Former Member Posted January 27, 2017 Share Posted January 27, 2017 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted January 27, 2017 Share Posted January 27, 2017 At the risk of confusing the turbine boys, Laser Jet Series or Laser Silver Jet? But not Laser Ink Jet! Quote Link to comment Share on other sites More sharing options...
trebor Posted January 27, 2017 Share Posted January 27, 2017 Black Graphite Quote Link to comment Share on other sites More sharing options...
Jon H Posted January 27, 2017 Author Share Posted January 27, 2017 As requested one video of my latest petrol development. The slow run needle needs to be replaced with a different one so the bottom end is a shade rich, but all in all the performance is not bad. I was using an 18x8 classic master peaking at 7500rpm. idle was 1500rpm. The day before this video I did a rough fuel consumption test using a 20x6 prop and the engine used about 3oz of fuel in just over 6 minutes using various throttle settings. This works out to around 14cc per minute which is 10cc per minute less than a certain competitor. The carb/pump/regulator has been designed and manufactured in house. The CDI unit is the standard rcxel unit. The fuel used was Aspen alkylate petrol pre mixed at 50:1 and the engine was cold/unrun prior to taking the video. Enjoy Quote Link to comment Share on other sites More sharing options...
cymaz Posted January 27, 2017 Share Posted January 27, 2017 Impressive stuff Quote Link to comment Share on other sites More sharing options...
kevin b Posted January 27, 2017 Share Posted January 27, 2017 Yes please !!! Quote Link to comment Share on other sites More sharing options...
Don Fry Posted January 27, 2017 Share Posted January 27, 2017 Jon, accepted new needles are needed, but is the carb pump also a possible route to a pumped Laser glow motor. Quote Link to comment Share on other sites More sharing options...
Former Member Posted January 27, 2017 Share Posted January 27, 2017 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Don Fry Posted January 27, 2017 Share Posted January 27, 2017 And may I have a small rant. I have read all the guff from my brethren on this site re chromatic spectra on engines. Picture this, painting the wonder, cos it's wrong on the scale model you are trying to persuade the world is powered by a Cyclone. And then it's a mess. And why oh why, do we put an insulating layer on the motor, and bother anyone to do a work around to correct. And why buy something that tells the world, I have been overheated. It's like a perfectly lovely lady laying cash out for cosmetic surgery. Seldom any improvement. Two rants on one post is enough. I am finished, even if provoked Quote Link to comment Share on other sites More sharing options...
Gordon Whitehead 1 Posted January 27, 2017 Share Posted January 27, 2017 Hi Jon, the 180 sounds great and throttles beautifully. If I might make a suggestion, replace the slotted head of the slow run needle with a hex socket head. I know that once the slow-run needle is set it shouldn't need further adjustment, but the slow-run needle head is not easy to get to on Lasers. Finding the sweet spot whilst experimenting with my 240v and 300v petrol conversions was made more difficult by having to angle the flat-blade screwdriver to clear the radial mount and having it slide out of the slot during running. A ball-ended hex driver would engage positively with a hex socket screw head and allow a much greater offset angle. Although it's often recommended that petrol engine slow-run needles should be adjusted with the engine stopped, that's generally for engines with just one carb. Doing this for twin carbs is a pain and not all that practical as you can't easily gauge the resultant effect of adjusting just one carb with the engine stopped. Only one of the carbs might need the tweek and guessing which one with the engine stopped isn't easy. Gordon Quote Link to comment Share on other sites More sharing options...
Jon H Posted January 27, 2017 Author Share Posted January 27, 2017 Posted by Gordon Whitehead 1 on 27/01/2017 19:15:59: Hi Jon, the 180 sounds great and throttles beautifully. If I might make a suggestion, replace the slotted head of the slow run needle with a hex socket head. I know that once the slow-run needle is set it shouldn't need further adjustment, but the slow-run needle head is not easy to get to on Lasers. Finding the sweet spot whilst experimenting with my 240v and 300v petrol conversions was made more difficult by having to angle the flat-blade screwdriver to clear the radial mount and having it slide out of the slot during running. A ball-ended hex driver would engage positively with a hex socket screw head and allow a much greater offset angle. Although it's often recommended that petrol engine slow-run needles should be adjusted with the engine stopped, that's generally for engines with just one carb. Doing this for twin carbs is a pain and not all that practical as you can't easily gauge the resultant effect of adjusting just one carb with the engine stopped. Only one of the carbs might need the tweek and guessing which one with the engine stopped isn't easy. Gordon Hi Gordon. I have to say I have never had an issue getting to the slow runners on my V's but they are mostly mounted inverted and my long screw driver has no issues getting to them. That said I cant recall which version of the engine you had as we have changed the dia of the radial mount on the 240v so its smaller and blends with the crankcase and this did make life easier. Its also possible your setup left the slow run needles very sensitive as the carbs were not intended for petrol. I would say that all needles must be adjusted with the engine running though otherwise its not only a faff but you can sail straight past the correct setting if you are not careful. In any case I am satisfied with the performance of the first prototype and will be building 5 pre production engines soon. Donald, I'm not quite sure I follow. if you dislike the black finish then that is fine, but it has to be said you appear to be in the minority. Not that it matters as the silver ones are not going anywhere. Also to clarify, the anodizing will only discolour if you badly overheat the engine and we have 10 year old black engines (some were done as specials over the years) that show no signs of distress as they have not been toasted. And given the countless layers of grass/oil/mud that encrusts the fins of many an engine without ill effect, I doubt that a few microns of anodizing will cause an issue. Quote Link to comment Share on other sites More sharing options...
