PAG logo


Saturday Hinged Seat Project

Here is a little project that I hope you will enjoy. You will need 8mm or 6mm ply wood , marine ply is best.

  • 12 x M5 toothed washers (I know them as T nuts - editor)
  • 12 x M5 12mm countersunk SS cap screws
  • Two nylon washers say, 25 od x 2mm thick with say m6 or M8 hole
  • Marine varnish and brush
  • Alloy sheet
  • 2 x M6 or M8 25mm bolts 4 x nyloc nuts and washers
  • 12 temporary wood screws

Recently I decided to build a new seat , my old one was fine for around town and say up to three hours, but more than that was a pain in the you know what... I wanted to keep the old one intact so I decided a new one was in order.

First I decided to make the hinges out of 2.5mm Marine grade alloy 6061 because I had it to hand, you could use 1.6 just as well.

I had already drawn up the hinges some time earlier but I wanted to sit lower as I look like a pumpkin on a pimple, I tend to sit on my car rather than in it. I therefore had to modify the hinges see the drawing and some dimensions. If you have access to laser cutting I will give you a DXF file with the drawing on it... Just ask.

First to make the hinges, scribe the hinges and cut out with snips or in the case of 2.5mm a jig saw works well then file the edges to a fine finish don't polish them just yet

Next is to fold on the line DONT FORGET there is a left and right hand

You will notice that there is a slot in the mounting hole this is to provide adjustment for various types of carpet. The alternative is to line it up and drill after marking it out.

Once the hinges are folded and de- burred use a 6 or 8mm bolt to complete the hinge. It's a nice idea to put a nylon washer between the two components the prevents the two parts from rubbing and thus scratching each other.. It is best if the back of the seat pivots inside the base hinge. This allows the the back rest to swing back without fouling the base

Now you have two pair of hinges one left one right, place the hinges in position install the seat belts and the hinge into the seat belt mount they should look like this, if you are doing this early in the build use some packing where the floor and carpet will go to provide the correct height.

Now make the base board first, I used 8 mm ply because I had it 6 mm will do just as well.

Measure between the base hinges then deduct say 4mm (2mm each side, this is to provide clearance for the upholstery , the trimmers need room for the fabric.) cut out the shape and lay it in place don't fix it just yet.

Now measure the back board and take once again 4mm off. You will notice that the measurement is different because the back hinges are sitting inside the base ones, if you use 2.5mm then the back should be 5mm narrower plus what ever thickness of nylon washer you used, if you even bothered.

Cut the height of the back a little higher than you need then clamp the back board in place. Next scribe a line over the hoop and make the board to say which side faces the boot, This is because none of the hoops are symmetrical .

Cut the ply to shape and sand the edges... if you are really happy with the fit you can now remove the hinges and screw the timber onto the hinges with self tapping screws.

Refit the seat and the seat belts to make sure it all fits. If you are happy with it take it out and dismantle everything.

Where the wood screws were, drill an M6 hole through each piece of timber and install the 'toothed washers' with M5 threads. Now is a good time to apply a generous coat of marine varnish to preserve the wood if you used cheap ply that is.

While you are waiting for the varnish to dry drill the alloy hinges to M5, use a counter sink bit and counter sink the bottom of the alloy hinges to allow for the M5 countersunk bolts to fit flush, the polish or paint the hinges

When all is dry assemble install then make your self a nice cuppa and admire your handy work.

See how the seat folds up nicely and you can even make a catch to keep it in place.

Valid XHTML 1.0 Transitional Valid CSS!