Main Table Not Aligned or Not Flat???

[BigSky]

I just completed (or quite on) a drilling task that I considered critical. It was a near bust. What might be wrong? I have considered everything, I think. 1. Quill has excessive runout; 2. Table is not properly adjusted (drill press mode); 3. Table is not flat; 4. Chuck jaws close on bits inconsistently; 5. Operator is incompetent.

Symptom: Dowels inserted into a series of holes are not all perpendicular to surface (visible to the naked eye). This is verifiable with a square. A Wixey, when moved around the table, shows the table to be level to within .2°. I don't know if that is excessive or not.

With the Mark 5 setup in drill press mode and a straight 3/8" rod mounted as a drill bit, an engineering square indicates the rod to be square to the table even when I rotate the chuck.

A Wixey, when moved around the table, shows the table to be level to within .2°. I don't know if that is excessive or not. I don't think I know how to use the Wixey except to tell if the blade is square to the table.

All inputs are welcome - even the mean ones.

[JPG]

What size and type of bit are you using to drill the holes? How deep are the holes? How long are the dowels? What material is being drilled.

[wa2crk]

Hi;
In order for the holes to be 90 deg to the surface being drilled the opposite face of the stock must be paralell to the drilled surface. If the surface being drilled can not be parallel to the opposite face then the surface being drilled MUST be flat and perpendicular to the drill bit. If you are edge drilling a 2X4 as an example you need one flat face and the drilled edge must be 90 deg to that surface and that surface must be held or clamped flat to the fence. Another possibility would be table flex but I doubt that for the moment. A photo of your setup may reveal a lot.
Bill V

[charlese]

First guess is the workpiece is not square. In other words, when viewed from the sides, the workpiece is a rhombus rather than a square or rectangle.

Second guess is table flex, if the bit is dull.

P.S. Third guess - Although your steel rod shows perpendicular to the table -- Have you tried a double bent coat hanger, or a sanding disk to determine table alignment to the vertical?

Fourth guess - perhaps the carriage table lock was not locked when drilling or while measuring. The table lock will cause the table to shift position a little bit.

[fiatben]

Also, I'm thinking if it's hardwood, there's a chance the bit is following the grain and deflecting between summer and winter wood. I know that's not the right terminology but someone can fix that for me. I'll learn.

(edit) Another thing, did you consider running pilot holes with a smaller bit first? This would help with the above and act as a guide for the larger bit, as well as give you a chance to check for perpendicular holes before running the larger bit.

[BigSky]

The main table was not properly aligned; the left rear corner has been shimmed an additional .009" and the table is dipped toward the center. The dip is only a problem when drilling a piece that does not reach clear across the low spot. I have not yet proven the repairs but I'll do that later in the week.

For right now I have cut a piece of 1" MDF to sit on the table - taking the dip out of play. If this works it will become a permanent jig in my shop because I do a lot of drilling that needs to be reasonably accurate and I cannot afford a new table that may have the same issue.

I lost an entire work day playing with this but it was fun.

Thank you for the thoughts and suggestions.

[charlese]

....
For right now I have cut a piece of 1" MDF to sit on the table - taking the dip out of play. If this works it will become a permanent jig in my shop because I do a lot of drilling that needs to be reasonably accurate and I cannot afford a new table that may have the same issue.

I lost an entire work day playing with this but it was fun.

Thank you for the thoughts and suggestions.

An additional flat just like your MDF is a good idea for almost any vertical drilling. It will overcome any depression or raise caused by the saw table insert. I've found removing the insert and covering the table with MDF or plywood is a good idea when drilling axle holes in toy cars. Properly aligned axles keep all 4 wheels touching.

[jm51]

I've recently drilled 4mm holes for some loudspeakers I'm building and there is quite a bit of wobble in the quill on my SS.

What I did was start with a centre bit to give me a countersunk cone for the 4mm drill bit. With the 4mm bit fitted and the SS off, I lowered the quill until the bit was in the 'hole'. Any sign of the bit moving sideways and I'd try again until the bit went in without flexing, then I'd hit the power and drill it.

[BigSky]

I've recently drilled 4mm holes for some loudspeakers I'm building and there is quite a bit of wobble in the quill on my SS.

What I did was start with a centre bit to give me a countersunk cone for the 4mm drill bit. With the 4mm bit fitted and the SS off, I lowered the quill until the bit was in the 'hole'. Any sign of the bit moving sideways and I'd try again until the bit went in without flexing, then I'd hit the power and drill it.

Just how much wobble (runout) are you living with? Whatever amount it is, it can be reduced to something on the order of .002" to .006" measured at the end of a fully extended quill. All you have to do is rebuild the quill with new bearings.

[keakap]

Just how much wobble (runout) are you living with? ...All you have to do is rebuild the quill with new bearings.

"Never Take Nuttin for Granted Department":

I recently went PowerPro. Full replacement. Quill drilling runout is visibly worse with the NEW unit.

Oh, well...