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.

Flying today...

...Just for a change. I say that as I've been a bit busy with other things lately. Nothing connected with flying or engineering, but a holiday aboard TQ, and since then, I've been decorating. Finished that for now and I'm moving my modeling workshop into that room. Its a bit smaller but I think less junk will be dumped in there as there's no room for it.

In the process of moving in.

The weather brought out a few more pilots than usual today. Wall to wall sunshine and a (cold) light breeze 6 - 8 mph from the North-West. Flew the Yak and the Sunbeam, and Malcolm asked me to fly his Flair Magnatilla, a maiden flight. Powered by an OS52fs four stroke engine it had plenty of oomph! Required some trim adjustments, and an increase in aileron and elevator movement, and some more down thrust on the engine to stop the "ballooning". All this knowledge is good information for me when I start building my Flair Legionaire for my Ketro KT54fs.

Sorry there's no pictures of todays flying, I forgot the camera.

Flying today after...

...a weekend decorating our bedroom. Eventually it's going to be my modeling workshop and the current workshop is going to be the bedroom. It'll be nice to have a clean start, but at the moment our house is a tip. So I painted the final under coat this morning, and while I was waiting for it to dry properly, I went flying. Took both trainers and the Yak, and actually flew the Yak - twice. It was quite a good day, although cold and windy, around 8 - 10 miles an hour from the North-West, almost on the comfort limit.

I did a proper radio range check on the Yak today and found it had a range in excess of 70 metres. Far more than twice that recommended.
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Conrods and a spinner nut.

Far too cold and windy to go flying today, so more on the KT120fst.

Getting there with the conrods, just the small end bushes to make and fit. After press fitting they'll need to be faced to length and reamered to size.

Another little project I made for my mate Geoff - a spinner nut tapped 1/4" UNF.

Conrods

The fixture I made earlier for machining the conrods is very successful.

Just the thickness and central section left to machine. To give you an idea of the actual size, the bores are 28.5mm between centres. Next is to turn up the phosphor bronze bearings and press fit them into the bores. I'll warm up the aluminium first to ensure a tight fit. Then I'll finish bore the holes to 6mm dia. to suit the crankshaft and the other end to 5mm dia. to fit the gudgeon pin.

A last minute decision

The weather forecast for today was really poor, and it turned out to be pretty good, so I took the decision, bit the bullet, grasped the nettle, and went flying. The wind was from the South at around 6mph and later increased to 10mph. Its what I consider the limit for comfortable flying. Later still it decreased to almost zero, and stayed like that for most of the day.

I took both trainers, ended up flying only one of them, but thats OK by me, though I wished I'd brought the Yak.

Crowded...

It was worth going today, as Ian turned up and flew his Excelsior and F15. Spectacular.

Ians Excelsior




Ians F15 - Sorry about the quality, it was recorded on a mobile phone.

This Also flew this afternoon, powered by twin Irvine 30s.

There'll be no flying this weekend. Have you seen the weather forecast?

High winds and horizontal rain, sleet and hail. Just as well, I can get on with my engineering project. Today I've made a fixture to hold various sizes of conrod and I've set it up on the rotary table to machine one of the conrods for the KT120fst.

For the conrod I'm currently making, a 6mm dowell is required to locate one end on the centre line. For the other end a dowell with a 10mm diameter is used to locate in the slot of the fixture and a 7mm diameter to locate in the big end of the conrod. So now I can machine various sizes of small end/big end/hole centre combinations.

Fixture for machining conrods

The process begins

...And I've made a start on machining a conrod.

...And I've finished the crankshaft...

Alignment and concentricity end to end is a lot better than expected.

More next time.

Its Sunday and guess what?...

...Its blowing a hooley. This is the first day for weeks where the weather has been too rough to fly in, and today is my only day off work. Oh well, its to the machine shop today. First job was to weld some extension tabs to the baffle plate on the inside of our multi fuel stove. It would occasionally fall down onto the hot coals and I'd have to let the fire go out before I could refit it. Hopefully this will stop this from happening.

