some tuning on the plinkster( build thread ill keep goin )

some tuning on the plinkster( build thread ill keep goin )

Joined: April 28th, 2010, 12:23 am

February 4th, 2017, 11:19 pm #1

so far ive opened up the transfer port, the barrel and the valve port to .153.. that did nothing.. Then i wet sanded the lead in on the barrel , that made cycling a dream.. Ive been messing with hammer springs, but theres really no room at the back for binding or coiling up, so i ground 1/8th inch off the hammer so the sear engages a bit earlier.. I tried the 760 and disco hammer springs, Yes they work but the length isnt right, so I just ordered a paintball hammer spring that Im familiar with and can be cut to length.. ( explaining the hammer spring constriction is hard unless you have one.. HERES THE VALVE pic



Anyway.. what I did was measure how much preload was on the valve stem.. Then , to add volume and reduce preload all at once i simply chucked it in the lathe, took a mm at the back wall , reassembled , and repeated till i felt a reduction in force to open the valve.. SO far soo good and I can still go further.. I did not have a good spring to substitute the stock valve spring , but when I do , that will be a huge gain.. I then proceded to part off most of the valve threads, they are not part of the seal , and again , a tiny gain in volume..
My stock numbers were 605 peak , and quickly dropped off to 585 ish for the rest of the usable string.. I just shot a crosman premier at 667fps for the first shot , and then leveled off in the 640s.. So im making progress. With the lighter valve stem spring , and longer hammer spring ,. I should be able to reach my 700 goal.Oddly , shot count hasnt changed noticeably , well yet'
.153 port job doesnt take much material , maybe .020


Last edited by robnewyork on February 13th, 2017, 12:54 am, edited 1 time in total.
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Joined: March 26th, 2008, 2:38 am

February 5th, 2017, 6:30 pm #2

Premiers were they, the 7.9 or 10.5s?

God bless,

Farmer
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Joined: April 28th, 2010, 12:23 am

February 5th, 2017, 6:36 pm #3



since the hammer impacts the valve and the stem is soo short, to increase the duration of the shot , i shaved .040 off the back of the valve thus increasing dwell time.. Time to go outside and chrony now.. The obvious risk now with the lighter valve spring installed and the preloaded hammer spring , is the valve will leak while not cocked , easily reversible..ALL WORKED perfect, 670 fps high, then settles into the low 650s and high 640s ,so the settled numbers are better, even if the peak is only 3-4 fps higherr.. if i wait a min between shots 667 popped back up.. Im LOVING THIS GUN.. really responsive to these small tunes..USable shots is still over 30 (600fps+
IM now at 678 fps high.. Not too shabby from the 605 starting point.

and as i go along , im upgrading hardware, need to get some cap heads black , but these lil things take 4 mins so why not have imperial pitch with better grade steel



AND AGAIN , more volume , numbers still sitting the 650 average range with peak 670

Last edited by robnewyork on February 5th, 2017, 10:15 pm, edited 1 time in total.
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Joined: March 28th, 2002, 6:54 pm

February 6th, 2017, 3:22 am #4

which is why you don't see less shots with higher average power.

Unless you see evidence of the striker hitting the valve body under normal pressures, trimming the back wont do anything but encourage leaks (shorter bearing area for the valve stem)the impact you mentioned..at normal fill pressure?

With the valve head down in a pocket like that one, more wall clearance will boost power...it wont take much increase at all.

Is the poppet really a cone base on a cone seat, like it appears in the pics?
Last edited by classicalgas on February 6th, 2017, 3:25 am, edited 1 time in total.
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Joined: April 28th, 2010, 12:23 am

February 6th, 2017, 5:26 am #5

also, the gun Does crash the hammer into valve from the factory.. so i am getting more stem travel now id assume... ive not reduced the length of the " shelf" where to the 2 cones meet.. Didnt do much for numbers.. Im leveled off for now .. what im trying to figure out is why my peak number stays the same , yet my 10 shot average goes up ( shots 2 through 10 have a higher average, but shot 1 on fresh co2 is the same)
Last edited by robnewyork on February 6th, 2017, 6:46 pm, edited 1 time in total.
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Joined: April 28th, 2010, 12:23 am

February 6th, 2017, 6:56 pm #6

i got 805 but im not believing it , because i think the cloud caused the reading and nothing else has even been in the mid 700s.. NEW paintball hammer spring today!
Last edited by robnewyork on February 8th, 2017, 3:09 pm, edited 1 time in total.
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Joined: October 14th, 2003, 4:56 am

