Jon H Posted November 19, 2019 Author Share Posted November 19, 2019 Posted by Paul james 8 on 19/11/2019 10:44:32: I've always used pi r squared x height for volume of a cylinder, I am intrigued now so will have to take the head off and measure again. Lol That works for cylinder volume but not engine capacity plugging .87 and 1.04 into this gives me the same .74 result so im not totally mad **LINK** Link to comment Share on other sites More sharing options...
Manish Chandrayan Posted November 19, 2019 Share Posted November 19, 2019 Posted by Paul james 8 on 19/11/2019 10:44:32: I've always used pi r squared x height for volume of a cylinder, I am intrigued now so will have to take the head off and measure again. Lol That perfectly works for calculating the swept volume as long as we know the bore and the stroke. For example if the laser 75 had a bore of 26.42 mm (radius of 13.21 mm) and stroke of 22.22 mm Applying the formula give us a volume of 12.18147 cc Or in other words a radius (of bore) of 0.52 inches and stroke of 0.875 inches will give you a swept volume of 0.74 cubic inches Edited By Manish Chandrayan on 19/11/2019 12:37:44 Edited By Manish Chandrayan on 19/11/2019 12:38:41 Link to comment Share on other sites More sharing options...
Chris Walby Posted November 19, 2019 Share Posted November 19, 2019 If you don't want to measure bore and stroke you can always do it by swept volume, but would seem a lot more effort in my book. Slacken valve adjusters or remove rockers Remove plug and rotate crank to TDC Fill cylinder head with oil Rotate crank to BDC Measure quantity of oil to fill back to operation 3 Done! Reassemble and find missing oil that has leaked passed the piston ring! Link to comment Share on other sites More sharing options...
Jon H Posted November 19, 2019 Author Share Posted November 19, 2019 Or you could just read the number off the crankcase...oh, wait.. This is why i stamp sizes on current engines Link to comment Share on other sites More sharing options...
will -0 Posted November 19, 2019 Share Posted November 19, 2019 Jon you're taking away the mystery of it all However, good to hear something happening to "current engines" if you know what I mean. Link to comment Share on other sites More sharing options...
Paul james 8 Posted November 19, 2019 Share Posted November 19, 2019 Posted by Jon - Laser Engines on 19/11/2019 11:03:04: Posted by Paul james 8 on 19/11/2019 10:44:32: I've always used pi r squared x height for volume of a cylinder, I am intrigued now so will have to take the head off and measure again. Lol That works for cylinder volume but not engine capacity plugging .87 and 1.04 into this gives me the same .74 result so im not totally mad **LINK** Seriously, there was me thinking that engine capacity was the swept volume??? Ergo piston radius squared x 3.1417 (near enough to pi for our purpose) x stroke. Assuming for the sake of argument a bore of 20 mm and a 20mm stroke the c.s.a of the piston would be 100 x 3.1417 so 314.7 square mm. Multiply that by 20 would give 6295 cu mm so divide by 1000 to get cc equals 6.295. That converted to cu inch is 0.384 The only way I've ever used to find engine capacity. Edited By Paul james 8 on 19/11/2019 14:49:35 Link to comment Share on other sites More sharing options...
Paul james 8 Posted November 19, 2019 Share Posted November 19, 2019 Sorry duplicate post Edited By Paul james 8 on 19/11/2019 14:48:08 Link to comment Share on other sites More sharing options...
Manish Chandrayan Posted November 19, 2019 Share Posted November 19, 2019 Posted by Jon - Laser Engines on 19/11/2019 13:51:33: Or you could just read the number off the crankcase...oh, wait.. This is why i stamp sizes on current engines By far the best method of all. I would go with this Link to comment Share on other sites More sharing options...
