Reaming Props The Fast Way

So if you're at all like me, you've probably bought some cheap props online and at some pointed needed to ream them out to make them fit on a multirotor or some such. So here's some of the approaches I've tried and the levels of success I've had with them. 

1. Drill: Don't do this. It seems like it would be perfect but the problem is that the tapered cutting edge of the drill grabs and pulls its self though the prop and will certainly not go through straight. I've done a few tests and even clamping the prop down doesn't help. If you can get a straight hole drilled with one of these you know something I don't. 

2. Prop Reamer: Right so this is what you're supposed to use. However I've bought a couple of cheap ones online and they just don't work. I couldn't ream out a cheese prop let alone a nylon or even carbon fiber one. 

3. Step Drill: I found one of these down at my local hardware store and thought I've give it a try. Turns out, Its awesome! Because it doesn't have a tapered cutting edge it doesn't pull its self through the prop. You can simply bore it out all the care and attention you need to make sure you do it straight. Also because its being operated by a power drill and its really sharp it will ream out a prop made of pretty much anything really nice and fast. So it may not be what the pros recommend but its sure worked for me. 

Note: If you have any other ideas or experience put them in the comments and I'd be glad to include them in this list of prop reaming tools. 

Lipo Conversion Part 2

So I had such great success turning my battery drill into a lipo powered device I thought I'd give something else a go.

I've got a headlight for my mountain bike which has a cree LED in it. Its fantastically bright but its hard to mount it on the handle bars and have it point where I want it to and also the cord is long and gets in the way and finally the battery pack is big and bulky and takes ages to charge. Looks like a good time to break out the lipos and see if I can sold all those problems at once.


Step 1.
The light in its unmodified state.

Step 2.
Cut off the normal plug from the light and solder on a plug that matches the plugs on your lips. I'm using deans plugs here. I chose this 2S 1300mah battery because the voltage the light was supposed to work with (according to the writing on the battery pack)  was was 7V and a 2S is close enough.

Step 3.
Cut and glue a mountain bracket onto your helmet. I did this because mounting it here made a lot more sense to me that mounting it on my handle bars. this way it pointed where ever I wanted it to.

Step 4.
On the back I glued a little bit of foam as padding and a Velcro strap to hold the battery in place and to offset the weight at the front on the helmet.

Step 5.
All ready for riding at night! It charges faster and is way more useful than the original set up. Plus while I was at it I removed the little green LED inside the on button of the light to prevent battery drain when it's not actually turned on. The other good thing about this set up is I can use my lipo checker to see how much charge is left in my battery before using the helmet so I know I've got enough power to make it through the ride. I've also discovered that 3S batteries work with this particular light.

FrSky Taranis Antenna Upgrade Part 2

Well it seems that I am unable to stop modifying my FrSky Taranis so here's the next step.

Firstly I do not take credit for the design of this antenna. That came from the great IBCray and his tutorial for the calculations, theory and measurements can be found here. So I'm not going to go over those again. This is just my build log and application of his design. So that being said lets get started.

Things you'll need.

For the antenna:
1. A small coax cable
2. Copper or steel wire, about 14 AWG
3. Metallic plate
4. Two Nylon bolts
5. Plastic container (optional as this is just the cover)

For the antenna mounting (this is just my solution but many others would work as well):
1. 12mm x 12mm square wooden dowel.
2. Two M3 bolts (atleast 30mm)
3. Heat shrink


Other:
1. Heat shrink
2. Hot glue
3. Solder


Lets get to the modding......




Step 1.
Cut the backing plate and the wire. I used G10 board for the reflector plate.

Step 2.
Start bending the wire at the section lengths for a 2.4 Ghz (see the IBCrazy thread for the calculations to get the dimensions for your frequency)

Step 3.
The reflector plate and the resonator.

Step 4.
Drill a hole in reflector for the coax cable and also mount the nylon bolts to hold the resonator.

Step 5.
Strip the coax cable back and solder the shielding to the reflector.

Step 6.
Solder the resonator to the coax cable and glue it to the nylon bolts

Step 7.
Glue the coax cable and nylon bolts to the back of the reflector and glue the plastic container to the front of the antenna.

Step 8.
You'll need to get the coax cable into the Taranis so instead of drilling into it I ran it though the hole in the ORX module left when I did the antenna mod on it.

Step 9.
New antenna connected to Taranis.

Step 10.
Solder new coax cable to the Taranis module board where the other antenna was connected.

Step 11.
Antenna ready to be mounted.

Step 12.
Cut four sections of the dowel about the length of antenna. Doesn't matter if they are a bit shorter.

Step 13.
Clamp them together and drill a hole where they meet at the top about 4mm in diameter.

Step 14.
Take the handle off the Taranis and put some heat shrink over it to give the clamp more grip.

Step 15.
Drill mounting holes in the dowels just bellow the main semi holes.

Step 16.
Screw the mounts together with the M3 bolts and clamp them to the handle of the Taranis.

Step 17.
Glue the new antenna to the mounts.

Step 18.
All Done!

Note: this reduced my SWR reading down to 16. This is probably fine but I read that to get it even lower you need to make sure that when you're soldering the coax cable to the board you want to expose a very very small amount of the core and make it as close as possible to the soldered shielding.