Steps to making your own extension cable ---------------------------------------- Stuff needed: 4x "2x2 Plate" 1x "1x2 Grille" 4ply wire supaglue soldering iron solder wire strippers pliers (2 are handy) modeling knife / scapel 8x flat connecters (mine were from old paralell port cable) (please refer to img_5735.jpg mostly) - cut one side off from the "Tile 1 x 2 Grille with Groove" (2412b) near to each end - sand/scrape the inside lugs flat (optional) - thin by removing up to the groove line. - use an existing PF socket to get the length just right. It will fit into the slot that has the contacts. Round the ends slightly. The fit shouldn't be too tight and it also shouldn't have much movement / slop in the socket. - place into PF socket and mark edges of contacts. Notch these out slightly - put aside for later. - remove the inner parts of the top lugs from the 2x2. (refer top 2x2 in pic) - remove half of the center circle on the underside of a "2 x 2 plate" (3022) - place this on top of the existing PF socket and mark with sharp knife (I used a scapel) the raised lug postion - remove the marked out bottom edge of the 2x2 plate (refer middle bottom 2x2 in pic) - check fitting against PF socket. Should fit really snug. - remove 2x2 and place a trimmed piece of thin card into socket - put flat piece back into socket and apply a film of supaglue (top surface only!) TIP: Supaglue works by fusing and capillary action, so ensure that both surfaces are flat and smooth with no finger oil. If you get supaglue on some plastic you want, bad luck it's ruined forever, so be careful. You'll have around 3 seconds of fitting time to get a good fix before it will set. If something goes wrong, wipe as much as you can off and try again after everything has hardened (about 5 mins). I found the bottle with a brush works the best. Keeping it in the fridge will lengthen its usefull life too. Just don't put it next to food :) (I keep my glue in the butter area). - fit 2x2 on top, press down, then and remove evenly. The flat piece should now be bonded to the 2x2. Allow to dry before next step - find some metal contacts. Mine were from an old paralell printer cable. They need to be easily solderable and less than the original PF contact widths. - cut one on a diagonal so you end up with a shape like: | | \ | \| - modify the other end so it can be attached to your soldering iron. Most irons have a nut on the end to hold the tip in, I sandwiched the contact between the shaft of the iron and the nut. - Get a sponge/rag to wipe the contact with for later - turn on and wait until contact can melt through the plastic - plunge the contact through the 2x2 where you have marked the flat piece. Keep the contact straight and touching the notched out space all the time. Try to avoid sideways movement. Wipe the contact every second hole you make. It helps limit the width of the hole if the contact is kept clean. If you use the point of the contact as the start of the critical side of the hole it will help with sideways movement. I suggest you practise this on some scrap until you are comfortable with what your iron does as it goes into and out of the plastic. - compare to img_5733.jpg. Hopefully it looks something like it :) - There are two ways of installing the contacts. You can pre-solder and pre-bend them, then insert and have to bend the tips over, or bend the tips over first, then insert and solder. TIP: I worried about the solder melting the plastic further when tinning the contacts, so I did it the first way. In hindsight the contacts took to the solder easily and so I should have done it the second way as bending .5mm of metal precisly took a lot more work than I thought it should. I kept on pushing the contacts back out instead of bending them. If you bend over the tip first, trim to size, insert and bend flush to the 2x2, it would be the easiest way. - either way you should now have the contacts in tips bent and tinned - select your wire. it should have 4 wires and be as thin as you can find. My first prototype used telephone cable and this worked well but was a little chunky. The wire you see here was from a retractable phone connecter travel kit; the type that you pull both ends to extend. - trim off about 2mm or insulator and tin the wire. The phone cable was easier to do here, the thinner wire was a bugger to trim the plastic from the wire. - test wires for breaks with a multimeter. This will save heartache later if there is a problem. - solder the wire to the connecter. Because you have tinned both components, it'll be easy and quick to do this, just press both bits together and give a light, quick tap with the iron (maybe with a small amount of fresh solder on the tip to help). TIP: Place the wire so that the bulk of it is on the same side as the flat piece. See how in the pic all wires run from the same side as the contacts. You want to do this the same too, put 2 motors on a receivers and you'll see why. If you don't you can still use your cable, just not with the receiver. My prototype had this wrong so it can only connect the battery pack to something. - repeat process for the other end. make sure that each pin matches the other end: +------------+ +------------+ 1 2 1 2 & 1 2 1 2 3 4 3 4 3 4 3 4 +------------+ +------------+ - test your cable with a multimeter before going any further! Correct any mistakes / bad connections. - supaglue connectors in place on the 2x2. It should now look like the top one in the pic (horiz wire) - remove the center circle from another 2x2 and modify it to fit the one with the contacts - gently scrape meeting points of contacts with small screwdriver to remove any traces of supaglue (used in fixing them). - gently prise the contacts apart so the have some spring in them so a good contact will be made. - test cable again - supaglue cover 2x2 on Note: For some bizarre reason I found that my cables only worked in one direction. Reciever X a-------wire-----------b X Motor (it works fine) Reciever X b-------wire-----------a X Motor (it doesn't work) I notice that the actual extension wire has a half twist in it, I wonder if this has anything to do with it, but hey! it works at least one way, so I'm happy...