I am in the process of testing out / tuning my model's engine
Is it OK to start the engine (OS 70) with the wing unattached?
It is just much easier for me to transport the fuselage/engine alone to the back yard. The 76'' wing detaches easily after removing 2 screws

Didn't think this would be a problem but wanted to double check just in case

Thanks

You bet arukum17 just make sure your fuse is secured so it dosen't take off and make sure you do every thing behind the prop and not in front of it.

Blackie

DON'T DO IT!!!

A good bit of the raw fuel and oil from the exhaust will go right into the fuselage no matter which way the muffler is pointed. The vortex created by the prop blast will send oil everywhere. That's what happened to me anyway...

I knew I was going to forget something, nbcguy, is correct but if you place a rag or a towel over the hole then that will keep the exhaust out of your electronics. I have done it with no problems.

Thanks for the tips guys...
Will gently tape a piece of cloth over the hole / secure the fuselage as suggested
Don't plan to have the engine on for an extended period of time anyway - just to get things started. Was worried about the fuselage jumping off or rotating over due to the effect of decreased weight

BTW the engine is a 4 stroke OS 70 Surpass fitted to a GP Cub 40
in case that makes a difference

This RC forum is great !!! Very helpful bunch of people

-Arun

Just make sure you have that fuse closed well.

No, the fuselage will not rotate over on it's own. It'll be fine... And yes, there is a wealth of information about the hobby on these pages.

Not a big deal.

Some of the most fun you can have with a trainer at a fun fly or saturday evening event are trainer races, no wings allowed!

Picture two cones on the runway two hundred feet apart line four or more wingless trainers up at the startline and at the flag first one to complete 10 laps wins the bragging rights. Now you want to talk about kaos and uncontrolled laughter.

well worth the couple of extra minutes wiping down.

John

Arun,
Looking for a lot of vertical? You should get it.

I have an 81" wingspan Cub with a 52 four stroke that has plenty of power.
Dennis-

GP Cub and OS 70 were meant for each other

How about a gp 90 in wing and a saito 130 twin. That is what i am trying this summer when i think i have guts to fly my first winter project

Yep,
trainer races, remember them well,
I seemed to forget my wing a few times so I got to practice taxiing my trainer. Got real good. Figure 8s, power slides, slalom, drag racing.
With a little imagination and nobody using the runway, you can have a lot of fun without a wing.

In all the other information, I want to make sure Blackie's advice is not missed. To repeat, this can be safe, IF you secure the fuse well. However, it can also be really dangerous. If you're thinking it will be just the normal hold the starter in the right hand and reach around and hold the fuse with the left, you're setting yourself up for an accident. A fuse without a wing, particularly after it gets a little oily, can be really hard to get a hold on.

I have to admit I learned this the hard way, although I didn't injure myself. But it was pretty scary, and I wouldn't do it again without someone to hold the fuse, or perhaps a good hold down.

How about putting a web strap around the tail and staking it to the ground so it is held DOWN and BACK?

I do this regularly and find it worthwhile. I secure the wheels to the ground, and I use stretch all wrap around the fuse opening, starting from the front going toward tail, this allow any overlap to prevent seepage through the layers, two wraps is usually all it takes. This allows you to see inside fuse with engine running and watch the servos move, etc. When done unwrap and toss into garbage (Other advice - get the original roll back to kitchen before the wife notices).

I've never tried a trainer races, sounds like fun.

Thanks for all the tips folks!

I tried it out today and it worked without a glitch
scotch taped piece of a4 paper to seal the opening
Used a piece of fish cord to strap the tail and fuselage
to a stake in the ground

Man that OS 70 Surpass sure packs a punch! - wingless
fuselage was a fiesty little devil.
Thanks for both the tips which were essential!

Wife is at my in-laws in India playing Monopoly
so could enjoy my Cub in piece!

Take care all

-Arun

My testing 'stand' for engine tuning consists of this:

3/4" sheet of plywood
Lengh of nylon cord
2 BIG holes drilled at one end
1/2" strip of wood nailed about 1/2 of distance on the sheet

*I set up the model (no wing unless it is one of my tail draggers) on the sheet with the wheels against the strip (acting as blocks)
*Loop the cord thru the holes and over the stab and in front of the elevators and tie in a square not
*The sheet is long enough to 'catch' the exhaust puke coming off the muffler so as not to make a mess
*It is portable - I just stand it on end against the back fence (dirty side in) when not in use
*It is hands free as the cord holds down the plane while I adjust the bits
*It's CHEAP!

All the best
Dave