Firstly, let's start with frame size. The pattern calls for either an 8.5" or 12" internal tubular frame. This is measured hinge to hinge. The seller I buy them from 3D in Hong Kong is by far the best seller I've found of these frames, they have pretty barrel covered hinges and snap open and closed very easily.
You can get the Small 8.5" here and the Large 12" here.
There are other size frames available though so today I'll be showing you how to adjust the pattern to fit your frame. Far easier than trying to adjust the frame!
If your frame is only 1/2" bigger or smaller, then just use whichever pattern piece (small or large) is nearest and adjust the frame channels only using the calculation at step 40) in the pattern.
Firstly measure your frame and mark the centre. I've done this with a Sharpie.
Next, choose which pattern size to adjust. I wouldn't recommend adjusting more than 2" up or down as this could affect the shape significantly and you will end up with a wonky looking bag!
First let's reduce the pattern size. (It's a lot more simple than a Small Bust Adjustment!)
Lay your marked frame on the pattern piece B (Bag main) that is too large.
Then make a mark where the centre frame mark is and draw a line parallel to the edge of the pattern. This piece should have 'fold' arrows on this piece but my testers and I have decided that midnight elves snuck in and took them after testing but before release!
Cut the pattern piece for B along this line. Multiply the width of the piece you've cut off by two. This is how much you will need to DEDUCT from A - Gusset for it to fit the newly altered B - Bag main.
When you come to the frame channels, follow the calculation at step 40) in the pattern to cut those accurately for your newly sized pattern.
Next let's add a bit on!
Mark your frame as before. Lay a new piece of paper behind the pattern piece and tape them together.
Make a mark where the centre of your frame falls. Draw a line parralel to the edge of the pattern piece, and then connect them along the top and bottom with straight lines.
Cut your new pattern piece as though the newly drawn lines are the original lines.
Measure the width of the amount added on then multiply by two. This is how much length you will need to add to A - Gusset for it to fit.
Then follow the calculation at step 40) in the pattern for how to cut your frame channels to fit your newly altered pattern pieces.
Hope this helps, please let me know if you find the barrel covered frames anywhere else and I'll pass the info on to the facebook group!