A look at Shocker Turbo Mode.

 
A video capture of the oscilloscope software running on Mike Scott's notebook PC. The red line expresses the input voltage value with its vertical position over a period of time. When it is flat up high, it represents +3 volts. Voltage drops to 0 volts are represented as downward spikes, and continuous switch contact is the lower flat line at 0 volts. 

 
Close-up of the wave form. This wave form was generated by two quick taps on the trigger. What felt like two trigger pulls, when viewed in detail, actually included some very small, and very fast trigger bounces making up 4 clearly visible trigger events (when the voltage drops to 0 volts). It is the inability of the human nervous system to feel movement with this level of detail that has lead to much of the confusion and dispute over the Shocker Turbo Mode. 

The Smart Parts Shocker 

 At the World Cup in 1997 Smart Parts made the Debut of the Shocker Sport 4x4. This paintgun came after the original Shocker which had been manufactured under contract for them by PneuVentures. It is lighter weight than the original Shocker, easier to maintain, capable of higher rates of fire, and includes 3 shot burst and full automatic modes (which can be locked out with a tourney cap). Through 1998, the Shocker has gained quite a following with its low pressure operation allowing it to fire quietly with less ball breakage and according to Smart Parts, giving it better accuracy and range. 

The Controversy 

At the Challenge Cup in June of 1998, a few of the All Americans (Smart Parts factory team) drew some attention when their Shockers fired in a very distinctive pattern, "pop! pop! popopopop!" Quietly, and quickly, there were whispered allegations that they had a secret way to get the Shocker to fire fully automatic in violation of the tournament rules. 

At the Chicago NPPL tournament, later in the month, similar allegations were brought out in the open, as Bob Long, Jerry Braun, and other pro team captains protested the All Americans' use of this new Shocker feature known as Turbo Mode. After firing the Turbo equipped shockers themselves, some people came away convinced that it was a true NPPL defined semi-automatic, firing one shot per trigger pull, while others said that no, it was not. The terms "trigger bounce" and "switch bounce" started floating around, describing what was going on inside the Shocker Turbo to allow such a rapid, steady rate of fire. It was decided that further study was necessary to make a determination, and the use of the Turbo Shockers was allowed at that tournament. 

In August of 1998, at the Xtreme Media Group sponsored Paintball Industry Conference (held one day prior to the start of the Zap International Amateur Open) the topic of firepower, and how much is too much was put forward and openly debated. Field owners, store owners and paintgun manufacturers discussed the pros and cons of high rates of fire. The first to speak was Jack Withers, a field owner from Texas who spoke about the problems he has had with players with high end paintguns overshooting the newbie rental players. An interesting debate ensued, with some people saying that today's high tech semis fire too fast to be safe, and others saying the move toward greater rates of fire was driven by customer demand and thus inevitable. Much of the debate and discussion tended to focus toward the Turbo Shocker. 

The Super Semis 

After the meeting, Bill Gardner of Smart Parts, Tom Kaye of Airgun Designs, John Rice of WDP and Bud Orr of Worr Games Products held a private meeting. They agreed to use the term "Super Semi" to describe paintguns which, through the use of electronics, mechanics, or pneumatics, aided the user in cycling the trigger faster, and thus firing faster than a traditional semi-automatic. Tom Kaye mentioned that new feed systems could be on the market in less than a year capable of reliably feeding paintguns at rates in excess of 19 shots per second, as until now one of the limiting factors in rates of fire has been reliable feed. According to Tom Kaye, in an announcement after the meeting, they agreed that they would not manufacture Super Semis capable of firing more than 13 shots per second. 

Noticeably absent from the group was JJ Brookshire of Brass Eagle. Brookshire did not make any public comments about changing the Rainmaker, which is advertised as capable of firing at 14 shots per second. 

Through later discussions different people had very different views on the Shocker, some claiming that when fired fast it switched modes and fired more balls than trigger pulls, others claiming it was legitimate, one ball per pull, and relied on counting each "bounce" of the trigger as a pull. The Shocker remained the focus of the firepower debate despite it's maximum rate of 11.2 cycles  per second as compared to the manufacturer's claims of 26 on the Automag RT, 15 on the Angel, and 14 on the Rainmaker. 

