Setting up an OS50 - Help in East Sussex

[chopperboy]

After destroying my last os50 by increasing the headspeed when the engine was running a little lean, is there anyone in the East Sussex area who could give me some pointers one weekend?

many thanks,

James.

[machasm]

Can't be there physically as I live in Poole Dorset and its a bit far to go!
However can give you some "remote" guidance from here.
When you get your OS you need to ensure it is rich for the first few tanks.
Set the needles as per the manufacturers instructions for running in at around 1.75 turns out from the fully in position.
Depending on your nitro content you may need to adjust this differently. Higher Nitro contents require richer settings so the needle may need to come out a quarter of a turn more when running 30%.
If in doubt always start very rich.
Start her up then take her for a quick hover around 30secs.
Bring her back in then, with the engine idling, put your finger on the backplate of the engine. It should feel warm to mildly hot. If you cannot hold your finger on it then it is too hot.
Run the engine smoothly avoiding lots of power climb-outs and the like for the first 3 to 4 tanks.
As you get on to the later tanks begin to lean the engine out 1 click at a time. Each time check the backplate after a short hover.
You should find that the power begins to increase and the temperature of the backplate starts to warm.
Keep leaning it out until you are happy with the engines response or until the back plate becomes too hot. If it does become too hot then richen the mixture back up by 2 clicks and leave it there.
Fly a full tank out giving it a bit of welly then check the backplate as you get near the end of the tank (naturally leans out towards the end).
That should do the trick.

[Steve]

Just posted this in another thread...

My rule of thumb is approx 10 tanks for running in along the lines of.....

1 flight just hovering - main needle 3 turns out, then
1 flight hovering again - main needle 2.5 turns out, then
1 flight gentle circuits - main needle 2 turns out, then
3 flight gentle stuff - main needle 1.75 turns out, then
5 flights good flying - main needle 1.5 turns out, then
fine tune the main needle to approx 1.5 to 1.25 turns out for an OS50 and engage the governor.

The number of turns out depends very much on the engine and the fuel being used, and no two engines will ever be the same, but the above is about right (from my experience anyway) for an OS50.

Keep your eye (or finger!) on the backplate temp and listen for any harsh rattling noises - land immediately and richen it out if you get any. If in doubt, richen it out. Too rich never killed an engine, too lean always does.

[barney]

I would agree pretty much with Adrian, but also make sure it's not screaming its nuts off.

After a few tanks set your Mixture at your Highest H/S as that will likely need a slightly richer setting. The trouble with the finger method is one persons Hot is anothers Warm! So err on the cool side. Also setting the mixture at 1/3rd tank will help avoid the leaning out excessively.

Chopperboy you had the bearing rust too if I remember from an earlier post. So when your finished flying. Re-fuel the heli fully and leave it like that till the next outing. This expells any Exhaust gases (corrosive) It also prevents the clunk lines deterating.

Best if possible to store indoors as the moisture in the air is minimial. If you have to store in a shed/Garage shut the throttle barrel, turn the motor to TDC and plug the Exhaust and chuck a sheet over it. Damp air is a bearing killer.

Hopefully it will give you a long and reliable service.

cheers Brian

[rspblake]

http://www.evorc.com/page.php/page21

Hope this will help!


Cheers Rob

[chopperboy]

Gents,


thanks for the responses. I was not the guy with the rusty bearing, that was some other poor soul.

The confusing thisng for me is that the align / OS manual states 1.5 turns as normal and that you can adjust up to 1.5 turns more for bedding in. the 600 just spewed neat fuel over the floor when running at 3 turns and flooded the engine / exhaust.

Are you supposed top set-up / run-in without the governor running then?

ta


James.

[Steve]

Only engage the governor when it's fully run in - safe answer

[robgt]

You can use a governor to run in with, but make sure the headspeed is quite low. Revving too high while running in can cause damage to the engine internals.

Cheers,
Rob

[chopperboy]

Chaps,

I have the aux channel of my DX7 controlling the governor, this is set at quite a low % for a low ish headspeed. If the governor is off, what controls the headspeed - just the throttle curve in the DX7?

ta


James.

[robgt]

If the governor is off, what controls the headspeed - just the throttle curve in the DX7?

Yes!

A low headspeed governing the engine will be fine. It's high headspeeds that hurt them when running in.

Cheers,
Rob

[machasm]

Yes!

A low headspeed governing the engine will be fine. It's high headspeeds that hurt them when running in.

Cheers,
Rob

Good point,
Does anyone have any numbers/targets at what headspeed should chopperboy be targeting for his run-in?

[chopperboy]

up up bump

[robgt]

1600 to 1700 ballpark should be fine.
Using hard dampers (in a trex600) will likely cause nodding at this speed or a bit lower...

Cheers,
Rob

[simm0]

i normally dont use any governor etc while running in the engine.as its makes it harder to see what the engines actually doing..i have seen many a pilot running there engine lean because the governor masks the lean run..so i personal dont recommend using a gov untill you are sure its run in
cheers craig simmons

[trebor27]

When I ran my OS50 in I did it with no gov. Only thing is 3 tankes later, when I finally engaged the governour fo rthe first time the head speed plummeted!!!! Yes it was CRAZY high during all teh runnign in!!! <sigh>

No problems yet, but onyl 1 gallon of fuel through it so far! Unless you know the sound of the correct headspeed, or have a tacho it can be hard to judge... (Well I foudn anyway!)

If the engine is very rich (I was running 2.5 turns out) it clearly runs 4 stroke not 2 stroke and does spew a fair amount out the zorst... Under this circumstance using the gov has gotta be better than over-revving it!

Just my 2p....
Rob
Rob