How to fit this to base of oak post?

[fobos8]

Hi guys

I need to fit this post base to the bottom of a air dried 150mm x150mm square oak post. The post is almost square but not bang on. Sorting out the slot/mortise is easy enough but I'm not 100% sure about the 12mm holes for the stainless steel dowels. I'll mark out the hole positions on each side using the base as a template but I'm worried about the holes not being drilled through to the exact same position on the other side.

What do I do? Drill half way through and hope each hole matches up?

Any tips will be very welcome.

Kind regards Andrew

 

[frankendoodle65]

Funnily enough I'm about to use some very similar brackets, my plan is just to measure and drill from both sides and hope for the best. Though I'm using coach bolts rather than dowels, so I may drill slightly over sized as it won't make much difference to strength.

 

[Spectric]

The most accurate way is either a pillar drill which is not so easy with a long post or a router which will ensure the hole is square to the post. Failing this use a smaller long series drill from each side, using a long series drill will allow you to see if it is upright. Then Drill it out to size from one side and your bolt should go through.

 

[Phil Pascoe]

Mark the holes on the side that's nearest to square to the face and drill from one side. Find a way of ensuring the first couple of inches is drilled square- the bit shouldn't deviate much after that.

 

[fobos8]

Thanks guys

I bought the posts over length so I can afford a couple of mistakes

 

[Terry - Somerset]

Drill from one side only. Drilling from both sides (unless very accurately aligned) risks creating a "V" shape hole and a dowel or bolt will never go through.

The only evidence that the hole is not at 90 degrees to the post sides will be the entry and exits on different sides of the post (which will never be seen at the same time).

If the two hole are drilled equally, It is the slot which will determine whether the post is vertical.

 

[fobos8]

Drill from one side only. Drilling from both sides (unless very accurately aligned) risks creating a "V" shape hole and a dowel or bolt will never go through.

The only evidence that the hole is not at 90 degrees to the post sides will be the entry and exits on different sides of the post (which will never be seen at the same time).

If the two hole are drilled equally, It is the slot which will determine whether the post is vertical.

I will set the holes out accurately on both sides using the metal plate as a template. I will drill one side 75mm deep, and will then drill the other side 150mm deep or all the way through to the first side. The first hole should act to steer the drill bit drilling the 2nd side towards the first side.

I think it will work, as long as I'm not totally out of alignment with each side.