I recently came across an old Hercules Woodworking Vice. This thing is massive with an impressive jaw width, even bigger than my good old Record No.52 1/2.

Unfortunately the 'Drag bar' or 'Screw Bracket' was broken! Since it's cast iron it's not an easy thing to weld up, especially since I don't have a welder. I'd love to be able to braze this up one day, but for now, let's just fix the thing.

As part of this fix, I'm going to be repainting the vise, but I'm not going to focus on this for this instructable. I just want to show you how to duplicate a broken part.

Supplies

Some scrap steel or offcuts
2 Bolts
Glue (5 minute epoxy)
Photocopier
A glue stick
An M6 or similar size thread tap and tap wrench
Centre Punch
Drill (drill press recommended)
Large drill bits or step drill
Round metal file
Drum sanding bit for drill
Scrap piece of think board
Scissors
Angle grinder with cut-off disc or hacksaw.

Step 1: Make a Pattern for the Part

As with most replacement parts it's very important that it fits correctly for whatever you are fixing to work. Not all of us have access to CNC machines to make everything perfectly. So let's do this the cheap and easy way.

Start by gluing the broken part together as best you can, in my case it was easier to glue the drag bar onto an offcut of some thin MDF board. Now use a photocopier to make a perfect template of the part, you may need to adjust the copier's brightness settings.

Cut out the template of the part using scissors and glue this onto a piece of metal bar.

Step 2: Drill the Holes

Use a centre punch to mark the centres of the holes, now using a smaller drill bit drill a pilot hole through the steel.

Measure the diameter of the holes an slowly drill these to the correct size, use some oil to lubricate the drillbit and avoid overheating it. I didn't have a bit big enough for the two outside holes so had to use a file and step drill to get it up to size. I ended up using a sanding wheel on the drill to take the holes up to the final size.

Step 3: Cut the Parts to Size

I realised the dragbar didn't need to have a complex shape and instead marked out a simple design and cut this out using an angle grinder and cutoff wheel. I then finished this off with a sander belt.

One complexity with this part is that I didn't have any steel thick enough and two of the holes needed to only go halfway through. So I just got a second piece of scrap and using the first half as a stencil traced out the size, then cut and ground this as well.

Step 4: Joining the Two Halves

To join the two parts together I just drilled a couple of holes through both parts and then taped the first part. Then I used some lock-tight on the bolts and screwed them together. If you don't have a tap you can just bolt it together using a hex nut.

I then drilled centre hole all the way through and gave the completed part a final grid down so the two sides were flush.

Step 5: Test Fit

Now test that everything fits and the vise operated correctly. You can stop here if you want or go on and paint everything up so it looks nice.

Step 6: Clean and Paint Everything (optional)

I cleaned all the parts down and stripped the old paint off. Once all the parts were prepared I primed them and gave them a few coats of paint. I also used a wire wheel to polish the handle and guide rods.

Now I put everything back together, gave it an oil up and it's almost ready to go.