Our multi fuel stove - repaired.

I've not done much to the engine over the last few weeks as I've been doing other things (Christmas etc.) however today I've had a go at the rear end of the crankshaft, and formed the shape of the counter weight. I still have to drill and tap the clearance hole and M3 thread for the grub screw, then this part will be finished.

First step is to set up for drilling 3mm holes to form the corner radii

Sorry, they're a bit out of focus - trying too hard to get the detail in.

This unusual clamping method was the best way I could devise to hold the part firmly enough to machine into the 3mm holes.

Using the unusual clamping method to mill the 109 degree angle set up using slip gauges.

Sorry about the focus.

Back from the Christmas holidays.

Trust you all had a great Christmas, and here's wishing you a Happy New Year. Check out my other blog to see what Lin and I were doing.

Yesterday I was in the machine shop and I fitted the present Lin gave me for Christmas to the Milling machine. I then proceded to set up for milling the other counter balance weight as I did on the front part of the crank shaft. I've only done the setting, I've not cut metal yet as there were some dimensions I needed which were omitted from the drawing.

Those dimensions have now been added to the drawing, but today I'm going flying. More later...

OK its now later, and a great afternoons flying. There was no-one there, and the weather was very dull and the temperature was 1.5C, but the wind was non existant, well maybe a slight air coming from the SW. I took the two Sunbeam Trainers and flew both. One distinctively flies better than the other and I can only put it down to the slots in one of the wings. They don't work. I've been meaning to cover them up for ages but I've not got round to it yet.

No more blogging 'till the New Year

Which leaves me to say have a Merry Christmas and Happy New Year, and thanks for watching this space in 2008.

A great flying day so no engineering.

I took my time preparing stuff this morning, and until very late I was undecided as to which aircraft I was going to take. Finally I chose the Sunbeam and the Yak54. Both flew superbly although starting was a little more difficult probably due to the low air temperature, after all it is winter. At this time of year I tend to use fuel with 5% nitromethane mixed in to help with cold starting.
Met Geoff at the airfield and he brought along his Mustang which was developed from a trip to Cornwall earlier in the year. That's another story.
All in all a lovely day, wall to wall sunshine, and just a light air moving from the North East.


Yak54 in the late afternoon sunshine.

Geoff with his Moki powered Mustang. The tail wheel bracket failed just before this picture was taken, and that curtailed its flying for the rest of the day.

More on the Crankshaft

A day off work, and as the weather forecast is better tomorrow, I'm in the machine shop today.

Finished the front crankshaft part, see pix below:-

I've made a start... To give you an idea of the scale, the 3 jaw chuck is 80mm dia.

A 6mm dia. pin is used to aid setting.

Nearly finished, just the 3.1mm dia. clearance hole and M3 thread to be cut.

Finished and assembled to the centre web with an M3 grub screw.

The hole is clearance size down to the centre and threaded into the 6.0mm hole where the centre web assembly is clamped with an M3 grub screw. Sorry the photo is a bit out of focus, I wanted to get as close as possible to show greater detail.

Flying tomorrow - with a bit of luck!

What did I say?

I was spot on yesterday when I said today the weather would be glorious. Its been wall to wall sunshine and light winds all day - aaargh!

No flying again today...

...but you wait, tomorrow will be glorious when I'm back at work - 'hit happens, aaargh!

So, into the machine shop for some more exciting swarf making. This engine I'm building is my own design, and I'm drawing it up on AutoCad before making the parts. Occasionally I have to go back to the drawing board to make alterations to the drawings because in practice, sometimes things don't quite turn out as you'd expect. Its called research and development or R & D. The engine I've named, the Ketro KT120fst. is 1.2 cu.in., 20cc swept volume and about 22cc full capacity. Its a horizontally opposed twin cylinder four stroke engine also known as a "Boxer".

Centre drilling position for the crank pin.


Having drilled the hole its now ready for reamering.



Finished, and its a good fit.

All the bearings arrived this week, so now I'll be able to finish the diameters on the crankshaft parts, as I will use each bearing as a gauge to test the fit.

