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Member postings for Jon - Laser Engines

Here is a list of all the postings Jon - Laser Engines has made in our forums. Click on a thread name to jump to the thread.

Thread: Laser Engines - Technical questions
21/09/2020 15:46:09

Nope, not really. But ultimately if the oil quality is poor then its no good for either.

21/09/2020 08:12:48

Never tested it so cant say. It will probably be ok, but who knows?

Thread: Pre-ignition ?
20/09/2020 18:32:05

To confirm ED's post and clarify my comment about temperature sensitivity i dont mean external, i mean internal. If you give it the big one a small engine will quickly heat up, and equally if you slow it down it will cool very rapidly. I also had this trouble with an SC400 radial as it didnt know if it was hot or cold depending on the throttle setting. 

These temperature changes play havoc with the tuning so long full throttle blasts while trying to figure it all out will not impress them one bit. Bigger engines are better able to handle it as they have more metal to heatsink.

Of the two fuels you mention i would use the laser 5. I repaired a pair of ASP 30's for a customer (weekend job during the rona) recently and they ran well on the laser 5 when i tested them.

Edited By Jon - Laser Engines on 20/09/2020 18:33:47

Thread: Flair Puppeteer Help Please
20/09/2020 18:26:38

On paper a 61 is ok for the pup, but i fired up my laser 61 a few weeks back and was reminded that its a bit of an animal and gives some 70's a run for their money. Try something like a 14x5 prop to tame the beast a little.

On the bright side, the old 61 is a porker by modern standards so will help with the balance issue.

Also, how much elevator deflection do you have? i only ask as its actually very hard to stall a flair pup so perhaps lower rates will help

20/09/2020 14:42:58

My dad taught me to fly on his pup and it should be a delight to fly. He did however tell me that he found the c/g was not right and ended up adding an extra pound of lead to the firewall. Having flown others balanced per the plans i have to say i agree with his added weight idea.

His model was build per plans with a 50 4 stroke fitted. I cant recall if he had any lead on it before he added more but i think he did finally end up with one whole pound on the front.

What power plant has your model got? in recent years everyone tries to shoehorn a 70 into these for some reason and its just too much. If overpowered the model will climb like crazy if you just slam it open.

Thread: Pre-ignition ?
20/09/2020 14:38:17

Over the years i owned one ASP, two Magnum, 3 SC and 2 OS 30 4 strokes. All of the chinese ones would 'crackle' with pre ignition to varying degrees and were on often quite tricky to set up. The problem i had was that the knurl on the needle was so coarse that it didnt allow fine adjustment.

In the end i gave up and just tuned them the best i could. Some fuel tube stretched over the needle did help with tuning stability and prevented the needle leaking air when you touched it.

I would recommend 5% nitro fuel, they just dont need any more, the OS F plug is perfect, and i used a 10x5 prop if memory serves. These small engines are also quite sensitive to valve clearance so make sure that is correct as well. They also very temperature sensitive as they have low mass and are not as temperature stable as a larger engine.

Thread: How do you clean your glow engined models after flying?
18/09/2020 19:48:57

i just use a dab of wasing up liquid in a trigger spray bottle. works fine as most of my models are pretty clean as they are all 4 stoke powered

Thread: Petrol or Glow?
17/09/2020 16:20:02

I dont want to get drawn into another prosynth debate as we will be here for a week and then the mods will send the heavy gang in to break it up. Its also not the point of the thread.

I also have a problem as i am walking the tightrope of saying what i want as a modeller, and representing a company as Laser.

So, all i can really say is this.

it is not suitable for use in Laser engines as it does not comply with our warranty spec and use may result in mechanical failure.

Consider for a moment what would cause us to make such a bold statement. Especially when we are working with other fuel manufacturers on reduced oil options that we know are perfectly safe.

 

This is not a bias thing and i dont own a dog. Sure model technics make our laser fuel but we get no kick back from that and i hate plenty of their fuels as well. If the product isnt good enough i wont warranty the engine. For example...

Duraglo - Please, i beg you all to stop using this.

 

I am also not a fan of Contest 10. Its expensive, messy, awful. Engines run ok on it, but techpower 10 would be so much better.

 

Gary, your point about cleaning is mostly valid but it depends on the engine. I have had a number of customers come back to me after finding their petrol engines were spewing gallons of black stuff everywhere. I think you need to get to about 40:1 before they go clean. The 20:1 2 strokes etc i believe are still pretty messy.

 

 

 

Edited By Jon - Laser Engines on 17/09/2020 16:23:57

17/09/2020 14:18:16
Posted by Brian Cooper on 17/09/2020 11:55:45:

Yup, another vote for Pro-Synth here. . I changed to this fuel over 20 years ago, and haven't looked back.