February 9th, 2017, 7:24 am #7

so far ive opened up the transfer port, the barrel and the valve port to .153.. that did nothing.. Then i wet sanded the lead in on the barrel , that made cycling a dream.. Ive been messing with hammer springs, but theres really no room at the back for binding or coiling up, so i ground 1/8th inch off the hammer so the sear engages a bit earlier.. I tried the 760 and disco hammer springs, Yes they work but the length isnt right, so I just ordered a paintball hammer spring that Im familiar with and can be cut to length.. ( explaining the hammer spring constriction is hard unless you have one.. HERES THE VALVE pic



Anyway.. what I did was measure how much preload was on the valve stem.. Then , to add volume and reduce preload all at once i simply chucked it in the lathe, took a mm at the back wall , reassembled , and repeated till i felt a reduction in force to open the valve.. SO far soo good and I can still go further.. I did not have a good spring to substitute the stock valve spring , but when I do , that will be a huge gain.. I then proceded to part off most of the valve threads, they are not part of the seal , and again , a tiny gain in volume..
My stock numbers were 605 peak , and quickly dropped off to 585 ish for the rest of the usable string.. I just shot a crosman premier at 667fps for the first shot , and then leveled off in the 640s.. So im making progress. With the lighter valve stem spring , and longer hammer spring ,. I should be able to reach my 700 goal.Oddly , shot count hasnt changed noticeably , well yet'
.153 port job doesnt take much material , maybe .020

Not doing much in an effort to increase velocity; just making sure the stock internals are cleaned up and polished where need be.

As you mention you did on yours, I polished the lead in on the chamber. Also lapped the port and throat to remove any burrs. Lightly polished the bolt. Smooth as glass now.

3 set screws holding the barrel to the receiver were really tight (center one had loctite on it) and they kicked up burrs on the OD of the barrel. The burrs scratched the anodizing on the ID of the receiver a bit as I removed the barrel. No biggie; I polished the mating surfaces.

Striker - I polished the two areas on the OD where it bears on the ID of the tube, as well as the angle where it meets the sear upon cocking. ID where the spring rides was a little rough and had some heat treat scale in it. Polished that up and radiused the "mouth" where the spring enters.

Tube - After cleaning (excessive) grease out I noticed what looked like minor corrosion, and little bumps on the ID in the area where the trigger housing is welded on. A little polishing with a flex-hone cleaned it up easily though. Slot where the bolt's cocking screw rides was a little rough, so I polished it up.

Trigger assembly - All parts looked good (after I cleaned off all the grease). I stoned the sear lightly where it contacts the striker. Minor trigger blade side play was easily corrected by squeezing its housing with pliers.

Valve - Looks beautiful as is (modding optional).

Transfer port - Bullet proof.

Co2 retaining cap - Perfect.

Magazine/single-shot tray - No issues.

Stock - Fabulous. Great fit & finish (comb is a bit high for stock sights if you have a fat head like mine. but great for a scope).

Be advised that the above-mentioned minor negative details are the nitpiking of an aerospace Quality Assurance dude. This is a fantastic little rifle with tons of potential.

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Joined: April 28th, 2010, 12:23 am

February 9th, 2017, 2:23 pm #8






not much to mod really , unless looking for power gains./ Smoothing out the lead and the bolt really makes cycling nice.. I may chamfer the inlet to the magazine where the bolt passes so it will be somewhat self centering and perahps smooth that a bit .. Pretty crazy a gun for this much money doesnt really need much in the way of repairs
Last edited by robnewyork on February 10th, 2017, 12:42 am, edited 1 time in total.
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Joined: April 28th, 2010, 12:23 am

February 10th, 2017, 12:42 am #9



made this from carbon fiber and delrin , ridiculously quiet.. not that i needed it quiet, just for kicks
Last edited by robnewyork on February 10th, 2017, 10:15 pm, edited 1 time in total.
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Joined: April 28th, 2010, 12:23 am

February 12th, 2017, 5:52 am #10



this will have a gauge and a drop down asa p[aintball adapter this week,then ill be able to fill the gun 5 different ways
hpa regged tank
co2 tank
12 gram
88 gram
stock co2 arrangement ( which i may bypass )



need to add 2 .750 orings
Last edited by robnewyork on February 12th, 2017, 2:32 pm, edited 1 time in total.
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