Thread: Drill press table alignment

G'day Sean,
It's got to work doesn't it??
I've been mucking about with the bent bit of coathanger most of the day......and its just "so -so"

Good idea Sean. Another method:

• Get the table to top of height and centred.
• Scratch an alignment line in the clamping collar that goes around the post and the post itself.
• Lower the table 12" or so and re-centre.
• Make another scratch on the post.
• Scratch a fine line from top mark to lower mark and use to position the table in future. If it gets out of whack, loosen the head and reset it.
• Go over the line with black texta then re-scratch it to highlight the mark.

My GMC DP has laser cross-hairs for centering the bit. BUT the laser is not positioned like yours Scooter. The two beams come from either side and below the chuck, so that when you raise the work the alignment can often go off. I've tested this. I wish I could maintain a reliable centre no matter what the distance to the chuck, but I can't align each laser with the same angle of attack. Any ideas?

Groggy - that won't be reliable with my GMC, because I've got quite a bit of slop in the collar, i.e. it wiggles about +-1mm.

Originally Posted by Knurl

Groggy - that won't be reliable with my GMC, because I've got quite a bit of slop in the collar, i.e. it wiggles about +-1mm.

Hmm, no-one likes slop in the collar....

Have you tried filing the mating faces of the collar to get better grip?

Originally Posted by scooter

To set up, you would locate the pointer unit in the middle of the front of the belt casing. Rotating the table out of the way, you would adjust the positioning of the laser so it was directed at a point located in the middle front of the base. Then swinging the table back in under the beam, the dot should be split by the line no matter where in the vertical travel the table is.

You also need to ensure that the laser is aligned with the chuck. You can see in your mock-up, the laser is a fair bit off.

If you're just worried about centring, and not levelling, then you just need your laser aligned left-to-right (as defined by your first pic). You could do some poor-mans levelling if you aligned the laser back and forth and had a cross on the table to align with.

Originally Posted by Knurl

My GMC DP has laser cross-hairs for centering the bit. BUT the laser is not positioned like yours Scooter. The two beams come from either side and below the chuck, so that when you raise the work the alignment can often go off. I've tested this. I wish I could maintain a reliable centre no matter what the distance to the chuck, but I can't align each laser with the same angle of attack. Any ideas?

Only thing I can think of, & is a bit out there, is making a sort of hollow mandrel that could fit in the chuck, that has a laser pointer centred inside it.

The idea being you fit this mandrel in the chuck and the beam points at dead centre below, regardless of the distance from the chuck to the table. Once set, the mandrel would be taken out & the drill bit inserted.

For it to have any accuracy, you would need a laser pointer that had an accurately cylindrical outer, and the actual beam would need to be in the dead centre of the cylinder.

Bit out there as I said but it may be doable.


Noel, I would still use the bent coathanger method to actually level the table to the chuck.

Greg, your scratch idea has merit too if accurately done. Still have to have a means of centring it to the bit at the bottom of the column though.


As pointed out in the OP, the idea is only to correct the inevitable minor rotation around the column that takes place when the table height is altered.


Cheers...................Sean

Good idea scoot! With my luck the doohickey on the fandangalar I was drilling would get in the way of the beam!

I've also read of someone who mounted the laser on the table support arm, firing backwards.

Then they snapped a vertical line down the wall behind the drill press, and aligned the laser dot to the line after adjusting the height.
Their thoughts were that
1) they could still align if there was a workpiece already clamped to the table.
and
2)the additional distance to the wall meant greater accuracy. If the distance from column to wall was twice the distance from laser to colum, a 1mm movement of the dot = 0.5mm movement of the table.

I've just bought a $3.00 laser pointer, but it's way off centre in the housing, so I'm toying with either pulling it apart (and thereby risking my entire investment), or making an adjustable housing to centre it in. I'm interested in how lined up my lathe centres are, but have been keeping the drill press in mind.

Cheers,
Andrew

... and the other thought I had was, instead of the wall, if you used a "target" attached to the head of the DP, you could swivel the head (if needed), and still easily align the table.

Hi

Originally Posted by scooter

Only thing I can think of, & is a bit out there, is making a sort of hollow mandrel that could fit in the chuck, that has a laser pointer centred inside it.

The idea being you fit this mandrel in the chuck and the beam points at dead centre below, regardless of the distance from the chuck to the table. Once set, the mandrel would be taken out & the drill bit inserted.

For it to have any accuracy, you would need a laser pointer that had an accurately cylindrical outer, and the actual beam would need to be in the dead centre of the cylinder.

Bit out there as I said but it may be doable.
Cheers...................Sean

That idea is not so "out there" model engineers though have gone past this method and now use a web cam for setup/alignment THIS is the best method

http://www.miketreth.mistral.co.uk/centrecam.htm

ALthough woodworkers rarely venture into the thousandths of an inch for their accuracy

G'day Sean,
woke up for a wee at 1am and this popped into my head........laser pointer.......mounted in the chuck........hunky dory.
Available from
www1.jaycar.com.au/productView.asp?ID=ST3106
or dick smith have one 60mm long with a diameter of 9mm.
Back to bed now!

Brilliant my Dear Watson. Greeny on the way.
I have a laser pen and I'm gonna give it a try. I just know it's going to solve my problem. I can imagine that it will be useful in other woodworking applications other than the DP. More later....
One little problem with the pointer is that the "spot" is about 2mm across at a distance of 300mm. How can I improve the focus?

You could try slitting it down.

Drill/make a hole is something (metal) and put it in front of the laser.

Be careful that you don't reflect it into your eyes.


Alternatively, instead of crosshairs on your drill table, you could draw a little circle; the laser has to be entirely within the circle. I'd probably try that first...