Turbo Mode Engaged 

While Bill Gardner was a hot commodity at the tournament, embroiled in many a debate, I managed to get him aside for a few minutes to talk about the Shocker Turbo mode. Briefly, he explained that with the electronic switch that is a part of the Shocker's trigger system, the person using the 'gun actually typically closes the electrical circuit at least once and often 3 or 4 times in one large movement of the finger. The trigger "bounces" the switch against its closed position. The Shocker normally ignores the second, third, fourth, etc. trigger events, firing only on the first event. However when it goes into turbo mode, it tries to fire once for every trigger event, no matter how close together in time those events occurred. Typically these events will exceed the 11.2 shot per second limit of the Shocker's firing capability, and several will have to be ignored. 

Bill had started his explanation with "this would be easier to show you in my electronics lab" so when Monday morning (the tournament ended Sunday) rolled around I called up Smart Parts. Bill wasn't in the office yet, but I left a message for him and decided to risk the fact that he might not have time for an unscheduled visit and simply drive over. Latrobe, PA (home of Smart Parts) is about a 40 minute drive from Pittsburgh, and close enough to our route my wife Dawn and I were taking home that it would not be much of a time loss if he wasn't able to fit a demonstration into his schedule. 

Into the lab 

When we arrived at Smart Parts we found a lot of company packed into a little building. Adam Gardner was seated at a desk by the door. Their entry area is full of so many of the All Americans' trophies that they could use a separate building just for display space. 

Bill Gardner came out and took us to the offices in the back. As we made our way through the stacks of bins of barrels, Shocker parts, lathes and honing machines, Bill explained that they had secured a new building, and would be moving over the next few months to have more space for expansion, and to bring the Renegade production facilities under the same roof. A quick walk through the offices in the back, a hello to Karen Barber, and some of the other staff members and then we went into Adam Gardner's office for a demonstration of the Turbo technology. 

Bill Introduced us to Mike Scott, the engineer who designed the Shocker's electronics. He then explained a little background on the Shocker's board. The Circuit board rests inside the lower half of the Shocker's receiver. On its top are banks of DIP switches (small sliding switches in a DIP style integrated circuit package) and assorted electronic components including the board's microprocessor. The shocker uses computer technology rather than analog circuitry, and is literally controlled by a software program. At the front of the board is a three position toggle switch. This normally sticks out of the front of the receiver and is used to select between semi auto, full auto, and burst modes. It is protected from damage by a guard that can be exchanged for a tourney cap, preventing access without tools. On the bottom of the circuit board is an electronic dome switch. This is very similar to the switches used in computer keyboards, and other consumer electronic applications. Gardner explained the function of the switches. 

The first switch he pointed out was the Turbo switch. This switch tells the software to either allow or disallow the use of Turbo Mode. Another group of switches are used to adjust the maximum rate of fire. By changing the on/off combination (that's binary for you computer types) of these switches 8 different maximum fire rates are selectable between 8.2 and 11.2 shots per second, whether in semi auto/turbo, 3 shot burst, or full automatic modes, this governor setting limits how many shots per second the Shocker can shoot. 

"We want to give the customer as many options as possible." Gardner said. If one field doesn't allow Turbo mode the customer can still use the Shocker. If a field says Super Semis shoot too fast, the rate of fire can be restricted to be on par with regular semis on the field. The dip switches can not be accessed by a player on the field, one must use tools to open the receiver in order to set them. This way if a tournament disallows the use of Turbo Mode, a player can not secretly change modes during a game. 

Bill then showed is the I/O portions of the board. Small plugs are mounted on the board for power (the battery pack stored in the grip), an external trigger and the solenoids that drive the 'gun itself.  The reason for the external trigger port is that Smart Parts has thought ahead for disabled athletes who could potentially plug in alternative trigger switches such as breath or head switches.  As someone who has worked in the field of special education and dealt with adaptive equipment for special needs clients all I have to say to that is "Bravo!" 

At this point Bill turned things over to Mike. For the demonstration Mike brought along some special equipment. 
 

