LR4 4-Inch Sub 250

By ꓘamiKwadze on Mar 21, 2019

3  489  4

This is my first under 5 inch light quad. I originally received this 4 inch frame as a Christmas gift. Unfortunately, the original bottom plate, which had folding arms, was not symmetrical when the arms were folded out. The extra screws needed to have folding arms also made the bottom plate a bit heavy. So, I cut a new bottom plate out of some 3mm CF I had laying around on my router table. I don't think the frame will survive a hard hit, but I do like the design and the space for a double stack. Maybe I'll throw a Caddx Turtle in there someday.
Other than that, the main stack is mounted with 3mm nylon, and the rest of the hardware is titanium with some nylon nuts and standoffs. The main frame standoffs are 20mm aluminum. I built it so I can rip around the backyard a bit with it under reg weight (must use a 650-700mah), or throw on a fat battery when I take it to the fields.
If you are wondering how it performs, it is actually a little beasty...very quick, agile, very balanced CG...punch outs with the larger batteries make me smile ear to ear. I'm using all 4s batts, Tattu 650, Lumenier 700, and Tattu 850. Admittedly the 650 is a little under spec, but it does ok as long as I don't beat it up. I was really impressed with the racerstars...not what I expected for a $10 motor.

Base weight, no battery, no hd cam = 165g



Sign in to comment

RusikFPV   Apr 04, 2020  

Hi! I've got this frame recently. And I want to make Longe Range on this frame. I ordered alluminium bolts, to achieve 40 gramms frame weight. Also I like concept of this frame and I decided to cut with CNC a 5 inch version for LR. I purchased emax 1306 2700kv and also I rewinded 2 of 4 1106 to 2700kv Y15T. I will make comparison indurance test with them.

ꓘamiKwadze   Apr 28, 2020 

Cool Rusik! Let me know how it goes. For the five inch, did you cut the foldable or did you go with a solid plate. Looking forward to seeing the results. This quad had crazy power. A quick punchout would put it out of sight. Very light, very good for an actual long range.

RusikFPV   Apr 28, 2020 

Hi! Still need couple of days to get emax 1306 2700kv from the post service. But today I make couple tests with 1106 2700kv. 5 inch hq5030 biblades shows the same indurance result, as GF 4024 biblades. I need more tweaks and tests. Next I change bearings in this motors, and I will make more stiff 5 inch arms. I did not cut new frame, because of waiting carbon from China.

ꓘamiKwadze   12 days ago 

Nice build Rusik! Did you finish? What kind of flight time are you getting? Dude, you rewind motors?...that is bad ass hardcore! I've been wanting to give it a try, but it seems like such a daunting task.

Guides & Reviews

39 3,807  46
May 05, 2020

This guide will walk you through the process of building your first FPV quad. The goal with this design was to build a low-cost, lightweight quad, yet powerful enough to safely carry a GoPro in close proximity areas. I chose these parts to minimize the amount of soldering at no cost to the quality. A typical build requires around 30 solders while this only needs 25. It's not a huge difference, but..

Read more
28 7,660  38
Nov 30, 2019

In late 2019 DJI made inroads into the FPV scene with their remarkable low-latency digital system. It gave us a 720p video feed with latency on-par with the status quo, analog video. Traditionally we've used analog video systems for low-latency video, but the video quality is far from ideal. It's a trade-off we've been willing to accept for the control. Now we've got the best of both worlds and what..

Read more