16 Oct 2015

Back piece



Just to be sure that you don't make the piece to short cut it 2-5 cm longer than needed. The last briefcase I made could have used a few extra cm. so I did not know exactly how long the finale piece should be. Therefore I added 5 cm to work with.

The way you chose to round the corners on the flap have a huge impact on the expression of the final bag. I chose a simple "quarter circle". One thing to keep in mind is to make sure that the transition from the rounding to the straight edge is very smooth. If not it will make the bag look "handmade" in the bad meaning of the word and we do not want that. Also you should mark the center of the front to help position the lock... I forgot to and it made it a bit more difficult.



With the corners rounded the edge can be burnished but only on the actual "flap part" as the sides will be burnished after the gusset have been sewn on. Also the bottom edges needs to be rounded and the strap holders needs to be sewn on just like we did on the front piece.

To determine the length of the back piece close the lock and allow enough room in the top so that the briefcase can expand when full. Then cut the end off. To find the actual "top" of the briefcase you can either estimate it or you can calculate it. To calculate first measure the distance from the "hole" on the lock to the bottom edge of the front piece(17 cm). Then measure the distance from the hook of the catch to the bottom edge of the back piece (54 cm).

What we want is the distance from B to D and divide by 2 to get the position of C.

Length from B to D = 54-17 = 37 cm

Length from B to C = 37/2 = 18,5 cm

Length from C to E = 17+18,5 = 35,5 cm

This means that the top of the bag will be 35,5 cm from the bottom edge of the back piece.

Now we are able to position the top strap "assembly" and make the holes for the screws before sewing it on. I made a major mistake when making these marks. I thought that I would just scribe a line across the entire width of the bag because it would be covered by the top assembly. This if of course not the case. Sure some of the line will be covered by the top straps but underneath the handle you will be able to see it. Damn!

At the same time scribe two parallel lines 2 cm from the center line and connect the ends with a wing divider. Then mark holes with the pricking iron.

When attaching the top assembly do it without the metal bar at first. Otherwise you will not be able to pierce the leather with the awl. Sew it in place and attach the metal bar. Remember to put Loctite threadlocker in the screw to ensure that they don't come loose.

Hold the cutting guide firmly in place. Pretend that this picture was taken before I cut the curve
 I made multiple small cuts to get through the leather. You should user your second hand to hold the plate down firmly.
 Don't tell your wife that you use your 60$ porcelain plate as a cutting guide!
 The transition from straight to curved needs to be perfectly smooth.
 Bevel the edge before burnishing
 Also bevel the back side
 Edge on flap burnished
 use the square to position the catch.
 Mark the holes and be sure that you are dead center in each hole.
 It was easiest to drill the holes as I do not have a small punch.
 All 4 holes in place.
 All 4 rivets in place. Its a tight fit so they don fall out.
 And with the back plate.
 To help protect the back plate I made this cover from duct tape and a piece of plastic.
 It's hard tell but there is a piece of plastic covering the sticky part.
 You get the idea.
 To prevent the rivet heads from deforming I use this block of lead. It is in a bag to prevent scratches. Also the red fabric covers my anvil.
 Cut of the rivet around 1,5 mm from the base.
 The clipper will not cut it off flush.
 File the rivet so that is flush and around 1 mm from the base. Yes 1 mm is sufficient!
Yap it gently with a small ball peen hammer around the edges. It is very hard to tell where you actually hit the rivet but try your best. That's what I do.
 It is not super pretty but it will hold everything in place.
 All 4 rivets done.
 You see that the rivet head are still round. This would not have been the case if you do not use a lead block.
 Round the corners.
 Sew on the strap holders the same way as on the front piece.
Side view of the bag.
 Measure from the hole to the edge (distance A to B= 17 cm)
 Place the ruler like this to measure the length of the back piece.
 54 cm long. (Distance B to E)
 The top of the bag will be at 35,5 cm. (Distance C to E)
 Make a small mark with a pen. Dont worry. The mark will be covered.
 Looks about right. The lock is locked and the bottom of the back piece touches the table.

 Now make the same mark on the front.
 Also make a mark on the opposite side.
 DO NOT DO LIKE THIS. Major mistake! The line should not go all the way across. It should only be where the top strap will cover it.
 Make lines 2 cm from the center line and connect the ends using a wing divider 5 mm from the edge.
 Center the metal bar.
 Use the center line as a guide.
 Mark the holes.
 Punch a hole that is a bit larger than the screw in order to have some wiggle room.
 Yes its a hole.
 Mark with the pricking iron.
 Attach the top assembly but leave out the metal bar so that it is possible to sew it.
 No metal bar for now.

3 comments:

  1. Dear Mr. Andersen, where did you get the metal bar? Did you make it yourself? I want to thank you for this wonderful tutorial. I want to try it and save myself $3000.00 dollars instead of buying a Swaine bag, thank you again...

    Raul

    ReplyDelete
    Replies
    1. I got the metal bar from my local leather shop: https://www.laederiet.dk/produkter/119-for-suitcases-and-briefcases/4564-metal-track-for-portfolio/

      It should be very simple to make your own. If you wish I can give you the dimensions? I could also send you want if you want. Depending on where you live it would cost 5 euro total.

      Delete
    2. And good luck making your own bag. If you have any questions just ask :)

      Delete