Modding Home-made cable combs

Does anyone have any tips of guides on how to make home-made cable combs. Everywhere I have looked in the UK are either sold out or ridiculously expensive, so thought I might have a go at making them myself

 

What do you call expensive I bought a set of these that i ended up never using.

 

Instructions make a comb similar to those CrapBag linked to:

1. Determine wire diameter. If you are planing to sleeve the wire don't for get to include the sleeve. If you don't have calipers and don't want to buy a set you might be able to google the information. For example I was using #18 AWG unsleeved, and measured a diameter of 5/64".
2. Add a tolerance to your measured diameter. From my example, I selected the next drill size up 3/32". The thicker your comb material is the more you will want to increase the tolerance. I think I was using 1/8" styrene (not the best material for the project).
3. In some scrap, drill a couple test holes and check fit. Adjust the hole diameter as required. If the holes are too tight it will make it very difficult to move the combs into position.
4. I suggest that you use a CAD program to help with layout, if you don't have one there are several free ones, Google can help.
5. Layout the hole spacing, I recommend starting with a spacing of 1.5D on centre, where D is the hole diameter. From my example, I was using a 3/32" drill, so I started with a spacing of 9/64" on centre. Make sure you include a centre marker in the CAD layout.
   Alternatively if you want to match the spacing of the ATX plug use a spacing of 0.165" on centre.
6. Print out layout at 1:1. Glue the print out (spray adhesive works well for this) to a scrape piece of material. You'll probably want to cutout the print out so you are not dealing with a whole sheet of paper. Drill the holes, test fit and look, and adjust spacing as you like. If designing for a 24 pin ATX plug I'ld initially test by only drilling 2x4 to 2x6 pattern.
7. Repeat steps 5 to 7 until happy with the layout.
8. Once happy with spacing then determine overall size and shape of the comb, i.e. have round corners or square.

I recommend using a drill press if you have access to one.

If you want a comb that you can clip the wires in then you also nee to cut out a notch to each hole. I not sure about this design as I have not attempted it.