drilling gaps

[r-ice]

Hi, well Im in a bit of a problem. Not 100% sure where its originating. However I've been drilling wood for sierras/gatsbys whatever. When i put the brass tube in, I find it doesn't fit snuggly, I find the hole slightly too big on one side! I don't have a pic yet, I'll try to get one later. i've been fixing them with some thick ca, but I want to be able to have it fit snug.

I'll have to get a pic later.

 

[dbarbee]

I had a similar problem recently when trying out a colt 7mm bit. The entry hole would be oblonged. This was due to the drill bit not entering the wood where it should. It would flex and skate along the top of the blank. As the chuck comes down the bit continues to flex and creates the oblonged hole. I would end up with my hole being drilled at an angle.

David

 

[r-ice]

er how do you fix this then? new drill press =] lol anything to buy new gear. but seriously how do fix this?

 

[mredburn]

Are you drilling the hole in steps or just all at one shot?

 

[ThomJ]

I always center drill mine first

 

[dhammis]

I had that problem with drilling until I did two things. I drill on the lathe and instead of the three jaw chuck that I was using, which technically worked, I got the drilling chuck from PSI. I also bought a drill doctor and having sharp bits prevents that walking quite a bit.

 

[r-ice]

Are you drilling the hole in steps or just all at one shot?

yes this is the problem? i am drilling steps because the drill bit doesn't go all the way through! however I am using a psi vice i believe. the one from lee valley.

 

[mrcook4570]

Sounds like you may have some runout in your drill press. Here are a couple of ideas:

1) Cut the blank longer than necessary and drill deeper than necessary. Then cut off the end that is too big.

2) Switch to a Z bit. The 27/64" bit that many instructions require is really slightly too large. Switching to a slightly smaller bit will remove some of the slop.

 

[darrin1200]

I had a similar problem. I believe the biggest problem was heat. The drill bit would heat up and pull slightly off center.
I found this happening even when drilling on the lathe. My only solution is to gather all my patience and drill very slowly. As soon as the drill bit starts to heat up ( about 1/2") I pause for about 5 min while the bit cools down.

 

[dhammis]

For the issue of heat I've done two things. One was slowed my speed down. The second thing was when drilling acrylics squirting the bit with WD-40 and blowing compressed air into the hole while drilling wood.

 

[1080Wayne]

What style of drill bit are you using ? A standard bit will tend to skate when the end of the blank isn`t square to the bit or if the blank end has areas of different hardness . A brad point bit reduces the first problem and thin CA on the blank end prior to drilling will help the second .