I'm in the process of building a Carl Goldberg Eagle II. Having built a number of kits previously w/out any noticeable right thrust (low and high wing), is it actually needed. This will not be used as a trainer being built as 4 channel with the flatter wing option.

What determines wether a design needs right thrust or not?

Mike, with the Eagle II, and with your question, I would make it up with no thrust offset. Decide for yourself what you need. Notice what happens on take off. Notice the difference in left and right turns under power. Then try it inverted and Decide for yourself. You can always put thrust in it on that plane later if you think you need it.

OK.. thanks... I will keep the down thrust for now.

This older kit uses a mounting plate with a recess for the engine that sits on hardwood rails to obtain the correct right and down thrust. I assume I can add a lite ply wedge the dimensions of the current vertical firewall that would match the needed downtrhustt and bolt an engine mount to it

I built one with the "flatter" wing option.. and built it with the right/down plans call for. It was a sporty plane as it was built. Matter of fact, built like that, it was one of the best flying planes I've ever had . Also.. somewhere in the plans/manual/addendum it tells you how to set-up the ailerons for the differential.. I did that too.. as well as the bolt-on wing.. I think all of those options/mods combined really did make it what it was. I'd vote for all these options as per plans.. and I think you'd end up with a very spirited aircraft that will fly like no other.. These are one of the best designed planes ever IMO.

thanks.... I just don't like the hardwood type mount and wanted to use the glass filled type so the angles would need to built onto the firewall which has no built in angles in the design. I'm looking at using this a weekend knockaround / fun fly plane

Hi Mike.. as much as the wood bearers/engine plate might seem out of date or otherwise.. it really is a nice way to mount the engine.. and.. those bearers play an integral part of the forward structure, and cheeks of the plane.. they add alot of rigidity. They really are nice to use if a little time is taken in building them. I've found just liberal coats of dope is all that's needed to keep them solid for years... and nice thing is its all there in the kit. If my memory serves me.. all I remember having to do is dremel out a bit of clearance for the engine mount screws(engine to plate)... as the plate just seats in and secures with 4 screws... you really can't beat that mount.. even with a plastic/resin mount.. The stock mount will definately give you a stronger front end.. it only stands to reason.
Just a thought here.

the wood mounts, if they are beams that protrude back into the plane, will also help dampen vibration. and as for longevity i purchased a 30 yr old pattern plane with an original engine mounted on beams. it took me 3 days to remove the engine. the screws were so tight i would strain until my hands locked up. of course i didn't want to strip the screw heads. but a little at a time, a tiny partial turn at a time and i finally got the screws out. not a setup that i would ever worry about.

I understand what your saying with the hardwood beams being integrated into the fuse thorugh the firewall.
The hardwood beams stop at the firewall (angled down to provide the downthrust) on this design. The mounting plate sits on those with an angle cut in it ot provide right thrust.

The issue that started this was me wanting to 90 degree mount the motor so the muffler hangs out the bottom which makes this beam and mounting plate unusable. I was going to duplicate the down angle and maybe add a bit of right thrust as well... It's there for a reason on this design so I probably shouldn't mess with it to much. ( I feel like Brett Favre in the commercial buying the TV... indecision!

)

I see your dilemma... I think I'm reading that your wanting a side mounted engine.. which is a cool thing really.. and its a tough call decision wise to compromise what is already a decent design for the most likely.. sportier look of an engine mounted at 90d.. w/ a down-facing exhaust. With that.. you just might loose one side of the cheeks anyway.. and do check your clearance on lower firewall for the muffler.. what ever muff you might use. Pitts style mufflers do have a great sound to them.

The memory is coming back a bit on that airframe though.. as if I'm not mistaken.. there's another set of balsa doublers that go on the lower cheek cowl area.. on the inside of the engine compartment..they butt up to the bottom of the bearer's/and sides.. and they have recess's cut in for engine bolt clearance(engine/plate area).. if you go the stock route though.. all it takes is some nicely applied coats of dope..I painted my engine area to match the plane.. it was very clean.


Its totally your choice though... of course.. Just offering up ideas/exp/etc.. I actually really liked my Eagle II with the options I mentioned in my above post.. and the stock engine set-up was just a piece of cake with no worries ever.... and I don't think I'd hesitate to build another identical to it...I sold it to a father/son and they learned to fly with it.. this is after we all(the whole family) flew the feathers off of it..... matter of fact.. I'm sitting around here with a P-51, and a few other planes... kind of wishing one of them was an Eagle... excellent planes.

Mike, leave the downthrust alone, but cut the right thrust in half. I think you'll be pleased with the results. Even after 40 years of flying RC, the Eagle 2 is still one of my favorite knock-around planes.