Questions regarding drilling small holes, and runout.

Home Model Engine Machinist Forum

Help Support Home Model Engine Machinist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Probably a final update to this post. I am now successfully drilling down to 0.3mm. The smallest I have tried so far.
No issues, perfect hole size. I broached slightly from the bottom to remove burr / material that was deformed, but I attribute that probably to the fact I didn't drill the piece with bottom support.
Stage seems to work well, and though it's 80x80, I am getting a cheap custom made fixture plate to give me extra room for easier mounting. I believe I have a range of about 25mm of movement on each axis. Which is plenty for a watch mainplate / bridges. I did also mount the drill to a granite surface plate as planned, so I don't have to worry about accidentally shifting it when in use, or knocking it over. I plan to plug the un-used holes with set screws to minimize debris that may find it's way to the linear rails. I will probably also spend the $30~ to purchase the depth gauge holder from Cameron, and put my dial indicator on it.

Now if I can just manage to sell my pantograph, or somehow get a cheap lathe like Sherline, I'll really be good to go lol

Thank you everyone who helped, and to @timo_gross for suggesting to use a stage.


  • drill1.jpg
    1.5 MB · Views: 0
  • drill2.png
    3.8 MB · Views: 0
  • drill3.png
    8.6 MB · Views: 0
Now then lastly, a bit off topic, but I was searching around for edge finders and centering scopes, but it seems the smallest available shank size is 3/8", where as the maximum I can hold I think was either 1/8" or 5/32".
Fisher makes a small diameter edge finder, but it is 1/4":

Fisher Small Dia Edge Finder.jpg

You can always use the cigarette paper/dowel pin trick, using a 1/8" dowel pin (I'll add a link to a suitable video when I track it down - I know I've seen a comparison of methods).

For center point location, I stole this idea from Frank Hoose. He uses a bit he found in an assortment of carbide micro drill bits, which I think is the same thing I "made," taking the smallest available bit (0.1mm) and snapping off the drilling tip:

Center Pointer.jpeg

The very point of the 1/8" bit is at most 0.1mm.