Dallaire Spirit of Yesteryear CG???

[donjiskra]

Any one know how far back from the leading edge is the CG located? I replaced the Robbe 410 plus brushed motor with a GWS2208-18T outrunner brushless, which only weighs 1.3 ounces (37.5 grams), which has made the plane tail heavy. Seems like adding 1.5 ounces (42.5 grams), of lead to the nose brings it back to an apparent balance but I'm not sure where the CG point is located. Need to balance this beauty before flying. Total AUW is now 17 ounces (481.94 grams) with the added weight.
Thanks,
Don

[Jollyroger]

The CG would be at about 30% of the wing cord. Try at the main spar.
I had one of these but don't remember exactly where it is. Also try contacting Spirit of Yesteryear. Good luck

[donjiskra]

Thanks Jollyroger,
That might work. I have contacted them but no answer as yet.
Appreciate your reply,
don

[donjiskra]

Maidened the Dallaire today, using the GWS 2012-18T motor with the 7,5 x 4 Graupner folding prop, 1500 3s li-po, producing 59 watts/lb at 6.3 amps.
it would'n't ROG of the frozen grass but no problem with a gentle hand launch. Plenty of power but reduced to half and she still flew along smartly. Wind was about 10mph. Nice flight until I chilled out in the 27 degree temperature.
Going back to the 8 x 4.5 Graupner folder produced 67 watts/lb at 8.6 amps and make grass ROG's.
Has to install 1.5 ounces of lead to make up for the brushed motor removal.
Still not sure of the CG balance point, (waiting to hear from Spirit of Yesteryear).
Back to the field on Friday when it's going to be 45 degrees.
Till then,
Don

[merlinsoars]

Generally you should start out with a forward CG, 25% of the MAC (mean areodynamic chord). It will be safe there for the first few flights. You can start to move it back a wee bit at a time until you like the feel as it will get more resposive in pitch. I would not suggest anything aft of 33% unless you going after extreme aerobatics.

Got lift
Merlin

[donjiskra]

Thanks to Stuart from SOY, the CG is just aft of the 2nd cabin fuselage former, which places it 2.5" behind the wing's leading edge.