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Ham Hill is an Iron Age settlment and was a Roman Fortress and quary. Ham stone is famouse for its redish colour and is used in most of the local houses.
The monoliths were erected as a stone circle as a monument to the Millenium 2000.
Ham Hill is still an active quary for limited extraction or stone.
I have just had a look at your Phantom Vision Video - I take back my comment re IQ. It is very nice. the flight time of the V2 over the V1 is a vast improvement - 25 minutes Vs 7! I am happy with my 15 minutes but plan to get another LiPo battery later.
I apologize to everyone who doesnt need or want to know about prop palancing but this is for Steve and all RC Aircraft/Drone/Boat enthusiasts...
Yes, my props were out of balance - I had ordered a DU-Bro prop balancer but it hadn't been delivered & I was too keen to see my baby in the air.
When the balancer arrived, I just could not get proper results. I discovered one of the cones was off centre - I did a video of it and showed it to the manufacturer - They sent me another cone but that too was out of balance... they are sending me 'a few' more for me to try. http://vimeo.com/79600704
However, I have researched the whole subject of prop balancing and have made a simple laser + mirror balancer that dynamically balances the motor casing, prop hub and the prop itself.
I got the idea from this video Laser balancing
I slightly modified their methodology and found that using a laser and mirror gave outstandingly sensitive results. I did a write up for another group I am a member of. It may be of interest to you:
Well, well, well! I am very surprised at the ease of balancing this is. I found it very sensitive and apparently very accurate.
The ethos I adopted was 'consistency leads to repeatability and accuracy' ...
* A small red laser unit salvaged from an old spirit level. (Cost when the level and tripod was new at B&Q £10)
(Do an eBay search for a laser pointer.)
* A small mirror. (salvaged from a defunct scanner in which there is a mirror with the silvering on the front surface) I put a small strip of double sided carpet tape on the back
* small vice to clamp the laser unit on.
* a roll of sticky insulating tape (for balancing)
* Bottle of Tipp-ex (for marking parts)
Once set up, I had balanced the four propulsion units on the quad in about half an hour. I say propulsion unit because following the methodology, balances the outer motor case, prop hub, prop and the prop nut as a whole and not just the prop.
I did not disconnect any of the motors. Each of the 4 motors were powered up in the process.
My quad has the larger landing legs that lift the motor arms above the deck. If your drone relies on the short stubby legs on the arm, you will need to lift the legs free while doing the test. I suggest a book or something similar under the body of the drone.
1) First, remove all props.
2) Mark each arm with its appropriate motor number (I used a CD/DVD pen)
3) Mark ONE tip of each PROP with a small touch of Tipp-ex.
4) Mark the orientation of each prop to the orientation of the motor shaft and on the outer casing of the motor. (I used a small dollop of Tipp-ex.)
5) Using the CD/DVD marker pen, give each prop the number of the motor it will be associated with. The same with each prop nut. I don’t believe the nuts will be out of balance anyway but there is no harm in being consistent.
6) Still with no props fitted…
7) Connect freshly charged battery
8) Attach the mirror to the stubby leg on the end of #1 motor arm, using double sided sticky tape
9) Put the drone in position with the mirror at 45 degrees to the laser, the laser should be in front of the drone. The reflected laser spot will be projected a 90 degrees, hopefully on to the wall adjacent.
9) Arm and start up the un-propped motors on slow revs. Adjust the laser and mirror so that you can see the projected spot on the adjacent wall.
10) Holding the top of the drone to stop it from moving, slowly rev up the motors and observe the laser spot. Hopefully, the motor will be in balance and the spot will not move.
11) Stop motor.
12) Install the prop and nut in the orientation previously marked.
13) Arm & start motor on low revs – observe the laser spot. Keeping your hand and arm well clear of the prop, apply gentle downward pressure of the drone. ( You don’t want it tipping over during the next steps)
14) Slowly advance the throttle to rake off speed and to flying speed. Observe the laser spot. If it doesn’t move, it may well be a well-balanced propulsion unit. However, deliberately unbalance the prop by adding a little insulating tape on one side of the prop (Note which side, the one with the Tipp-ex or the other) and do the test again. This time there will be a marked difference in the behaviour of the laser spot!
At this point you will have to experiment with the size and placement of your favourite balancing tape until you get the spot to be as steadty as possible. Once yiou are happy with the balance of the prop, remove it and its nut from the motor and start over again at (8) above until each motor unit is done in turn.
When finished, remove the battery and assemble each prop on their respective motor, observing the orientation of the prop on its shaft and lock it down with its nut. You’re done. Now go for a test flight.
A note on motor balance:
I have only seen the inside of two motors (different manufacturers). Both had some hardened ‘goo’ that was obviously there to balance the outer case of the motor (as my daughter would describe it: “the spinney round bit”
One of these motors I noticed had some metallic debris (AKA: FOD) stuck between some of the magnets. This could have been ingressed during a crash near metal shaving contaminated ground or even if the motor had been rattling around a tool box or other environment where metal shavings were present. The magnets are extremely powerful and can attract fine metal FOD during its life. At the rotational speed the spinney round bit travels, this could/might//may/will unbalance the motor.
The method I adopted will counteract any unbalances in the motor case, propeller boss, propeller and its nut.
Here endeth the lesson