More engineering - started a new part.

I did some work on the cylinder heads today, and drilled and counter bored the ports for the inlet and exhaust. They're finished now, apart from the holes for the rocker shaft. Check out the pictures:-

Cylinder heads very nearly finished

I started the gearbox, not much done yet, just the flange face, location diameter, bore for the bearing, and clearance drilling for the primary gear.

Gearbox started

Weather stopped flying (yesterday)...

...But it didn't stop me doing some work on the Ketro KT120fst engine. I've not been satisfied with the design of the crankshaft where two M3 grub screws hold it all together. So I've come up with a design modification that will beef up the strength and rigidity. I made two special screws from M4 cap head socket screws and I turned off a section of thread to form a 3.0mm dia. pin whilst leaving a threaded section intact. Then I drilled and reamered a 3.0mm hole through where the original M3 thread was in the crankshaft parts, followed by an M4 thread down to the center, and counter bored 6.0mm dia. to contain the screw head, which incidentally, I turned down to size. Now I have far more confidence in its integrity.

More integrity

You can see the screw head in one crank and the pin in the other. Unfortunately there is a little bit of run out along the length of the shaft, but I'm hoping the rear bearing set will contain it.

I went flying today.

The weather this week has been appalling with heavy rain and gale force winds at times. Today, it was superbe with sunshine and light cloud and light winds. A day not to be missed. Tomorrow is forecast to be back to heavy rain and gale force winds.



Jamies Bobcat now fitted with larger Jetcat P80se

The Front Housing and some assembly

Well, just enough to see if it fits. I made the Front Housing and fitted the crankshaft and conrods together in the crank case. 'Tis at this point I've discovered I need to remove a very small amount of material from the bottom of the sleeves because they foul on the crankshaft. Oh! well I can't see it making any difference to performance other than it just makes the engine that little bit lighter. Every little helps.

Here's some pix:-

Front Housing in the lathe for final machining

Note how its bolted to the mandrell

The rear end view

Assembled (temporarily)

Next will be the gudgeon pins and the PTFE end pads to prevent the gudgeon pins from scoring the bores. Then I can get the pistons moving.

Some engineering works

As I haven't blogged for a while, especially on engineering, I thought (careful) that I'd make an update. I've finished the inside of both cylinder heads today leaving just the ports to do, and to give an idea of how far I'm ahead (or behind), I've taken some pix of everything.

Using a boring bar to form the valve seats

Crank case, cylinders and liners

Pistons and valves

Cylinder heads, port and starboard

Crank shaft complete with conrods and bushes

Preparing for finish machining

The best conditions...

...for flying today. Jim flew his Mig, Ian flew his F16, I flew the Yak, and Brian flew his Piper Pawnee. The weather was so good, I managed a couple of flights with the Ember.

Brians Piper Pawnee

Brians Piper is a nice model, built from a Hangar 9 kit, its an ARTF powered by an OS 52 fs four stroke engine and guided by Spektrum 2.4 Ghz radio.

Ians F16 was impressive, together with smoke system, he has afterburners in the tail pipe. Actually, its an array of ultra bright LEDs switched on by a micro switch at 3/4 throttle and above. Had me and Jim fooled as there was some flames exiting the tail pipe on start-up, so we thought it was alight while it was flying.

There was a lot of microlight activity today, this is a particular menace to the jet pilots as jet aircraft use up so much airspace. Microlight pilots don't seem to be aware of the dangers of flying through our airspace. A record of the number of movements was taken today.

A drawing error - oops! conrods

Its about time I blogged some engineering, so I've done the following:-
Some how I cocked up. Its not the first time, nor will it be the last. Getting down to it, I designed, drew and made the conrods too short. The piston was unable to pass bottom dead centre. Oh! dear, how sad, never mind. But now I have two new conrods of the correct (longer) length. This also means I'll have to remove some more metal from inside the cylinder heads to maintain the correct compression ratio.

Ahh! Bottom dead centre

Conrods increased in length by 0.5mm

I went flying today, and it was a sad day. I lost an old friend. Yes the red Sunbeam met its match or rather terra firma. It was pilot error, I heaved in too much elevator and the wings folded and it went down into the bean field. Engine and radio are OK but the airframe has had it. At least I know it was my own fault.

