the oil helps reduce the charge temperature. If the "compression chamber" gets hot, it will build pressure faster, but then let off as it cools.

[HPP-Mechanic]

I got a 30fps gain with 19g pellets after oiling the pump tube (behind the o-ring).

Interesting that the passages are sized (stock) more for .177. Curious to know what a .177 is seeing for fps...

A valve with more volume might get this pumper even more power, but how many more pumps would that require?

 Next, try 20 pumps?

[splitbeing]

SB
I had a faint Idea that a little more could possibly be obtained.
I am happy thou, BUT curiosity grabbed me and won't let go.............LOL.

There will be more follow up tests, this lubing and fps increases JDLR, in mho.
I think this OEM valve is the major hiccup??

Jason is a lot smarter on this stuff than I am, I am still learning, I hope.

With good new "O" rings, I am hoping it will settle down to a good average.
I'll take 800 fps all day long, and I can change to a lower level if needed,
via pumping, which I can't do with my PCP's as easily.

On to some heavier weight pellets, I can't wait to try out the NOE WC -vs- Sage bunnies.

Tia,
Don

[laughing] Bunnies beware! The sting of the dragonfly is swift and fatal!

[splitbeing]

I got a 30fps gain with 19g pellets after oiling the pump tube (behind the o-ring).

Interesting that the passages are sized (stock) more for .177. Curious to know what a .177 is seeing for fps...

A valve with more volume might get this pumper even more power, but how many more pumps would that require?

 Next, try 20 pumps?

Here are some mps numbers from a recent comparison between two hammer springs (stayed with stock). Will do a before lube after lube test tonight if able.  Mine is a DF I in .177.

[Nvreloader]

SB
LOL.......
I hope so, not too sure about this DFII, sometimes, she is throwing out some curveballs,
with a couple inside sliders thrown in for good measure.
But, I am hard on her trail.......

Once the new valve gets here, I can do some careful measurements and planning
on the inlet and poppet seals. I just have to know...........

Tia,
Don

[laughing] Bunnies beware! The sting of the dragonfly is swift and fatal!

[nervoustrigger]

Regarding the valve volume, you may want to search up Bob’s guidance on the sweet spot for pumpers.  If memory serves, it’s somewhere in the range of 1/3 to 1/2 of the barrel volume.  So for example if the .22 barrel is 20in long, its volume is about 0.74ci.  Meaning a valve whose volume is larger than about 0.37ci is running hard into the wall of diminishing returns.  You indicated the current valve is closer to 1.04ci so it’s already quite large.  So installing an even larger valve…well it might be fun and educational to see how it turns out, but not so much for casual everyday use because of all the pumping necessary to adequately pressurize it.

[splitbeing]

Here's the DF I .177 numbers.  I redid pump numbers 6 and 7 on the lube again! third test, thinking I didn't fully extend the arm when pumping. The redo numbers suggest I was correct in that regard. Overall, a 10 to 20 fps increase on most pumps from lubing.


Also, I remember getting a couple lighter hammer springs after seeing the home depot spring (stronger than stock) do nothing. The power output from the lighter springs didn't do much good, the stock spring was better across the pumps. Wish I took notes but don't see any. Might have been bad enough I didn't write it diwn, though maybe I didnkt have the notebook.

Regarding fliers, deburring made a big difference but I'm sure you did that, Don!