Topic: SE5 restoration

OMG that is so beautiful! I will have to start looking for a model to justify one!

OMG that is so beautiful! I will have to start looking for a model to justify one!

I will have to start looking for a bank to rob so I can afford one!

OMG that is so beautiful! I will have to start looking for a model to justify one!

You need to build one! I have only got into this building lark because I couldn't find a model big enough for me! Once I had flown a large model I preferred it to the normal sized planes. Big models fly in a much more realistic way.

Giles

If you do decide to route the exhausts through scale pipes then I’d recommend that you use Laser flexi pipes silver soldered to brass pipe and not the rubber.

See the link below!!

http://www.scale-models.co.uk/showthread.php?t=708&page=10


Exhaust smoke exiting the model in the correct place is always a bonus and with your V Laser you’ve got the perfect set-up to enable you to do just that.

Grahame

Thanks for the info about the flexi pipes, I did talk about them with the chap at Laser engines so I'll go down this route when I get there. I must finish off the scale details that I've skipped over too.

What do you think about the engine mount Grahame? You can see a picture of the back of the engine in my recent posts. There are four mounting holes to hold the engine to its mount. How would you do it?

Sorry but I can’t talk with any confidence about radial mounts, my Lasers use “standard” engine bearers, I can’t afford a twin more’s the pity!  But for what it’s worth this is how I’d tackle the job.

I would make square “rings” of ply with the square closest to the back-plate not cut out.  Laminate the rings to give the required thickness, glue everything together with epoxy, then use bolts long enough to pass through the lot into captive nuts in the original bulkhead. I wouldn’t glue the unit to the bulkhead and then if necessary you could adjust the thrust angle by placing washers between the mount and the bulkhead.

This sounds about what I was thinking, but I hadn't thought of ply, although it makes perfect sense. I don't have to use captive nuts in the bulkhead as I have easy access to the other side. I like the idea of laminated ply though - very strong and unlikely to crack! I can't get on with this until the middle of the week - very frustrating.

This engine has been quite an outlay, funded by selling off all sorts of bits of Ford Capri that I didn't need anymore. I was happy to spend the money on what promises to be a life long modeling companion. I find that swapping engines from one model to another is easy - in other words once an model is set up for an engine it is quite simple to put it back in from being used in another model.

I will need bolts that are 80-90mm to run from the engine, through the plywood block I'm going to make, and then through the bulkhead. I'm wondering if threaded bar would be OK for this as I'm struggling to find 4mm bolts that are this long.

Well Giles,

The Laser is looking good and I'm sure your SE5A will be great with it but have you seen the photographs of that other little SE5A restoration job there doing at Old Warden?     

Spider Pig brought these photgraphs to my attention 'cos of the Storch shots but look at the SE.   It's looking absolutely fabulous!  I feel a trip to Old Warden coming on very very soon

http://forum.planetalk.net/viewtopic.php?t=4873

Alan B

That does look very nice, I'm looking forward to seeing that one when it is complete. I wonder if there are any other original SE5's left in the world?

There's one at Hendon and one in the Science museum apparently, one in  Canberra australia

http://www.sciencemuseum.org.uk/objects/aeronautics/1939-324.aspx

http://www.houseoftheorangemonkey.co.uk/monkey/trips/trip4611.htm

erm

http://www.rafmuseum.org.uk/london/collections/aircraft/aircraft_info.cfm?aircraft_id=89

however, the shuttleworth one is the only one that flies......... ::cc

I've been making progress installing the Laser Twin. So far so good, and I wanted to post some pictures to see if anyone can spot me doing something wrong!

Here you can see the general layout. Two fuel tanks, each feeding its own carb. There is a breather for each tank pointing forwards on the top of the fuselage as required by the Laser, and there is a separate fill for each tank underneath.  Vertically, the fuel tanks are in line with the carbs.





I had a stroke of luck when I found that the throttle servo position I'd been using for the Super Tigre was exactly the right place for the Laser, very handy.

I bought two remote glow units, but now I find the plugs are so recessed into the top of the engine that the remote glow 90 degree rubber thingy is not long enough to reach the plug. Blast! I suppose I'll have to have a hold in the cowel on each side to connect the glow sticks directly.