• A power supply - We didn't run the board on batteries for the test, it was simple and convenient to use a 3 volt lab power supply. 
• A dual wave form oscilloscope - This was a computer based oscilloscope, and it let us watch two electronic signals simultaneously. Since it was computer based, rather than analog, it was able to freeze a wave form after it happened to let us look at it in detail. The dual wave form generator was critical to comparing the number of trigger events to the number of times the Shocker fired. 
• A wave form generator - This is a device which generates an electronic signal at varying speeds and of varying shapes and intensities. 
• A set of Shocker Solenoids - It was much more convenient to access everything for testing without dealing with the receiver and valves on the table too. Smart Parts has a small box with a set of Shocker valve solenoids mounted in it which they use when testing boards at the factory. It was important that we have these wired into the board for the test, as running the board without the circuit load it normally operates under would be an unrealistic simulation. We needed to run the board the way it runs in the paintgun, on the field.  Also, by the sound of the solenoids operating, it was easy to hear when the board was operating in Turbo Mode.
Trigger Bounce 

The first question I asked was "What is trigger bounce?" First Mike explained the structure of a dome switch. It consists of a metal dome shape which acts as a spring. When the center of the dome is depressed far enough, it touches the contact on the bottom completing an electrical circuit - allowing electricity to flow between the dome and the contact. When the switch is near to making contact the dome is providing quite a bit of spring resistance relative to its size. According  to Bill Gardner the entire distance the dome must be compressed is only 0.005 inches.  Mike explained that while a solid, hard push on the switch, then release will make, and then break electrical contact making one trigger event, a fast tap will cause a situation where the dome shaped spring and the trigger that rest against it will bounce two or more times making, and then breaking, and making electrical contact again, as a series of trigger events. Because the distance involved in this trigger movement is so minute (a fraction of that 0.005" distance), and the length of time involved so short,  it is not possible for many people to feel the bounce. 

Not expecting me to take this on his word, Mike set up the first demonstration. He connected the oscilloscope up to the trigger port on the Shocker circuit board with power and the solenoids attached. The oscilloscope showed a 3 volt signal - a flat line at the 3 volt level. A push of the switch and the voltage level dropped to 0 volts due to the power drain, indicating a trigger event. With a fast tap, the multiple spikes of the multiple trigger events appeared. One major movement of the trigger with a finger actually results in a multiple small taps, a number of trigger events. 

Turbo Engaged 

Bill then explained the concept of Turbo Mode. During normal semi-automatic operation, even if Turbo is turned on, the firing software only responds to the first trigger event in a short series.  If there are two  trigger events from one large movement of the trigger and finger it only fires once. Gardner said that this was for both player safety, and operating in response to the user. If a player wants to fire one shot, they do not need to worry about the fact that they may unintentionally be pulling the trigger two or three times.  One single tap on the trigger fires one shot, even if it bounces and sends two or three trigger events to the microprocessor. 

If the Turbo switch is in the on position, the Shocker can go into Turbo mode. Gardner did not give the exact criteria for what is required for the microprocessor to activate Turbo mode.  He stated  that it was proprietary information, one of their trade secrets. However he did say that the software engages turbo mode when the player shoots number of fast, consistently timed shots.  In Turbo mode, the software reacts to the trigger events differently.  It fires, as normal from the first trigger event in a series. The second trigger event, because it happens so quickly after the first, happens while the Shocker is still in the process of firing the first ball.  The microprocessor recognizes this trigger event and fires the next shot as soon as the Shocker has finished resetting from the first. The microprocessor immediately switches out of Turbo mode if the high rate of trigger pulls is stopped. 

The reason that Turbo mode has been mistaken for full automatic fire is that the timing between shots is perfectly consistent, it is firing as fast as the Shocker is capable of firing, in an attempt to keep up with the trigger events it is receiving from the player using it. That "perfect timing" of a steady 11.2 shots per second coming out of the Shocker sounds exactly the same as if it were firing fully automatic at 11.2 shots per second. The feel of Turbo mode also is deceptive as, due to the trigger bounce, users generate more trigger signals to the microprocessor than they realize, so it can feel as if it is firing more shots than there are trigger events. Without proper test equipment,  one can't see the detailed picture that accurately describes Turbo mode operation. 

