D34 Pistons

D34 Pistons

Joined: August 16th, 2006, 10:39 pm

June 26th, 2012, 3:14 am #1

How common is it for the piston body to be out of round at latch stem end of almost .011.

Mounted a dial indicator while I had it in a lathe chuck for some polishing. Took measurement with a mic at 90 degree angles to each other and it verified the dial indicators readings.
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Dizz
Dizz

June 26th, 2012, 9:01 am #2

one,but have noticed some slight egg shape.Good fitting buttons would make it a non issue,I would think.You know how it is,a mass produced $200 German gun.
You might find much the same on a HW gun.The UK Webley Patriot had more out of round that you found on your Diana.
Dizz
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Joined: July 24th, 2010, 1:44 am

June 28th, 2012, 2:09 pm #3

How common is it for the piston body to be out of round at latch stem end of almost .011.

Mounted a dial indicator while I had it in a lathe chuck for some polishing. Took measurement with a mic at 90 degree angles to each other and it verified the dial indicators readings.
an R9 piston that had .060 latch rod runout when the piston was spun in my lathe. I've also measured R9 piston diameter variations of .010 along the length and one even had a similar "ovality" at the skirt. LOL....for my home tunes one of the first things I do is to "true up" the piston via "latch rod bending" and "vise squishing a piston skirt into round".

Lately I've started buttoning the skirts of my HW pistons and fitting the buttons to the receiver so "skirt squishing" hasn't been much of an issue.

By the way, the most recent R9 piston I bought last year was really good with a latch rod runout of only .005 and the piston body was real consistent too!
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Joined: September 8th, 2009, 1:53 am

June 28th, 2012, 4:20 pm #4

Here's an aftermarket piston for the HW30 made in India that has the rear "wear ring" to keep the piston skirt from contacting/galling/grinding against the compression tube.

http://target-tune.in/international/pro ... iston.html



Considering that the RWS34 has a known galling problem, I don't understand why someone hasn't come up with a similar design for the 34?

That's what other fine springers have, such as the AirArms TX200III, as well as the new Walther LGV. You'd think either RWS/Diana would update their design, or someone in the aftermarket would see the potential in offering this for the 34...which has gotta be the most common springer out there.



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Joined: August 16th, 2006, 10:39 pm

June 29th, 2012, 3:31 am #5

an R9 piston that had .060 latch rod runout when the piston was spun in my lathe. I've also measured R9 piston diameter variations of .010 along the length and one even had a similar "ovality" at the skirt. LOL....for my home tunes one of the first things I do is to "true up" the piston via "latch rod bending" and "vise squishing a piston skirt into round".

Lately I've started buttoning the skirts of my HW pistons and fitting the buttons to the receiver so "skirt squishing" hasn't been much of an issue.

By the way, the most recent R9 piston I bought last year was really good with a latch rod runout of only .005 and the piston body was real consistent too!
for this price point and usage? Should I worry about it and try and true it up or just have fun and shoot it??

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Joined: December 14th, 2007, 5:44 pm

June 29th, 2012, 11:19 am #6

Tom:

the least the BETTER

BUTTONS help if you are trying to maximize the GLIDE inside the comp tube

warren

and remember "it's 30% the gun and 70% the shooter"
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RedFeather
RedFeather

June 29th, 2012, 10:15 pm #7

How common is it for the piston body to be out of round at latch stem end of almost .011.

Mounted a dial indicator while I had it in a lathe chuck for some polishing. Took measurement with a mic at 90 degree angles to each other and it verified the dial indicators readings.
These are not car pistons. The front end, where the seal is located, seems to be the business end. Buttons will help center the piston and prevent canting which can rob it of some speed. Still, I've yet to hear of one wearing a tube out. Consider the price point for these guns. They are akin to 1950's car engines. Lots of loose tolerances but they still run. Neither one will stand up to a micrometer inspection.

I was just shooting my box stock T05 34 with the standard RWS 4X scope and mount last night. Finally got it benched in the basement - card table with a front rifle rest atop two phone books and nestled upon one of those bead-filled poly pillows. (In this case, a "Peeps" candy brand pink Easter bunny - my "bunny bag", just for S's and G's.) Shot ten rounds of CHP's, cheap from the can. Put them all under a dime. For me, that's pretty good. I ain't obsessing over egg-shaped pistons, seal leakages, pellet fit, etc, etc, ad naseum. KISS, as they say. And all this from a gun that's under $200.
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Joined: December 14th, 2007, 5:44 pm

June 30th, 2012, 5:41 am #8

that last paragraph, puts you in the Hall of Fame of M34 users, LOL

last line: "And all this from a gun that's under $200."

warren

and remember "it's 30% the gun and 70% the shooter"
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Joined: August 16th, 2006, 10:39 pm

June 30th, 2012, 10:46 pm #9

The out of round of the piston is less than .002.

The Compression chamber finish looks like my Vortek honed D54 chamber when it came back from him.

So I guess I'll need to get some butons for the D34K....whose do you recommend?? The JM ones???

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