Seen from the front it looks lovely. However, it all needs blanking off to force the air through the cooling fins. The entire bottom of the engine bay is open, an area of about 6 inches by 4 inches. The exhausts point straight down through this hole.



Is this much blanking too much?



This is the plywood mount I've made. 5 layers of 9mm ply all epoxied together and M4 stainless steel threaded bar running from the engine through this plywood and through the bulkhead to large washers on the fuel tank side of the bulkhead. Should I use spring washers on here? What about threadlock or superglue to stop things coming undone? I'm going to paint and varnish this ply to stop it getting fuel soaked.

Giles South Herts Models make an excellent glow clip called a cent-r-lock or similar its designed for deep recessed heads and grips excellently onto OS type glow plugs this may be what you're looking for it would be a shame to put unnecessary holes in the cowl after all your hard work
http://www.southhertsmodels.co.uk/index.htm

Giles
Can't you extend the centre posts of the plugs with copper tube so that you can use your remote connectors?
Mike

I agree, you don’t want to cut holes in the cowl where there shouldn’t be any, while you’re about it why not extend the tank vents and let then stick out slightly through a couple of holes in the front “blanking plates”.

To connect my remote glow I use one of the metal bits from a 2amp terminal strip; the type that have 2 screws set into a small brass block for each wire and come in strips of about 10.  Remove the screws and the brass bit will usually push out.  I use one screw to hold it to the glow plug, before I fit it to the engine using a tube spanner, then the wire from the remote glow connection is simply held by the other screw.  Makes a really good contact and as an added bonus it’s dead cheap!

Thanks for the ideas chaps, I'll have a look at lengthening the plug.

What about the baffles at the front - does this look about right?

I don't know why I didn't think about running the breather pipes to the front of the fuselage - a much better idea!

The baffles look perfect!  There’s no point having air entering the engine bay that doesn’t cool the engine by flowing through the cooling fins, in fact it’s detrimental to the engine cooling; so long as there’s enough for the carbs that is!  I'd leave them as they are then test run the engine, but I'm sure the carbs will get enough air, if your cowl is anything like mine it won't be airtight.

Agree with Greyhead, the baffles look great. Air will enter the front at full frontal area, then it gets forced between the fins and the baffle, this air therefore speeds up as it goes through, perfect.

Looking great matey

Ian.

Air inlet is fine, remember to have a larger outlet than inlet, normally 3 x.

I used to use the core from curtain wire - you know the stuff like bowden cable outer?  Take a 1/2" length, remove the covering from the end couple of turns and stretch it slightly until you've got room to solder a length of moderately heavy flex on, then cover with heat-shrink tube.  Solder tag on a second cable, under a mounting bolt  gave the return, with a conveniently sited DC power socket (like a Futaba transmitter charge lead fitting) providing an external connection.  The curtain wire I had was a nice spring fit on the centre of a glowplug, and proved reliable over a couple of years of weekly use on a Tiffie.   

Hello everyone,

I was able to fire up the Laser twin at the weekend for its first run:

<a href="http://www.youtube.com/watch?v=A8S9MMCN-2s" target="_blank">http://www.youtube.com/watch?v=A8S9MMCN-2s</a>

It started first time and runs very nicely. I have to run it in now which I'll be doing at the model field.

I'll be making a new cowel for the model, and I think I'll need a hatch so I can get my fingers in to choke the carbs to get the fuel through as spinning the engine over on full throttle does not pull it through. I shall also make up a return fuel pipe that will attatch to the breathers poking through the front plate and will run back to  the field box so I will know when the tank has been filled.

I will also be making up a new front plate with radiator details etc - all in good time.

Giles

mmm, sounds gooooood!

Can just imaging those long slow low flypasts ..... on high tickover..

That is a truly heavenly sound! awesome

It's a great looking model,

oh yes I'll have abit of barnstorming!

Both sounds and looks lovely.  I bet you're anticipating some excellent flights.

Can't you draw fuel through simply by restricting the exhaust outlets?  That method works OK on the OS52 Surpass 4 stroke in my own Flair SE5a and has the merit of simplicity.

Geoff

The Laser does not use the forced pressurised fuel tank system, the tanks are able to vent to the open air, so restricting the exhaust to force fuel through does not work, which is a shame because as you say it is very easy!

That sound has just destroyed my desire to go for a (2 stroke)petrol engine!

