Spool valves have a bad rep for cold weather preformance. This experiment aimed to solve the reason why this is the case or if this myth has any merit to it. The ion based platforms of the xe and sp-1 were used at temperatures of 18.8, -4 and -19 degrees celcius. No bolt stick issues were observed and the markers were functioning at all temperatures.
Cold weather is an issue to paintball players playing outdoors during winter months. Spool valve markers such as the extcy, g4, and g1/envy/vibe have been getting a bad reputation as failing to function properly in cold weather environments. In this experiment I aimed to solve the reason this myth is based on, if any, by isolating variables that might affect the marker from functioning properly. The main culprit blamed was bolt stick due to the larger surface area of the o-rings and the fact that it uses grease instead of oil which might congeal at lower temperatures,
3 brand new duracel alkaline 9v batteries were bought and taken from the same box. A sp-1 blackheart was used, a stock sp1 and an ion xe with techt bolt were used. All were lubed with dow 33 as per manual. With adjustable boards, dwell was set as per instruction (5ms above critical)
First treatment - Each setup ( battery, marker and tank) were placed outdoors at a temperature of -4 degrees celcius for no less than 40 minutes. At the end of the cooling period the cold battery was connected and the marker was fired 10 times with paint with the eyes on (if present) and 10 times with eyes off.
Second treatment - Each setup was placed in the freezer fat a temperature of -19 degrees celcius for no less than 40 min. At the end of the cooling period the cold battery was connected and the marker was fired 10 times with paint with the eyes on (if present) and 10 times with eyes off.
Control: Each setup was fired at room temperature to assure proper funtion before and after treatments.
Battery isolation experiment: batteries were placed in freezers and tested with room temperature setups. These were regular 9v duracels from the experiment, as well as full and 3/4 discharged NiMh 9.6v 230 mah rechargable batteries.
All markers operated normally at all temperatures in each of the treatments. No bolt stick was observed and markers chronoed normally. It is to be noted that some leaking was observed at the banjos at -19 degrees for the ion xe, but the marker still operated correctly.
All batteries in the Battery isolation experiment worked with the exception of the 3/4 discharge Nimh 9.6 volt at -19C. This battery led to the bolt travelling half way every 2-3 shots. It is to be noted that this same battery operated normally under room temperature conditions.
The myth that spools dont operate well in cold weather sems unwarranted in light of the data above. Particularly the blame on the "bolt stick" due to the grease or the larger o-ring surface area. The grease is designed to operate effectively in temperatures as low as -73 degrees celcius, so it shouldnt congeal or not lubricate as designed. (1). In the experiment the markers operated with no evidence of bolt stick or bolt slow down under factory conditions with a new battery.
My original hypothesis was that the battery might be to blame for this phenomenon. So that is why I included the battery as part of the setup in each treatment, each battery getting to temperature. But still, each setup preforemed well. The only instance where the setup skipped shots was the 3/4 discharged 9.6 volt (may have been more discharged, 3/4 is conservative). And the marker was at room temperature. This suggests that it is the battery to blame.
In fact, batteries reduce power output in colder weather. Alkalines are more succeptable, and Li ion is the least to cold weather. If the battery is really drained, this may result in power starvation leading little current to operate the solenoid correctly.(2) This may result in the false diagnosis of bolt stick as the bolt might not make a full cycle.
But why spools? Wouldnt popits be affected by this too? Yes, popits can be affected the same way, but spools are slightly more succeptable as they have higher dwells on average than popits, and this required more power as the solenoid remains open for longer.
What can you do? Keep your batteries fresh and name brand during the cold, or keep them warm. As you can see, a fresh alkaline can operate well in -19C with no issues. A 3/4 or more discharged battery will have issues at that temerature so warming is neccisary if your running used batteries. I havent tested below -20C because It is unsafe to be outdoors in that temperature. Furthermore, one of these markers may fail to operate (board turns on, but solenoid does not trip) if the battery is too low in regular temperatures, so replacing you battery with a fresh one is essential.
Hope this helps for those who play in the winter.
Edited by Danny D, 13 January 2012 - 10:31 PM.