Introduction: The ICD 'Cat Family Getting Started: Tips for a New Owner    Bobcat Exploded View and Schematic    Puma Exploded View and Schematic    Thundercat/Alleycat Exploded View and Schematic 'Cat Theory of Operation and Differences    'Cat Theory of Operation    Differences: The 'Cats    Differences: Other ICD Markers Tweaks: Things you can do for your 'Cat    Trigger Work    Bolt Polishing    Adding a Rear Trigger Stop Accessories: Aftermarket Parts for the 'Cats Links: 'Cat Info on the Internet

'Cat Theory of Operation

Indian Creek Designs' semi-automatic Cat series all use an inline bolt and hammer with a unique vertical valve and open-bolt blow-back operation. 'Open-bolt' means the bolt is normally open so that a paintball can drop into the chamber at any time. 'Blow-back' means that the bolt moves forward under spring power, and gas pressure released from the valve during firing also pushes the bolt back against the mainspring force to re-cock the gun for the next shot.   Since the special inline bolt and valve assembly are hidden inside the marker, you cannot see the little dance of parts as each cycle is completed. OK, so 'Theory of Operation' sounds pretty technical. I could write a really long and complicated description of the movements that would be really hard to understand. Nahhh. So here it is, one step at a time...     The forward (right, above) side screw blocks the air jet to the bolt and controls velocity, along with the preload adjustment on the mainspring. The rear side screw blocks the air jet into the recock area of the hammer.   The Mainspring Adjustment at the back of the marker controls how much force is imparted to the valve when the Hammer Ring strikes it, and how long it stays open. These markers seems to cycle better with a little finagling; reducing the mainspring preload and opening the Velocity and Recock screws is more gas efficient and will reduce wear on the mechanism (and give a smoother shooting marker). Follow the ICD setup procedure for initial positions and work from there.   Once you get everything dialed in, a broken-in 'Cat with a polished hammer will give amazing consistency; better than other low-priced markers, even better than most high-priced markers. Reports of plus or minus 3 feet per second are common. That means you can set your gun closer to the field limit with less fear of 'hot gun' issues, and have better range and accuracy.

Differences: Model Changes in ICD 'Cat Markers

ICD Panther Jerry Dobbins originated the vertical valve design in the ICD Panther, which looks identical to a Puma. I've never actually seen one of these, much less taken it apart, so I'm not sure of anything about this marker.     ICD Puma The second generation Panther was renamed Puma. It had the now-classic ICD vertical valve semi-automatic blow-back operation with dual ASA adapters, front and rear. It and the Bobcat were introduced together, and share almost all components. All valve parts are interchangeable with newer models. The Puma and Bobcat receivers do have a few unique features from the later Thundercat and Alleycat markers. The lower receiver is taller and heavier. The grip flange and trigger guard are machined in one piece into the frame, later models went to two parts to reduce material waste. The upper receiver has two large ribs that fit into deep square grooves in the lower receiver, with the frame screws threaded into the thicker sections. These guns are very strong with complicated milling, and were expensive (US$300.00+).   The vertical adapter on the Puma can be rotated 180° to point forward so the user could mount the CO2 tank running under the barrel like a VM68. Not the best location for keeping liquid out, but interesting. It came with a 10 inch barrel and the original foam grip over the barrel connection.     ICD Bobcat The Bobcat was the sibling model of the Puma, both were introduced in 1994. It was intended as a short and maneuverable marker, with a 7 inch barrel and no rear ASA connection. The Bobcat had a special vertical adapter, called a 'Vertical Angled Tank System', or VATS. The theory of the VATS was that it angled the tank back towards the grip, which placed it under the center of gravity for the gun and made it more stable without the rear stock-like bottle position. The Bobcat also came with both a Lonestar M-16 grip and an aluminum 45 grip adapter with rubber side panels. The lower receiver has the same deep location grooves of the Puma and the same heavy one-piece construction.     ICD Thundercat and Alleycat The Puma and Bobcat were re-engineered and cost reduced to produce the Thundercat and Alleycat. Once the new models were in full production the old models were phased out in 1998, though some are still available as 'new old stock'. The valve and and inline hammer and bolt for all these markers are interchangeable with each other and, except for the hammer, with the Puma and Bobcat. Most cost reductions were made in the design and milling of the receivers. The lower receiver is shallower so the grip is closer to the barrel and the center of gravity is lowered. The trigger guard and grip mounting flange are milled as a separate part and attached with bolts hidden under the sear. The safety was redesigned to run through a hole in the trigger instead of blocking the front tip of the trigger lever as in the Puma and Bobcat. This safety design was also used for the Desert Fox. The vertical ASA adapter was moved from the angled front of the lower receiver when the height was reduced to attach directly in front of the trigger guard beneath the valve.   The Thundercat is ICD's in-house model. Instead of different names for each model, ICD now uses code letters like ES, and offers 'Deluxe' models with added aftermarket parts like expansion chambers, 45 grips, splash anodizing, and bottomline adapters. Some Thundercats have rear ASA connections, some don't.   The Alleycat is distributed only through National Paintball Supply, which provides wholesale guns and parts to most paintball retailers and mailorder outfits. So the Alleycat has broader marketing presence than other ICD markers. It has a 7 inch barrel in place of the normal 10 inch ICD barrel, but otherwise seems identical to the Thundercat, with front and rear ASA connections. The standard grip is the 'Eurogrip', which is mounted like the M-16 style grips on other 'Cats.

