Bosch cordless drill internal plug (connects with external battery)

thingiverse

This is a plugin for a big number of Bosch tools (7.2 to 14.4 volt). Mine is a Bosch PSR 14.4 volt VES-2 from 1996. Don't know about the socket of the later introduced 18 volt tools. It replaces my died NiCd-battery using an external NiCd battery pack attached via its loader. The plug can be used even with some tools made in China on the cheap (even common 18 volt batteries). Check the connectors, blades/pins and the socket layout first. . The drill can be powered from external sorces i.e 3d party batteries or car battery chargers now. . Some soldering and extra tinkering required. This is the plug only. -The files: choose one of your liking. The first rev requires you to put two holes by hand. The v2 has this fixed plus some minor cosmetic changes. -The required parts: 2x screws, (selflocking) nuts M4x16 (small heads) 2x screws , (selflocking) nuts M4x40 some scrap material makes the tension retainer and a mounting plate if you wish red/black wiring LY10 or similar (1.5mm2), slightly thicker might work too strip of sheet metal (9x40x0.5-1mm), taken from a binder clip Post-Printing Follow the pics please. Start inspecting your drill. Check the shape of the socket, compare it with my files. It has to have a symmetrical shape with two channels. Otherwise this thing will not fit wo. modifying the files. . Modify the lower part first. It requires to put two holes (ca 2mm dia) next to the short screw to giude the wires through. Fixed with updated files now. Make the contact blades from the metal sheet strip. Clean them. Remove the dirt and paint if there is any. Bend the strip (2x) to l-shape put the contacts through the small opening slots of the lower part. Cut the wire to the desired length. Feed them through the parts Bend the wire ends to a ring shape, put some solder on if you can. Feed the short screws from the middle parts top side through the ringshaped wire ends now. Put the bottom part against the wires Stack the midplate with the lower plate. Put the nuts on (from the lower part bottom side) and tighten the (selflocking) nuts. Put the upper part against the screwed together parts. Feed the long screws trough all the parts. Mount the (selflocking) nuts. . A small gap may remain depending on the wire thicknes you have used. IMHO this is the only thing you can run into a dimensional related problem. The lower and mid part clamp the wires against the blades inbetween. If you have choosen the wire to thin it will not get safe contact with the blades. . Put the assembly next to your power source. Check the wiring, no shorts please , all leads are conductive. Put power on, check the cabled plug using a meter. Preferable power a lamp or similar before attaching it to the drill. . If all is fine put on the tension retainer and a mount plate you have to make as you like on the drill. . Next to the electrics. This is no guide, be creative. I have used the battery charger of a cheap 18 volt cordless drill. I have opend it and put the red wire to the positive pole, the black to the negative. . -Important: Check the polarity ALLWAYS. if your drill has some electronics within: check the power source, the max. voltage must not exceed the operating range of the usualy internaly used battery.