Square Wave Regulator

It’s not often you get to meet a real inventor, in fact, thinking about it, this is a first for me, but Alan Page is such a rare animal.

The reason I was at Alan’s house was to talk about, photograph and see demonstrated the Square Wave regulator (or reg as most people call them) that he has designed, developed and patented for pre-charged pneumatic air rifles - and now he has put the Square Wave into production.

It’s All a Matter Of Pressure

A quick look at the drawings showed a pretty solidly designed reg, not unlike several I have seen and worked on in the past, but when I ran such names as Korrick, Welham and Cardew past Alan, there was little sign of recognition, at least when it came to regulator design. What this said to me was that Alan has designed this reg straight out of his head, and in doing so has bought a degree of understanding of high pressure air that I have not come across before, hence the name Square Wave, which refers to the way the air is released from the reg when the shot is fired.

As we talked through the design and prototyping processes, I was shown early models made of brass and Delrin, but none had come up to scratch and so once the final design was seen to be working correctly a local company that carry out a wide range of machining processes, including some for military contracts, were engaged to machine up the main parts of the reg in aluminium.

Once the parts come back to Alan and his assistant Simon, they are assembled into working regulators and meticulously calibrated on custom built pressure testers. Only then are they ready to be sent out to customers.

What Do You Get?

Currently there are two models in production; both designed to fit Air Arms rifles. The models demonstrated were both in S200 rifles, a .177 Match rifle and a .22 hunting rifle. The reg will also fit in the S400 range, with a number of other models in development and due for release very soon, keep and eye on the website for updates.

All of the regs are designed either to be owner installed, or installed by a competent gunsmith. There is not really very much to the installation, but you do need some experience and basic workshop tools like a pillar drill. A full set of installation instructions are included with each reg.

It is worth noting that the same reg will happily produce from 6 to 12 ft/lbs without internal adjustment. Adjusting the pressure of the standard hammer spring within the rifle brings about the change in velocity.

Consistency

A lot of testing hours have gone into the development of this little reg and when I asked Alan about the number of shots, he was able to rattle off the numbers without hesitation.

So, using the S200 as an example, in .177 Match rifle form, producing around 7.5ft/lbs, you can expect up to 80 shots for a 200 Bar fill. Take the velocity up to 12 ft/lbs and you will get around 50 shots per fill. In .22 calibre and again at 12 ft/lbs, you can expect around 55 shots per fill. At this point we took Alan’s S200 Match rifle for a meeting with the chrono.

Alan is clearly a meticulous engineer and I was tasked with noting the velocity of every single shot. Unfortunately for Alan, I am a little more slap dash, and so here we have an abbreviated version of the results.

Allowing a couple of shots for the reg to settle in (my decision, not Alan’s) the S200 was soon producing a regular string of shots in the 625 fps range, shot 20 was 625.8, 30 was 631.3, 40 was 633.7, 50 was 638.5, 60 was 640.6 and 70 was 636.5. At around shot 72, the velocities dropped off very steeply, an indication that the reg was no longer involved in the process. The variation over the whole 70 shot test between the fastest and slowest pellet was 18 fps, but as this was with unsorted pellets straight from the tin I don’t think that is too shabby at all and is a measurable improvement over a standard S200.

The .22 hunting version was even more consistent, with several strings of shots producing identical readings. In fact Alan shot a couple of much heavier pellets through the chrono, just to prove it was still working.

I asked about servicing of the reg, as even with the best seals you can get, there are still moving parts involved. Alan thinks that the regs should be good for something like half a
million cycles, but as he has yet to wear any seals out, that is just a rough estimate!

A Masterpiece Of Miniaturisation

What it is difficult to get across in any photo, and especially as I agreed not to take photographs of the working parts of the reg, is how small this little device is, and how tiny the internal parts are.

I have worked on Air Arms regs, as found in the RN10, Pro-Target and EV2 for a goodly number of years, and although the Square Wave reg has a similar basic layout, internally it is a fraction of the size, to the point where it looks like a watchmaker, rather than a precision engineer made the parts. The result of the clever design and miniaturisation is that each shot uses less air. This more than compensates for the room taken up by the body of the reg, which has always been the downside of any after-market installation.

What About The Future?

Well, as I said, there are regs for other rifles currently in development; there are also plans to look at C02 rifles, as the reg will work just as well with CO2 as it will with air.
After that there is the likelihood of maybe a trigger assembly or a complete rifle or any number of other clever ideas that Alan has already drawn up, but not yet prototyped.

My advice is keep a regular eye on Square Wave’s web site, as I’m sure there are some fascinating products on their way.

I would like to thank both Alan and his able assistant Simon Parker for their hospitality during my visit, I especially enjoyed the fine Italian coffee, another area of expertise that Alan has!

The Square Wave Regulator is currently available to fit Air Arms S200 and S400 series in .177 and .22 calibres. The price is £140 and it comes with instructions and a 2 year warranty. You can contact Alan Page on 01747 823981 or buy the regulator from the website www.squarewave-design.co.uk