Cornwall - The Show

The two day event at North Cliffs near Camborne was a total success all round. We ('erin doors and I) trundled our way down the A30 to Camborne and arrived on site at around 09:00hrs on the Friday. First things first, set up the caravan and put up the awning. Geoff and Mary arrived shortly afterwards and did likewise, only theirs is a motor home, and then Terry arrived and erected his tents. Yes plural, the other one is his dunny. I won't go into details. After a spot of lunch we chilled in the afternoon and enjoyed a couple of flights with the Pico-Jet and Geoff flew his very pretty looking Bae Hawk. Evening, and we went into Portreath and paid a visit to the Bassett Arms for a jar of Cornish Knocker and a bite to eat. After a stroll down to the sea front to watch the Sun set we made our way back to the site and crashed 'till morning.

Saturday, and up with the (bleary eyed) lark, took all the models and equipment down to the flight line and made ready for the days' flying.

Early Saturday Morning

Terry watches Geoff contemplating his "Ork"

Getting to grips with the Laser 200

Spotted at the show. I just had to take this photo.

Apparently they're called Truck Nuts

Sunday wasn't quite as good as Saturday weatherwise, although it didn't rain it was cloudy all day. In fact it rained most of the day on the South Coast, so prospective spectators were probably put off attending and as a result there were fewer spectators on Sunday. But it was still a great day.

In preparation for Cornwall

Flew all the usual suspects today and gave the Pico-Jet a particular airing to test all four li-po batteries. Everything performed well.

Ian flew his F16 Fighting Falcon Fitted with a smoke system. Boy did we have some fun with that. After landing Ian taxied back to the pits, and as he got close to Geoff, who was working on his plane, switched on the smoke and Geoff completely disappeared in a huge cloud of white vaporised diesel.

Pete brought along this nice example of a Comet. It crashed on its first take-off but there was little to no damage, just a few scratches, and the second attempt was a success. Sounded nice in flight for an electric job.

deHavilland Comet "Grosvenor House"

Next weekend, its a trip to Cornwall to fly in the Annual Two Day Model Airshow hosted by Redruth and District MFG at their site on North Cliffs West of Portreath. This has coincided nicely with the NSA who are having Westonzoyland Airfield for the weekend for their "flying" event. (NSA is the National Sprint Association. They ride motorcycles).

Yeovilton - a big disappointment...

...and it was mostly down to the weather. A few aircraft flew in the morning, but the show consisted mainly of helicopters. Lynx Mk blah de blah, Sea King Mk whatever and Merlin ad nausium, sorry, helicopters just don't do it for me. However there were some exciting bits, a Sea Vixen (remember those?) put on a sedate display, the Red Arrows flew in and did a couple of flypasts and buggered off to somewhere, a Rafale did some impressive manoeuvres and an F16 Fighting Falcon showed off its afterburner. With the cloud base at only 300ft anything fixed wing was very limited and much was cancelled, which included the Avro Vulcan, not just because of the weather, but because it had suffered a hydraulic oil leak in its braking system. Ah well, such is life.

It started to rain at around 16:00hrs just after the Commando assault got under way. We watched it for a while but the start was so slow and we got bored and walked back to the coach. Then it all started, very large bangs with huge plumes of flame and thick black smoke, and the dreaded helicopters buzzing around like demented buzzing around things. While we sat on the coach we could see bit of it going on in the distance and when a plume of fire and smoke went up it was some time before the boom reached us and when it did it shook the coach.

I have to say that despite all I had a good day.


Here's some short video clips:-

de Havilland Sea Vixen

Visitors from Belgium and a real flyer

The cross wind from the South made flying a little difficult and with the speed at around 12mph it was really beyond the limit for me, but I did manage to fly the Pico-Jet and both trainers, but I left the Yak on the ground.

Jack and Josie B from Gent in Belgium were here this weekend on a visit. They used to come to the Top Gun events which the Sedgemoor Club hosted many years ago. Its great to see them again. Jack flew a large scale Extra 300 with a 3W engine running on Avgas (used in full size aircraft) which gave a remarkably slow and smooth tick-over and good top end power. Its also equiped with a smoke system using lamp oil (not much smell). It produces an excellent smoke trail even in todays windy conditions.

Jackies Extra

Another unexpected visitor to the airfield was this beautiful owl brought here today by Paul and his wife.

The eyes are amazingly clear as crystal

And of course there's always a poser

Dull day and a new jet

Strange weather today, 90% cloud and very warm and humid, winds light and from the South East. Positively tropical. The pits were full and crews were overspilling the pits area at both ends, and despite the wind direction we were deployed on the South side pits.