All the parts together, nearly finished. Just the counter balance to mill and the holes for the clamping screws.

And yet more engineering

It looks like this is going to be the norm for at least the rest of this month and probably well into December as the weather situation is leaving a lot to be desired. Even the long range forecast doesn't look promising. Anyway it gives me a chance to get on with the Winter project. I'm hoping to have this engine fitted, working and flying early next year. No pix today, (sorry) but I've started on the rear part of the crankshaft. After I'd nearly finished it, it didn't look right so I had to do some cross referencing with the other drawings, and indeed I found an error. Having now corrected the error I can proceed with the part. Luckily nothing was spoiled. The other thing is I've ordered all the bearings for the engine. Six in all, but one size was not available in britain (would you believe it?) so I had to get it from Hong Kong of all places. Then I had to buy ten and I only needed three. Hey ho!
Soon I'll order the cross helical gears for the gearbox. These come in mild steel and will need to be case hardened. The supplier could do that for me but the extra cost makes it more than prohibitive, so I'll do that myself. It was successful on the KT54fs I made earlier, so it should be OK for the KT120fst too.
More on Sunday 30th all being well.

Very bad weather all week-end - NO FLYING...AGAIN!

So more engineering. I've made a start on the crank shaft front part. All the diameters are turned and the M6.0 hole has been tapped. Its now ready for parting off. I'll do that with a hacksaw, and although this sounds a bit crude its my preference in this case as the part protrudes out of the chuck by a long way. Parting in the conventional way would be a bit risky.

Notice the DTI on the cross slide to assist with accuracy.

Turning the 10.0mm dia. Revolving centre for support and helps prevent chatter.

Ready for parting. Note the M6.0 thread has been cut.

Oh! yes, and I've cut the flats on the central web as seen in the log below.

More engineering today

Made the central crank web this afternoon, turned up a piece of mild steel to 29.5mm Ø, drilled a 6.0mm Ø tooling hole in the centre, and parted it off to 3.0mm thickness. Placed it in a 3 jaw chuck mounted vertically on the milling machine, and clocked the tooling hole to centre it on the machine. Drilled and reamered 2 holes through 6.0mm Ø in 'Y' +10.0mm position and 'Y'- 10.0mm position.

Then I cut off two pieces of 6.0mm Ø silver steel to 17mm length, and silver soldered them into the central web. I've not cut the 3.1mm wide flats yet, that'll be done the next time I work on it. Check out the pictures...

No flying today, poor weather conditions

The wind was blowing a hooley today, so I spent the day in the machine shop. Finished the finning on the cylinder heads, and now I'm thinking about the crank shaft design change. I have to enable the use of one piece conrods due to lack of clearance on the lower parts of the cylinders and the pistons. This will necessitate the design change from a one piece shaft to a three piece.

Some pictures as promised

After a bit of household maintenance this morning I managed to get out to the machine shop to do some work on my KT 120fst engine. I've been looking at the Cylinder Block and thinking that it probably won't make as the design is at the moment due to the large size of the big ends. So I'm thinking about making the Crank Shaft in three pieces to enable attachment of one piece Conrods. Anyway, enough of that, today I set up the mill with an angle plate and a fixture to cut the fins in the Cylinder Heads. Take a look at the photos, they can explain far more than I.