Paul james 8 Posted November 19, 2019 Share Posted November 19, 2019 Posted by Manish Chandrayan on 19/11/2019 12:35:15: Posted by Paul james 8 on 19/11/2019 10:44:32: I've always used pi r squared x height for volume of a cylinder, I am intrigued now so will have to take the head off and measure again. Lol That perfectly works for calculating the swept volume as long as we know the bore and the stroke. For example if the laser 75 had a bore of 26.42 mm (radius of 13.21 mm) and stroke of 22.22 mm Applying the formula give us a volume of 12.18147 cc Or in other words a radius (of bore) of 0.52 inches and stroke of 0.875 inches will give you a swept volume of 0.74 cubic inches Edited By Manish Chandrayan on 19/11/2019 12:37:44 Edited By Manish Chandrayan on 19/11/2019 12:38:41 It does work perfectly, the swept volume of an internal combustion engine is its swept volume. 👍😊 If Jon's figures shown above are put into the equation I use the same results are achieved. Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted November 19, 2019 Share Posted November 19, 2019 As far as I'm aware, engine capacity has always been quoted as the cross sectional area of the bore times the stroke. Chris's method is normally used on multi cylinder engines being "blueprinted", for balancing the cylinder head "squish" volume, which is due to the clearance between the piston and head and will result in slightly more volume than the theoretical engine capacity. Edited By Martin Harris on 19/11/2019 15:31:16 Link to comment Share on other sites More sharing options...
Don Fry Posted November 19, 2019 Share Posted November 19, 2019 Are we just checking Jon can do maths, or is this displacement activity? Guilt; for owning unemployed engines (BTW, a looked newish, 7 year old, 160v went for £475 on EBay this week) lawn darting (love that phrase) running the engine after it has broken up. Link to comment Share on other sites More sharing options...
Jon H Posted November 19, 2019 Author Share Posted November 19, 2019 I think we are counting the number of ways to skin a cat Anyway 475 for a 160? If i had one it would be cheaper than that new. alas... Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted November 19, 2019 Share Posted November 19, 2019 Supply and demand? Should we organise a deputation of modellers to picket your boss's office? Link to comment Share on other sites More sharing options...
Don Fry Posted November 19, 2019 Share Posted November 19, 2019 Sharpened APC at the ready. I can do a very good edge grinder. That'll disturb lunch time curries. For the technically minded, attaching a duff motor to a stick, AKA shillaghly, will do. Link to comment Share on other sites More sharing options...
Jon H Posted November 19, 2019 Author Share Posted November 19, 2019 i had a look at prices of 2nd hand engines on ebay and what people are prepared to pay for what i would consider an old nail. Quite staggering. Anyway i intend to show him tomorrow. I am also going to see if i can work out a plan to get the twins back in production. Its clear my original plan is never going to work as its been several years now and nothing has changed. I also got bored and designed a new engine (or 3 as i can use the concept on others) but its unlikely i will get to assemble a prototype while the twins are off the table. Even so its still very unlikely which is a shame as saito are dishing out new engines every 5 minutes, although some i think could have done with spending more time in RnD One final thing is we are still looking at running the engines on lower oil content fuel. We know 10% is fine and i am happy with 5% but in the interest of being cautious i think we are going to shoot for 7.5%. When i get time im going to talk to model technics about mixing some up but we will need people to test it out and see how they find it. If anyone is interested in testing it let me know. Please note that by test it i mean just use it and report. There is no need to do anything more than fuel it up and fly it as you normally would. If nothing breaks (it wont im sure) just keep flying. Unless something is wrong i dont need anything more than a 6 monthly update on proceedings Link to comment Share on other sites More sharing options...
Don Fry Posted November 19, 2019 Share Posted November 19, 2019 Jon, I have said this before. But; the sale on EBay last week is another clue that there is a demand in the market. You lofted a load of motors onto the market last week. No motors for sale today. Another company might, if presented with the opportunity, might put their price up. Now I detect there is a socialist core on your soul. But you can't beat the market. Why not price them higher. Please the boss. And I will point out, when did the price last go up. And if they don't sell, you can then come down, And, note, I can still lecture the bloke who makes them. I have an ancient 75, an early one, no idea how many hours it's done, bought well run, and it's done many hours since. I've lawn darted it twice to my memory. Washed of, it goes. You sell a premium (fairly) indestructible product, why price as an ASP. Link to comment Share on other sites More sharing options...
Chris Walby Posted November 19, 2019 Share Posted November 19, 2019 Don, I think you are missing the point Jon is doing the best he can with what he has available and if you want to vent your spleen I suggest you write to the company owners and make you points to them. Hopefully they will push more resource Jon's way so he has more time to build engines, but in the end that's down to Jon's boss to decide. If we all make a really big nuisance of ourselves then the directors might just cut their losses and stop making engines. PS I am up for a bit of engine testing with my Acrowot 70 if it helps out. Link to comment Share on other sites More sharing options...