Differences: Other ICD Markers

ICD Classic Desert Fox The Desert Fox looks very similar to the blow-back ICD markers, but has a very different internal design. It functions much like an improved Automag; an open-bolt blow-forward design. Like the 'Cats, 'open-bolt' means the bolt is normally open so that a paintball can drop into the chamber at any time (though double feeding is normally prevented by a stop that holds the chambered round in place below the powerfeed). 'Blow-forward' means that the bolt moves forward under air power when the trigger is pulled, and the mainspring pushes the bolt back after the air is released to re-cock the gun for the next shot. Velocity is controlled via an integrated regulator. Increasing the regulated air pressure in the air chamber increases the energy transfered to the paintball. The advantages of the blow-forward design include higher Rate of Fife (ROF), less reciprocating mass to reduce recoil and marker jump while firing, and very consistent shot-to-shot velocity.   The original, or 'Classic' Desert Fox had a more complicated valve assembly which included an On/off valve to shut off the flow from the regulator while the bolt was released. In the earliest models this On/off used a ball-bearing seal which was troublesome, it was later replaced with a poppet-style seal, and all older valves are replaced when sent into ICD for repairs with the newer and more reliable design. The Classic 'Fox also had a rear ASA mount and an optional front-mount vertical ASA connection (which was useful for preventing liquid from entering the regulator and a common upgrade).     ICD 98 Desert Fox The Desert Fox was redesigned in 1998 to remove the On/off and reduce the chamber pressure of the marker. Low pressure operation is a hot feature in paintball, as many feel the larger volume, lower energy air pulse gives better accuracy and [slightly] longer range. For a detailed description of the operation of the 98 Desert Fox see Fox Tweaks: Regulator Theory and Tuning. The newer version also comes equiped with 45 grips, a double trigger, and removed the rear ASA for a vertical mount with swappable connections (1/8 inch NPT connections can be moved to either side of the marker, or a hose can be directly attached at the rear of the trigger frame).   98 Desert Fox: Main Page     ICD Bushmaster 2000 In Spring of 1999 ICD released yet another all new marker, the Bushmaster 2000. The B2k is an electronically controlled pneumatic design with solenoid valve control and built-in variable fire modes (semi-auto, multi-shot burst modes, or full auto), and variable firing rate (up to 10 balls per second). It was designed to compete with the new high-end electronic tournament guns like the Angel and Shocker.

Links: 'Cat info on this Site

Introduction: The ICD 'Cat Family Getting Started: Tips for a New Owner 'Cat Theory of Operation and Differences    Bobcat Exploded View and Schematic    Puma Exploded View and Schematic    Thundercat/Alleycat Exploded View and Schematic Tweaks: Things you can do for your 'Cat    Trigger Work    Bolt Polishing    Adding a Rear Trigger Stop Accessories: Aftermarket Parts for the 'Cats Links: 'Cat Info on the Internet   ICD 98 Desert Fox ICD Barrels: Aftermarket Barrel Review Basic Airsmithing Links to ICD Resources on the Web

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All Graphics and HTML Copyright © 1999 pRCarter and Cognitive Event Horizon. All Text Copyright © 1999 pRCarter and Cognitive Event Horizon, except as noted. All rights reserved.   Indian Creek Designs, and the Panther, Puma, Bobcat, Thundercat, and Alleycat are registered trademarks of Indian Creek Designs of Nampa, Idaho. Teflon is a registered trademark for PTFE manufactured by the Dupont Corporation.