Here is a list of all the postings Roger Dyke has made in our forums. Click on a thread name to jump to the thread.
|Thread: Exhaust Cleaning?|
You have given me lots to think about and thank you for the link that you gave to me for justengines. I have already looked at their website but cannot find one with my fixing spacings. My spacing is 34mm which is a lot less than most silencers for a 61. Earlier today I boiled it in antifreeze. This removed a tremendous amount of gunk from the inside. Whilst it was still really hot I tried to part the two halves by unscrewing them (with success). I've tried before without success but didn't know whether they were screwed together or had been pressed together with a machine. Anyway, the half with the fins on (see photo) is just a chamber and is completely empty. The smooth half contains a blanking disc all the way across the chamber with an 11mm hole in it. If you look down it, you can see right through it and out of the exhaust outlet. There is an 11mm tube all the way through this chamber which has rows of 2mm holes from one end to the other. With a small right-angle tool I have I tried to poke into several of the holes to see if it was just a cavity. It wasn't. It appears to have a wool or mesh or something in the cavity. I don't seem to be able to dismantle it any further so I don't really know just how clean it is after it's washing. I don't like to run my engines over 10,000 RPM as I think it helps to keep the noise down. That's why I have the 12 x 7 prop fitted. Perhaps I need to run it in an open field and try the dB meter there.
Could do. I'm not sure where I could put it as it is a pattern flying low-winger with a very wide chord at the root. The wing is removable. Also, the fuselage height above the wing is very narrow. One way or the other, I will overcome the problem.
Thanks for the link. I could do. But as the silencer is mounted underneath the front of the aircraft, I'm not sure there would be room because of ground clearance.
Prop is balanced and the plug is a Firepower 5.
About to have a go at cleaning the silencer.
Denis, I will try my best to clean it out. It probably wasn't the right place to do a noise check. My garden which is 26 feet wide has a tall hedge each side and although the stand was about 50 feet from the house, it was only about 8 feet away from the greenhouse so (you are right) maybe the enclosed environment didn't help. Two photos of the silencer.
Sorry, but I forgot to say. I am using an APC 12 x 7 prop. It is also a 2 stroke engine.
Edited By Roger Dyke on 15/01/2019 06:39:29
I tried the engine on a bench stand in the garden. The engine was about 3 feet from the ground and at full throttle was about 91dB at about 7 metres measured in 3 different places. The silencer looks like one of the extra silent types with a plain section between the main body and the outlet. I would have expected it to be quieter. There is no way that I could use the aircraft at our field with that level of noise.
Thanks for that. I will have to visit the £1 shop. I have a camping gas cooker so I can probably use that in my garage.
Do you think it would have any affect on the noise levels it's supposed to silence?
I have recently rejoined the hobby after a 14 year lay-off. In resurrecting my old models and equipment I have a 25 year old Super Custom 61 engine which runs great. The only problem is that the exhaust which is the type with a 'plain aluminium' exhaust extension has a large amount of brown crud and gunge inside which I think may affect it's performance. It looks like a build up of castor oil/burnt deposit which has set. I have tried to part the exhaust extension from the front part to no avail. If I look down the outlet with a small torch I can see a perforated tube running down it's length heavily contaminated in gunge. The holes in it are not blocked though and it works okay.
Also would this condition affect it's operation? I say this because running the engine at 10,000RPM the sound level at 7 metres is about 90dB.
Any advice on how to clean it out would be appreciated.
Edited By Roger Dyke on 14/01/2019 20:21:13
|Thread: Aeroloop model retriever|
I have no idea what it's made of. I replaced our club's broken one so I could see it's construction. It has many telescopic sections starting at about 50mm diameter or more finishing up at about 8mm. It was the last section which broke (my fault). Examining the broken section it looked like it was made from wood and looked like a black/brown grain very thin and tubular. Thinking about it, the wall has to be thin because at 7 metres extended it would be too heavy to manage if it was any thicker. The pole at 7 metres is quite manageable. It has a nylon loop on the end, to loop around the model. The end section must be treated with respect as it's extremely bendy. My problem was that I got the nylon loop jammed between the tree branches and the model and couldn't release it to free it. After endless trying I used too much force, bent it too much, and it snapped. My plane was 40 feet high and had to use a telescopic extension from home gaffa-taped to the bottom of the Aeroloop to reach the plane. I did manage to retrieve the plane though so success.
Because of it being so thin at the top end, the manufacturers recommend a horizontal lift of 3 lb max only, but more if lowered down vertically.
Would I recommend one? Definitely
The Aeroloop website doesn't work any more. I purchased mine from Sussex Model Centre just over a month ago. In stock price £39.99.
Edited By Roger Dyke on 05/01/2019 18:10:58
|Thread: Christmas wishes|
A very Happy Christmas from me too and a great 2019.
May all your landings be soft ones.
|Thread: Plug Problem?|
As a retired electronics design engineer I had no problem with your request.
The current drawn by the glowplug is 2.8 amps with an applied voltage of 1.24 volts. In reality the current would be a fraction higher as the meter shunt and cables have a small resistance and this was in series with the element. The figures sound about right to me.
I didn't bother monitoring the voltage directly across the plug as I thought just the simple test what I did was near enough.
Edited By Roger Dyke on 29/11/2018 20:14:57
I agree, it does look worn out. I really do not think it is a fake (although no way of knowing) as I purchased it from a top UK Model Shop retailer. The plug has only seen max 1.24 volts from a single NiMH battery. It is about 3 - 4 weeks old from brand new and has seen only about a one hour (or less) running from an Enya 15 glow engine. Engine runs perfectly with another glow plug. This experience has really put me off purchasing this make and type of plug in the future.
Maybe as Nigel says, that their glow plugs are now made by a third party and can be of dubious quality.
Nigel, Ron, and Don,
A few good tips there. I'll have a go.
Thanks for the link. I see what you mean by how it reads. I wouldn't have thought that they would use solid platinum elements though, with platinum currently costing about $800 an ounce (I may be wrong).
I have tried taking a photo but cannot get close enough in focus. still working on it. I have a camera with a macro facility if I can remember how to work it.
It's funny you should mention Model Technics. I have just sent for two Model Technics F5 (medium) glowplugs as I have always had very good service from them.
Edited By Roger Dyke on 28/11/2018 13:06:28
I have just had a look inside the plug with a strong magnifier (no battery connected). From the point where the heating filament is 'welded' to the face of the plug thread to two coil turns inside, the heating element is an 'orange' copper colour. The rest of it as far as I can see as it disappears down into the plug is bright silver. All of my other 'old' plugs are bright silver from one end of the filament to the other.
That sounds like a good recommendation. I will have a look at that. Thank you.
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