Topic: O.S 200FS

YS for OS: Laser engine change

DSC00020The blue Laser has got a new engine, a YS 160. The Hatori 828 pipe has a much larger opening so the YS header does not fit. I fixed that with a silicone tube over the header which gave a very tight fit. The engine mount is new (Hyde mount from Central Hobbies) and I have redone the cowling fasteners which turned out lighter and easier to remove.

Laser/OS 200 first flight video


This is a really nice video filmed by my friend Audun Thinn. It shows the first flight of the blue Lorenz Laser, powered by the OS 200 FS with an added Perry pump. The exhaust is a Hatori #824 pipe. The engine runs rough and rich and finally dies but the plane lands safely. The 200 failed to perform as hoped after break-in and was sold in July 2009, will be replaced very soon by a YS 1.60 DZ. A larger version of the video can be found on Youtube

Mid-season status update

I have been quiet here on the blog but very actively practicing and tuning models. Here’s a quick update on how me and my planes are doing.

The red Laser (OS 160) is performing extremely well. A better manifold (thank you Just Engines) and shorter pipe lenght has produced more power and it now pulls the 18×10 APC at a steady 8300. The idle RPM is comfortable at 1500 but possible to get down to 1300 (!). That said, I have made a decision to sell it and make the switch to YS fourstrokes entirely, because…

The blue Laser (OS 200 FS) is not performing like I had hoped, reaching only 7500 rpm on an 18×10 and being sluggish in the air. I have decided to sell the engine and swap it for a used YS 160 that a friend of mine sold me. So now that I’m a proud and slightly apprehensive YS owner, having never owned or operated one before I have made another bold move…:

I have made a deal to purchase a ZN line Integral complete with YS 170 from an F3A pilot who’s switching to electrics. The plane is just ready built and complete but not yet flown. Sometimes you just have to jump on a chance to get a professionally built plane like this. I’m hoping to get some flights on it at the end of this season when I get in in a month or so and that it’ll be my new primary model.

Blue Laser ready

blue_laser
The second Laser is ready to fly. I’m not sure about the weight but it should be lighter than it’s red sibling.
Here’s the list of goodies:
– OS 2.0 FS w/ Perry pump
– Hatori header and pipe
– Emcotec DPSI-mini RV dual magnetic switch w/regulator
– 2x Kokam 800Mah LiPo
– Graupner SMC-16 Scan SPCM receiver
– Hitec Servos
– Tettra 560ml Crank tank

It balanced perfecly without any adjustments. The spinner from Dave Brown will be substituted for a light backplate tru-turn after the next Central Hobbies order. And on tuesday this week, it flies. Wish me luck.
Pictures are here

Laser progress

It’s amazing what can happen in 30 minutes in the workshop. Suddenly several evenings worth of fitting, adjusting, drilling, grinding, fitting, throwing away, grinding more and even gnashing of teeth came together on one go. Once you decide that a good fit is good enough, go for it. And the damned thing fit like a glove. This was just a dry-run, gluing and fuelproofing comes later. And when that’s done, I don’t know what’s left. Fly maybe?

Here’s the tail linkages. Done with that too. There’s a good lad. 

200 pumper

I have finished installing a Perry pump in the standard (unpumped) O.S 200 FS that will power my new Laser F3A model.  As you can see the pump is hung on to the engine mount, adding minimal weight and is a compact installation that I’m very happy with. 

The fuel line that pressure feed the pump is routed through the engine mount, as straight and short route as possible. The tap is a 4mm pressure tap. Tapping the crankcase is tricky- there is no clearing on the inside and the cast backplate is VERY thin. I did my best so I hope it’ll hold. The crankcase is in fact already tapped on this engine. Not visible, but just above my pressure tap is a cast hole that has a pressure feed going into the carburettor. No Idea why, but I hope there’s enough pressure left for the pump…


The whole assembly including pipe. The Hatori header requires some work to fit this engine. The exhaust port is deeper than on the 200 EFI so I needed to cut a big spacer from a plumbers copper joint in order to be able to tighten the header nut. I also had to drill and tap the top to accept the screw from the header fastener. Presumeable this fastener is to prevent the header from cracking from soft-mount vibration.