Engines run faster, cooler and sweeter on this fuel, and they also remain clean inside and out. . It is by far the BEST glow fuel available, regardless of what some detractors might say.

.

By detractors i guess you mean me as i wouldnt recommend this fuel to my worst enemy and will not warranty any of my engines on it. I know its see as a marmite issue, but if it wasnt a problem then i wouldnt be avoiding it would i?

As a curiosity, beyond anecdotes i am curious regarding your qualifications to grant the award of best fuel

On the OP, as has been stated both have advantages and disadvantages but the one everyone loves to talk about is cost. 'oh the fuel is so cheap' they all cry.

True, petrol is cheaper than methanol, but does it really matter? I drive 70 miles round trip to my flying field. While i am there i order a pizza for lunch, and then consider flying a bit. On the BH weekend i flew 5 flights with my 50cc glow powered P39, 2 with my laser 80 powered hurricane and 2 with my saito 45 powered Niuport 17. That little lot cost me about 2/3 of a gallon of glow fuel so call it 12 quid for the fuel? Certainly the cost of the glow fuel was less than the cost of travel and lunch.

Petrol engines have their place for sure, but forget the cost argument as like for like a petrol engine will be more expensive to buy and (depending on how often you fly) could take a decade to break even vs a glow.

Ignore the reliability claims too. John Stone's point is absolutely correct.

Thread: Laser Engines - Technical questions
16/09/2020 17:14:02

Tigerman - 15x6 wood will be ok. I used one on my 80 in my hurricane and it was ok. In the end i broke it, and the 14x7 apc suited the hurricane better, but the moth is a different animal.

As for props, they are single most neglected thing when it comes to tuning the performance of a model. Robert's point about the cost of testing new props on big engines is totally valid though and its why i have generally recommended the menz range over the years as i have used them myself and found them to work well. The price is also not too bad.

Im sure biela props are good, but i cant be spending 60 quid each time to test one and find i need another size.

As for the 180 in the pattern ship, as we discussed at the time its a bit of a fringe use case for the 180 so i dont really have any information on how it will perform. You can always try the 17x12 as you already have it. I suggest running something with a lighter load first though just to give it some run in time at higher rpm

Thread: Topflite GS P47 Build
13/09/2020 22:14:12

P47's always fly well but in the case of a big one like this moving the fuselage can be a bit like trying to move a beached whale!

Dont know what power plant you are looking at but i have sold a bunch of 300s and 360v's for these over the years with very positive reviews from customers so any equivalent 45-60cc class power plant will do the job nicely.

Dont get too worried by the weight. Clearly you dont want it to be a total porker, but 20-22lbs will be no bother at all.

I would use 6.5kg servos on all primary controls (perhaps 9kg if using a single elevator servo) but make sure you use 9kg or so on the barn doors that call themselves flaps.

Should be awesome once done.

Thread: Laser 80 - what would YOU build for it....?
12/09/2020 19:31:54

A Laser 80 in a flair anything is massive over kill. None of them need anything more than a 60 4 stroke and with the exception of the DVII which will take a 70, our engines really are not suited to the flair scout range. The bristol fighter is fine with an 80 though.

The seagull isport is also a popular choice for the 80.

As for foss kits..err, the 70 is great in the wot4 and acrowot (kit or artf) and i am told the 70 and 80 work well in the wots wot as well. There are many people flying our 70 in the acrowot so i dont see where you get unsuited from braddock.

As for the fuel, you already know the score. Weston fuel is not recommended for Laser engines and we will not warranty our engines on that fuel. I know you will disagree with me, but the fact i am the manufacturer and is up to me what is safe to use in our engines and what is not. Like it or not, i simply know more about it than you do.

Beyond that there has recently been a trend towards fitting our engines in panics! Bit of a surprise but i am reliably informed they go well on anything from a 70 to a 100!

Edited By Jon - Laser Engines on 12/09/2020 19:33:20

12/09/2020 09:38:46
Posted by Jonathan M on 12/09/2020 08:23:34:

Or the Balsa Cabin Smooth Operator / Spin Doctor....

Spin Dr will work well. We have a few out there with 80's at the moment.

12/09/2020 09:37:59

That 55 inch p47 had prompted a little bit of a tangent here about power requirements.

AT 55 inch, i would expect to fly that on a 40-46 2 stroke, 50-60 4 stroke, and have it weigh..what, 6-7lbs. It would be fine like that and its all good. But, the quoted weight for the 55 inch model is 8.5lbs and to my mind that is pretty flippin porky. I wonder if that it why they gave it those droops as i doubt it will fly very well without them.

