Magnetic screwdriver handle for 1/4" bits (repairable) by magonegro

Last crawled date: 3 years ago

I have lots of 1/4" screwdriver bits and adapters and sometimes I need a short handler for some works. I have tried some of the designs out there but I found some problems. Some of them are too little for my hands and the grip doesn't feel great. Some others can handle a little magnet hot-embedded that ends up popping out of the whole thing. So I started my own handle with magnets actually embedded inside (that don't pop out). This handle is a bit greater that some out there (contained in a 50x30mm cylinder) and has inside two 10x5mm rare earth neodymium magnets, one for retaining the bit and another one in the back for attaching the handle to a metal surface or even to catch ferromagnetic screws. The cool thing is that you can also use it as a fridge magnet ;-)
There are two models, a fixed one and a repairable one. The short handle is the repairable one. See 'updates' section below for more info.
You will need two of this magnets (you can grab 10pcs out there for a couple bucks) and some 3D printing skills, as you will have to pause printing TWO times to insert the magnets in mid-print to allow the printer to enclose the magnets inside the handle (can't supply instructions here for every slicer). Magnets are fragile and oxidizable, that is the reason why they are totally enclosed inside the handle to protect them, and also the reason to be 10x5mm powerful magnets to compensate the extra distance of atraction from the metallic parts.
Part prints with baseplate support only, don't use normal support as you won't be able to insert the magnets. Don't print the handle without at least the bit magnet as it behaves as an structural part. ABS recommended. At least 40% infill, 3mm shells and 0.2mm layers. Always be careful when working with this brave little magnets 'cause they are strong and can easily pinch your fingers. Don't let the kids play with them, these are not toys and extremely dangerous for little kids. So keep them out of reach of children and irresponsible people. Don't let them play with them unless enclosed in the handle.
Enjoy !
HINT: For those of you that usually buy at DX, I bought my magnets from there, SKU:388437 or SKU:374922 or similar. Not sure about the convenience of giving real links here.
UPDATE (21-MAR-2017): Redesigned the short handle to be repairable. Now the handle (the most expensive part due to the magnets) has a hexagonal hole to insert the little part that holds the bit. If this part (that has no magnet) becomes broken due to stress you just have to print it in minutes extract the damaged one and insert the new one, or just print a cople more just in case. Handle rebuilt! I have also included a hole to ease this little part extraction. Insert it with the hole in the right position. Why my need for this? well, I have strong hands... And may be a separate/interchangeable bit holder allows for different kind of bits without reprinting the whole handler and buying some more magnets... Easy part to design. I'll include some new bit parts if you ask for them with the exact specs. I have also enhanced the handle's grip decreasing the teeth number. This way you can also print the handle and the bit part in different materials. It seems to me a good idea for a plastic design. This way you can also put a separate fixed bit part with a color code for each of your favourite bits!!! I'll post pics in a couple days if I have the time.
UPDATE (20-MAR-2017): Added a new model for 10x10x5mm square magnets. I ended up with all my stock of cylindrical magnets :-) As these new magnets I bought seem to be milder, I made the design 10mm shorter to decrease overall weight, now handle's height is 40mm.
UPDATE (17-FEB-2017): Refined model for a better print and enhanced tolerances. It works straight of the bed right now, No post print work required (unless support removal). Pics of a transparent PLA print added. Maybe I design a shorter model, anyway enough and easy grip for me.