I arrived shortly after 09:00hrs and started the days flying with the Ember as there was no wind. Whilst in electric mode the Picojet was next. Two new digital, metal gear servos were fitted this week and their reaction to stick movement is very fast. I still need to add lead to the nose as its very twitchy on the elevator. I hate doing this but I can't lighten the tail any more. I'm also a bit worried about over heating the lipo battery so I use full power frugally. The heat in the air was creating thermals and a short five second burst of power would take the Picojet vertically to near out of sight. Stopping the motor and gliding seemed to last for ages before much height was lost.

Late in the afternoon I decided to give the Yak an airing, but as I prepared to fuel it up it started to rain; just a few big spots, so I took that as a warning and packed up all my gear. Turned out it wasn't enough to damp the dust - typical.

The Bobcat

A New Jet on the Blog

Jetcat P60

The connection at the top of the engine is a PTC heater where fuel is ignited as it enters the combustion chamber on start up. This eliminates the need for gas and the associated equipment.

Ballistic

First flight today was with the Picojet, and its fast, really fast at 22,000 RPM it positively honks along. From gliding into wind I can point the nose upwards, open the throttle, and it accelerates vertically and within seconds its almost out of sight. I had a serious problem on a later flight, the elevator was responding abnormally. Up elevator would force a left turn, so would left aileron. Right aileron would force a right turn but it would also lose height rapidly. Eventually it crash landed in the grass and without damage, luckily. The cause? Starboard servo failed in the centered position. Reason undetermined.

Quite a good turnout for a Saturday:-

I was last to leave!

Also flew both Sunbeams, I took the Yak54 but I didn't fly it because the wind was directly across the runway from the South and it was up to maximum strength where flying is concerned.

Its been a funny old day

Arrived at the airfield at around 08:40hrs. and set up on the South side of the runway. The weather was cloudy, but brightening up, and a light air moving from the North East. Time to fly the Ember but not long after it got airborne the wind became a bit stronger, so it was time to land and put it away. The direction settled South Easterly which meant changing the pits to the North side of the runway. That done, Picojet next, and I had a new motor arrive for it yesterday, an in runner this time, and its a bit longer and heavier than the out runner fitted previously, so I thought there may be an issue with the centre of gravity. A balance test showed it should be OK but only a flight test would prove it. I tested the speed of the out runner motor before I removed it and the result was 18,000 RPM on a 5.25" x 4.75" APC propeller. This new motor tested out at 22,000 RPM on the same prop. Imagine what it does when it "unwinds" in the air. Right, lets get it airborne, and what a difference. Its now positively ballistic, but tail heavy making it twitchy on the elevator. I glued some lead into the nose (something I hate doing) to improve centre of gravity position, and a flight test proved it was better, but more weight was required in the nose. But what I'm going to do is move the motor forward as far as it will go so hopefully, no more lead needed. Will keep you posted.

Later a Club Committee member arrived (who shall remain anonymous) and insisted, despite the wind direction, that I change to the South side as it is the Club rules (its not, I double checked),and he refused to fly from the North side. So this means taking off and landing down/cross wind. Anything for a quiet life, so I moved all my gear back to the South side. Paul M and Jim E arrived later and they both asked "Shouldn't we be over the other side?". I had one flight from this side but landing was a bit awkward as the pits were in danger of being in the way, so I didn't fly again until he'd gone and then we all moved to the North side. One for the AGM in December me thinks.

Jims OS Gemini 240 powered Firecracker

I haven't seen this aircraft fly for years, in fact I can't remember the last time I saw it fly, and I still haven't seen it fly. Jim put it together, fuelled it up pumped up the retracts, and prepared to fly and it started to rain. We had enough to seriously wet the aircraft, but barely enough to dampen the dust on the runway. So Jim defuelled and dismantled and packed it up into his car. then the Sun came out and it turned out nice again. Sh!t happens.

Also in the picture is Pauls Ducted Fan F15 Eagle and Fournier powered glider.

31st May 2009

I should have done this on the day, that's why I've dated the heading.

A really superb day weather wise although the wind was a bit strong at 8 - 10mph. I took the Yak 54, Sunbeam 1, and the Ember (tempting fate) and flew them all, but the Ember was a very short flight, just up and down again during a quiet spell. That was enough, it was still too windy. I wanted to take the Picojet, unfortunately one of the magnets had displaced itself and It was difficult to get it back in place. Also the bearing had come out of the rear cover so I had to glue it back in again. I think that's poor design. I don't think I'll buy another out runner motor.

