Finding center line along the length of a piece of pipe

[Doug247]

I like to lay a piece of channel of angle iron against the pipe and use it to draw the line, but if you find the drill bit is trying to wander off the material, even with a punch mark, just grind a little flat spot and repunch your mark. this method works very well with shafting.

[Tom Kroscavage]

After you get your line you can index your pipe with a 1/4" tape

[fbrown333]

I found this tool on here a while back and made one. It works great, you place your pipe in the vice, place a level on the home made tool and slide it down the pipe to where you want the hole and use a punch to mark it. Then drill your hole.
I coudn't get the picture to load. SO what you do is get a peice of flat stock 1/8" thick and drill three holes in it, one near each end and one in the center. Then place a metal dowl thru each end and tack in place. when you place it on the pipe pivot it to the left or right so the dowls touch the pipe. the center hole will be in the center of the pipe every time. this will work on several sizes of pipe it is only limited by the size of the tool. Works great. You will find a lot of good stuff on this site. hope this helps you in you grape vine quest

[prop-doctor]

here s one that was on a while back
i found it but can t seem to get it to cut copy and paste grrrrrrrrrrrrrrrrrrrrrrrrrrr
was posted by ( ctardi ) on 5-24-06 name of thread: simple center marking jig
hope that helps

[fbrown333]

Found it tried from work, this time I did it from home

[DSW]

That same idea will work to divide anything into equal parts.

Lets say you have a 23 1/4" x 48" wide plate and want to lay out for 6 equal strips 48" long.

Take your tape and hook it on a corner or side of the plate. then measure across to a number divisible by the increment you want (6 in this case) So for the example 24", 30", 36" and so on would work and make your marks at numbers you used divisible by 6. So if you used 36" you would mark every 6" on the diagonal tape 6 increments x 6( inches on tape to layout marks)= 36, For a 30" diagonal the layout # would be 5, 10, 15 and so on.

You can use this to divide by any number you need as long as you can get the diagonal to measure to your number side to side. Same 23 1/4" plate with 20 equal spaces. I'd use 40" on the tape if possible and mark every 2". If you wanted 20 holes with equal spaces and equal dist to the end, lay out for 22, 1 to start, 20 for the holes and 1 to end, layout diagonally at 44 and mark every 2".

Once you have your marks you can measure from an edge to the mark to set the dist and snap your lines.

[Magnetic Mechanic]

Originally Posted by denrep

pilebuck, thanks for the nice tip.

Any simple tips for centering on a verticle pipe?

2 ways to scribe a line centered on a pipe.

[dakook]

This post is kind of old but. If you just want to drill a series of holes down a pipe with a drill press clamp this on the end of the pipe and find level for each hole. Is also good for keeping more than one bend in pipe and tube on plane.

http://gilchrist-electric.com/Images...l_top_view.jpg

[jimmys]

You can't be sure you're in a straight line unless using levels, or the channel/angle jigs. Even with a level, you have to clamp the pipe so it doesn't roll any.
Jim

[farmersamm]

Originally Posted by TozziWelding

I love my Curv O Mark, but on small non critical applications, an angle or a channel and a chalk line is just fine. A level and square is also handy dandy. If you can find a good combo square with a center head on it you will never put it down. I can think of about 10 ways to do it just sitting here. Just use whatever you are comfortable with.

Centering Head... way to go on that small dia. pipe(and I've seen bigger ones too). You can mark both sides, and drill each side seperately. If you try to drill from one side clear thru to the other, chances are the holes will be misaligned because the drill bit will walk on the inside of the pipe. Better to punch, and drill from both sides.

[ol' Stick Guy]

You say a 2" pipe, which has an OD of 2.375" half of that is 1.1875"
Now you take your framing square lay it with one leg vertical and the other horizontal to the pipetake a level and place it on the horizontal leg of the square once level measure 1.1875" from the crotch of the square and put a mark (scribe, marker, soapstone, spit) this is top dead centre of the pipe repeat this as often as is necessary along the length of the pipe.

howz that for clear as mud

[Nitesky]

Centerheads are great for one or two holes.

At work they used to lay a 20' length of pipe on the ways of a L A R G E lathe and scribe a line. Were making 40' shower bars with holes every 12" and they were all in line nicely.

For home you might better afford to make a jig from wood, angle, or some other device and a reasonably flat surface. For that I use the secondary highway out front and lay it on the pavement. Can hear the hillbillies coming for miles so no problem.
Hmm, don't want to be bending over when they come upon me

[Bozzza]

im assuming its not seamless pipe so all i would do is mark the two ends where the seems r and get a straight edge and line them up

[S.t.t.G.]

I wouldn't trust the seam, could have a bit of spiral to it from when it was made...depending on how long or the diameter, the ol' angle iron trick is usually the fastest, or grab yer trusty centering head and center punch each end at the top of the pipe and snap a line down the length......my 0.02

[tinner]

You need to stabilize you pipe either in a piece of angle or a vise with a pipe clamp if you have one. I then use a center head that has a center punch mounted in it with a protracting level to make all of my marks the same. Here is the tool that I use: http://www.flangewizard.com/products115.html

[violatedppl]

A good way on big pipe without the use of fancy tools, all you need is some soap stone, and a two foot level. Rub the soap stone on a section of the pipe about 3 inchs long and about 2 inches wide, place the 2 foot level ontop of the pipe hold it dead level and run back and fourth over the pipe. If it is done right you will have the center of the top of pipe exposed. This method allows you to find center of pipe with common tools while the pipe is installed. The larger the pipe the easier as you can straddle the pipe while your working on it.

[roy_Robinsonv]

chalk a line prob the easyst way

[Gerry1964]

You could just simply lay a lenght of angle on the pipe to get a straight line down the middle

[Brazin]

In bicycle framebuilding the tubes are set in blocks, placed on a perfect table and a small square is run down each side, this gives 2 scribe lines exactly 180 degrees apart, necessary for laying out the end mitres

[coltsmith]

I wasnt aware there were so many complicated answers to this question. I guess the drill press mounted to a table throws a curve? I dont know i always use a drill motor anyway. But if you wanted it dead nuts you would need to lay out top and bottom