Note: I have not noticed any restriction on positive displacement pumps in the various Big Gun rules, but I amy have missed someone. There is no such restriction in NTXBG. I have actually used gear pumps and diaphragm pumps/ As to the two fears - "something's gotta give" and the pump, tubing, etc. "exploding," frankly, I haven't seen it happen - the motor just stalls our or loads up and slows down. As to overcoming the restrictor (though most of the gear pumps I have used have not had enough flow to need a restrictor at all), again, the motor just loads up and slows down. Gear pumps are somewhat susceptible to debris, though. Mo concern would be that if someone built a grossly overpowered pump with a 550 sized motor and sas able to stAll it out, the 80A+ current draw would either melt the wiring or drain the batteries pretty darned fast. Of course you can adjust the output with a speed controller pretty easily. Cheers
The something giving in your case is that the load exceeds the capacity of the prime mover. The reason that you don't see restrictions on positive displ. pumps in Big Gun or Battlestations is probably related to the fact that they regulate flowrate by gpm, not by a restrictor.
Hmmm. I think we may be kind of on the same page, Tug. Yep, the something that gives is load on the motor. Too heavy a load, the motor slows or stops if the flow is restricted too much for the system. However, regulating flow by GPM as we do in NTXBG means that we often have to add a restrictor to get the flow rate down to spec. Though the positive displacement pumps I have are within GPM capacity specs and need no restriction. Cheers,
Early in my combat time, I did use a windshield pump but.... I found that it was not made for contiuous duty and it burnt up the motor. It did not pump really great but then we were using baby lid pumps (penny pumps) then with dumas 4.8 motors. Marty
