Valve mod - pcp pistol - Kiwi Airgunners Forum

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RangerPete View Drop Down

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Posted: 19 Nov 2024 at 5:48pm

Thats really good Pauly

Walk quietly, but carry a big stick.

nunga

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Posted: 25 Nov 2024 at 3:37pm

I found this video on youtube, might be of some use.

https://www.youtube.com/watch?v=cWCf2Tp1Pic

2nd place HP springer - WFTF World Championships 2014

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Posted: 25 Nov 2024 at 3:42pm

Thanks Ian, I had actually watched that on Saturday.

I would be keep to give the threading a go as opposed to pinning the valves. I am cautious with all that pressure, so until I have seen the correct calculations from a competent person, I wouldn't try it.

nunga

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Posted: 25 Nov 2024 at 4:49pm

yeah you need to be very careful with the threads. Pinning is the safer way to go for sure.

1 psi = 0.070306958 kilogram-force/sq. cm
1 kilogram-force/sq. cm = 14.2233433071 psi

Example: convert 15 psi to kilogram-force/sq. cm:
15 psi = 15 × 0.070306958 kilogram-force/sq. cm = 1.0546043695 kilogram-force/sq. cm

So 3000PSI equals 210.9KG of force.

2nd place HP springer - WFTF World Championships 2014

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Posted: 03 Dec 2024 at 10:18pm

Work has been very busy the last couple of weeks, so progress has been slow. I have also had issues drilling and tapping this damn stainless probe. I thought I had it sorted, but I now think I had the drill speed too fast.

I also bought myself some decent metal cutting paste too.

Anyway, one thing I bought off FB marketplace was a Rotring drawing board for $30. When I was at school I loved Technical drawing and used to have a similar board. I have a few of my parts hand drawn, so now I can draw them to scale.

When making the part, I can now concentrate on the making rather than design and turning at the same time.

The probe is on it's 3 rd design change now and I am pretty sure this is going to work. I also made the hammer which you can see in the photo.

It is made from steel, but has a delrin skirt that is just a touch bigger, so it runs on the delrin. Aluminium is quite a sticky material and the delrin solves the friction between the steel and alu, especially when cocking. In my other pistols I have had to generously lube the tube to overcome this issue.

I also started on the grip, doing a trial run using some birch ply glued together. I plan on making the grip from some walnut I have. So I'll update that once I get into it properly.

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Posted: 03 Dec 2024 at 10:31pm

Probly is to fast pauly.
Was watching video a week or so back and dude was having trouble with the drill hardening stainless around holes. Apparently stainless tempers at very low heats.
Might have to set up cutting fluid bottle with gravity feed and flow adjustment or something to keep temp down

kruzaroad

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Posted: 03 Dec 2024 at 10:39pm

Just had nosey on web.
Starts at around 400° depending on stainless. Recomends a cutting fluid, breaks to let metal cool if drilling to long and this
Use a drill bit designed for stainless steel
Use a cobalt or titanium nitride (TiN) coated high speed steel (HSS) drill bit with a 135° point.
Begin drilling at a lower speed, around 30-60 surface feet per minute (SFM).

Edited by kruzaroad - 03 Dec 2024 at 10:42pm

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Posted: 03 Dec 2024 at 11:11pm

Thanks Kruz. Yea, I now have a couple of cobalt 4.2 mm bits on the way with the 135 deg point. I was probably spinning the drill at around 1000 rpm, so far too fast. I did a test hole at around 400 rpm and it was day and night.

I got RTD metal cutting compound. Its a paste that sticks to the bit as opposed to flooding it.

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Posted: 03 Dec 2024 at 11:19pm

Yeah but the flooding pulls heat away from the metal and drill constantly, which im assuming a paste wouldn't, or at least as well.

nunga

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Posted: 18 hours 17 minutes ago at 2:43pm

Hard steel equals very slow drill speeds and use thread cutting paste with it. The slower you go the better. High speeds will only burn out your drill bit and work harden the metal even more. Those gold coated so called titanium bits are crap. Only good for soft metals like alloy.

2nd place HP springer - WFTF World Championships 2014

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RangerPete Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 18 Apr 2023 Location: Cambridge. Status: Offline Posts: 895	Post Options Post Reply Quote RangerPete Report Post Thanks(0) Quote Reply Posted: 19 Nov 2024 at 5:48pm
	Thats really good Pauly
	Walk quietly, but carry a big stick.

nunga Members Profile Send Private Message Find Members Posts Visit Members Homepage Add to Buddy List Forum Moderator Joined: 08 Mar 2013 Location: Pukekohe Status: Offline Posts: 1014	Post Options Post Reply Quote nunga Report Post Thanks(0) Quote Reply Posted: 25 Nov 2024 at 3:37pm
	I found this video on youtube, might be of some use. https://www.youtube.com/watch?v=cWCf2Tp1Pic
	2nd place HP springer - WFTF World Championships 2014

Pauly5 Members Profile Send Private Message Find Members Posts Add to Buddy List Forum Moderator Joined: 10 Mar 2013 Location: Titahi Bay Status: Offline Posts: 1426	Post Options Post Reply Quote Pauly5 Report Post Thanks(0) Quote Reply Posted: 25 Nov 2024 at 3:42pm
	Thanks Ian, I had actually watched that on Saturday. I would be keep to give the threading a go as opposed to pinning the valves. I am cautious with all that pressure, so until I have seen the correct calculations from a competent person, I wouldn't try it.