The Laser does not use the forced pressurised fuel tank system, the tanks are able to vent to the open air, so restricting the exhaust to force fuel through does not work, which is a shame because as you say it is very easy!

Ah,yes - good point.  OK, how about blowing down the vents?

Geoff

No need to cut holes in your cowl, this is how I prime my fully enclosed Lasers.

As you suggest I also use a fuel line from the breather / overflow pipe(s) back to the fuel bottle, both feed and return pipes have plastic fuel line clamps on them.

With the throttle closed fill the tank and allow some fuel to return to the fuel bottle, I’ll explain why I do that later, then reverse the pump and “suck” the fuel back to empty the return line.  This stops any residue of fuel in the breather pipe dribbling out all over the model when you remove the return pipe.

Before removing the return pipe clamp it off, fully open the throttles and give the pump a short burst, this forces fuel into the carburettor.  If you practice with the cowl removed you’ll see fuel drip from the carburettor and soon get to know how long a burst is required to prime the engine.

You also needn’t to cut holes to get at the needle valves; with a Laser once set they won’t need to be constantly “tweaked”.  If they do then there is something wrong, probably a blocked fuel filter.

Talking of fuel filters, call me paranoid if you must, but I use them on every fuel line except the return line to the fuel bottle. I fit fuel filters to the following fuel lines for these reasons.

Fuel line from fuel bottle: to stop any contamination in the main fuel bottle getting into the fuel tank.

Fuel filler and breather pipes:  as the engine uses fuel from the tank it is replaced with air drawn through these pipes.  During the take off run there is a lot of dust and grass cuttings thrown up by the prop blast which would be sucked into the tank.

Crankcase breather pipe:  it is usual practice to extend the breather to the bottom of the model to get rid of the oil expelled from the crankcase.  As the piston moves up in the cylinder air equivalent to the engine capacity is drawn into the crankcase. I know this isn’t a fuel line but grit in the crankcase is definitely a thing to avoid!

Tank to engine: shouldn’t really be needed but just to be on the safe side.

Allowing the fuel to flow back to the main fuel bottle when filling the tank clears any muck caught by the breather pipe filter, which is usually the pipe closest to the ground and hence most likely to get blocked.  The fuel filler line filter is the only filter that sometimes gets blocked and if this happens it is a simple job to reverse it and pump some fuel through to clear it.

Whilst on the subject of filters, I always use air filters as per the nitro car people: grit in the valves is also not to be recommended.  Remember, filters are cheap, engines are not!!

Excellent advice as ever, thanks Grahame.

Speaking of adjusting the mixtures, I didn't find much difference as I adjusted the needles on the first run, in other words there was not the same ammount of difference in the running of the engine for quite a bit of movement of the needle, but as you say they shouldn't need adjusting anyway!

4 strokes in general but Lasers in particular are nowhere near as critical of the needle valve settings as 2 strokes.  Once your engine is run in and set up correctly you really shouldn’t have to adjust the needle valves unless you change something else like your fuel or prop size.

I shall add some more filters as you suggest, I have plenty so I might as well fit them.

My next task is to make a new cowel and rocker covers. The old one was first made for a petrol engine before I owned the model, then it had the Super Tigre with the old home made exhaust and then I made it fit for the dustbin silencer I bought from that delightful gentleman at World Models - so it needs a new one now.

I am planning to fit new rocker covers to the fuselage and have holes through the litho cowel for them to poke through. However, for my first flights I will be adding the new cowel for the flights and adding the details later.

I also need to remake the front plate for the fuselage - the panel which the propeller sticks through and where the radiators would be. Again, I shall be doing this later as I want to make sure everything works properly first!

Right, I need to start thinking about a tail skid hinge. I've made two which have not laster more than a couple of flights. One was using a large Kavan plastic hinge, the other was home made using a small brass tube as a hinge.

Can I have some suggestions on the best way of hinging my tail skid. It uses a closed loop. I'll upload a pic later.

Here are some pictures of my tail skid.

I have used a plastic Kavan hinge and also I made up a hinge from a brass tube bound to a piece of plywood and epoxied on with some piano wire running through it. Both of these methods failed because the strength of the hinge was not enough to take the force that goes through it, presumably when I'm landing and taxying and using up elevator to control the model there is a large ammount of force pushing the tailplane down and if the hinge is weak then it will come apart.