Maximum Rate of Fire 

To show that the Shocker doesn't exceed the 11.2 shot per second rate Mike hooked up the wave form generator to the trigger port on the board. He set the generator to a 3 volt square wave at 4 Hertz. This means that the generator would create pulses of  current 4 times per second. These pulses are a square wave, meaning that the current rises and drops off instantaneously, as opposed to a sine wave where the current would smoothly vary back and forth between 0 and three volts.  This wave simulates 4 trigger events per second. Mike fed the trigger port signal to one input on the oscilloscope, and the solenoid output to the other. This put two traces on the oscilloscope software window. The top trace was the trigger input, and the bottom the firing output. Turning on the wave form generator the Shocker board started firing, at a steady 4 shots per second. Clearly on the oscilloscope output, one shot followed each trigger event. He turned up the dial to 5, 6, 7, 8, 9, 10, and 11 Hertz. The Shocker kept up, firing one shot for each trigger event. Then he turned up the generator, 12, 15, and finally 20 events per second. The Shocker never cycled more than 11.2 times per second, that's the top end. 

At this point, they'd completed the demonstrations, and Bill offered to let us fire the Shocker at the test range.  Dawn took him up on the offer, but there was one more test I wanted to see, one they had not volunteered. I asked Mike to remove the wave form generator and manually fire the Shocker, in Turbo mode, so that I could compare the wave form from the trigger to the wave form of the solenoids. This is the real test, this is Turbo Mode as it happens on the field, with a person pulling the trigger. Would it reveal more trigger pulls than shots fired? 

Something doesn't look right 

Mike cycled it a few times, and then faster, and then the Turbo Mode engaged. We looked at the frozen wave forms in the oscilloscope software. On the screen, in a one second time sample, we saw 11 shots, and the start of the next shot (that .2), however we only saw 9 trigger events. 

What happened? Did this prove the Shocker fired more shots than there were trigger events? I have heard that a number of people have performed a similar test with similar results and claimed that it proved conclusively that the Shocker Turbo fired more shots than there were trigger pulls, thus violating the NPPL restriction of one shot per trigger pull. 

The Nyquist Limit 

The problem was the size of the sample. We were missing some important details, and its easy to see how someone who didn't understand the trigger function, or how digital sampling equipment operates could make this sort of assumption. With one whole second's sample on the screen so that we could count the shots per second, we couldn't see the trigger signal with enough detail to distinguish all of the trigger events. There was no hint on the display that what looked like a single trigger event was actually a series of very closely spaced trigger events. 

In technical terms this is because the level of detail we were looking at was below the Nyquist limit of the wave form we were observing. When you take a signal and digitize it, as with a computer based oscilloscope, you need to make certain that the resolution of the digital sample is 2 times greater than the fastest change in the wave form in order to prevent aliasing (signal distortion due to loss of data).  Proper sampling should be made at four times the Nyquist Limit.  In audio, aliasing from undersampling can cause a flat, metalic sound to music, in video it can mean blurred picture quality, or moire patterns.  I knew my senior seminar paper in digital vs. analog signal handling would come in handy someday.  Who knew that a degree in broadcasting would have a crossover application into paintball? 

To put it in plain english we weren't zoomed in enough to see all of the trigger events. Sure enough, if we changed the scale of the sample to one tenth of a second displayed in the window, we could clearly see that there were actually more trigger events than there were shots fired, and that in Turbo Mode the shots fired did not exceed the number of trigger events. Rather, there were more trigger events than there were firing actions. 

Conclusions 

Is the shocker in Turbo Mode too much firepower to have on the field?  Turbo mode or not, the Smart Parts Shocker is not capable of cycling its valve and bolt as fast as some of the other Super Semis which have been on the market for years. 

How much firepower is too much, and how much can a paintgun assist a player to shoot at a higher rate?  That remains to be answered by the paintball insurance companies, field owners, and tournament rule writers. 

Does the Smart Parts Shocker fire more than one shot per trigger event? Not in these tests.  Does it keep firing a series of shots after a person stops pulling the trigger? 

From Bill Gardner and Mike Scott's demonstration I saw that the Shocker is quite versatile, and does provide the player with many options. For fields and tournaments where its firepower is considered too powerful, it can easily be adjusted to comply with limited shot per second and Turbo Mode restrictions, and locked that way for game play.  Shocker owners aren't likely to find semi-auto games where they can't use the paintgun in which they have invested. 

