Theoben Rapid Forum

KevG Lathe work undertaken => kevG section => Topic started by: martini1215 on March 01, 2024, 10:48:18 AM

Title: Regulator Setup on a Rapid
Post by: martini1215 on March 01, 2024, 10:48:18 AM
Gooood morning from a wonderfully rainy Cleethorpes, roll on summer lets get some of these great British puddles dried up.
I gained a rapid Mk 2 and at first is was shooting OK although it did have a loss of air pressure at pressure testing so I went along with it and just topped up before shooting.
Anyway I am an avid tinkerer and tried putting it over the chrono which has proved I can get no more than 8 and a bit Ft/lb from the gun as I reported in an earlier thread which you kindly replied to Kev.
You did mention setting the pressure to 1500 psi but I would be first to admit a tinkerer I may be but an engineer I am not.
Is there anyone on here who takes regulators in and gives them the TLC required and who would set it up for me please and if so what is the normal charge and are they in England?
Many Thanks for any help advised Regards Neil
Title: Re: Regulator Setup on a Rapid
Post by: angrybear on March 01, 2024, 12:04:07 PM
You could buy a reg tester & set them yourself  ;) It's fairly simple (although Kev is the expert)
setting the pressure is just screwing the nylock-nut down while holding the core with a hex key.
This sets the pressure the reg allows to pass before it seals the bottle, a tester allows you to see that pressure & set it to the required level.

Have you checked the technical section for a set-up guide ?
Title: Re: Regulator Setup on a Rapid
Post by: martini1215 on March 01, 2024, 01:50:38 PM
No I haven't looked in the technical section yet.
I have been playing round with a couple of guns tat need resealing and also shooting a few rounds through my 1918 Lee Enfield.
Its strange you retire early thinking you will have more time to play with and find you are even busier.
Many thanks for the reply now I will try to find out where to get a tester from.
Regards Neil
Title: Re: Regulator Setup on a Rapid
Post by: Brooksy on March 01, 2024, 02:22:01 PM
You can do it without a tester. To be honest, 1500 PSI should be more than enough pressure. Have you tried inserting a washer behind the hammer spring guide as a first port of call?
Title: Re: Regulator Setup on a Rapid
Post by: Ca_Varminter on March 01, 2024, 04:01:39 PM
There are 2 ways of checking the Reg's cutoff pressure...
Using a reg tester, like the one by Dr Bob..
(https://photos.imageevent.com/scl_electronics/gun/air/websize/regtester_1_.jpg)
It connects to you filling tank...using it's gauge

Or you can connect a Gauge to the bottom of the block where the Blanking plug is located on the MKII..
You will need a 1/4" Bspp fitting to attach to your Rapid.
(https://photos.imageevent.com/scl_electronics/gun/air/websize/guage.jpg)

Good Luck
Stuart
Title: Re: Regulator Setup on a Rapid
Post by: Kernal on March 01, 2024, 06:47:54 PM
If your struggling and need a reg tester i have one i can lend you as long as you send it back when done  :)
Title: Re: Regulator Setup on a Rapid
Post by: martini1215 on March 01, 2024, 09:19:29 PM
Oh you would definitely get it back and in good condition still.
I just need to work out what to do with it when it gets here.
I ll have a read around and see if I think it within my capabilities and if it is then yes please I would be very grateful.
Regards Neil
Title: Re: Regulator Setup on a Rapid
Post by: Ca_Varminter on March 02, 2024, 12:04:14 AM
Using Dr Bobs Reg test is very EZ...
One end has 1/8"Bspp thread, the other is 3/8" Bspp to fit the Regulator.
So attached the Testor with the required plumbing to you decant setup.
Now screw in your reg to the Other side.

With your  Tank Decant, main valve and bleeder valve are closed..
Screw in a fully pressurized buddy-bottle to the reg.
Once it pressurizes, you decant gauge will show the cutoff pressure you Regulator is set at.
You can Verify this pressure by bleeding off some air with the bleeder valve on the decant setup.

