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Laser Engines development.


Jon - Laser Engines

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I was going to revive the old thread we had on this topic but it was suggested by the mods i start another..so here we are.

Firstly, i want to know how many people would be interested in a reduction drive for our engines. The idea would be to drop propeller RPM to a much lower level to reduce noise. Props make a great deal of noise and a larger prop at lower RPM is much quieter and more efficient. If these were available would you want to retrofit one? What sort of price would be reasonable?

As a guide, the smallest engine i would attempt to convert would be a laser 100. Using this as a base line, you would exchange (in theory, i gotta test it!) 15x8 @ 8000rpm for a 20x14 @ 4500rpm. Fitted in a scale model this would also look great, and perhaps allow the use of 3 blade props in a warbird. These could be made available for a whole bunch of engines and would be well suited to our twins. If you would actually buy one, please post your comments below.

Part 2, Many of you will know there are a number of things i am working on in the background and i am making some headway. Our new fuel is being tested by a number of guys with positive results and there is also a move to get 180 petrol development back on track as well as the potential for some new glow engine designs.

What this means is i am going to need people to give me a hand testing new engines.

The exact format is yet to be worked out but we are going to have to have some sort of system in place to prevent the same problem i had the last time i sent engines out for testing where only 3 of 10 people actually used their engines. Its a real shame, but the whole thing is pointless if i get no feedback.

In essence, when the time comes the engines need to be fitted and in the air immediately. No asking for one for a project that is a year away and no wanting one just to be the first to get one and stick it on the mantle piece as its likely there will be only a few of each available. I need them fitted and flown within a week and the engine may become available at very short notice. If that is not for you please dont ask for one.

Also note that these will all be prototypes and not production spec. The engines may be a bit rough and ready and while i will do my own testing ahead of time they might need parts changed or updated as we work through the testing. They might have to come back to the factory if things to wrong and the model might be grounded as a result. There is also a chance the engine might stop so i wouldnt recommend fitting them to a model you spent a decade building. If you are not prepared to accept potential inconvenience of this nature, please dont ask for an engine.

So with all that in mind i need a show of hands for those willing to test one or more of the following:

Petrol 30cc
Glow Multi cylinder 25-30cc
Glow Multi Cylinder 50-60cc

Take your pick and let me know.

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Jon,

Sounds like a great idea, because my standard off-the-shelf model engines seem to be borderline re the 82 db limit. But, I would need to know a little bit more before committing, e.g.

- Roughly what would be the weight increase?

- If the reduction drive is to be offset from the crankshaft, by roughly how much?

- What proportion of the power would you expect to lose in the drive? (This one not so important.)

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Jon,

  1. Petrol 30cc
  2. Glow Multi cylinder 25-30cc
  3. Glow Multi Cylinder 50-60cc

I have my Yak with a 180 in it from the Hurricane so the airframe was cheap, its easy to fit different engines if needed and it glides a bit better than a manhole cover!

If you want a petrol thrashed I can do that, but I'll give it back at the end.

A multi 25-30cc... bring it on and I'll give it a go

Multi 50-60cc would like to but don't have anything that big to stick it in...crying…...unless it was a pair!

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Posted by Doc Marten on 06/07/2020 14:06:56:
Posted by Doug Campbell on 06/07/2020 14:03:44:

None of those. A return to smaller engines please

Jon has already stated with his reasons why this is a non starter I'm afraid.

Must have missed that what did he say? I realise that economically they would cost as much as a larger engine but I would pay that for a 30 or 40 size Lazer

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Posted by John Stainforth on 06/07/2020 14:26:18:

Jon,

Sounds like a great idea, because my standard off-the-shelf model engines seem to be borderline re the 82 db limit. But, I would need to know a little bit more before committing, e.g.

- Roughly what would be the weight increase?

- If the reduction drive is to be offset from the crankshaft, by roughly how much?

- What proportion of the power would you expect to lose in the drive? (This one not so important.)

Weight increase, dont know until i build one. This is just an idea at the moment.

Power loss, see above as i have never tested one but a few bearings and a gear is not likely to suck much power away.

Offset, yes it will be offset on singles for 2 reasons. First, the whole thing is more cost effective with as many common components used as possible. As such the drive will be 45 degrees off centre to suit the V twins where the drive would then sit between the cylinders. On a single, this will mean its off centre like the old Webra used to be. Its not all bad news though as this allows cooling air to the cylinder which would otherwise be obstructed and this is the 2nd reason why i am happy with the offset design.

Frank, can you message me with your email address. Im going to start a new list of people who want stuff as my old ones are so out of date it just not worth it.