A minor accident occurred today, a Club member had landed an electric biplane safely and parked it in the pits. No problem so far, and then picked up his electric glider, and after changing models on the transmitter proceeded to launch the glider having not done the full pre-flight checks. Once the glider was launched, he then switched on the motor, which also switched on the motor on the biplane he'd been flying earlier! It moved forward and hit him in the legs, and whilst looking down to see what had happened, the glider nosedived onto the tarmac. Fortunately there was no injury caused but the glider didn't get away with it so lightly. What he didn't do was disconnect the battery in the biplane before launching the glider, both aircraft being on the same frequency. We live and learn... or do we?

I took some photos of Malcolms Magnatilla to record the how he fitted his four stroke engine. This will be useful information for when I build my Legionaire. The aircraft has a very short nose and its a bit of a tight squeeze getting it in there.

Malcolm says the OS 70fs is way overpowered

Firewall cut away to accommodate carburettor

All pictures shown with rather nice aluminium cowl removed.

That's all for now folks.

Its all about change

Well, in case you were wondering, I didn't get to fly the Ember when I was on holiday, the wind was far too strong even early morning and late evening every day. The strongest wind for flying it in is a light air movement, and we had more than that. (understatement).

Today...

A 180 degree turnaround in the wind direction today meant changing to the other side of the runway - twice. When I arrived we were on the South side. The wind soon increased in speed and the direction settled in the South East. All change, pick it all up and move to the North side. By the afternoon the wind changed and steadily moved to a Westerly direction. At around 15:30hrs the wind dropped to zero mph for about 10 minutes and I managed to get a flight in with the Ember. (Designed for indoor flying). Then it quickly built up speed from the North West to about 15 mph. Then it was time to go home. But I did fly all the aircraft I took up there today, and brought them home safely. Others weren't so lucky. Clive brought along his Harmony,a nice twin engined job which had an engine synchronising unit on board which used sensors one on each engine to monitor rpm.

Clive Halls twin engined aircraft met its demise on the tarmac - what a shame, nice plane.

Ian arrived later in the afternoon and flew this beautiful example of an F15 Eagle. Powered by a single Jetcat gas turbine it has bifurcated jet tubes to simulate twin engines. Also there is retractable under carriage with synchronused doors, wheel brakes, air brakes, flaps, and a canopy that opens using compressed air.

A fine example. This photo shows the wash-out on the wing tips.

A side view

I nearly forgot, I flew the Pico Jet today as well. First time since...must be last year.

I'll post more later...

Home again

Been away for a break on TQ, thoroughly enjoyable but the weather has been awful so I've not been able to do any flying at all. We were on the River Severn last Sunday and ahead of us at Upton-on-Severn was a glider, two, in fact, so there must be a club site nearby. That Sunday was the best day of our holiday weather wise, but I was unable to find the time or place to do any flying. The weather today is still pretty appauling so lets hope next weekend is better. No pics today, however I've got a new camera so I'm dying to try it out at the airfield.

Another great flying day

The fly for fun went really well. No-one knows where they came in the competition, but everyone enjoyed themselves. All I can say is I think I came second in the climb and glide event with 4 minutes and 52 seconds of glide from a 30 second climb. Not bad in my book! The events were Pylon Racing, Climb and Glide, Touch and Go in a minute, Spot Landing, and Loops in 30 seconds. Thanks go to Mike Clark and Niel Hincks for organising and running the event.

Another highlight of the day was this Piper Cub built by John Wright and flown by Paul Mancini. The pictures say it all...

Well thats it from me for the next three weeks as I'm doing this instead. However I may just slip in a post or two as much to Lins disgust I'm taking the Ember. Cheers for now!

Fly for fun today...

...and the weather forecast is good. This is a club day where we fly as individuals in competition events such as Spot Landing, Climb and Glide and Pylon Racing etc. I'll be flying my Sunbeam trainer with the Super Tigre 40, and the other Sunbeam (Irvine 25 powered) will stand by in reserve. The Yak would be useless for this as its a bit of an animal.

I'll blog again later today if I can find the time as we're doing this for the next fortnight. If not then I'll write it up when I'm doing this.

Fantastic day

Definitely the best day so far this year. Wall to wall sunshine and WARM! The pits were nearly full all day, that's amazing for a Monday. Jim who was there yesterday said there wasn't as many people.

Good for a Monday

I've been flying the Yak 54 today and doing some engine tuning. The engine runs fine on the ground but when it gets airborne it misfires even at full throttle. I've changed the plug for a cooler type and it has improved a little but the biggest improvement came from a change of propeller. A 15" x 8" Master Airscrew for a 15" x 8" APC. It hasn't cured it but it has improved.

