Robin's home on the web

130X New bevel gear

robin — Thu, 25 Apr 2013 21:04:43 +0000

As I mentioned a couple of days ago, the Blade 130 had a little argument with a patio and stripped a couple of teeth from the bevel gear which feeds power to the tail rotor. Thanks to quick delivery from Fast Lad a new, upgraded metal gear has arrived.

Tonight I sat down to fit the new gear and tail, this is where I made a small mistake which cost me about an hour of time, but thankfully no damage to the heli. I now know that to replace the bevel gear you can simply disconnect the swash from the head, remove a couple of screws and yank the head and main shaft straight out of the heli. I tried this, but it didn’t feel like the main shaft was going to part company from the main drive gear at the bottom. So I decided the only way forward was to separate the two chassis halves and take the shaft out that way.

DON’T DO THAT! Of course does work, but it is one hell of a job. The proper way is shown in the video below, oh well it’s back together and flying OK. At least I learnt a bit about how it is all held together

Blade 130X

robin — Tue, 23 Apr 2013 21:22:15 +0000

Between house moving noise and a silly busy period at work, I’ve not been getting out much. The Tuc is seeing some progress in the evenings, but that has been about it. The clocks went forward a couple of weeks ago, bringing lighter evenings but since then we have had seriously strong gales. This week however we have been graced by a nice spot of low wind and sunshine.

As a result I’ve been getting out into the garden with the 130x almost daily, most times putting all three batteries through it. I’m getting a pleasant 6 mins out of the two Overlander batteries, with the charger reporting about 300/350 mAh going back in so they could be pushed even more.

Last night I had a little crash which snapped off the lower 2/3 of the tail fin, so I’ll have to order a new one and I have stripped a couple of gears on the main bevel gear which feeds power to the tail shaft. I’m going to replace it with the metal optional part (BLH3735). Even with a few teeth and the fin gone she flys just fine though!

Diamond Demon build – part 9

robin — Sun, 07 Apr 2013 21:38:42 +0000

Well, I’m pleased to say that after 8 months she is finished! Weighing in at 550 grams gives me a little under 100 watts per pound, so that should be plenty for a little vintage model. I took her over to the flats today for a maiden but it was a bit too windy for me to want to chance it.

I’ve sort of fallen out of love with it over the months, it was a struggle to push myself to finish it. The covering was the final annoyance, the Litespan not shrinking enough for some of the curves, and then after I added the blue trim to the front of the fuselage I ran out of balsaloc. Being too tight to buy a new tub just for a few strips on the wings and tail I ended up painting those, which moderate success!

I’m pleased I’ve finished before starting on the next one, I don’t want to end up with a few unfinished models hanging around the place, beside which, I’ve got no space for the ones that are finished as it is

I’ll write some more once she has flown.

Right, NEXT!

Modelflying.co.uk forums search

robin — Sat, 06 Apr 2013 21:52:54 +0000

This is a custom search box which restricts google.co.uk to the modelflying.co.uk/forums/ url.

If you want your own Google custom search just click here. Anybody can make one and either publish a public URL or host it on their site like I’ve done.

New feed location

robin — Mon, 01 Apr 2013 21:21:50 +0000

I’m moving away from feedburner, so my RSS feed location has changed. The new url is http://riviera.org.uk/feed/ please update your RSS reader!

Monitoring beanstalkd with monit

robin — Tue, 19 Mar 2013 21:27:22 +0000

A new project I’ve just deployed onto live uses the fast and lightweight beanstalkd work queue. As part of putting it into live I wanted to get at least some basic monitoring on the beanstalkd daemon. All my servers run monit for keeping an eye on processes I care about, so that seemed a good place to start.

I had a bit of a look around the interwebs but couldn’t find any examples, so I set about putting something together myself. As it turns out beanstalkd has a nice simple text protocol, detailed in protocol.txt which is included in the source, and monit has the ability to send and expect arbitrary strings to a given port. For starters I’ve set it up to issue a stats command and check for the expected response which is:

OK \r\n

Adding this to my monit config file for beanstalkd gives me:

check process beanstalkd with pidfile /var/run/beanstalkd.pid
 start "/etc/init.d/beanstalkd start"
 stop "/etc/init.d/beanstalkd stop"
 if failed port 11300
   send "stats\r\n"
   expect "OK [0-9]{1,}\r\n"
 then alert

This is a pretty simple check but at least will enable monit to alert if beanstalkd isn’t listening or is returning garbage.

