How can I tell if I need right thrust, and how much to put in?

I would say in general most planes do need right thrust and it is typically 1 or 2 degrees to the right. Also you add in a litte down as well depending on the plane.

That's part of "trimming" a plane with adjustments to the plane itself. There's a "Trim Chart" that walks you through the procedure on (for example) the NSRCA home page.

http://nsrca.us/all/flying/177-trimchart.html

You will find "side thrust" toward the bottom. That means there are a lot of other things to look at first, so go through them from the top down.

And enjoy it! You will be delighted with some of the modifications you make, like when you pull into that upline, and the plane no longer wants to pull to the left!

Best wishes,
Dave Olson

Does it turn to the left while climbing when you add power? If it does then add some right thrust.

Fly at full power into the wind and pull straight up. Add or remove thrust until it goes straight up without rudder correction.

Issue resolved. Hang around some guys that fly Pattern. A good learning experience.

Scar's trim chart is written by pattern flyers for pattern models.

The procedure I use for sport or scale models is to trim out the model at half throttle in straight and level cruise. Then bring it in on a nice steady straight approach and at 10 to 20 feet go to full power for a go-around.

If it climbs out and turns left it needs right thrust (assuming conventional layout).

If it turns right it needs less right thrust.

If it doesn't climb out (dives for the runway) it needs less downthrust, or maybe a further forward CG (or both).

If it climbs TOO steeply then it needs more downthrust.

What we want is a smooth transition into a straight climbout at a slightly higher airspeed than the approach. It may initially need a nudge of up elevator to a nose up attitude but should not need much trim change.