Drill Press and drill bit question.

[GazzaS]

HI everyone,
I am a plastic model builder. For a long time I have been considering learning how to machine metal parts to enhance plastic kits. Because scale models are small, most of the drilling is done with .5mm (.1819 inch) bits or smaller. Many of these fine bits get broken while using a pin vise in plastic alone. I use carbide and HSS bits.

My current project requires me to drill small holes into 8mm (3/8 inch) stainless steel tubing with relatively thin walls. I know that I cannot do it without a drill press. But I don't know if it can be made to work with such fragile bits.

I don't even know if a center drill has a fine enough point to start such a small hole. So all of this makes it difficult to invest in tools that may be too big for small tasks.

Thank you for your thoughts.

Gary

 

[bill stupak]

do you mean .0181" ? .181" is close to 3/16" which is not overly fragile. If so what you should be looking for is a high speed sensitive drill.

 

[jwmelvin]

A few years ago I wanted to drill small (0.032”) holes into stainless tube. This was before I had machine tools, but I’m not sure my approach would be different. The bit was so small that my drill press was not useful (too slow and not enough feel). I used a Dremel with its little 3-jaw chuck. My tube was thick enough (0.035” wall) that I made some transverse slices to thin where I drilled, as shown below. The bit noticeably degraded but made it through the six holes I wanted.

I’m not sure how helpful it is to your example, but I’d want a pretty fast spindle (5-8k for the 0.032” drill I used) and something with feel. I know there are “sensitive drill presses” that seem well suited to it. My current drill press will go to 4K rpm, but I don’t think there’s enough feel to avoid breaking a bit.

This is an “atomizer” that goes across the nozzle of a backpack leaf blower and lets me dispense insecticide as a mist; for mosquitoes.

 

[BladesIIB]

As mentioned, speed can be an issue with the smaller bits. You can get a center drill that is pretty small, and to start on the curve you only need to make a very small mark with the center drill to make a spot to get your drill started, you should not have to go all the way in with your center drill.

 

[T Bredehoft]

Sensitive drill press.

Remove the return spring and replace it with a number of rubber bands, hooked from the quill to the body of the drill press. It works a charm.

Starting holes, Right, just a dimple for the drill to start, don't need a thru hole, that's what you're trying to make. I drill .038 holes on a regular basis in aluminum for .032 wires. No special drill press, just high revs and sensitive fingers. (.5 mm = .019 ±) THAT is a tiny hole.

 

[RJSakowski]

The 0000 and 00000 center drills are fragile too. Unless your drill press has zero runout. The tip of the drill will start the hole but when you reach the chamfer, the runout and relative stiffness of the shank will take over and snap the tip. I drilled sub-millimeter holes for forty years with a small drill press that I made from a small motor and a frame made up in the form of a parallelogram. Although the drill tip swings through an arc, if the frame is set horizontal at mid depth, the deflection for a .25" deep hole is less than .0002".

This drill press has drilled tens of thousands of holes, mostly in fiberglass pc board and still occupies a place on my workbench.

 

[Superburban]

How about one of those setups that holds a dremel tool and uses it like a drill press?

 

[Dave Smith]

Gary,
best to get an air micro pencil type die grinder, which HF offers for $20-$30 for a kit. it can run speeds up to 65k rpm and can handle the tiny bits. then just make a small press to hold it firm and rigid and make a controled precise feed. doesn't have to be fancy, just solid. Dave *note you can also use all the tiny diamond grit shapes for starting tiny holes with this grinder.

 

[brino]

Hi @GazzaS

I have heard great things about the Proxxon sensitive drill presses; but have never used one myself.
I did see one used, but wasn't sure that I'd use it enough to justify it.

Welcome to the group!

-brino

 

[GazzaS]

How about one of those setups that holds a dremel tool and uses it like a drill press?

I have one of those. Because it has so many plastic parts, it is not rigid enough fro precise work.