Artto Ilmanen Posted January 27, 2017 Share Posted January 27, 2017 Posted by Donald Fry on 27/01/2017 18:51:46: Jon, accepted new needles are needed, but is the carb pump also a possible route to a pumped Laser glow motor. Jon, Great video! many thanks I too would like to know if there might be pump version for glow engines at some point as well? I know pump arrangement can be potential source of troubles (my personal expereince) but the pump has its advantages, too. -Artto Quote Link to comment Share on other sites More sharing options...
Jon H Posted January 27, 2017 Author Share Posted January 27, 2017 There might be a pumped glow version but i have my doubts about its popularity when you could have a petrol version of the same engine for similar money Quote Link to comment Share on other sites More sharing options...
Mark Reynolds Posted February 19, 2017 Share Posted February 19, 2017 Like the black engines. Great for choice. Any update on a 360v Petrol twin yet? The petrol 180 looks great btw. I would really like a 360V in petrol Cheers Quote Link to comment Share on other sites More sharing options...
Jon H Posted February 19, 2017 Author Share Posted February 19, 2017 Until the petrol single is sorted and 'out in the wild' I am not looking at anything else. I need to get the first one working 100% before moving on to other things Quote Link to comment Share on other sites More sharing options...
Manish Chandrayan Posted February 19, 2017 Share Posted February 19, 2017 Do you expect to offer for sale the Petrol Laser in 2017 sometime or would that be later? Quote Link to comment Share on other sites More sharing options...
Jon H Posted February 19, 2017 Author Share Posted February 19, 2017 It will be ready when its ready I'm afraid but in theory pre production engines could be available within a month. But there is a lot of flight testing to do. I did fly the latest version of the engine on Friday and am pleased with how it went, but I still need to make a new carb body, a new slow run needle, new prop driver and front housing...the list runs on and on! But, all that said I will have the engine on sale as soon as I am happy with its performance and have enough experience with the engine myself to write the instructions. I know this will sound like a right cop out, but the first people to buy and use the engine will be guinea pigs in some respects as its not possible for me to test every possible permutation of installation and experience every type of issue that may or may not come in to play, and then write a solution into the instructions. Regular feedback from early customers will be vital as instructions can be updated to help cover off problems that customers have that I have not due to my experience with the engine. While I will not let the engine into the wild before the mechanical side is 100% the instructions will have to evolve as more and more people share their experiences. When the time comes I may keep a list of email addresses so that revised instructions can be distributed with ease. It will all depend how the pre production engines behave with their less experienced (than me) owners. Quote Link to comment Share on other sites More sharing options...
Mark Reynolds Posted February 20, 2017 Share Posted February 20, 2017 I'm sure most people would be willing to give feedback on the initial batch and help out. After all we will all benefit eventually! Quote Link to comment Share on other sites More sharing options...
Derek Stevenson Posted April 4, 2017 Share Posted April 4, 2017 Jon Would you please give me a good starting place for a Laser 70? Both main needle and especially the low needle. Thanks Quote Link to comment Share on other sites More sharing options...
Jon H Posted April 4, 2017 Author Share Posted April 4, 2017 errr, I just turn it until it goes! we don't have a factory setting as I just twiddle it on the test bench. We can sort it, but I might take this opportunity to go through trouble shooting a needle setting. First off, which carb do you have? if you aren't sure post a photo. Second, have you tried to run it as is and if so what did it do (or not do) This might sound like I'm being a pain and not giving you the simple way out, but if we can go through the diagnosis procedure you will never have to ask for 'base settings' for a carb ever again as you can work it out in a matter of moments with the engine on the bench Trust me, its for the greater good Quote Link to comment Share on other sites More sharing options...