So now to get the reg off the tester.. unscrew the buddy-bottle 1 1/2 turns.
Open the decanter bleeder valve to depressurize the setup
You can now remove the buddy-bottle and regulator.
Adjust as needed and repeat

Good Luck
Stuart
Title: Re: Regulator Setup on a Rapid
Post by: martini1215 on March 02, 2024, 09:57:34 AM
So I use the tester to see what pressure the reg is set at, bleed any dead pressure off then take the reg out, wind the nylock nut tighter onto the core if the pressure is low to increase(back it off to decrease pressure) then reassemble and pressurise to check what I have reset it to?
Sorry if I seem dim I have never played with a regulator on an airgun.
Many thanks Neil
Title: Re: Regulator Setup on a Rapid
Post by: Millingman on March 02, 2024, 10:57:09 AM
It's easy, check pressure, bleed pressure as described by Stuart, wind in nut to increase pressure, use a torx t15 bit for (Kevg reg) to hold the centre of the reg while adjusting the nut, older regs might have an allen key.
Recheck untill 1500psi or 93.4bar.
Title: Re: Regulator Setup on a Rapid
Post by: angrybear on March 02, 2024, 12:55:08 PM
Quote from: martini1215 on March 02, 2024, 09:57:34 AMSo I use the tester to see what pressure the reg is set at, bleed any dead pressure off then take the reg out, wind the nylock nut tighter onto the core if the pressure is low to increase(back it off to decrease pressure) then reassemble and pressurise to check what I have reset it to?
Sorry if I seem dim I have never played with a regulator on an airgun.
Many thanks Neil

This may help, the blue nut sets the operating pressure, the red ring sets the opening gap at the green arrow between the reg core & the bottle pip.

With no belvile washers/nut screw the reg shaft down with the red ring until it has 0.5-0.7mm play on to the bottle pip, (the O ring is to hold the red ring in position)
fit the belvile's ()()() the spacer & the nut, Hold the shaft with a hex key in the end,  as the nut is screwed down it tries to compress the belviles (between the blue & red) where they act as a spring lifting the shaft off the pip which sets the pressure the pip seal opens/closes.
once the air pressure from the buddy bottle equals the sping pressure from the belviles it closes the shaft/pip seal at the green arrow & the rifle chamber now contains the pre-set operating pressure, the more the blue nut is tightened the more pressure the belviles are under & the more air pressure is needed to overcome it & close the seal at the pip, the more air pressure the more muzzle energy.
It will only take a couple of flats on the nut to go from 8ftlb to 12ftlb.
Once the buddy bottle pressure drops below the belvile spring pressure  the green seal remains open & the rifle goes "off reg" using whatever pressure is left in the bottle.

Title: Re: Regulator Setup on a Rapid
Post by: Ca_Varminter on March 02, 2024, 04:12:16 PM
Quote from: martini1215 on March 02, 2024, 09:57:34 AMSo I use the tester to see what pressure the reg is set at, bleed any dead pressure off then take the reg out, wind the nylock nut tighter onto the core if the pressure is low to increase(back it off to decrease pressure) then reassemble and pressurise to check what I have reset it to?
Sorry if I seem dim I have never played with a regulator on an airgun.
Many thanks Neil
(https://photos.imageevent.com/scl_electronics/gun/air/websize/rapidreg4_1_.jpg)
Your have the basics down..
You tighten the Nylock nut to increase Reg pressure
You loosen the Nylock nut to decrease Reg pressure

Good Luck,
Stuart
Title: Re: Regulator Setup on a Rapid
Post by: KevG on March 02, 2024, 04:21:44 PM
bloody hell Stuart that picture still around😁
kevG
Title: Re: Regulator Setup on a Rapid
Post by: Ca_Varminter on March 02, 2024, 06:01:25 PM
:o  :o  :o  :o  :o  :o
Hey KevG..
Yes I still have that Moldy Oldie...You know how many Rapid owner it has helped through the years!!
Maybe I have to fire up my photoshop, I think the Rabid Zombie Fox should join in!!
(https://photos.imageevent.com/scl_electronics/gun/misc/websize/kevgws21.jpg)

Take Care M8
Stuart