martin collins 1

Finally got the maiden flight done on my Flair 1/4 scale DR1, i have been waiting for the wind and rain to ease and the grass at the strip i do my maiden flights on to have dried out and been cut, the track across to this strip has been unpassable due to the standing water for several months. A bit of a hurried session as the full size gliders here were getting ready for a day of thermal hunting so only the one flight but it was enough to tell me i need to add a bit more weight to the tail end to counter balance the Zenoah 26 mag engine up the front. Full up elevator trim was needed which didn`t quite give hands off level flight, 36g more lead has now gone on the tail end, i think more will be needed but i will try it like this first to see how much up the up trim i can remove. Thoroughly enjoyed the flight once i had sorted the trim out (needed a bit of right aileron as well) and to cap off a good first flight i managed a greaser of a landing, not always easy on these Trip up Tripes i`ve been told, left with a smile on my face. Next job is to work on the silencer to try and get down to the noise limit at my other club, i have some ideas and if they work out i will post on here to help others overcome the problem.

I believe so, it says made in Germany on it.

The prop fitted to it was a Super Nylon, i know APC are great props.

Thanks for your advice Jon it is much appreciated, prop on it was a 15x8 and the airframe is a MedelTech Nutten Special, similar to their Dragon Lady but different cowl and tailplane.

Prop was a 15x8 Chris.

This engine was made in 1993 and has the vertical plug in it so safe to run on the lower oil content fuel, is that the general consensus?

AS some of you on the forum know i am not a fan of glow engines having given them up 25 plus years ago due to the oil residue and mess they make of many models, i still occasionally have to pick one up, both two and four stroke for club mates following a flight and get covered in the same oily mess. I have flown mostly electric with a few larger petrols over the intervening years but now find myself considering flying a glow powered model again. The reason being i am a member of two clubs, one of which is mostly out of use over the winter months due to waterlogging of the track across to it and the length of grass for anything with undercarriage during those months, come the summer weekends are out as full size gliders use the site as well. My other club which i can fly at 24/7 from 10am till dusk has a noise limit of 82db which i am struggling to get down to with my 2 stroke petrol models, i am currently finishing off a quarter scale GeeBee Sportster which has an NGH 48 4 stroke petrol on it which hopefully will get under 82db. I bought a model at the BMFA Buckminster Swapmeet which would be a very nice large general semi scale sports flyer and it was fitted with a Laser 4 stroke which Jon tells me is a 100. Initial thoughts were to sell the glow engine off and put a petrol in it as to go electric would require 8s and i tend to limit myself to 6s due to the costs involved on the ESC and multiple expensive batteries to get 3 or 4 flights in a session. However to fly at my main site a 2 stroke petrol is going to be too noisy, i was leaning towards a Stinger 26 RE but there is a thread on here about making a new custom silencer with stinger tubes and filled with wire wool and still being 2db over 82. So the other option (and cheapest) is to put the Laser back in the model and fly it, i know they have just finished as a business and they have a great following on here but how much mess do they put out of the exhaust, i see there is a low oil content Laser fuel, would that work on my 1993 100 and what advice would laser users give to a glow sceptic like me re operating this engine?

The engine is a 1993 one judging by the L stamped on it, would a 93 100 have been this tall in the cylinder, the other one pictured by Brian is definitely shorter, obviously Jon is the expert in these engines so hopefully it can be identified between the two sizes. I still can`t grasp why the size was not stamped on them at manufacture to avoid this confusion?

I looked at you link John and didn`t even notice the diagram showing the measurement points! 🙄 . Your link plus Brian`s picture and description of the cylinder height difference have nailed it as a 150, if anyone is looking for one with good compression it is up for sale send me a pm. Thanks to all those that chipped in with information and thoughts.

Many thanks for the replies but i am still confused, the weight does not equate exactly to any of the above, mine being 842g with the exhaust rubber tube and remote glow removed, it was flown on a 15x8" prop. In that last table provided by John Lee, height from crankshaft to cylinder head, is that from the centre of the crankshaft to the top of the rocker cover on the head as that measurement on mine is 101mm, or from the centre of the crank to the top of the cylinder head if you ignore the rocker cover which is 93mm on mine in that measurement! In which case it indicates it as a 120 OR a 150 with the width between the bearers the same as mine at 45 but the weight is nearer the 150. But Paul`s sheet has similar dimensions to mine for a 90 though the weight is a bit less as mine is 29.70z as opposed to 28.5, is his sheet for newer engines as the 150 single is not shown. I am leaning towards it being a 120 or a 150 as shown in the last table, any thoughts from the collective? Wouldn`t it have been easier to stamp the engines with the size when manufactured!

Thanks John.............

I have just removed a Laser engine from a model i have just bought as i am fitting a petrol to the plane, the only markings on it apart from the name Laser are NHA L does that correspond with the size of the engine? I am going to be selling it so would like to know what i am advertising, thanks for any help.

Happy to wait for the second batch Richard, finishing up a 1/4 scale GeeBee Y, should be finished in the next couple of weeks.

The unit has on it 4.8v to 8.4v but the instructions say 4-6v, i have an Etronix ET0556 Lipo regulator here which would limit voltage to 6v, can that also be used to limit a LiFe 2s battery as well? Until the model is balanced i won`t know if the ignition pack will be readily accessible for removal to charge which may mean not using a lipo for the ignition but presumably a LiFe would be ok to charge in the model?