In the 120mm to 127mm size class of fans, there are two fans claiming to produce 29 pounds of thrust (equivalent to a P-120 sized turbine). All the rest of the fans in this class produce much less thrust. The DS-94 HST with the 700kv motor and the XPS conversion of the Dynamax fan.

Here are the spec's for both fans:

<span id="result_box" lang="en"><span class="hps">DS</span><span class="atn">-94-</span><span>DIA</span> <span class="hps">HST</span> <span class="hps">with</span> <span class="hps">DSM6745</span><span>-700
I</span><span class="hps">nner</span> <span class="hps">diameter:</span> <span class="hps">128 mm</span>
<span class="hps">Fan Swept Area</span><span>: 94</span> <span class="hps">cm^2</span>
<span class="hps">Weight including</span> <span class="hps">motor</span><span class="hps">:</span> <span class="hps">1330g (2.9 lbs)</span>
<span class="hps">Thrust Range</span><span>: 22.5 to 29.2 lbs (100-130</span> <span class="hps">N)</span>
<span>Exit Velocity (Efflux):</span> <span class="hps">210 - 241 mph</span>
<span class="hps">RPM:</span> <span class="hps">28,000 - 30,500
Amps: not given but calculated based on cell count and watts: 144A to 182A</span>
<span>Input Watts:</span> <span class="hps">6.6 to 9.7</span> <span class="hps">kW
Number of Cells: 12S to 14S

<span id="result_box" lang="en"><span>XPS Dynamax Pro II
I</span><span class="hps">nner</span> <span class="hps">diameter:</span> <span class="hps">128 mm</span>
<span class="hps">Fan Swept Area</span><span>: not given</span>
<span class="hps">Weight including</span> <span class="hps">motor</span><span class="hps">:</span> not given but from other threads it was stated at over 3 pounds
<span class="hps">Thrust Range: 29 lbs</span>
<span>Exit Velocity (Efflux): not given</span>
<span class="hps">RPM:</span> 36,250<span class="hps">
Amps: 205A</span>
<span>Input Watts:</span> not given but calculated based on cell count and amps: 12.5 kW<span class="hps">
Number of Cells: 16S</span></span>

So, the comparison shows the following when each fan produces 29 lbs of thrust:
- The DS-94 runs at a lower amp draw than the Dynamax
- The DS-94 runs on 14 cells vs the Dynamax running on 16 cells
- The DS-94 runs at 5750 rpms less than the Dynamax
- The DS-94 consumes 2.8 kW less than the Dynamax
- The DS-94 weighs less than the Dynamax

The comparison shows the DS-94 is a lighter <font color="#000000">setup</font> (fan weighs less and less number of cells required) with longer flight times (less amp draw and less kw consumed) when using the same amount of mAh. The DS-94 is not as low cost as some of the other fans recommended but take a look at the photos below and you will see that German quality is second to none. This weekend, weather permitting, I will be maidening a 35 pound 1/6th scale Hawker Hunter that is powered with the DS-94 HST. It will be the largest and heaviest EDF to fly with a fan in the 120mm - 127mm size class to date.

If you want to go bigger, the TF-8000 is 140mm fan that will produce 30 pounds of thrust in the 5 balded version and 40 pounds of thrust in the multi-bladed version.

Here are some photos of the DS-94 HST. The last one is of the TF-8000. If you're interested in the TF-8000 send me a PM.

Kirk</span></span>