nunga Members Profile Send Private Message Find Members Posts Visit Members Homepage Add to Buddy List Forum Moderator Joined: 08 Mar 2013 Location: Pukekohe Status: Offline Posts: 1014	Post Options Post Reply Quote nunga Report Post Thanks(0) Quote Reply Posted: 25 Nov 2024 at 4:49pm
	yeah you need to be very careful with the threads. Pinning is the safer way to go for sure. 1 psi = 0.070306958 kilogram-force/sq. cm 1 kilogram-force/sq. cm = 14.2233433071 psi Example: convert 15 psi to kilogram-force/sq. cm: 15 psi = 15 × 0.070306958 kilogram-force/sq. cm = 1.0546043695 kilogram-force/sq. cm So 3000PSI equals 210.9KG of force.
	2nd place HP springer - WFTF World Championships 2014

Pauly5 Members Profile Send Private Message Find Members Posts Add to Buddy List Forum Moderator Joined: 10 Mar 2013 Location: Titahi Bay Status: Offline Posts: 1426	Post Options Post Reply Quote Pauly5 Report Post Thanks(0) Quote Reply Posted: 03 Dec 2024 at 10:18pm
	Work has been very busy the last couple of weeks, so progress has been slow. I have also had issues drilling and tapping this damn stainless probe. I thought I had it sorted, but I now think I had the drill speed too fast. I also bought myself some decent metal cutting paste too. Anyway, one thing I bought off FB marketplace was a Rotring drawing board for $30. When I was at school I loved Technical drawing and used to have a similar board. I have a few of my parts hand drawn, so now I can draw them to scale. When making the part, I can now concentrate on the making rather than design and turning at the same time. The probe is on it's 3 rd design change now and I am pretty sure this is going to work. I also made the hammer which you can see in the photo. It is made from steel, but has a delrin skirt that is just a touch bigger, so it runs on the delrin. Aluminium is quite a sticky material and the delrin solves the friction between the steel and alu, especially when cocking. In my other pistols I have had to generously lube the tube to overcome this issue. I also started on the grip, doing a trial run using some birch ply glued together. I plan on making the grip from some walnut I have. So I'll update that once I get into it properly.

kruzaroad Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 02 Jul 2022 Location: Hastings 4 now Status: Offline Posts: 2306	Post Options Post Reply Quote kruzaroad Report Post Thanks(0) Quote Reply Posted: 03 Dec 2024 at 10:31pm
	Probly is to fast pauly. Was watching video a week or so back and dude was having trouble with the drill hardening stainless around holes. Apparently stainless tempers at very low heats. Might have to set up cutting fluid bottle with gravity feed and flow adjustment or something to keep temp down

kruzaroad Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 02 Jul 2022 Location: Hastings 4 now Status: Offline Posts: 2306	Post Options Post Reply Quote kruzaroad Report Post Thanks(0) Quote Reply Posted: 03 Dec 2024 at 10:39pm
	Just had nosey on web. Starts at around 400° depending on stainless. Recomends a cutting fluid, breaks to let metal cool if drilling to long and this Use a drill bit designed for stainless steel Use a cobalt or titanium nitride (TiN) coated high speed steel (HSS) drill bit with a 135° point. Begin drilling at a lower speed, around 30-60 surface feet per minute (SFM). Edited by kruzaroad - 03 Dec 2024 at 10:42pm

Pauly5 Members Profile Send Private Message Find Members Posts Add to Buddy List Forum Moderator Joined: 10 Mar 2013 Location: Titahi Bay Status: Offline Posts: 1426	Post Options Post Reply Quote Pauly5 Report Post Thanks(0) Quote Reply Posted: 03 Dec 2024 at 11:11pm
	Thanks Kruz. Yea, I now have a couple of cobalt 4.2 mm bits on the way with the 135 deg point. I was probably spinning the drill at around 1000 rpm, so far too fast. I did a test hole at around 400 rpm and it was day and night. I got RTD metal cutting compound. Its a paste that sticks to the bit as opposed to flooding it.

kruzaroad Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 02 Jul 2022 Location: Hastings 4 now Status: Offline Posts: 2306	Post Options Post Reply Quote kruzaroad Report Post Thanks(0) Quote Reply Posted: 03 Dec 2024 at 11:19pm
	Yeah but the flooding pulls heat away from the metal and drill constantly, which im assuming a paste wouldn't, or at least as well.

nunga Members Profile Send Private Message Find Members Posts Visit Members Homepage Add to Buddy List Forum Moderator Joined: 08 Mar 2013 Location: Pukekohe Status: Offline Posts: 1014	Post Options Post Reply Quote nunga Report Post Thanks(0) Quote Reply Posted: 18 hours 17 minutes ago at 2:43pm
	Hard steel equals very slow drill speeds and use thread cutting paste with it. The slower you go the better. High speeds will only burn out your drill bit and work harden the metal even more. Those gold coated so called titanium bits are crap. Only good for soft metals like alloy.
	2nd place HP springer - WFTF World Championships 2014