Gimbals

I've been thinking about doing an article about gimbals for a while now, particularly looking at consumer grade gimbals that cost hundreds of dollars rather than the many thousands that it's possible to spend on top of the range equipment aimed at professionals. The reason that I never got around to writing the article in the past is that I was always disappointed with the results from the cheaper gimbals and invariably footage shot from a fixed camera looked better than the jittery images created with the use of a cheap gimbal.

In the last few months however we have seen big advances in the affordable gimbal market, thanks mainly to the work by people like AlexMos, with the development of the brushless gimbal controller. When DJI released the Zenmuse with the direct drive system, it was immediately obvious how much better results could be using direct drive and thus eliminating any backlash or play in the system. The motors on the Zenmuse are prohibitively expensive, so the rush was on to create a direct drive system using conventional brushless motors.

If you're in the market for a brushless gimbal then my advice right now would be to wait a bit longer because the current crop of 'cheap' brushless gimbals are very hit and miss, with manufacturers rushing to get a product to market with very poor quality control. You just have to follow the release of the Mastor system from BEVRC to get an idea of some of the problems that people are having trying to get them to work: Mastor thread on RCGroups

Despite what I said above, this is still an exciting time for AP enthusiasts and with a bit of tinkering and a little luck with quality control they can be made to work extremely well for a fraction of the cost of the Zenmuse. To avoid repeating what others have already said, I am just going to provide a few links to threads on RCGroups where you can find out all about the latest releases in the brushless gimbal arena.


This link will take you to the Brushless gimbal mania thread which provides a comprehensive list of most of the newly released gimbals on the market, including prices and links to support threads.
Brushless Gimbal Mania

The next link is to a post that I read and found to be really useful if you're new to setting up a brushless gimbal and am sure will be useful to a beginner wondering why their gimbal isn't performing as well as it should.
Brushless Gimbal Setup Principles

The last link is to a blog that has some great information about general gimbal principles, including some great videos demonstrating gimbal behaviour under varying conditions. If you're a bit of a geek that really likes to know the technical intricacies of how something works then you will love this. Scroll down a bit to get to all the stuff about gimbals.
Technical Gimbal Description

March Update!

Again I find myself working a long way from home and living in a hotel once more, but at least this time I have brought a few toys to play with. I've finally got around to installing those silicone anti-vibration mounts that I posted about a few weeks ago. My initial impression is that they feel a bit too rigid and probably only good for really high frequency vibration, but I haven't found the time to make a test to properly test them out.

Here is a picture of them mounted. Sorry about the poor picture quality, I took it using my tablet in bad lighting conditions. If the weather is good tomorrow, I will try and make a before/after video to show how well/bad they work.

In other news, I finally received the 450 V2 kit that I purchased from RCTimer and am starting to put it together. Unfortunately I don't have all of the items with me that I need to finish it, but I hope to try and get it in the air soon and do a little build log along the way. Eventually I plan on holding a little competition to give it  away, but I have no idea when that will be.

Apart from a couple of missing screws for mounting the motors, I'm pretty happy with what I received for $115. I'm going to add a Naze32 controller to it for control and will probably fit a set of Tarot folding landing gear to it. I recently learned a lesson to read the description on ebay a bit more carefully as I thought that I was ordering a landing gear set and was a bit disappointed when only one leg showed up in the post. The quality seems reasonable, so I will order another matching leg to go with it.

Here's a couple of pictures of what I received in the post:

Hubsan X4

Well I've finally got my hands on one of these tiny little quadcopters and I have to say that my first impressions are really very good! It was a bit of an impulse buy as I needed something to kill the tedium of living in a hotel for a few weeks while I was away on a work trip. I purchased it in ModelZone at £45 ($70) and I thought that it was a bit expensive but I know that it's possible to purchase the same model on-line for about half of that amount, which would make it an absolute bargain.

In beginner mode it is a super stable and extremely docile quadcopter that even a complete novice would be able to fly with very little difficulty. Switch it to expert mode and you really unleash the inner beast and it becomes a very lively little model capable of doing some impressive aerobatics in a very small space, but still somehow managing to remain super stable.

As you can imagine, when doing aerobatics in a relatively small and cluttered space like a hotel room, the model has had more than a few crashes. So far it has proven to be very crash resistant and despite my best efforts I have yet to break even a prop.

The controller is very ergonomic and feels nice to hold and the sticks are nice and positive with good centering. Programming is very straightforward and the well written manual gives good, clear instructions for changing modes, calibration etc. The manual also explains how to perform aerobatic manoeuvres, which are very simple once you have switched to expert mode.

I'm now on the hunt for some very lightweight FPV equipment so that I can do some urban exploring with this little wonder, although I might just have to check the range of the transmitter before I commit to purchasing the FPV equipment.

Shipping times from China!

Just a quick reminder that the Chinese New Year this year falls on February the 10th. If you're planning on ordering any items from China then be sure to get your orders in soon or risk long delays as everything shuts down for a few weeks and then there will be a big backlog to clear.

2013 is the year of the snake. As the Chinese use the Lunar calendar for their festivals the date of Chinese New Year changes from year to year. The date corresponds to the new moon (black moon) in either late January or February. Traditionally celebrations last for fifteen days, ending on the date of the full moon. In China the public holiday lasts for three days and this is the biggest celebration of the year.

Silicone Anti-Vibration Dampers

I just spotted these at  http://www.infinity-hobby.com and they seem to be pretty good value for money compared to what I have previously seen for silicone dampers. They come in 3 different compounds, which will presumably help filter out different frequencies of vibration. I've ordered the a set of 4 medium compound dampers to test and will report back with the results when I receive them.

A Quick Look At The RCT800 Smart MultiRotor

I just thought I'd do a quick 'show and tell' on the RCT800 Hexacopter frame which is available from RCTimer for a very good price at $59.99. At this price and from what I've seen so far, I may just have to add one to my collection.

It's a surprisingly large copter at 80cm motor to motor distance which allows the use of some 14" props for serious amounts of power. The good thing with the arms is that they are also compatible with the 450 frames, which would allow you to fit upto 16" props on a 450 style quad put together with these arms. The extra length does of course make them more prone to flex and wobble, but nothing too bad. 

My friend Guillaume has put his together incredibly using 6 2830-14 750KV motors spinning 14" props on 4S!!!! This just shouldn't work, but somehow it does and it flies remarkably well, with no noticeable heating of the motors (this might change in summer, but it's currently winter here in the Alps and the outside air temp is quite low) and it comes in at ~2kg complete with a 5000mAh 4s lipo. With this setup he is getting about 10 minutes of flying time, with quite a bit of aggressive flying thrown in.

Here's a couple of photos and a video of the RCT800 in action. 

Happy New Year 2013!!!

I hope that everyone has had a great Christmas and that Santa brought them all the RC gadgets that they wished for! 2012 proved to be an epic year for multirotor aircraft and all of that looks set to continue in 2013 with loads of new products set to come out this year. With the competition really hotting up last year we really saw prices like never before and although I can't see prices coming down any further we might expect better quality products for the same price in 2013.

With it now being cheaper than ever to get into flying RC models, particularly multirotor flying hand and face shredders, the start of the New Year seems like a good time to remind people about safety. Please be careful and have a fun and safe 2013! Check out my Multicopter Safety blog for some hints and tips on keeping things safe. Multicopter Safety