Addendum

Since the initial publication of this article, there has been quite a bit of feedback.  Here are some quotes and comments:

"..when we read your review we were Flabbergasted (shocked) on the first read i personally was looking for the innacurate personal views, then after 3 reads all i found that you had formated a Factual / Comprehensive / intresting / understandable too none eggheads and in fact you even played the Devils Adovocate (think thats how its spelt?) and really looking for the so called "cheat mode".  but all you did was just about teach us here at Paintball Butiken more about the firing system/microswitch/Analog/binary/ cycle rate etc etc etc. than we would have ever been able to learn Basically Bill WELL DONE!!!! you stood up and put your [explicative deleted] on the line by being the first respected Central figure in the paintball world to find the make a atempt at finfing the facts. and we hope that all the other people learn a lesson, unless you really really really know what your talking about
its best too shut up!"

-Simon Applewhaite
on behalf of Scandinavian Paintball butiken
Stockholm 
Sweden

Thanks Simon.  The reason for the article wasn't to solve the debate over what tournaments or fields should or should not allow the Turbo Mode, but rather to explain what the Turbo Mode is, so that people debating its use can do so from an informed standpoint.  A few people have missed that and are convinced that the article is meant to confuse the issue, because it refers to trigger events rather than trigger pulls.  The reason I didn't refer to trigger pulls is that it's difficult to get several people to agree on a definition of what must happen for a trigger pull to take place.  Is the trigger bounce a trigger pull?  That depends on how you define a trigger pull.  Does the Turbo Mode fire more than one ball per pull?  Again that depends on how you define the trigger pull. Unlike the allegations of some, who haven't researched the matter, the Turbo Mode does not go into full automatic - it never fires without receiving a signal from the trigger switch.  A full Automatic fires repeatedly from the time the trigger is pulled until it is released. 

"So what I figure is that the gun 'remember' how many pulls you made and shoot this pulls after you stopped?  So would it be the same if I was able to 'load' my gun with a lot off pulls, lets say im sitting in a bunker pulling the trigger like a mad man and then pop up and the gun just firing by it self, or?"
Magued Idris, 
Team Joy Division
Sweden

No, that is not correct.  If the gun is operating in Turbo Mode, and it senses a trigger event while it is still in the firing process, it will fire once the cycle is completed. It does not store multiple shots. For example if it's in a cycle and it picks up 3 events, it doesn't fire 3 times after the first cycle is done. The longest time delay from a trigger event to a shot fired is 0.089 seconds (based on the 11.2 shot/second limit). If you stop hammering on the trigger, it stops shooting.  The ability to delay one shot is the key to how Turbo Mode works.  A lot of people have said things like "the Angel or Rainmaker can fire in Turbo Mode if you just take out a capacitor or resistor that buffers out the switch bounces".  That's just not true.  The switch bounces happen while the shot is still being fired, without a delay, the paintgun must ignore the bounce, or it will have timing problems. 

However, while the shocker does not work as Magued mentioned  (programming in trigger pulls for firing actions to be played back later), operation like that is legal under under the NPPL rules. The limit is one shot per trigger pull, with no requirement for the time interval between the two events.  Being in the rules is only part of the battle though.  The ultimate judge and tournament promoter in the NPPL can make additional rulings.  For example, at the Portland 1998 NPPL, it was recognized that teams were advanced to the finals in a way that did not match the rules.  The ultimate decided to let it stand because it was consistant with how the other tournaments had been done in the season.  At this year's World Cup, Turbo Mode will be allowed with a rate of fire restriction.  That's not in the NPPL rules, but the promoter is making a ruling that he feels will best serve the players.

"I still have to stick by my original assessment of this whole thing. I think that buffering (if I understood the article correctly) shots and treating unintended bounces on the switch as intended shots is garbage."
-Jon Olkowski

Its acceptability (whether it should be allowed in semi-auto play) really boils down to what tournament promoters and players want. When practical semi autos came out, many people said they were garbage and would not allow them in tournaments.    The same went for constant air (refillable CO2 tanks), and even direct feed and interchangeable barrels.  The original NSG tournament rules only allowed Splatmasters and NelSpot 007s.  The only modifications allowed were changes to the last inch of the barrel, or a pump or extended cocking knob on the NelSpot.  Other model paintguns, or direct feed, constant air, etc., were considered to be technology that was ruining the sport.  Certainly most paintballers have moved on to new technology.  Judging by the back order rate most dealers have on Shockers with Turbo Mode, there are a lot of people out there who like the Turbo Mode (or at least like the Shocker's other features).

