[How do I?] How do I Line Bore Square Tubing?

RonRock

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So my son wants to build a weight machine. Should be a good project, we'll work together and both learn some skills.

First thing is figuring out how to bore series of 1" holes in a 90" length of square tubing. Six times! Similar to what would have to be done for an adjustable shop press, as well as other items.

The "Machine" will have 6 legs (uprights) that will have different styles of pegs or standoffs that need to be adjustable in height. So the holes have to be very accurate positioned with each leg.

The material is 11 gage 2 x 2 mild steel. Would prefer to not drill/machine clear through. Might need to do front and side on corner legs.

I have a Bridgeport with a dro and of course a stand up drill press. I figure that the BP will be the machine to use, but the length of the tube is going to be an issue. The DRO may not be the best help in this instance because of the number of holes, and the need for 6 pieces to match. I'm thinking some kind of jig to locate a series of holes after the first one is done. Then the lengths could be adjusted to match. Or simply accurately drilled the first hole.

Any thoughts?

As a little kicker to the project, he has mentioned Keyholing the holes if possible. That would compound the project, so not sure on that.
 
Sounds like a long row to hoe- The modern factory would probably use a computer controlled plasma cutter
Can you change the design to reduce the size and/or number of holes needed?
Mark
 
Don't move the table. Hold the tube in the mill vice and make a jig to index the hole spacing so you can move the workpiece the precise amount in the vice.
 
Yes I don't plan to drill the entire length. Just a guess without his input, but I'd think that the holes could stop at around 24" up from ground. They might not need to go all of the way up, not sure on that. So that reduces the number significantly. Still a lot of holes that need precision.

I forgot to mention the spacing of 3" center to center. So A quick figure of 90" - 24" = 66" drilled length. At 3" spacing that is 22 holes on each side.
 
A shop that does laser and/or water jet cutting can do that work for much less money than you might expect, especially if you provide the electronic file of the job in the format they use, and offer to wait a while if necessary so it can go on the table at the same time as other similar work. Done correctly, laser and water jet cutting can both leave equally accurate and beautiful cuts. Plasma cutting can also be nicer than you might expect. They will supply the material, and often they will let you supply it if you have it. We would email the file of what we wanted, along with a maximum time frame we needed, and it usually took less than a week before we went and picked up the parts. Sometimes the total end cost was about the same or slightly more than buying the material alone at retail pricing. Sometimes DIY simply does not make sense.
 
Don't move the table. Hold the tube in the mill vice and make a jig to index the hole spacing so you can move the workpiece the precise amount in the vice.

That is what I was thinking. I was thinking that I could remove the vice completely and fabricate something to use as a jig to locate.

Hoping someone would have already crossed this path or similar and had suggestions.

The DRO would be accurate, but too slow for the number of holes. Maybe for the first one, then it could be used as a template for the rest somehow.
 
A shop that does laser and/or water jet cutting can do that work for much less money than you might expect, especially if you provide the electronic file of the job in the format they use, and offer to wait a while if necessary so it can go on the table at the same time as other similar work. Done correctly, laser and water jet cutting can both leave equally accurate and beautiful cuts. Plasma cutting can also be nicer than you might expect. They will supply the material, and often they will let you supply it if you have it. We would email the file of what we wanted, along with a maximum time frame we needed, and it usually took less than a week before we went and picked up the parts. Sometimes the total end cost was about the same or slightly more than buying the material alone at retail pricing. Sometimes DIY simply does not make sense.

Interesting thoughts. Might be worth investigating. Seems a shame to have my own equipment and pay someone else. But I will consider this route.
 
Pay others to do work you cannot easily do yourself.
 
Just found out that the holes are 2" on center.

Anybody know about annular cutters? Never used one, but that seems like the best way to drill the holes.
 
This is simple on a BP w/DRO.

Move the table to one side, locate the first hole, 0 the DRO, drill the hole, move over to the next hole, drill, rinse repeat until you run out of table. Move the table back to 0, slide the work over to the last hole, use the drill bit as a locating pin, move over to the next location, drill, rinse repeat.

Support the tube end on a roller stand or anything that you can fab up quick.

That is the way I did the holes for the crossbars in my shop security door. The bars go all the way through the uprights.
288483
 
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