LoPro 164 Mini Quad for up to 3.75" props by andimon

Last crawled date: 3 years ago

Meet v1 of the LoPro 164 mini quad for up to 3.75" props. This is my first frame design, so I thought it would be best to share it with you guys. The frame is a low profile design, optimizing battery position for better center of gravity. The frame has a 6mm depth and counterbored holes for bottom screws. The mid plate allows for a 850 mah 3s or 4s battery, but I should push back the XT30 plug for a little more room (note revised V2 mid plate). This design is for 1306 or 1407 motors, and the frame offers a little bit of protection for them. There are mounting holes for both flight controller sizes, so you can run an ultra low setup with arm mounted escs, or do a short stack with a 4in1 like I did.
I printed the main frame with Raptor PLA at 90% triangular infill. Baked at 215 degrees for 10 minutes for max strength. Its not very light– I would need to continue tweaking infill percentage to dial in a more lightweight option. Seriously, this frame seems bombproof though.
Components used in the build–
-RCX 1306 3200kv
-Racerstar 20A V2 4in1
-FuriousFPV Radiance
-DSMX Lemon diversity
-Hawkeye 200mw VTX
-Eachine 1000tvl cam
-Cam mount here - http://www.thingiverse.com/thing:1110726
-TrueBlood antenna flex mount - get from RMRC
-xt30 power connector and plate - get from Banggood (don't have to use)
-Gemfan Nylon 3545 props - I have a few different kinds to try. A slightly cut down 4" prop might work well.
-Standoff lengths used in photos– 20mm between main frame and mid plate, 35mm in front, and 13 between mid and top plates.
I will try to get the quad out this weekend for a maiden flight and some DVR FPV. Please, if you decide to print this frame, post your photos so I can see your builds! If you have any suggestions about the frame, please let me know. I'd love to hear back from you guys who can experiment with an optimal infill percentage for the best possible strength to weight ratio. I hope you enjoy!
UPDATE (02/11/17) – Maiden flight is linked below. A few notes about my personal build– 3.5 inch props definitely have more thrust than 3 in, but the motors are surely pulling more current. It flies smooth and balanced, but I need to tune my D settings to soften up the sticks. I need a little more space to fly before really opening up the throttle. Until then, more balanced props should take care of the cam vibration. I don't care for the Gemfan Nylon 3545 props– they seem fragile and unbalanced. I think cutting down DalProps V2 4045 (efficient) props might be a better solution (gotta try my tri-blades).https://www.youtube.com/watch?v=M6bk6dnnM-s&feature=youtu.be
UPDATE (02/13/17) – I trimmed down a Dalprops 4045 v2 to 3.75" and it just barely fits inside the back of the frame. I will need to relocate the zip tie antenna mount in order for the prop to fully swing past the frame. I have not flown these props yet, but they seem way more efficient than the bullnose 3.5". I posted a photo so you can see the prop clearance.
UPDATE (03/07/17) – I made some modifications to the mid plate with the V2 release. The antenna ziptie mounts have been moved forward, allowing for more prop clearance (for 3.75" props). The XT30 battery plug mount has been moved backwards to allow for more battery space. The mid plate thickness is the same as V1, but I decided to print it at 3mm for slightly more strength. Lastly, I posted another photo of the LoPro with DalProps V2 (efficient) 4045 tri-blades cut down to 3.75." It was raining today, so I didn't have a chance to fly. Hopefully I can provide some more DVR footage soon. I just received some Nylon Alloy 910 filament and intend to test a lower infill frame print.
UPDATE (03/28/17) – I was able to get out and rip around a larger property with the LoPro. It is quite nimble at high speed but still need to tune a bit. I will print a PETG frame this week and load it up with 4000kv red bottoms. See the FPV clip below–https://youtu.be/ab0Oe-vOBUg
UPDATE (04/16/17) – LoPro rebuild complete. The frame was printed in Nylon Alloy 910 for extra strength and lower weight due to optimized infill (60% triangular). Nylon was dyed and then baked for 10 hours at 170 degrees F. Militia Brothers 3530 props, a direct solder antenna, and RS1306 4000kv motors round out the build. It feels at least 25-30 grams lighter than the first build. I hope to maiden it Easter weekend.
UPDATE (04/16/17) – Maiden flight went well with better PIDs and rates adjustment. I still need to tweak a few things here to smooth stick movement. The incorrect cam color is based on a new lens I am trying out (2.5). It does not have the little glass piece on the back of the lens like the original that comes with the 1000TVL. I will replace this glass piece to fix the color. The motors offer smooth power.https://www.youtube.com/watch?v=pXOblt_CiUI&feature=youtu.be