Jeremy Scott-hake Posted November 19, 2019 Share Posted November 19, 2019 I would like to thank Jon for my new 155 Laser and for the refresh or my 150 on my factory visit last week. I would be happy to test some fuel , I have just bought 2 gallons of Model Technics Laser mix so better get flying and use it up a bit Sharpish! Link to comment Share on other sites More sharing options...
Jon H Posted November 20, 2019 Author Share Posted November 20, 2019 Plenty of people have mentioned price rises and i really dont see the need. I wont cheat people by setting some totally made up price on a product. There was an engine on ebay recently, it might even still be there, which the owner bought for about £350 and is now selling for 750. This is just straight dishonesty and greed in my view and a deliberate attempt to con someone. That is not something i want to be a part of. I also do not see what a price rise would achieve. The additional cost would just put people off buying, and while margins would be better turnover would probably be the same with reduced orders and the only advantage would be less people calling giving me more time to do things. But, that isnt really the right way to look at it is it? I have customers who want to buy my products but im going to price them out of it to stop them calling to buy stuff? Seems very strange to me. And with no improvement in overall profitability the options for RnD remain at zero so i dont really gain anything. My stock shelf might be full, but if nothing sells then its all for nothing. Also, to play devils advocate, if cos is no factor but availability is then buy an OS. They are in stock at many shops but you pay more for an OS 70 than our 180. Somehow, i doubt that is going to be a very popular choice so why would i shoot myself in the foot by pricing the engines that high? If you consider Laser, OS and Saito to be equal in terms of quality etc (this is an assumption clearly ) then why would you buy one which is twice the price of another? All of the problems would be solved if we just made more engines. We used to make more, but for some reason we now make less than 1/3 of what we used to. Perhaps its because the jobs once done by 3 people are now being done by 1 Link to comment Share on other sites More sharing options...
Paul james 8 Posted November 20, 2019 Share Posted November 20, 2019 We should be talking about a new business venture Jon, you sound slightly disillusioned with the current situation (been there, have that shirt) so why not give it some thought. Link to comment Share on other sites More sharing options...
Ron Gray Posted November 20, 2019 Share Posted November 20, 2019 Personally I don’t think that increasing the price of Laser engines will really improve matters for the same reasons that Jon has stated. But for me the price is largely irrelevant, I want a Laser because I want top quality and top after sales service and having had both OS and Saito imho neither come up to Laser. My ‘collection’ now numbers 12, and yes, all but 2 80s have airframe ‘homes’ and I will buy more as the need arises and if it means waiting a year (I have done that) then so be it, ideally I would like them to be in stock but in, the meantime, I’ve other ‘planes I can fly. Link to comment Share on other sites More sharing options...
Edgeflyer Posted November 20, 2019 Share Posted November 20, 2019 In Britain we have a history of producing excellent products with skilled engineers and high quality standards. So often our best effortd get undermined by managerial or supply issues. I hope that won't happen to Laser Engines. In my view the best British model engine range produced, certainly since John Oliver stopped producing wonderful little diesels. "Come on Jon",! We are all behind you. Link to comment Share on other sites More sharing options...
David Davis Posted November 20, 2019 Share Posted November 20, 2019 So what are we talking about here? Setting up a new business? If so how much would it cost to do that? Crowd funding? Link to comment Share on other sites More sharing options...
Edgeflyer Posted November 20, 2019 Share Posted November 20, 2019 PS.. Well said Ron. Lovely to have some good sense in one of our debates. Are you standing on Oct 12th?😂 Link to comment Share on other sites More sharing options...
Jon H Posted November 20, 2019 Author Share Posted November 20, 2019 Posted by Paul james 8 on 20/11/2019 09:28:26: We should be talking about a new business venture Jon, you sound slightly disillusioned with the current situation (been there, have that shirt) so why not give it some thought. Its very frustrating and not just on the engine side. As i think i have mentioned before finding decent retracts at sensible prices is very hard now. Scale details like spitfire wheels are available from robart but the price... I was looking at retracts for my 5th scale spitfire. It was going to cost near £700 just for retracts and some nice looking wheels. That is ridiculous as a scale wheel is a doddle to make from an engineering point of view as the tolerances can be a mile wide compared to an engine as most of the work is only cosmetic. As long as its a nice fit on the axle its all good. The above has been my goal from the start but after nearly 9 years here i am further back than when i started Link to comment Share on other sites More sharing options...
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