Drill Press Drift Problems

[Kevin Beitz]

Carbide bit and high speed...

[glenn bradley]

A couple folks are heading the direction I would go. A brad point bit of unquestionable quality; HSS, lipped geometry and choked up in the chuck to start the hole on one end, finish from the other side. That way the entrance and ext are dead-on even if the meeting point wanders a bit.

An auxiliary table for your DP built out of scrap for the purpose will help as well. Something to allow you to clamp in close. Not just like these but, these will give you the idea.

DPT x-brace 006.jpgDP holddown-v2 005.jpg

[Tony Gardner]

SUCCESS!

Thanks to everyone who helped with this post. In my case, the best solution was to
1. Use the TiN 1/16" bit that came with my impact driver set (smallest flute)
2. Place the bit half-way into the chuck
3. Increase speed of DP to 1,7500 (originally at 1,000)
4. Use pecking method with frequent removal of sawdust.
5. Repeat on opposite side (due to reduced bit length).

Success rate is now at least 90%, and even better if I have my wife watch from the side.

[John K Jordan]

...I need to literally drill 1/16" holes all the way through the 1-1/2" boards.

Those are very "deep" holes for that diameter bit. My experience with drilling deep holes on the lathe is that if the drill is straight for some distance it will tend to drill straight the rest of the way. I always start holes with a center bit, but even the smallest would leave a chamfer on the surface.

Eliminating the flex at the start can help a lot. Sometimes I'll "choke up" on a bit so a smaller length extends out of the chuck. A 1/16" drill guide carefully made from metal might help a lot.

I'm wondering how you can precisely mark and start the center on the back with even the Incra rule. I'd probably try to rig up a pin indexing method. It's been a 1/2 century since I used one but in the Berea collage college wood industry shop I used a type of pin router with a single fixed pin coming up from the table and the router bit above. This was used with a template to make dished depressions for marble games, but seems one could be devised to precisely align the start of the hole on one side with that drilled on the other side. Mount a short pin to on a base to extend about 1/8" or so vertically aligned with the bit in the drill press. Position the work with a hole on the pin and then drill.

JKJ

[Gary Ragatz]

Even if I had a published reference, I don't think it would be useful. Most of those speed guides are for metals & plastics, i.e. materials that are uniform in density, hardness, rake angle requirement, etc. They aren't particularly useful for a material like wood, which can vary significantly just in the same board, let alone different species. Even by changing the angle of the hole relative to the grain (perpendicular vs parallel vs angled) will affect things.

Here's a DP speed chart from Wood Magazine that includes a variety of materials (including hardwood and softwood) and cutting tool types. I keep a laminated copy near the drill press.

https://www.woodmagazine.com/content...ss-speed-chart

[Dan Hahr]

It looks like you can buy end mills and solid carbide bits for routers or 1/8" collets. A lot of them are short in cutting depth. Maybe you could make a jig to start two very accurate holes from each side and then finish them with a longer bit.

Thanks, Dan