# Terminology for drill component?

I built/assembled a small drill press recently and used a part from a Junk Drill because I couldn't figure out what a particular component I needed was called.

What I was looking for was a way to step up in chuck size so I could accommodate a bigger bit on a rod that was a smaller size (see: 3.17mm motor shaft driving 1/4"+ bits).

I now know the function of what I was looking for, it's a chamber of gears driven by a central D shaft gear the motor shaft can be inserted into. It's the internal component used to drive keyless chucks available in most retail drills.

Does anyone know what this would be called so I could look for it properly next time? I resorted to stripping an existing finished product for a part just because I couldn't figure it out, I was originally wanting to mount a keyed chuck

• I don't know if this question qualifies for EE.SE. You might be better off in DIY. However, I think it is not the chuck, but you've taken the planetery gearbox*(full of planetary gears, may be called orbital gears instead) and the *torque limiter from a battery operated drill, so it seems likely one of those words will help you. If I may ask, is there a reason you've gone this route instead of buying a cheap drill press? Mine isn't industrial grade, but it's more robust than the one in your picture and only cost $40 CAD on sale. – K H Mar 13, 2019 at 4:28 • @KH THAT'S EXACTLY IT. I recently got into electrical engineering as a hobby and realized I need to be able to make cases, so to better my understanding I wanted to build a drill rather than buying one. It had a few small purposes but I just wanted to learn and be flexible. I very well might end up swapping my current one out with one of the more preferred gearboxes to get more height to work with on the press. Mar 13, 2019 at 4:32 • K I realised that qualified as an answer so I made it one. – K H Mar 13, 2019 at 4:33 ## 2 Answers I think it is not the chuck you want, but you've taken the planetery gearbox(full of planetary gears, may be called orbital gears instead) and the torque limiter from a battery operated drill, so it seems likely one of those words will help you. If I may ask, is there a reason you've gone this route instead of buying a cheap drill press? Mine isn't industrial grade, but it's more robust than the one in your picture and only cost$40 CAD on sale.

Also be advised that if you want the torque limiting function, broken battery operated hand tools can often be found cheaply on second hand sources, so you could take the gearbox from a higher quality hand drill and put yours back in service. If you go shopping for broken drills I'd go for Milwaukee(Extremely well documented, high quality) if you can find it.

Chuck

Some filler text because SE won't allow me to post fewer than 30 characters!

• generally just looking for a chuck will restrict me to options that only accommodate bits as large as the shaft they're mounted to. Looking for 3.17mm chucks return results for chucks that support up to 3/16, looking for larger chucks do not return chucks that can be mounted on a smaller motor shaft. I believe the narrower term I'm looking for is what's inside the chuck - though I could be wrong and it's one of those things that just is the way it is
– Sani Evans
Mar 13, 2019 at 4:21