setting up material larger than table

[Runner4404spd]

how do you do setup a part to be drilled on your table if its bigger than your table? i basically have a tube that i need to drill holes in. the tube is 28 inches long and the table travel is 18.5 inches. the holes are 18 apart but are located five inches from one side of the tube. basically i need to figure out a way to indicate the end of the tube as it hangs off my table so i can drill the holes in the proper location. i have a couple of ideas but i want to see what you come up with.

thanks
Jerry

[Verfur]

ok,

Just one tube or a thousand tubes?

just one locate the one hole and drill it then move part to exstents of the machine re-zero/ index from the hole you just drill useing a pin gauge or drill bit into the hole to ensure proper indexing.

Many more than one machine a stop and locate so as to index the end of tube and zero from a known location on said stop and viola good for thousands of parts.

any thing like you were thinking?

John

[Runner4404spd]

i've got about 18 tubes to do for this job and it will be recurring every couple of months. your description of the known stop was kinda what i was thinking. although i was thinking of using my dial indicator on a 4 or 6 inch extension and then indicating off my rotary index chuck.

thanks for the reply and keep the ideas coming!

[Zippi]

I'd make a couple of these:

[miljnor]

you can rig a stop with a peice of aluminum. and index of off one of the hold down bolt holes

[Runner4404spd]

Well guys i'm stuck again. i need to figure out a way to indicate the end of the tube and its past my travel point on my mill. any help here would be appreciated.

thanks

Jerry

ps thanks zippi i used your clamp idea and my rotary index and its all indicated for height and the tube is perpendicular to the spindle.

[One of Many]

Originally Posted by Runner4404spd Well guys i'm stuck again. i need to figure out a way to indicate the end of the tube and its past my travel point on my mill. any help here would be appreciated. thanks Jerry

You could use a dog bone(solid standard piece of scrap) to place on your tube that will catch the end , but put a reference surface within the reach of your mill travels. The length of the piece does not need to be precision other than how well you can measure it. If it ends up 3.4567, who cares. Just use that to calculate the actual move. As long as the important surfaces are square and parallel, you're good to go.

Look at what Miljnor posted. If you can hook that short leg over the end of the tube and use that dimension of the long leg for your reference to compensate actual travel, it should be reasonably close to indicating from the end. Same for your right end other than having to straddle the support there.

DC