Tims 63 inch P47 is similar in specs to the old topflite one. Our 80 would fly it fine there is no worry about that, but the 100 is better suited as its able to fit in the cowl and offers a little more performance and turns a bigger prop. At 63 inches and i assume around 9-10 lbs a 120 is really excessive and i wouldnt be looking at a 120 until you were up at 70 inch and 12lbs.

Its a known fact that most models are well over powered and i suspect part of this comes down to poor propeller selection. Prop selection is a bit of an art but the wrong prop can ruin a model and the right one just make it perfect.

Keeping on topic, take my 9.5lb, 63 inch laser 80 powered Hurricane. Originally flew on 14x6 but was too fast and not at all speed stable with acceleration in dives and really slowing up in gentle climbs. ok, 14x7 3 blade. Flew ok, looked good, but it felt like i was dragging a parachute behind me. 15x6 2 blade was similar to the 14x7 3 blade but without the parachute feeling. 14x7 2 blade...now we have it. Great speed stability irrespective of the attitude, much better pull through loops etc and i can now run around at half throttle. With this prop the model is easier to fly, easier to land, sounds better and is just perfect all round.

The point of this little story is that had i only tried the 15x6 for example i might have concluded i needed more power when i didnt, i just needed a better prop.

This is why Laser dont quote hp figures as they mean absolutely nothing if the prop you are turning is either wrong, or has woeful efficiency.

Thread: Seagull Hurricane Laser
11/09/2020 21:33:35

In order to make life easy i landed a little diagonal to reduce the cross wind component. That is why i nearly fell off the runway the first time. I didnt want to use the rudder too much as it causes a large nose down pitch at high deflection.

As for the ailerons, they were busy keeping the wings level but its the elevator that is hard work.

Thread: Laser 80 - what would YOU build for it....?
11/09/2020 15:25:02
Posted by Chris Walby on 11/09/2020 15:03:45:

How about a VQ Tiger Moth?

**LINK**

Other suppliers are available.

i would use a 30 in that tiger moth. its only 55 inch!

The seagull gypsy moth would be more suited

Thread: Price of Kits
10/09/2020 21:15:34

As has no doubt be mentioned already, the 'problem' is the wide range of options we now have.

Looking back models were generally powered by a 20-40 2 stroke and that was about it. As a result everyone flew models that size, and everyone had engines to suit as it was all you could get so spitting out a new kit was easy as you had a captive audience.

Now, the hobby is so vast in scale with ultralight indoor electric at one end and models big enough to sit in at the other.

If you wanted to pitch a new kit now, where would to aim it? I personally wouldnt touch anything aimed at less than a 120 4 stroke, but others dont want anything aimed at more than a 3s 3200mah electric setup, and i am sure there are others who dont want anything smaller than 50cc.

As it happens i remember skyshark kits and i had 3 thoughts about them:
1. nice kits that look really good quality
2. not big enough (most were 55 inch if i recall)
3. too expensive for their size.

needless to say i never bought one.

10/09/2020 13:30:21
Posted by Nigel R on 10/09/2020 13:05:32:

I bought a few bits from Sarik recently, not a complete kit though, I doubt that counts.

If someone could resurrect the Flair Meteor that would be nice, don't see it though, it was from the glass fuse & foam wing era, glass seems to be completely out of fashion for kits, I guess the time invested in making moulds doesn't add up for low volume sales.

I am a fan of the glass fuz/foam wing combo. Glass fuz/built up wing is also fine by me but the foam wings are faster to build.

As for low volume sales, i wonder if the manufacturers these days have the right mentality. Currently the work out that they can sell a given number of models, then make 10 less than that number so they dont get left holding the baby if they dont sell. Once the run is done, that is it!

It seems daft to me as models like the hangar 9 pulse series (and the 125 especially) flew so well i would recommend them to anyone looking for a model that was docile enough to be a trainer but mad enough to satisfy most of the aerobatics you could ever want. With 5 sizes covering 3s electric up to 150 4 stroke it was a superb range. Alas, it is no more.

When you consider than most chris foss designs and things like the panic biplane have remained popular and in production for what, 40 years? surely this 3 year life cycle for a model is a bit short sighted?

Thread: To stabilise or not to stabilise - the gyro question
09/09/2020 12:15:14

I am in the cheating camp myself and have never felt a need to gyro equip my models.

If i am having difficulty with a cross wind landing or model that is tricky to handle then its time for me to get good and learn some skills.

If the model just flew itself there would be no challenge, no reward, and i would get bored very quickly.

Thread: IC or Electric for Ripmax DeHavilland Tiger Moth
08/09/2020 17:11:12

The rear of the top wing centre section where the struts mount is going to be in the ballpark i would imagine.

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