Author Topic: Scratch built pcp........the RB4 (Read 6738 times))

rgb1 · « **on:** January 22, 2018, 05:27:54 PM »

I started making parts more than a year ago and at that point had no idea when the project would wrap up. So rather than do a post now and then to show progress, I decided to show everything at completion. Since there’s quite a bit of info to be presented, actually far too much to show here, let’s take a different approach. I’ve assembled everything into one package and made it available for download here.......

http://104.131.46.156/nextcloud/index.php/s/fNxGjSCX5rILtcD

Unzip it using any compression utility (7zip, winzip) and inside you’ll find several folders…....”schematics”, “parts”, “finished gun” (each with a "read me") and a text file “facts and figures”.
This gun shares common features with another one built and shown in ’09 and, in a manner of speaking, could be considered a pcp version of that earlier work. Long-time members will recall.....

http://www.network54.com/Forum/79537/thread/1257727426/SSP+rifle..........discovering+what's+possible

Edit on 5/29/2018
Due to the poorly executed migration of the network54 Yellow forum
archive by Tapatalk, the above link no longer works but can be replaced by......

https://www.tapatalk.com/groups/yellow/viewtopic.php?f=79537&t=156563&p=1475230&hilit=SSP#p1475230

And, to compound the mess, photo links are gone. The missing pics
can be downloaded as a zipped file here......

http://104.131.46.156/nextcloud/index.php/s/QK6GCS6hob17nkt

Regarding that old post, it was recently suggested to me that perhaps more explanation as to how things function inside would have been helpful, the “schematics” folder should take care of that.

Here's a thumbnail......

Ron

Geoff · « **Reply #1 on:** January 22, 2018, 06:23:19 PM »

looks nice Ron ... i dont have time to read the ZIP right now, though will snag it to peek .. thanks

dv8eod · « **Reply #2 on:** January 22, 2018, 08:57:28 PM »

Now that is a work of art to me. I love the design of your stock. You have given me an idea for my semi pup. Thank you.

KnifeMaker · « **Reply #3 on:** January 23, 2018, 01:21:54 AM »

Nice-Nice_Nice!

Knife

renowntwo · « **Reply #4 on:** January 23, 2018, 10:47:26 AM »

Well done.

lefteyeshot · « **Reply #5 on:** January 23, 2018, 11:40:36 AM »

Can you get it in .20cal.

QVTom · « **Reply #6 on:** January 23, 2018, 12:04:09 PM »

Beautiful work and documentation! Interesting valve design; you certainly didn't take the easy road

Tom

Finn · « **Reply #7 on:** January 23, 2018, 03:03:42 PM »

Always nice to see scratch built guns, how is the reliability/accuracy. Have you been happy with the design or is there anything you would change?

vanTeunenbroek · « **Reply #8 on:** January 23, 2018, 03:54:46 PM »

Wow.. Impressed!
Always wanted to build my own PCP,made plenty drawings over time but lack of machines and to busy at work to really get stuck in.
Would love to have machining skills like that..
Must be nothing like shooting something you've made yourself.
I know catching a fish on a lure you made from scratch feels quite satisfactory but shooting your own made gun and maybe getting something for the pot must be quite something else!

rgb1 · « **Reply #9 on:** January 23, 2018, 10:38:04 PM »

I sincerely appreciate all the positive comments.
If there's anything you want to know, just ask.

Finn, I've had little chance to play with the new
toy but nevertheless I doubt there is anything
I would want to change.

Ron

Duane38 · « **Reply #10 on:** January 24, 2018, 09:56:45 PM »

Ron! You're not mentioning that it is a 'dump valve PCP' - that has been conversations of yore elsewhere, "...it can't be done..." sort of business. A great deal of talk on the other forum once upon a time.

I see how it works. Very ingenious. Using the natural effect of surface areas and how air pressures affect them. Your given design may work very well in a big bore too. Say, 9mm/357.

WyoMan · « **Reply #11 on:** January 25, 2018, 12:18:09 AM »

Wow!... just wow!
I hope you don't mind a copy and paste of your pictures but I need them for a question or two...

In this state, the pellet is loaded but the thumb button is not closed. The valve is open but sees no pressure because the fill valve is closed?

Next picture, the fill valve has filled the firing charge. The precharged displacer pressure is at reg set point. The valve is balanced with a bias
to open becuase of the larger piston diameter at the rear. The sear keeps the valve from opening. So closing the exhaust valve (manually)
opens the fill valve? And the opening of the exhaust valve (upon sear release) closes the fill valve?

I might have it all wrong but I've never seen anything like this before... Thanks for sharing the details, Ron

Phil... I see what you mean about the dump valve.. but with a twist... the firing charge has a pre-charged buttress -

Thanks-

Wyo

Rob M · « **Reply #12 on:** January 25, 2018, 12:39:02 AM »

went through the pics, ill have to read the cliffs notes.. AMAZING LOOKING GUN . nice work.. ( reminds me a schematic I saw for a pressure differential valve on a QEV gun on youtube..) sudden pressure drop causes instant firing.

Gippeto · « **Reply #13 on:** January 25, 2018, 12:47:37 AM »

You do nice work Ron, glad to see you still at it.

Phil...you might find the GC2 of interest as well...it was Ron who provided me with the Patent information back when I was looking for it.

http://www.airgunforum.ca/forums/topic41824.html

AL

rgb1 · « **Reply #14 on:** January 25, 2018, 02:10:16 PM »

Philip, I see no reason why it couldn't be scaled up to a larger caliber.

Gary, you are understanding it correctly.

Al, thanks for the compliment, I try to stay "at it" as much as I can.

Ron

subscriber · « **Reply #15 on:** August 03, 2022, 01:02:47 AM »

Ron,

This is another brilliantly conceived and executed custom design of yours. Your thinking goes well beyond out of the box. You must have as much patience as you do, talent.

oldpro · « **Reply #16 on:** August 04, 2022, 04:56:11 PM »

WOW

How did I miss this thread!!! Amazing work...Outstanding

subscriber · « **Reply #17 on:** August 04, 2022, 05:51:32 PM »

I am not sure what path I followed that led me to it. It was new to me too. Only noticed the date after posting.

sb327 · « **Reply #18 on:** August 04, 2022, 07:02:54 PM »

It is a really nice piece of work. Glad you dug up the thread. Enjoyed it.

Dave

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Scratch built pcp........the RB4

Author Topic: Scratch built pcp........the RB4 (Read 6738 times))