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Laser Engines development.


Jon H

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WWXL's with 200's would be tasty. Even a 160 would probably do it (17x8 @ 8200) but for me the 200 is the way to go with an 18x8 fitted if you want maximum performance. 19x8 might also work if you want a more sedate/smooth performance with low noise. 

 

As already discussed, split the cowl in half like a clamshell for easy access and it should be very neat. 

 

The 160 prototype is already being sized up for some thrashing

 

 

20220126_123738[1].jpg

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12 minutes ago, Aerotec said:

These pictures are too much of a tease!

 

Jon, whats your view for the Acrowot XL? 240 too much? I'd be happy to go up to the 240 as can always throttle back if too much power. Guess it depends on size and if it would fit inside the Acrowot XL cowl?

 

It would work i have no doubt, but it would be overkill. With 180's fitted AWXL's are almost out of sight vertical and the 200 has more go than the 180. I am also not sure if i will offer a 240 flat. I will build a prototype and its future will depend on how well it works. 

 

As the 200 should fit in the cowl completely there should not be any issues there. 

 

Flying my own AWXL i enjoy it most flying big swooping aerobatics. It can be thrashed around, but i think its better flown smoothly and accurately. Its just really rewarding to fly like that and it looks awesome. A 200 will be more than powerful enough for this sort of flying and this combo would be better than mine with the OS240 due to its lighter weight for very similar power output. 

 

In other news, if you fit exhausts from long dead laser 75's the exhaust is rather crisp. Also, for some reason the FT seems to tolerate a T in the fuel line much better than the V's do. The V's idle and throttle very badly when a T is used in the fuel line but this one seems ok. I will still recommend twin tanks where possible, but in a pinch it looks like one might work. I will be testing this in the air when i get the model finished before making a final recommendation. 

 

 

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Can someone please put me right, are we saying.....A Laser FT 200 would fit straight in a Acro WOT XL with just the usual cowl cutting and not much else....

 

Or a Laser FT 160 in a WOT 4 XL?

 

I need to sit in a dark corner and consider a swap from an Acro WOT (Laser 70) to an Acro WOT XL..... or wait for the inline twin.....I blame the little voices ?

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5 hours ago, Jon - Laser Engines said:

 

I got that part, i just wasnt sure which aspect you were asking about. As i mentioned in my reply to Ace i am waiting on the backplates. We only made 2 first time round in case tweaks were needed once the crankcases were manufactured, and sure enough...

 

But, we are getting there. Just need to sort backplates, exhausts, mounts, and get the liners back...3 weeks? maybe? 

 

 

 

 

20220126_094836[1].jpg

Ooooo! Those look so tantalizing. Standard Laser muffler arrangement? 

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On 26/01/2022 at 08:57, Jon - Laser Engines said:

 

I thought it was a 155 you wanted? I dont recall discussing a 120. Not that it matters, i could make a 120 petrol with the 155 parts, although i am not exactly sure what the point would be. The 120 is already a bit hot and its glow fuel consumption is not high. Its also got a smaller big end bush than the 155/180 and i dont know how well that will hold up. 

 

It would be fun to try one, but i doubt we will ever produce it unless people are happy to pay £450-500 for them, which i doubt. 

Posted by Ace on 09/01/2019 21:47:10:

Already on the list for a GA25 - I hope thumbs up

Zero waiting.

yup, you will be happy to know you are no1

 

Ops - been that long old age has crept in - I did mean the GA25 (155) sorry ?

 

Still willing to guinea pig field test one - if this is a potential offering?

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I should be able to offer a 155 assuming the backplates get made. I have a handful of front ends for them i just need the back. 

 

In other news the FT160 flew for the first time yesterday in our wot4xl test mule. Despite my best efforts to kill both the engine and the model both made it through the day! Even on the little dumpy exhausts the engine really isnt loud and is way too much power for the w4xl. The engine seemed to perform fine with a T in the fuel line but i will still recommend twin clunks i think just for the redundancy. I did drop a cylinder on one flight after a long series of very fast rolls followed by an inverted push all at full power. The tank level was getting low by this point though so i probably just pushed it too far. It didnt do it on the following flight in a similar series of abusive rolls. 

 

I was going to try and get a video but a mixture of sun in the face and wind noise made it rather pointless to try. 

 

So, once the backplates and mounts are sorted we will be good to go

 

 

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58 minutes ago, Aerotec said:

Exciting to hear! 

 

I've never flown a twin, is it obvious from the noise when you've lost a cylinder? 

 

This is an interesting point. On the ground, to me it sticks out like a sore thumb and i can even tell when my ASP 5 cylinder or OS 4 cylinder were missing one, but we have seen that many of our customers do struggle to tell if they are on one or both especially on initial startup and if they are not used to multi cylinder engines. 