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Jon, thanks for the reply. Of course, what matters for a scale model is where the propellor shaft is, not the crankshaft. Warbirds with V-engines such as the Merlin had the prop shaft offset upwards, which I think is what you are suggesting. For an upright mounted engine, the position of the crankshaft and bulk of the engine would then be lower in the fuselage, which could be beneficial as far as tank positioning is concerned (which is not currently a Laser strong point). Also, it might make it easier to hide the cylinder heads entirely in the fuselage. And then there is that added noise benefit; could even win back some of the lecce modellers and have them pulling the load-speakers out of their planes.

Anyway, sounds like a great project that could be very popular among scale modellers.

Edited By John Stainforth on 06/07/2020 17:08:07

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Hi Jon,

The Idea of retro fitting a reduction drive sounds very interesting. The reason being I’m away to start building a Jerry Bates Yak 11. Estimated weight 20+ lbs, It has a 11” cowl and the engine I was going to use for it was my Laser 180. I have had about 20+ flights with it in my light weight and streamlined Seagull Chipmunk and it has more than power for that. Recently I have been thinking the Yak would need a bit more, 300V or 360V. The extra weight wouldn’t be a problem. I know this is R&D and everything needs to be tested, But do you think the 180 with reduction would be more than enough for the Yak? Would the reduction be geared? Requiring an opposite hand prop or belt driven?
Price wise..?. .I'm a CNC machinist to trade and know about set up times, Large batches are always more efficient!

As for a multi glow... It’s got to be a radial, 3 or 5 cylinder. The 5 using your small cylinder heads the 3 cylinder using either big or small ones.

as for testing I’m not flying this year but I have got a 20+ year old President T240 as a hack I can bolt anything on but I’m not flying until next year.

All the best with your R&D

Vince

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Hi Jon

I have a 30% tiger moth which would be much better with a suitable laser than with its zenoah 38 .A 50 /60 cc single or a n in line twin would be great . I am also thinking of buying another 180 for my favourite hack .I bought a DB SE 5 and took the 180 out to power it .I could guarantee regular flying and regular reports if a petrol 180 was available

Alan

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Thanks for all the input.

Gearboxes are something i am keen on and clearly its of interest. However, if it was available as a bolt on accessory for what, 100 quid? would you actually buy one? I cant say for sure if that is how much it would be, but its not likely to be less.

On the testing side I have had a few PM's and wanted to clarify something about the test vehicles.

Whatever model you have in mind as a test bench dont worry too much about how well the engine will fit. The point here is to fly, fly, and fly some more. Richards wot4 extreme, wot4 x, acrowot xl etc are all perfect test benches but each will need a new cowl made to suit. Just bolt the thing on mad max style and roll with it. I dont care what they look like, they just need to fly. Once testing is over and the engine proven, then its time to fit it into that scale model and make it all look perfect.

Richard w2, drop me a line with your email or call me tomorrow

Vince, no radials at this time im afraid but if this little lot works out i will push for them as my 90cc 3 pot design is more or less done. A quick look at the yak tells me it needs a 300/360 but if its ok could we shift that conversation to another venue as i dont want to get off track here.

Alan, give me a call/email as well. I can fill you in as i might have the perfect thing for the tiger.

Also i dont want to over promise but a conversation with the boss today has me both in shock and actually excited about potential future prospects for the first time in many years. Fingers crossed i can start to offer more as time moves on.

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Jon,

I appreciate that OS used to make a reduction drive, but don't kid yourself that they are simple, if you plan to still use the propeller as the flywheel.

Thielert had no end of trouble putting a reduction drive on what started as a Mercedes A class engine. By the time they got it right, the company was in administration, and is now owned by the Chinese. A friend of mine has a BMW flat twin motorcycle engine in his microlight, and that has a centrifugal clutch between the engine and gearbox to isolate the gears from the destructive idle RPM region.
Robin

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At @ £100, a bolt on gearbox conversion would be something I would be very interested in - unfortunately I don't see any way it could be accommodated in my current build [very short nosed Tempest] at this stage so I'm unlikely to be an early customer.

Intrigued by your encouraging news - when will we get an idea of what's developing?

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Chris, i didnt know it was on sale in the shops. Are you sure they didnt ship normal laser 5 as this stuff is only available from MT direct as far as i know. If it is the real stuff (laser 5 diet?) they best not sell it to anyone for other engines as they might die.

Robin, the gearbox idea is in the 'thinking out loud stage'. I will worry about the technical aspects later.

Martin, one thing at a time! Right now i have 5 engines to develop and test plus a gearbox to investigate.

David, WWXL is a good test bed. A 180 petrol would do it as would my 'new' 30cc multi on glow. The petrol would need the least number of mods as the 30cc would need you to make a new cowl. That said, the more cylinders the more fun right? Take your pick

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