One other little thing, I've acquired an indoor R/C aircraft. It comes complete with everything you need to fly now - even the batteries. On the aircraft there is a very small circuit board with two servos, a receiver and a speed controller mounted on it. The transmitter has trims on all four channels, is switchable mode one or mode two (throttle right or throttle left) and is on the new 2.4Ghz frequency. As there was no wind first thing this morning, and I gave it its first outdoor flights. Its not easy to fly as its a bit twitchy and needs some expertise.

The 16.5" wingspan Ember

I'll finish todays blog now, I'm going to try the Ember in the garden before it gets dark. Until next time...

To the South West Model Engineering Show

Went to the Shepton Mallet Showground to see the SWME Show. A little disapointing really, not much flying going on and then only one aircraft airborne at once with long silent breaks in between. In the halls were a lot of working tanks and militaria complete with owners in camoflague, war gaming enthusiasts and a few interesting Stirling Engine projects, even a radial version. Another interesting project was a nine cylinder rotary, yes rotary engine, an amazing scale working model of a Rolls Royce original. Puts my attempt to shame.

A snapshot of the local Pitney Club stand

I must say I did enjoy the day, but would I go next year?...

Todays forecast is good

I've charged up all three aircraft overnight and I'm getting ready to go flying. I have to go today as I have to work Easter Sunday and Monday. But the forecast is good, so I'm happy. And this means when I get home I'll need to cut the grass for the first time this year. I don't like to cut it too early because it makes it grow much faster and another cut is soon required, but now I have to bite the bullet and get it done.

I tied up the tail feathers on the Ultimate this week so thats a bit further ahead. Theres a lot of work still to be done on the engine, its nowhere near finished.

Ultimate tail feathers

It was a bit breezy up to around 8 mph from the North West and very chilly but the sun shone all day.

I'm so pleased I went today as Gwyn from Cornwall arrived. Last saw him in early August last year. He's here with his caravan 'till Tuesday when he travels to Spain. Its great to see him again.

Gwyn in happy chappie mode

What a day!

Sunny at home, but as I got closer to the Somerset levels the fog was getting thicker, and at WZ it was too thick to fly in. I unloaded the car and parked up and as I was assembling the aircraft the fog was burnt off leaving bright sunshine which lasted all day. Winds were very light and variable to start with but increased later with a Southerly direction.
I'm beginning to enjoy flying the Yak as my confidence in the radio is being restored. I tried some knife edge flying today and discovered the aircraft does it very well, unlike me, and the new canopy stayed intact too, another bonus.
Flew both the trainers, and a former club member visited, haven't seen Martyn for 10 years and he hasn't flown for that time either, so he had to have a go, and he did very well. I didn't have to prise the transmitter from him once. Mind you, when it ran out of fuel he couldn't thrust it back to me fast enough.
Jim flew his Hotspot jet, always impressive, see the video, and he'd been flying an electric "jet" with a rear mounted motor which propels this thing along really fast. the motor turns at 45,000rpm and sounds like a Formula One style V10 engine. Unfortunately something went "pop" and all power was lost. Turns out the motor shaft snapped clean off, losing the prop.

Its early morning...

...and the birds have just started to sing. Earls up and off to a car boot sale (best of luck) and I'm left to feed the cat. Then I'm off flying all day. After all its my only day off this week. The new canopy for the Yak arrived this week and I fitted it last night. Its a better fit than the original and I glued it down with Pinflair silicone glue (from Lins paper crafting) as well as the screws provided. The glue will give it some stability and resistance to vibration. Also I fitted a volt watch monitor in the cockpit.

New canopy and Voltwatch

I've had my fix for the week.

For a Saturday there was a whole load of pilots here today. The weather certainly brought everyone out. There was a chilly wind from the North West at around 1 mph in the early morning, but it gradually increased in speed toward the late afternoon to around 10 mph.

Geoff enjoying a flight with his Mustang

I've made a temporary modification to cover the holes in the wing of the Sunbeam. It flies a lot better now, but I'll have to make a more permanant effort and use Solarfilm instead of Sellotape.

Wing slots temporarily covered.

Ron brought along this nice little delta. All balsa construction with tissue and dope finish - no paint!

Nice delta.

Now I can go to work tomorrow refreshed as having been flying today. Trouble is, two hours and its as if I've not had a week end at all.