 

In flight its easy to tell as you loose loads of power but the sound does change and this was the red flag for me. Throttling back quickly may save a dropped cylinder but if not throttling back also prevent the 2nd cylinder being overloaded and suffering a lean cut as a result. Its a tricky one as most people throttle up instinctively when they feel like they dont have enough power but in this case it will make things worse. dont use more than 70% throttle if you want to keep the other cylinder running. 

 

Anyway i also flew my ASP160 twin powered spacewalker yesterday and due to its single carb the right cylinder runs rich below half throttle so it misfires badly. As a result its an excellent training aid for the ears as you have the left cylinder firing strongly and the right only on occasion. Open up the throttle and the right cylinder joins the party so you can play with it and listen to the differences all day long. 

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Quick question for all those maybe interested in a flat twin. 

 

What exhaust do you want? 

 

There are numerous options ranging from none at all (like all our competitors), the dumpy type i used on my prototype the other day, a range of all new designs, some flexi pipes but no mufflers, flexi's with mufflers... The list is as long as my arm. 

 

I would like to point out that this is a standard exhaust that will come with the engine and not the specific exhaust you need for your model today. It needs to be a bit more generic. Also remember that the more complicated it is the more it will cost. 

 

Some have already said they dont want exhausts with theirs and will make their own, which is fine. 

 

The dumpy type of exhaust i used at the weekend is the same one we used to ship with the old laser 75's and replaced it in about 1989 as they were failing noise tests. In the air the 160 was not loud at all with these exhausts and was much quieter than the 100cc petrol job that flew after me.  it was also quieter than the ASP160 twin i flew the same day with no exhausts at all. But the note is a little crisp when you are up close and while its the quickest and cheapest to make, and has proven reliability it might struggle with club level noise testing on the ground even though its fine in the air.

 

I have loads of different new exhaust designs i could use and while better than the dumpy one, they will be more expensive. They also have an unproven reliability record. 

 

Flexi pipe. i can try and get flexi pipes back and offer a plug in exhaust for the end. This will be quieter than the dumpy type, only slightly more costly and the most flexible when it comes to installation. However, it will also be the most labour intensive to install as you will need to cut the pipe to length, silver solder it to the header, make up brackets for the support clamps, make sure its all nicely supported etc. It is also the most prone to failure over time due to vibration if its installed badly. 

 

Currently i am leaning towards a modified dumpy type exhaust which has the ability to accept flexi pipe with plug in mufflers as an upgrade if its deemed too noisy. The upgrade parts would be sold as a pack which would be about £80 (2 mufflers, 2 foot of pipe, support clips and screws). This is hardly an ideal solution though due to the added cost. 

 

Let me know what you think

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Jon, I am interested in the FT200 fitted to the Acrowot XL. Main issue for me is venting the exhaust out of the bottom of the cowl so a flexi pipe with muffler bolted to the bottom of the firewall sounds the best solution.

 

If I just use the dumpy type fitted directly to the engine I would need to see how well this fits in the cowl and if I can run my own flexi pipe or silicon tube to vent outside the cowl?

 

So you are suggesting the FTs will come with a dumpy type exhaust, with the ability for an upgrade pack to be added on which would be a flexi pipe that fits to the dumpy exhaust and has additional mufflers to fit to the end? Or would the upgrade option flexi pipe header go direct in to the exhaust outlet?

 

If possible some images would help visualise the options.

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35 minutes ago, Jon - Laser Engines said:

Quick question for all those maybe interested in a flat twin. 

 

What exhaust do you want? 

 

Currently i am leaning towards a modified dumpy type exhaust which has the ability to accept flexi pipe with plug in mufflers as an upgrade if its deemed too noisy. The upgrade parts would be sold as a pack which would be about £80 (2 mufflers, 2 foot of pipe, support clips and screws). This is hardly an ideal solution though due to the added cost. 

 

Let me know what you think

I would prefer a modified dumpy type with the option to purchase an upgrade if needed. 

 

I don't know what the noise limits are there but ours over here recommend 96 decibels measured at 3 meters (20 feet).  Although, each club is allowed to set their own limits as long as it doesn't violate local town laws.   One club I belong to follows the 96 decibels measured at 3 meters as there is a housing development nearby.  While the other club is at a local airport, and we do not have a set rule on noise since full scale fly there too.

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I think you've already provided the best suggestion yourself: a modified dumpy silencer is going to be required for the production version as you will have to get it somewhere near to the noise regs to make it viable.

 

Any add-ons could be made available and shared across other engines in the range, perhaps?

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Hi Jon,

 

As you are aware I struggle to get models through the 82dB limit which in part is due to the airframes "drumming" and the "whizzing" of the props in stalled air. So for me an option of flexi/quiet silencer as possible would suit me and anyone else that has to adhere to this noise limit.

 

Could you produce the FT's with no exhaust and then supply the various options as extra's, be it dumpy type, plugs/flexi, standard silencer? It depends whether the boss wants you to hold a load of options/spares that sit on the shelf for months/years or just supply a standard dumpy and let the new owner put something together to suit the model they have.

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