Angle plate & fixture mounted on the machine bed

Close up of Starboard Cylinder Head prior to finning

Cylinder & Crank Case with Sleeves fitted

Cylinder & Crank Case with Port Head & two Pistons

1.5mm slitting saw used to create the cooling fins

A late session

Went flying today, though I didn't go until late in the day, had some jobs at home to do first. Arrived at Westonzoyland Airfield at around 16:30hrs. Light winds from the West and glorious sunshine - and there's no-one here. Only brought along the yellow/red Sunbeam and the Pico-Jet. The replacement li-po charger arrived this week, and I'm now about to test it out having had a flight late this afternoon. Oh! yes, and the bearing fell out of the motor again. The Super Tigre engine in the Sunbeam ran well today although it was a bit difficult to start. It seemed I couldn't get enough fuel through by choking so I primed some fuel directly into the carburettor, and then I flooded it, but once it was running it was quite reliable in the air.
As the sun went down the wind dropped and my last flight was dead smooth, even at very low height. Flights like this are rare and are the most satisfying.
I intend to do some work on the engine I'm building tomorrow (Oh! did I not mention that?), so I'll try to include some pictures.
The weather forecast for tomorrow is crap (light rain and sixteen mile an hour winds) and I have to work on Sunday, so that's it for this week as the clocks change early Sunday morning. Winter has arrived.

Early Morning was Best

Yes, the weather took its toll on todays flying. I arrived at the airfield at 09:15hrs and it was dead calm. By 10:00hrs it was getting windy and by 12:00 it was rough. Took both trainers again and flew both and I flew the Pico Jet but there is a problem with the motor, there is excessive "slackness" in the bearings so I only had the one flight. The Super Tigre engine in the trainer is behaving better so I wonder if the problems were related to running in. I'm still a bit disappointed with the power output so I might experiment with some different glow plugs, fuel and propeller combinations. By 12:30hrs I'd had enough, the wind was cutting through me and I could feel my core temperature was beginning to fall so I packed it all back in the car and went home. At least I've had my fix for the week.

A Good Sunday

Probably one of the best flying Sundays this year. The weather has been amazing for Autumn, today starting off foggy but by 11:00hrs the sun burned through and resulted in a hot day. Took both trainers, the Pico Jet and the Yak 54 to Westonzoyland. A lot of pilots turned out to fly although I suspect the early fog put some off. I meant to have covered the slots in the red and white wing this week, but I've been too busy with other things. Thinking on (careful), perhaps I should try covering just the white section. Maybe all the sections are too much - hmmm. Worth a try.
The Yak was a bit unnerving today, my fault, there were a lot of other aircraft flying at the time and I was trying to fly Knife Edge. Got myself in a disoriented state, and near panicked when I wasn't certain which way up the aircraft was after I leveled the wings. Upright - phew! that was close. Time to land, too many other aircraft flying lead me to distraction. Or should that be destruction?.
The Pico Jet performed well, but is a bit lively on the controls and the motor is continuing to resonate at certain revs. Still not sure whats causing it. I'll check the propeller balance and also see if the motor does it without a propeller. With regard to the "lively" bit I think I need a little weight removed from the tail end of the aircraft. I always reckon to do it this way rather than take the easy option and add weight to the nose. I can't remember the last time I added weight to the nose of an aircraft. The need for this change is as a result of the use of Li-po batteries replacing the much heavier Ni-Mh.
The Super Tigre engine in the other Sunbeam is still playing up, I've been experimenting with the carburettor, but with little success. The spray bar position is adjustable, and its important (allegedly) to get it right, and I've found it does make a difference when its adjusted, but it doesn't seem to stop the revs from surging at the top end. I've found to stop it, I need to richen it up a lot but on closing the throttle and opening up again the engine runs extremely rich and needs to be leaned. There is nearly a happy medium I can use but it ain't quite right yet.


Its not likely there will be any mid week flying from now on untill the clocks change again next Spring, although I might be able to get the odd Monday in as shift work and weather allows.

Last of the Summer Flying - Revisited

I lied about the previous entry. Who would have thought the weather would have been some of the finest of the season at this time of the year. Wall to wall sunshine this evening. Last week I was on holiday and it rained every day, sometimes horizontally. This week there's hardly been any rain at all. Just my luck! Never mind, had a few flights with the Sunbeam trainers and I'm not happy with the slots and flaps on the red and white wing, so I'm going to cover them over. Thought I'd try inverted flight, and it was hopeless. Full down elevator required and still the aircraft decended. Those slots have got to go.
Two flights with the Pico Jet and as always good entertainment. Motor is making some strange resonating noises at certain revs. Don't know what this is all about, may need investigating.
19:00hrs., and its too dark to fly. Clocks change soon, Winter's on its way!