Build Details (Apr 26, 2021)

Here we go again, this is another Source One v3 deadcat 7” with 2807 motors. The key takeaway from this are the larger motors. I was very happy with the performance of the 2507 motors in my previous builds, but it is worth it to go with the larger motors?

I forgot to weigh the 2807 motors before installing them so I took whatever info I found online; the 2807 motors should be 47.6g (1300kV without wires). In comparison to the BH 2507 motors that weighs 39g with long wires. There is another thing that needs to be factored in, and that is the cost. Before Emax hiked up their prices, the 2807 motors were $14.99 each and the BH 2507 motors are around 21.99 – 24.99 each. The Emax Eco II motor in very cheap in cost and only time will tell if the quality reflects the cost. We all know that Brother Hobby’s established a great name for themselves, so you will expect quality motors from them. Because of this, it makes it difficult to decide which motors I should use. That is why I am here today to see what works best for me needs.

As expected, the 2807 motors will draw more amps, resulting in lower flight times. When I did a max flight time test with the Molicel 21700 P42a 4200mah 6S Lithium-Ion pack, it was able cruise for 23 minutes. So, I lost about 3 minutes of flight time, when compared to the BH 2507 motors. Keep in mind none of my test are scientific and many things can skew my results. While cruising around 10 - 20 mph (based on the GPS info on the OSD) the 2807 motor setup was drawing around 9 - 13 amps. I cruised around until the cell voltage drops down to 2.8v.

I built this quad like the last source one (purple tpu), with the DJI Air Unit attached to the top plate with double side tape and m1.6 screws. Normally I would only use double side tape but the 2 screws on the air unit happens to line up with the two standoff holes. So, why not screw the air unit down too. Because I “semi slammed” the quad (25mm standoff, instead of 30mm) the air unit sits right on top of the capacitor. If this becomes a problem, I will need to raise it back up again.

Weight Reduction (Apr 27, 2021)

The weight of this quad it really bothering me, and I need to do something about it. I will start removing the TPU printed arm guards and cap screws. As you can see in the picture, these guys pack on a lot of weight. I saved about 28g by removing these items and replacing it with Titanium cap screws.

Next, I replaced the camera mount with something more conservative. I like the idea of moving the camera forward but to save a few more grams (8g to be more exact) I went with a lighter setup. With these two changes, it has brought down my overall weight to 582g and this has exceeded my sub 600g goal. But I am on a roll and do not plan to stop here.

Since I am on a weight reduction craze, why not switch out the DJI Air Unit to a Caddx Vista. This might be a little more complicated to measure the weight because I must redesign the rear XT60 mount to accommodate the single antenna and I will also need to move the GPS to the top of the GoPro.

Remixed Squirt Parts (Apr 28, 2021)

I was talking to a friend about moving the fpv camera forward and how we like how the GoPro sits on the Shendron Squirt v2. I took the 3D parts that DroneCOproductions designed and remixed it. The width of the Squirt is 27mm (center to center) between the 2 standoffs, and the Source One v3 is 31mm. The easiest was to make this work is add 2mm to each side of the camera mount and nothing else needs to be changed. There are a few more issues I ran in to with this new mount. The camera angle is limited to 0 and 15 degrees… that is a bit too low. Plus, the camera is sitting a lot higher than a typical GoPro mount. To fix these problems I moved the rear pivoting hole up so camera will sit lower and increase the camera angle to 10 and 25 degrees.

Another issue is the length of the 12cm camera wire for the Caddx Vista is too short. I had elongate the mounting holes for the Caddx Vista so the camera can reach the mount.

Videos

Test Flight with Squirt Camera mounts - HQ 7X3.5x3 - CNHL 1500mah 6s

23 Minute Flight Time with Molicel 21700 P42a 4200mah 6S Lithium-Ion