Ok, I need to tap the expertise of the GolfRewind membership. FYI, I have a one-plane swing.
I think I'm failing to keep my left arm against my chest on the downswing and letting my arms get ahead of everything else, causing me to come outside of my plane.
I drill I practised was to take a 6 iron out into your garden and just swing it holding with just your left hand, roll the wrists through and turn the club head over through the swing, then just put your right hand on the club and swing the same, et voila - an in to out draw swing bias plane.
You can try to use the Inside Approach training aid
Or
Set up some headcovers when you practice (assuming you are a righty)
Put one behind you 2-3 feet on the same line as your feet and then put another one 2-3 feet diagonally from the ball. It's hard to describe so I'll try to draw it out. The idea is that you want to have your clubhead pass over the imaginary line connecting the 2 H's on the backswing and downswing. Hope this helps.
-------H
U----*
---H
Ignore the dashes (just used for spacing); U = You; * = ball; H = headcover
I think I'm failing to keep my left arm against my chest on the downswing and letting my arms get ahead of everything else, causing me to come outside of my plane.
I am thinking that you may be turning your shoulders too hard at the start of the downswing, with your arms still high up, causing the shoulders to pull your arms to the outside. (In that case your arms are actually catching up for most of the swing, so this is different from your perception, and this may not be your problem...) In any case, try swinging a little easier, don't swing too hard.
i got a great tipfrom here,place ball with logo facing target so that if it was a clock face you are striking ball at 3 o clock,turn the ball slightly right so that you will be hitting ball at 4 o clock,use thie line for backswing path,slightly in and follow through path slightly out,i practised this for a few weeks and its worked for me,it also helped when i started using my hips chest body turn to hit the ball,i tended to try and get swing speed with arms only causing me to snatch the club inside.
Generally this is caused by trying to hit at the ball with the arms and shoulders rather than swing. You have to start the downswing with your lower body first, if you don't then you'll swing outside in.
Can also try hitting shots with your right foot slightly behind you....this will allow for a full shoulder turn (most amatuers' backswing is mostly arm which is why they come back down to the outside) and help you approach the ball from the inside. Do this till you get the feeling of what swinging from the inside feels like...then take your normal stance and try for the same feel. Most times coming from the outside is also a result of the backswing being too far to the inside thus giving the person no choice but to bring the forward swing from the outside.
that Inside Approach training aid has been working for me. The deluxe edition with the dvd's is definitely worth getting.
The inside approach is a fine tool. If I were looking, I would get the Path Pro, though. You can use it exactly like the Inside Approach but it can be used for many different things as well.
I was looking at that path pro when I was deciding what to get. Only reason I didn't get it was because I just needed to focus on my swing path at the time, not my body position or all the other stuff it does. Otherwise i'm pretty stable.
I've found I have an outside-to-in swing path when I bend my left elbow too much during the backswing. Then, when I start my downswing, I'm more likely to cast because the arm straightens up and the extra momentum on the clubhead from straightening my arm throws it outside.
The only thing that works for me on this is to think about keeping my left hand as far away from my left shoulder as possible throughout the swing.
I am thinking that you may be turning your shoulders too hard at the start of the downswing, with your arms still high up, causing the shoulders to pull your arms to the outside. (In that case your arms are actually catching up for most of the swing, so this is different from your perception, and this may not be your problem...) In any case, try swinging a little easier, don't swing too hard.