Kiwi Airgunners Homepage
Forum Home Forum Home > Technical > Pauly's Technical Area
  New Posts New Posts RSS Feed - Valve mod - pcp pistol
  FAQ FAQ  Forum Search   Register Register  Login Login

Valve mod - pcp pistol

 Post Reply Post Reply Page  <1 456
Author
Message
Pauly5 View Drop Down
Forum Moderator
Forum Moderator
Avatar

Joined: 10 Mar 2013
Location: Titahi Bay
Status: Offline
Posts: 1439
Post Options Post Options   Thanks (0) Thanks(0)   Quote Pauly5 Quote  Post ReplyReply Direct Link To This Post Posted: 04 Dec 2024 at 3:49pm
I had a good drill bit, but too much speed. Have got a couple of good 135 deg cobalt bits from Sulco now.

Appreciate the help guys.
Back to Top
Pauly5 View Drop Down
Forum Moderator
Forum Moderator
Avatar

Joined: 10 Mar 2013
Location: Titahi Bay
Status: Offline
Posts: 1439
Post Options Post Options   Thanks (0) Thanks(0)   Quote Pauly5 Quote  Post ReplyReply Direct Link To This Post Posted: 05 Dec 2024 at 10:01am
Quick update on drilling. New bits arrived, halved drill speed, used new paste and it cuts like butter. 

What a relief, I was starting to hate stainless.
Back to Top
kruzaroad View Drop Down
Senior Member
Senior Member
Avatar

Joined: 02 Jul 2022
Location: Hastings 4 now
Status: Offline
Posts: 2359
Post Options Post Options   Thanks (0) Thanks(0)   Quote kruzaroad Quote  Post ReplyReply Direct Link To This Post Posted: 05 Dec 2024 at 10:25am
Lol.
Sweet Pauly. Be a shame to have to use a less durable metal.
Looking forward to progress resaults on pistols now you've beaten this problem.
Back to Top
JasonEdward View Drop Down
Senior Member
Senior Member


Joined: 21 Sep 2024
Location: Waihi
Status: Offline
Posts: 125
Post Options Post Options   Thanks (0) Thanks(0)   Quote JasonEdward Quote  Post ReplyReply Direct Link To This Post Posted: 05 Dec 2024 at 12:24pm
Yeah I thought a nice sharp drill was all i needed to drill S/S.
Blunted drills, hardened stainless and a fitter mate taught me the error of my ways.

Cry
Back to Top
BC_Clark View Drop Down
Member
Member


Joined: 15 Feb 2024
Location: Auckland
Status: Offline
Posts: 7
Post Options Post Options   Thanks (0) Thanks(0)   Quote BC_Clark Quote  Post ReplyReply Direct Link To This Post Posted: 23 Dec 2024 at 8:48pm
Looking good Pauly. Pity about the radius cutter not being as advertised.

The inlet screw does not really need the flat down the side and it causes more stress on the o-ring
to force it around a non-round shape. The air flows past a regular screw anyway
but if you must fill faster you can get a similar effect by oversizing the tap drill to 4.5 for M5 and 
leave the screw standard.

When you have stainless parts with a lot of machining time in them and the fastener
isn't working close to its capacity, it is advised to use larger tap drills to avoid broken taps.
Just adding 0.1mm can go from from walking on ice, to a walk in the park.

Anyone not having fun with stainless should try 303 grade for machining.
Not only stronger than 304 and 316 but much nicer to machine.

Back to Top
BC_Clark View Drop Down
Member
Member


Joined: 15 Feb 2024
Location: Auckland
Status: Offline
Posts: 7
Post Options Post Options   Thanks (0) Thanks(0)   Quote BC_Clark Quote  Post ReplyReply Direct Link To This Post Posted: 23 Dec 2024 at 9:11pm
The main thing with drilling stainless is high feed and lower speed.
It is not the heat that hardens stainless. Regular 304 and 316 are non heat-hardenable.
They only become softer with heat. But they work-harden very readily (316 moreso).
So applying too little pressure to the drill causes it to skim along the surface
without starting a chip. This work-hardens the surface you're trying to drill.

The problem with heat is that it blunts the cutting edge of the drill
which leads to work-hardening of the stainless, accelerating the issue.
HSS with cobalt can handle higher temperature.
Back to Top
 Post Reply Post Reply Page  <1 456
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 10.14
Copyright ©2001-2012 Web Wiz Ltd.

This page was generated in 0.064 seconds.