Why The Colossus 2 Under-Performs And How To Fix It

[jja]

From experience of using the Colossus 2 during JJA Duels and in other tests such as Duelfest it's performance has seemed to be underwhelming, being defeated decisively by blasters it ought to do better against (namely the Gorgon, the original Colossus and Python 2). As such i have done some testing and investigating into the internals to see what might be the issue. I think i have a plausible reason why it under-performs. The issue is the placement of the pump inlet/over pressure outlet pipe in the pressure chamber., this is a significant design flaw

Explanation

Note the position of the inlet of the tube from the pump - it is at the front of the pressure chamber. This means when the blaster is angled slightly up it is a the top of the pressure chamber. Therefore when pumped to full pressure and the pressure release valve opens, the blaster vents air back into the reservoir, not water. This means that some of the Air powering the blaster is lost, especially if one keeps pumping once the pressure release valve activates. Pre-charging is so important in separate pressure chamber blasters. But in the Colossus 2 this pre-charge is eventually lost and may only serve to mitigate the air loss each time the PRV kicks in. More pumps of pre-charge means there is more air to lose - this helps to a degree but is not a final fix. I noticed the air loss due to finding that the reservoir was becoming slightly pressurized by the vented air, an audible hiss was heard when opening the screw cap, sort of like opening a soda bottle. Has anyone else noticed this?

Other Separate PC Air pressure blasters like the original Colossus and Gorgon have the pump inlet/Pressure release outlet at the bottom of the PC - so do not suffer from this problem - this may be why they perform better. Looking at internals on Hydrowar the Water warriors Charger appears to have a similar configuration to the C2 so may also have this effect.

Colossus 2 PC


Colossus 2 PC open left side


Colossus 2 PC open right side


Colossus 2 PC open back


Drawing of the arrangement of the pressure chamber showing the outlets and inlets


How To Solve this Issue
the pump inlet/pressure release outlet needs to feed from the bottom of the PC so it moves water not air. this can be done in a few ways. I will be doing one of these mods to my friends colossus 2 once i have talked him through it.

Option 1
add a length tubing to the pump inlet/pressure release outlet parallel to the firing valve outlet to draw water from the bottom of the chamber when the PRV kicks in (the purple tubing in this image)


Option 2
move the pump inlet/pressure release outlet so it connects with and shares use of the firing valve outlet and plug the existing inlet/outlet

[marauder]

You did some awesome research! I did not even notice the tank being pressurized, however I've only used it 2 or 3 times before I started my own modifications. The diagrams are great. What if you added a check valve to pump inlet? That would keep pressure from going back into the tank.

[Redd]

I have also noticed an audible hissing coming from the C2 when unscrewing it after use, was sort of confused. Good work

[jja]

@Maurader - adding a check valve would solve the air release but would stop the Pressure release valve from working - it would be easier just to disable the PRV but this would be risky as there would be no safety system. ultimately adding plain tubing is the cheapest and likely most effective option

I elected do the first option - adding tubing as it does not prevent trying option 2 in future if the mod fails. Here is how i went about it:

First i cut the intake attachment along the red line as shown - making sure to cut in the middle so there is plastic to attach a cuff to later. keeping the cut off part to use later.


Next i drilled the inlet hole the same diameter as the tubing that i will add (4.5mm). I checked this size would fit inside to opening of the pressure chamber. Then i inserted the tubing into the hole and pushed it in till it was touching the pink tubing that leads to the pull valve. I then used long-nose pliers and twisting and pulling by hand to draw the tubing though. i did this till the tubing was the same length as the outlet tubing. I then glued the tubing in place


Then clipped the tubing outside the PC to about 1cm, and drilled the hole in the cut off piece of the intake attachment to 4.5mm to accommodate the stub of tubing still showing. Then i slid a ring of red plastic over the stub of the attachment on the pressure chamber and glued this in place. Finally i glued the cut off piece of the intake attachment in place, sliding it over the stub of tubing and inside the red plastic ring. You may notice that the ring cracked slightly when i did this as it was a little too tight but i don't think this will matter as this is a structural support not a sealed component.


Once this has had time for the glue to dry properly i shall test it to see whether the performance has changed or not. Hopefully the new parts will hold pressure where required. The tubing i used is a little narrower than the tubing in the colossus 2 but the inner diameter is about the same as the plastic fittings joining the tubing so hopefully flow when pumping will be unaffected as reduced flow would make pumping slower/harder.

[jja]

The new parts hold pressure perfectly. As i thought the narrower tubing does not make pumping stiffer or harder, i could discern no difference when pumping. The modification does exactly what I intended - Air is no longer vented into the reservoir. This means the colossus 2 performs much more consistently.

To test the effectiveness of this modification I fought a rematch against the Gorgon as round 4 of JJA Duels

Round 4 Colossus 2 (PC intake mod, Nozzle drill and 30 pumps of pre-charge) Vs Gorgon (30 pumps of pre-charge)

This Rematch was fought to test the effectiveness of my PC intake mod described here http://waterwar.net/forum/viewtopic.php ... 672#p60672. Similar rematches with the modded Colossus 2 will likely to occur to test validity of the improved results seen in this battle.

Results Gorgon 8, Colossus 2 7

round 1 (i have the Colossus 2) Gorgon 3, Colossus 2 5
round 2 (i have the Gorgon) Gorgon 5, Colossus 2 2

Analysis last time these guns battled the Gorgon smashed the Colossus 2 10 to 3, this time things were much more even. The Gorgon is still much more powerful than the colossus 2, but its additional weight and bulk slow the user down. The Gorgon has a stiff pump but that didn't seem to be a great issue in battle. The modification to the Colossus 2 ensures greater consistency of power as the battle progresses. Before one had a short window of opportunity to make hits before too much air was vented into the reservoir, once that expired the colossus 2 no longer could challenge the Gorgon. Now the Colossus 2 does not vent air the window of opportunity is extended throughout the entire battle as it is quite easy to keep the colossus 2 at full power as it tap-pumps at 1-1 (perhaps better). With full power available most of the time the colossus 2 can defend well against the gorgon, also it can take advantage of more opportunities to go on the offensive,and is more deadly when doing so than before modification.

[marauder]

Wow, very impressive. Shows that the mod really made a difference.