I want to drill a series of holes in a straight line in some 1 inch tube at set centres.

Whats the easiest way with no fancy equipment of marking a line down the length of the tube and keeping it true?

Its eamless otherwise i would drill it on the seam - its not structural btw just decorative!

Thanks

make a jig, 3 pieces of word in a U shape, drill a hole in the bottom of the 'u' and scribe a line along the pipe.

Hole doesn't have to be perfectly centred cos the tube can turn.

If you've got a bit of square section pipe with an ID the same as the OD of the tube its easy Just drill a hole in the middle of the square section, stick the tube down and drill.... If you paint a line on the end of the tube and keep it horizontal as you slide the tube in you'll know they'll all be lined up.....

Clamp the tube to a surface and then, using a square, rub along the side to mark the tube.

length of angle iron smaller than the tube, lay the tube in angle and scribe along the side. Easy , accurate and locost

Mark it up and post it to me.
Ive got a slide vice on my pillar drill that does this job just lovely.
See my posting mango BBQ grill

Rusty, good advice thanks

Mango thanks for the offer, its a variation on your grill that im copying!

Hope you dont mind.

Cheers

Tube centreline marker

http://www.rorty-design.com/images/centre_marker.jpg

When i was a structural engineer, what i used to do was clamp/tack the tube down, find the center pointer at each end by getting a small torpedo spirit level and setting it at the end of the tube so its vertical then just measure from the side of the tube so the edge of the level is bang in the middle of the tube then make a chalk mark at the top, repeat t'other end then use a chalk string to match up both marks.
Although this was used for somewhat larger tubes than i think you'd be using to build a car with!!

[Edited on 13/5/07 by Gav]