MattyB Posted April 5, 2017 Share Posted April 5, 2017 Posted by Jon Harper - Laser Engines on 19/02/2017 18:10:21: ...I know this will sound like a right cop out, but the first people to buy and use the engine will be guinea pigs in some respects as its not possible for me to test every possible permutation of installation and experience every type of issue that may or may not come in to play, and then write a solution into the instructions. Regular feedback from early customers will be vital as instructions can be updated to help cover off problems that customers have that I have not due to my experience with the engine. While I will not let the engine into the wild before the mechanical side is 100% the instructions will have to evolve as more and more people share their experiences. When the time comes I may keep a list of email addresses so that revised instructions can be distributed with ease. It will all depend how the pre production engines behave with their less experienced (than me) owners. I would not worry about this. From the looks of your video this engine is already significantly better than the competition, and that is before you have conducted your final round of refinements. Even if it is not absolutely 100% perfect at launch the market is hungry for a competitively priced petrol 4 stroke of this size with better performance, so early adopters will be happy to accept instructions that have to evolve over time. There are now plenty of modellers out there with experience of the OS, NGH and Saito petrol four strokes (plus those who have converted Lasers to petrol). Get your pre-prod engines distributed to some of these guys and I suspect you will very quickly be able to hone the instructions. Quote Link to comment Share on other sites More sharing options...
Former Member Posted April 5, 2017 Share Posted April 5, 2017 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Jon H Posted April 5, 2017 Author Share Posted April 5, 2017 Posted by Percy Verance on 05/04/2017 06:56:26: If indeed you did choose to let (dare I say it) a *select* few try/use the petrols for a while, it could save quite a bit of time for you personally. This is the idea behind the pre production run as the engines would be made available at a favourable price to those who are interested. They get V.1 of the instruction sheet and their experiences will come together to update where needed. Matty, your comment about people having experience with the OS etc petrols did make me smile as it confirms my fears about these instructions as people with that experience will just ignore them. I will then in short order get a phone call saying the engine wont start. To be direct about it, everything everyone thinks they know about petrol engines and all the 'standard practices' and rules of thumb will not apply to our engine. The carb/pump/regulator setup is different so if you follow these practices its unlikely the engine will ever start. If the proper procedure is followed the engine starts with great ease and you are then pretty much set. While i am here i might as well give an update on testing. I flew the engine again last weekend but this time i had an extremely ugly and badly made cowling fitted to the test the engine in that situation. I did the worst job i could of baffling the engine which was extremely difficult for me! In any event the engine ran very well in its hot house and i had no overheating issues in flight, even with an extended period of full throttle use and even some tail slides (not enough power to prop hang 23lbs!) at full throttle. All in all it was pretty much spot on with +ve and -ve G not causing any trouble. Hot restarts were a problem, but the carb is a test carb and lacks any thermal insulation and this is the primary issue here. I already have another design waiting to be made. Bubbles are an issue should you get them, and in fact bubbles are the engines nemesis as they make the fuel pressure vary. Felt clunks please boys and girls The final piece of good news is regarding the noise. Its pretty quiet. Certainly no louder than a normal 120-180 4 stroke and i think quite a bit softer in the mid range. I dont have any noise meter other than an app on my phone so i cant give numbers at the moment but it hardly raised an eyebrow at my field when i flew it. Quote Link to comment Share on other sites More sharing options...
MattyB Posted April 5, 2017 Share Posted April 5, 2017 Fair enough. I still think there is value in handing the pre prod engines to modellers with petrol four stroke experience though - they will be able to describe the differences in performance, handling and noise compared to their existing engines to help you develop it more quickly. As for not reading the instructions, well I doubt you will be able to identify a group of modellers who do not have that tendency. You may need to print a big red X on top of the box with "Do not attempt to start before reading instructions at least 3 times" in 72 point type underneath... Edited By MattyB on 05/04/2017 18:01:31 Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted April 5, 2017 Share Posted April 5, 2017 A couple of options. Test the engines out on people with no experience! They are far more likely to read & follow the instructions! Years ago we had a very complex/expensive liquid ink printer (the sort that date stamps eggs!) and there was a very long winded manual to go with it, but with a quick start guide in the appendix. Anyway the point is if the transit fixings were not removed & a couple of ultra important checks made the whole thing could be severely damaged if just plugged in and fired up.....The answer, in the quick start guide in plain text along with the checks was an instruction to remove a certain screw which allowed the machine to operate. The point is that once the transit bolts removed, checks complete & the small screw removed it was ready to go. Every time someone phoned them & said it didn't work they would say have you read the instructions....and remover the screw (not saying where it is)...oh errr...no, well read the quick start guide and call back when you have...not many return calls! Just put a plug in the fuel line and instruction that once all the other checks have been carried out to remove it and start the thing! Just an idea! Quote Link to comment Share on other sites More sharing options...
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