You can see the remains of the hinges and the bits of ply left in the fuselage side - all in all a bit of a mess.

I was thinking this morning that a small metal hinge from a hardware store might be a good option, although being so far from the centre of gravity the extra weight will be significant. Also - having a strong hinge is one thing, fixing it to the wood is also important othewise the hinge will simply pull out!

Any thoughts chaps?

In other news I have made a good start on my new cowel and I have bound the undercarriage using the elastic cord I got from a sewing supplied place a while ago. Pics to follow.

Giles,

How about making a hinge up out of brass tube, washers and piano wire?  The main thing you want is a thrust surface so washers soldered to the end of the fixed and moving sections will provide a bearing surface for the end load ie the weight of the backend pushing down.   You could probably get away with bonding the tubes to the structure although adding brass tabs or straps would make for a much better job.   Shouldn't have to be very heavy.    Does that make sense?  If not I will do a sketch to try and clarify things.

Alan B 

Alan, thanks for the reply. What you suggest is coincidentally what I did last night. I'll get a picture up soon but my camera has gone off for a repair! I've got brass tubes and piano wire running through them. I need to add the washers as you suggest to take the load though.

I had my first flight of the Laser V-Twin yesterday. What a fabulous engine, it has the right power for the model, it sounds superb, I'm very pleased. I'll try and get some video footage of it flying next time I go. The tickover low fly-bys were a joy.

My new tailskid did not survive though. I am going to get small steel hinge and use that. It needs something with more strength and a proper hinge should have it. Also, my undercarriage has had a problem too. The piano wire axle has bent and one of the wheels kept coming off on landing, some improvements needed. The bungee I used for the suspension did work though. Just teething problems to solve.

Also, I tried adding two 8 inch silicon pipes to the exhausts of the Laser - and it achieved 100rpm more on the tacho at full throttle. I'm very pleased about this as it means I can make up a scale exhaust, exiting the cowel on either side of the fuselage and running down the side of the aircraft. I'm going to mock this up first so I can do some trial flights and see if it works before I spend some considerable time making up a nice scale compromise to get this working. What an achievement it would be to have the exhausts working down each side of the model.

Good news Giles.  I look forward to seeing the video.

The working exhaust is a good idea.  I did think about it on my Flair version but couldn't find any suitably light tube.  It's broken (both lower wing tips and ailerons) so I've rather lost interest in at the moment.   A major benefit of course is all the muck should avoid a large amount of the aeroplane, a big draw back with glows I'm finding these days.   What we want of course is an engine that sounds like a Laser 4 stroke, has the cleanliness of a petrol engine, doesn't seize up on the second flight (Ah Ali?) and doesn't break the bank.   Any ideas anyone?   I need one for my Storch.

Alan B

Hello all,

I've been thinking about what to use for the length of the exhaust itself. I'm planning to make up headers like these:



from litho plate using a female mould chiseled out of mdf or something similar. A bit of a challenge given my limited litho skills, but I need to make four of the same thing so I get lots of practice, and I've got lots of litho! The idea is that the silicone tubes I'm extending my exhausts with will fit into these headers and then I'll attach as long an exhaust as I can get away with on the end.

I've found a company that sells aluminium tubes in all kinds of sizes. I'm hoping to experiment with the length of exhaust pipe. However, they speak in imperial, I don't! Can anyone tell me how thick say 10 swg is?

http://www.thealuminiumshop.co.uk/acatalog/Online_Catalogue_Alloy_6082T6___General_Purpose_Engineering_Grade_24.html

I'm going to tune the engine using a tacho and get the tubes as long as I can for the highest rpm - is this the best way or am I missing something?

I'm going to be making up a quick version of this exhaust design over the next few days, hoping to fly again at the weekend. The idea being I won't spend ages making up a lovely scale version only to find it does not work properly!

I Believe that 10 SWG is equal to 3.250mm      ,   but maybe one of the other guys can confirm this?

Personally I’d be tempted to make the pipes from brass tube and silver solder another pipe to join up with the silicone, the litho headers would be for show only and fit over the actual front section of the pipe.  I doubt that you could join litho plate together to make a joint that would take the pressure of the exhaust gasses.

I’ve extended Laser exhausts quite considerably and never had any problems with either the reliability or power but it always makes sense to experiment first.