I think in the long term I’d like nagios to alert on the current-jobs-delayed and possibly the current-waiting variables reported by the stats-tube command for a given tube, but that is for another day!

Another thought is possibly to have a cacti graph of the total-jobs field, it looks like a always increasing counter, so should be pretty trivial to hook up to cacti.

Jiffy!

robin — Sat, 09 Mar 2013 22:03:02 +0000

I just discovered I have the copy of Radio Modeller where the Jiffy was given away as the free plan. I’m not sure why this pleases me as much as it does, but there you go! I’ve scanned the article and bunged it up on the Jiffy page, here.

New Engine – OS 10FP

robin — Wed, 27 Feb 2013 22:42:33 +0000

Last week I succumbed to a spot of eBay therapy and accidentally bought a little OS 10FP 2 stroke. It was listed as good condition, but apparently the owner had never made it run properly. I’ve always quite liked the idea of a small glow engine and figured maybe trying to get it to run OK would be a bit of a challenge, so I placed a bid and won the auction. I think I got it for a good price considering it was essentially a non runner so if I could make it work I’d have a bargain.

When the thing arrived I was impressed by how clean the casing was and found it turned over ok, with good compression. The carb. seemed to move fine and there were no visible blockages, so I wondered what could have caused the problems the previous owner had experienced. While inspecting it I discovered both the silencer and the cylinder head screws were absolutely buggered, somebody had clearly been at them with a screwdriver and now a Philips head driver was just happily spinning in the heads. Right then, clearly some filling action was going to be needed to get them out and new ones would need sourcing. After a bit of a struggle I got all of them out, measured them and ordered new ones (M2.5 x 10mm for the head and M2.5 x 25mm for the silencer).

While inspecting it with the silencer off I noticed the transfer port in the piston was facing the exhaust port, not the matching ports in the other side of the cylinder casting! Somebody had taken it apart and put the piston back in the wrong way round which would have caused the fuel to be pushed up into the upper cylinder right next to the open exhaust port, almost certainly causing it to either run very badly, or not run at all! If I had to guess at the problem, this would be it.

New screws have now arrived, I’ve put it back together and yesterday afternoon I mounted it on my test stand and gave it a flick, I’m pleased to say the little 2 stroke now runs really nicely, throttle response is smooth, WOT sounds fine and it happily idles at a very low RPM.

Quite pleased then! Just need to find something to build to put it in.

Paragliding in Wiltshire

robin — Sun, 17 Feb 2013 07:31:12 +0000

I’ve had a bit of a rubbish weekend from a model flying point of view, it seems every time I go to fly events are conspiring to stop me. Firstly on Friday I managed to get some time in the afternoon to pop up to Bratton Camp, I was delayed by discovering a car fire on the way, then reporting it to the fire brigade and having to wait around until they turned up so I could give them a statement. Then I had to return home because I’d forgotten to take the pram out of the car, gah! When I finally got up to the hill I discovered 8 (!) paragliders in the air at once. When there are 1 or 2 of them up there, I’m happy to fly alongside them and aim for the gaps, but with so many up there at once I didn’t want to take the chance.

On Saturday morning I popped up the hill again nice and early, only to be greeted by what I think is the thickest fog I’ve ever seen. I couldn’t see the other side of the road from the car park! Oh well, maybe Sunday will be better.

The video below is of the Paraglider’s who were monopolising the hill on Friday afternoon.

Diamond Demon build – part 8

robin — Tue, 12 Feb 2013 13:43:48 +0000

Spot of progress this week, I’ve all but finished the covering. Just the front most curved section below the motor and the centre section of the wings to go. I’ve some acetate on order to glaze the windows and then she is done. The tailplane and fin are now glued on, the elevator is all hooked up and the closed loop wires are run through the fuselage ready for me to connect the rudder. After that I’ll need to install the ESC and solder the connectors to the motor and she is finished.

I am still pondering about coloured trim, I think I’ll finish her first then have a go at adding some colour.