knowing where to drill

jeepeater2003

Member
Joined
Mar 21, 2005
Location
raleigh
I hope this is the correct place for this, if not move it.

When you fab something up and you need to drill holes, how do you make the mark to drill the holes?

EX. I just made a fuel pump block off plate and had to drill two holes for the bolts to go through to hold it. Well I made a cut out out of paper and then stabbed holes in the paper where the bolts go through. Transferred it to the metal and drilled. Still a little less than a quater off... So I had to wallow it out a little. Im sitting here thinking to my self there has to be a better way!!!

What do the expert fabricators do?
 
I'm no expert fabricator but, typically when I do this type of work, I'll do it one of two ways either coat the part with something transferable (like axle grease) and press heavy paper against the part to transfer the image. The other way is I'll put heavy paper over the part and use the ball end of a ballpeen hammer and tap around the edges to make an imprint of the part. Usually I'll do this for making gaskets but it has worked in the past for locating holes that are difficult to measure out.
 
Grease method works, so does some gum, anything to make an imprint of the part on difficult pieces like that.

Otherwise I measure it with some calipers and then lay it out and use a center punch to mark the spot.
 
They make hole transfer punches, which I still do not own. Otherwise you just get better at the approach you outlined or use other creative methods.

I would have used the gasket for the pump or actually set it on the old pump and used those holes with a drill bit to start the hole. Reality is when its bolted on no one will probably see it...
 
A good measuring device & a center punch, transfer punches.
 
take a picture of the flat surface with the tape measure so you have something to scale it to. Then, draw it on the computer, etc, and print it out or have someone cut it out with a CNC plasma :D

or just measure two or three times versus just once
 
i just use a tape measure. Measure the centerline of the holes and center punch and drill. I do have the hole transfer punches but i rarely ever use them. If the holes are some crazy shape....like the support bearing on the yoke of a 14 bolt i would just use a gasket or shims that come with it. Each situation is a little bit different.
 
NCDieselWrench said:
I'm no expert fabricator but, typically when I do this type of work, I'll do it one of two ways either coat the part with something transferable (like axle grease) and press heavy paper against the part to transfer the image. The other way is I'll put heavy paper over the part and use the ball end of a ballpeen hammer and tap around the edges to make an imprint of the part. Usually I'll do this for making gaskets but it has worked in the past for locating holes that are difficult to measure out.
Click to expand...
Use the hammer and paper method. Works great, was amazed when this Hot dog salesman showed me that trick....
 
When finding the center of two holes that are the same size. Just measure from top edge to top edge. Or measure from bottom to the bottom. The edges are easier to get a good reading on and if the holes are the same diameter the distance to the center points will be the same, its simple gemomety.
In a bind to get a good pattern tape regular ol notebook paper to the part and lightly rub accross the bolt holes. If your fingers are dirty like mine useually are you'll get and imprint of all the surface edges like doing a rubbing with a pencil and stincile.:beer:
 
the most simple one is what Jeff was saying transfer punches work get and are really cheap at harbor freight. Had my set 12 yrs now and work great. That is the easiest for a novice to get perfect every time.
 
WARRIORWELDING said:
When finding the center of two holes that are the same size. Just measure from top edge to top edge. Or measure from bottom to the bottom. The edges are easier to get a good reading on and if the holes are the same diameter the distance to the center points will be the same, its simple gemomety.
Click to expand...



Exactly! I don't know why people don't do this more! I've tried explaining the edge to edge measurement is the same as the center to center measurement and they just don't get it. oh well...
 
Some good Ideas. I like the heavy paper and hammer approach.

I do have transfer punches but when you cant get in the whole they don't work...

Ill have to find out which one works best for me next go around

Thanks
 
rockcity said:
Exactly! I don't know why people don't do this more! I've tried explaining the edge to edge measurement is the same as the center to center measurement and they just don't get it. oh well...
Click to expand...


In retrospect, this would have worked the best.
 
Back
Top