Now, if the "garbage" is the idea that the trigger bounces should count as trigger pulls, that seems an arguable point.  Obviously the Gardners at Smart Parts say that the bounce is a trigger pull, but they are not alone.  At the Chicago Open out of about half a dozen pro team owners that I spoke to or heard comments from, half were saying they felt that the bounce, being physical movement of the trigger should count, and half said it didn't.  The definition of a trigger pull is not something that can be measured or metered, it's something that the rulewriters need to agree on. 

As for treating the bounces as intended shots, one could make a strong argument that by turning on Turbo Mode, a person has clearly indicated that they intend for the bounces to be counted.

"In your last 'test,' the one SP didn't volunteer, the trigger was _pulled_ nine times, for eleven-point-two-balls fired, correct? I'm no expert on Tourney Rules, but the debate has centered around the common 'One trigger pull equals one ball fired' ruling. 

"Next up; we start arguing what defines a trigger pull. Is it the single rearward-then-forward-equals-one stroke of the lever the player pulls to actuate the paintgun, or is it the movement of the actual device used to fire the gun, whether it be sear, switch or valve? "
-Barret "Doc" Nickel
Airsmith
Doc's Machine and Airsmith Services

Doc has hit the nail squarely on the head.  Were the nine "trigger pulls" Mike Scott made only 9 trigger pulls each followed by trigger bounces, or were they 9 short series of trigger pulls?  In order to decide if the Shocker Turbo Mode qualifies as semi-automatic one needs to decide if the trigger bounces are trigger pulls, and that depends entirely on the definition of a trigger pull.  In response to the Shocker Turbo Mode, various parties have been busy rewriting rules and definitions.  I read three or four drafts of the National Paintball Association's (paintball insurance company) rules before they went into efffect.  Some required a mimimum distance and amount of pull energy, while others refer to "intentional trigger pulls".  All of the drafts were rather different, each draft reflecting input from a number of people in the paintball industry.  The version that went into effect prevented Turbo Mode and the Reactive Trigger mode of the Automag RT from being used at the 1998 NPPL Portland tournament.  The modified rules for the 1998 World Cup are allowing turbo mode, with a rate of fire limit of 8.75 shots per second.  

"The way I read the write up was that each time the trigger is pulled, there can be as many as 4 trips, or vibrations of the switch, BUT the program, or electronics will only accept 1 of those 'trips' and use it as a trigger event. So with that, I took it as you can slam down the trigger 11.2 times a second, and have as many as 44 trips of the switch, but it only accepts 1 for each trigger pull, and that one becomes the eventual trigger event which actually fires the gun.

"Now what I also read, in my mind was that you could pull the trigger say 33 times a second, and the program, or what ever....I will stick with program, will only receive 11.2 of them a second, and through the rest out, so there
is no 'storage' of shots as rumored!

"Now, even with all the throwing away of trigger pulls or what ever, does it still meet the rules? Well I read the rule as, '1 pull 1 shot', not '1 pull many shots', and not 'many pulls 1 shot' If you see what I mean, then even though there are programmed limits, and throw out of shots does it meet the criteria? 

Actually I think as long as its not '1 pull many shots' it should be allowed, but by the 'letter of the law' then does' many pulls and 1 shot' mean legal?
-Tim Bratton
Captain, Killer Bees

As I've said many a time, the "one pull = many shots" depends on how you define a pull.  You bring up a very interesting point with the many pulls one shot argument.  Most rules that I have read which define semi-auto operation (many don't bother to define it) limit the paintgun to firing one ball per trigger pull, rather than requiring that it must fire one ball per trigger pull.  I have yet to hear of a tournament where a player was penalized for carrying a non-semi-auto because he ran out of paint, pulled the trigger and no ball came out.  There have been stranger things.  The Lively Masters rules used to state that a hit on a player or any of his equipment took you him of the game.   The game changed radically when a team realized that by shooting the loader pods their opposition left in their bunkers they'd make eliminations.