Glider Trim Guide
Adopted from Don DeLoach’s HLG Trimming Chart
Glider Trim Guide
Adopted from Don DeLoach’s HLG Trimming Chart
Glider Trim Guide
Adopted from Don DeLoach’s HLG Trimming Chart
Points to keep in mind when prior to making trim changes.
• Trim guide will not correct a poorly launched glider. Follow guidance in “First Flight” for proper launch.
• Rudder controls the launch and transition.
• Stabilizer tilt controls the glide circle diameter.
• CG (balance) and Incidence (decalage) work together to control the models pitch or glide attitude and air speed.
Changes to incidence will often require changes to CG. Incidence has more of an affect on flight performance as the
speed increases. Thus you’ll change the incidence to solve looping during launch or nose diving after transition. CG
changes more subtly affect the aircrafts flying attitude and will often be made to affect flight speed.
Points to keep in mind when prior to making trim changes.
• Trim guide will not correct a poorly launched glider. Follow guidance in “First Flight” for proper launch.
• Rudder controls the launch and transition.
• Stabilizer tilt controls the glide circle diameter.
• CG (balance) and Incidence (decalage) work together to control the models pitch or glide attitude and air speed.
Changes to incidence will often require changes to CG. Incidence has more of an affect on flight performance as the
speed increases. Thus you’ll change the incidence to solve looping during launch or nose diving after transition. CG
changes more subtly affect the aircrafts flying attitude and will often be made to affect flight speed.
Points to keep in mind when prior to making trim changes.
• Trim guide will not correct a poorly launched glider. Follow guidance in “First Flight” for proper launch.
• Rudder controls the launch and transition.
• Stabilizer tilt controls the glide circle diameter.
• CG (balance) and Incidence (decalage) work together to control the models pitch or glide attitude and air speed.
Changes to incidence will often require changes to CG. Incidence has more of an affect on flight performance as the
speed increases. Thus you’ll change the incidence to solve looping during launch or nose diving after transition. CG
changes more subtly affect the aircrafts flying attitude and will often be made to affect flight speed.
Problem
Cause
Solution
Model loops on full power launch and
stalls often in glide.
Too much incidence (decalage)
Decrease incidence by warping
trailing edge of horizontal stabilizer
down.
Model pitches up steeply at launch
then nose dives into ground.
Too little incidence (decalage)
Increase incidence by warping trailing
edge of horizontal stabilizer up.
Model launches high with good
transition but stalls often in glide.
CG too far back
Add small amount of clay ballast to
nose until stall disappears.
Model launches high with good
transition but is fast in the glide and
slightly pitched down.
CG too far forward
Remove small amount of clay ballast
from nose of model until slower glide
is obtained.
Model glides nicely from level toss.
Launches are high but model fails to
consistently roll left* into transition.
Not enough left* rudder
Increase left* rudder by bending the
trailing edge of the fin left* until left*
roll out is obtained at transition.
Model rolls sharply to left* on launch
additionally, model does not launch
high.
Too much left* rudder
Decrease left rudder by bending the
trailing edge of the vertical fin right*
until launch is high and followed by a
“flip” or roll-out transition to the left*.
Model launches high and transitions
well but glide circle is tight (less than
than 20’ in diameter).
Too much stabilizer tilt.
Warp fuselage boom to decrease
horizontal stabilizer tilt until the glide
circle decreased to about 40’
diameter.
Model launches high and transitions
well but glide circle is wide (greater
than than 50’ in diameter).
Too little stabilizer tilt.
Warp fuselage boom to increase
horizontal stabilizer tilt until the glide
circle increases to about 40’
diameter.
Model launches high and transitions
well but glide tightens up into a tight
descending spiral.
Not enough wash-in
Check model for warps and wing
misalignment. Add additional wash-
in on left* wing panel till spiral is
reduced.
*Applies to right-handed launch. Left-handed launch will typically trim for the opposite direction.
*Applies to right-handed launch. Left-handed launch will typically trim for the opposite direction.
*Applies to right-handed launch. Left-handed launch will typically trim for the opposite direction.
Build Instructions
scimon 30 V2 Build Instructions. © 2014 Stevens AeroModel all rights reserved.
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