I've tried all sorts of methods to stop my battery sliding around, especially on micro quads where we are limited to particularly crap battery straps like this. Velcro or even duralock was the defacto standard but maintaining these for every battery can be a pain in the arse (IMO) and they wear out. I've found a great (and inexpensive) alternative - the horribly named ​Honana HN-CH014 Sticky Gel Cell Pad Anti Slip Phone Pads Kitchen Bathroom House Car Holder

This is a soft gel-like plastic that does not use adhesive tape to stick but it's own tackiness. It leaves no residue and wiping with a damp cloth completely "resets" it to it's original tackiness. This is very similar to the pad that Joshua Bardwell discusses here (kyosho zeal vibration absorption) but this kyosho product is approximately $US13 whereas the one mentioned here is around $US2 at the time of writing. Check out the pics below to see how well it works.

As you can see on the picture at the left, it's easy enough to cut small pieces off as you don't need a lot to do the job and can keep the weight to a minimum. You'll still need a strap or band to hold the battery against it but since I started using this I've had no battery ejections. Not exciting but useful I thought.

Check out this cheap non-slip battery pad for yourself.

The Leader 120 is a very well thought out and put together micro quadcopter that I have reviewed on the bench here and after initial flights here. Flight time is good, especially compared to the quads with the smaller 2" blades. The standard King Kong 2840 3 blade props are strong and well balanced but also fairly agressive that can cause weaker batteries to sag on punch outs.

Since this quad has a lot of blade area for a light weight, I tried the twin blade Gemfan 3025 propellers that have one less blade and a more gentle pitch. Unfortunately the just fould on the frame so had to be trimmed by about 1-2mm to fit. For this job I 3d printed the flexRC jig from thingiverse which can also be bought directly from flexRC. To this you mount a standard nail clipper and can gaurantee the props will be even and balance.

So how do they fly? Excellent. They are slightly louder since they are now essentially bull-nosed but they were well balanced with similar performance to the 2840s although slightly less floaty. Nominal diameter is about 74mm compared to 70mm on the 2840s. But wow the efficiency! On a turnigy 2s 25c 950mah I got over 10 minutes of flight. On a 460mah 3s that is not is good shape I got 4.5minutes of hard flying. Battery sag was MUCH less and the roll dip that occured on a 3s punch out due to the ESC not keeping up was gone! I have a large pack of the 2840s to use up but am thinking of shelving them for the 3025 props. They seem less durable but have still not broken one after about 6 packs - some minor chips only that doesn't seem to have affected performance.

I'm amazed that more performance can be wrung out of this very good micro quad so I'll keep fixing it until it is broken!

The gemfan 3025 props can be purchased here
The KK 2840 stock props (still good) can be purchased here
The Leader 120 can be purchased here (use code HarvestRCnew7 to get this for $US93.99 until end September 2017)

Please comment here if you want to see flight times with the stock battery which has been given a new life!

Problem: a standard FC/ESC stack is too tall and heavy.

A 20 mm x 20mm 4 in 1 ESC and flight controller is the backbone of most micro quadcopter builds. They are usually joined together by m2 nylon standoffs in the middle and bottom that are about 6mm tall each. This can be too high for some builds but there is an easy fix that can even include some basic softmounts. Here are the parts you'll need. They are not expensive and can be used for several builds:

• 20 pcs M2 Black Round Nylon Screws Phillips Plastic Round Head Screws Bolt (get the 12mm ones)
• M2 nylon nuts - search aliexpress
• Suleve™ M2SW1 50pcs Black Rubber O Rings Anti Slip Aluminum Darts Washers

To make the low profile soft mounted stack:

1. Push M2 x 12 nylon screws from the underneath the frame and secure on to with 2 x M2 nylon nut per screw
2. Place the ESC on - ensure the esc and expose terminals completely clear the frame (remember carbon fibre is conductive)
3. On top of the ESC as as many of the m2 orings as needed to enure clearance from connecters. Add another to each screw to allow for compression.
4. Place the flight controller on, an extra o-ring to each screw and the secure with a nylon nut.
5. Tighen and recheck clearance given the orings will compress

Voila! now you have a low profile stack that is lighter and soft-mounted. After a big crash recently I find it is much stronger too as it relies on the tension of nylon rather than shear. ​