I'm buidling a Laser 3D 40-size kit. I have a new Saito 72 that I plan to use on it. The plans call for the engine to be mounted upside down and I'm reluctant to run the 4-stroke inverted for fear of idle problems.

The kit includes a wood engine mount that assembles to the fire wall and doesn't allow flexibility to mount the engine right-side up. I'm thinking of leaving off the wood mount, gluing on a second thin ply firewall, and using a conventional aluminum engine mount bolted on using blind nuts on the inside of the inner fire wall.

What have you all done with your Laser 3Ds?

Thanks-

Dont add weight man. Just go with the mount that they give you but be sure to use 30 min. epoxy on it. Dont worry about turning the saito .72 upside down. This is how mine is mounted and it does great. The only thing I would do different is to build the horizontal stronger. The plane has a problem with breaking the tail off (mine did it twice at below 1/3rd throttle, level flight). Go with a solid horizontal and maybe even solid elevators. Be sure to add flying wires (not included) and you should be alright. I have also seen one that had small gussets on EVERY corner in the horizontal and elevators and it stayed together fine.

Just whatever you do, dont ask the company anything. Hobbicos support sucks!!! I called to let them know about my hoizontal failing on me and told them that many others on RCU had theirs do the same thing. All I got was a "hmmm...thats weird" out of the guy. Its a great plane (when you rebuild the tail) but the customer service SUCKS and for that reason I am never buying anything else from them.

I have a Laser 3D with a Saito .72 and I love the combination. My only complaint is that it could use a little more right thrust. I would just sand the mount a little to allow a bit more right thrust than the stock mount allows. The Saito has never given me a bit of trouble inverted - because, I think, the tank is at the proper height relative to the inverted engine.


Leonard

I have a hundred flights on mine with the stock tail and no problems. A Satio .72 and an MDS .58. I put a thin ply firewall and used a nylon mout. The wood mout is quite weak.

The ratio for the stock tail failing to not failing says redo the tail.

I did reinforce the tail with a little triangle stock (inside the fuse) and carbon fiber flying wires a la Funtana (see the pic above). I dont know if it was necessary, but the tail is rock solid, it didn't add more than half an ounce, and I like my planes a little tail-heavy anyway.

Leonard

For what that airplane's designed for, the only time the engine's inverted is for takeoff and landing I know, that's a Laser in my Avatar.

Thanks for all the great informaiton. Should I plan to install a remote glow starter for the inverted engine?

NO, thats just weight and something else that can mess up. Its a bit annoying putting the glow driver on but I would just deal with it and fly the airplane

I strongly recommend it.

I tried to go without one, but with a Saito engine (wierd angle on the glow plug) it is very difficult to attach your glow lighter. I installed a Hanger 9 remote glow adaptor in about 5 min, and it has worked like a charm.

Leonard

I wouldn't. Just excess weight slowing you down and robbing power.