[How do I?] Square Hole ?

welded correctly you could bend the tubing with the weight - the welds will be intact so if the final product includes welding it's a non issue imo.

to satisfy the pass through theory you could drill holes for round tubing the id of the square tubing and pass the round through the square - welded no one will know but you unless your engineer puts it on the scale. - or use short round tubing stubs as the pass through.

or have someone punch them
 
It sounded like a lot more than 22 holes (10 posts, each with lateral and longitudinal connections). Given what I’ve read about the shop doing it, welding in a sleeve seems most likely to succeed. Laser cut posts would give a better result. You could hand cut with plasma and a template but it would require a bunch of cleanup with a finger sander.
The (22) number I cited is only for the pass-throughs. I just grabbed the drawing, which is very useful by the way, and I realize that I've made a mistake. There are indeed (22) pass-throughs, but I should've been more exact about how many holes that will require: (44). Needless to say, each side of the vertical "posts" will require a square hole that will accommodate the 1" x 1" square tubing that constitutes the horizontal structure of the design and which, obviously, transfers the load to the 2" x 2" "legs" in the unit.

Regardless, you are correct. There are far more than the (44) holes I just described in this project. When one considers the front-to-rear connections -- the "lateral" connections you mentioned -- the "hole job" aspect of this project grows. Although we don't own one ourselves, it may be possible to borrow a plasma cutter for this job. We are in Hypertherm country, after all. :grin:
 
Hi Alaska Jeff ~

Do you think that the "tool sleeves" that you so kindly photographed is available with an inner dimension that's conducive to passing 1" x 1" mild steel tubing through it? Erich had a similar idea, but the materials proved to be too expensive. Regardless, I haven't checked the sources you cited, so one never knows.
Hi RedOak,

Here's one source for 1" square, but wow, it's spendy!

 
Hi RedOak,

Here's one source for 1" square, but wow, it's spendy!

Yeah, they are! That is why I suggested a cheaper alternative of using square tube that has the right ID, put into a circular hole, and weld it in place..
In reality he probably needs 1-1/16" or 1-1/8".
 
Yeah, they are! That is why I suggested a cheaper alternative of using square tube that has the right ID, put into a circular hole, and weld it in place..
In reality he probably needs 1-1/16" or 1-1/8".
I was wondering the same exact thing, Erich. A tolerance of +/- 0.008" is pretty tight for the [relative] crap we'll be getting for this job...so perhaps I should think again about the square [in plumbing terms] "nipples" that will pass through the vertical 2 x 2 s. I've used the mag drill I mentioned earlier to great effect. In fact, we've cut holes into huge loaders with it -- for adding mounting brackets -- and it worked like a dream, even in some very awkward positions...so the idea of starting out with larger round holes does have its appeal...and, thinking about it some more, I could use our woodworking equipment to create a jig for repeat operations, which this job definitely has more than its share of.

As a Plan X, I was thinking about the possibility of using round tubing for all of the horizontal support members. In fact, we could add some nice hardwood strips with rabbeting that would effectively hide the round members. This means that only the horizontal steel members would be visible, and that would mean another "design meeting" to get approval...any thoughts on combining round horizontal and square vertical tubing?
 
I was wondering the same exact thing, Erich. A tolerance of +/- 0.008" is pretty tight for the [relative] crap we'll be getting for this job...so perhaps I should think again about the square [in plumbing terms] "nipples" that will pass through the vertical 2 x 2 s. I've used the mag drill I mentioned earlier to great effect. In fact, we've cut holes into huge loaders with it -- for adding mounting brackets -- and it worked like a dream, even in some very awkward positions...so the idea of starting out with larger round holes does have its appeal...and, thinking about it some more, I could use our woodworking equipment to create a jig for repeat operations, which this job definitely has more than its share of.

As a Plan X, I was thinking about the possibility of using round tubing for all of the horizontal support members. In fact, we could add some nice hardwood strips with rabbeting that would effectively hide the round members. This means that only the horizontal steel members would be visible, and that would mean another "design meeting" to get approval...any thoughts on combining round horizontal and square vertical tubing?
Making the round tube look square might be a nice effect. You're only holding a few hundred pounds, even a pure wood structure 1" thick could hold that no problem. You're likely talking about 10k weight capacity with steel bars as it is, so even just starting out with 3/4" round tube and welding that in would be fine if the customer approved of it.
 
For the design and purpose you are describing, there is absolutely no benefit to passing the laterals through the uprights. Much better off just welding.
 
For the design and purpose you are describing, there is absolutely no benefit to passing the laterals through the uprights. Much better off just welding.
Ah, I thought there was interest in it being a 'flat pack' kinda thing. But I read back and I don't see any motivation in that respect.
 
Making the round tube look square might be a nice effect. You're only holding a few hundred pounds, even a pure wood structure 1" thick could hold that no problem. You're likely talking about 10k weight capacity with steel bars as it is, so even just starting out with 3/4" round tube and welding that in would be fine if the customer approved of it.
Thanks again, Erich. The fact of the matter is that this custom A/V/D rack will have to transmit a dead load of at least 1K pounds on the first shelf alone. As the engineer/customer who designed it intended, the load gets lighter as you go up, but I agree with you, nevertheless. The steel "exoskeleton" of this design should support this gear, as heavy as it is, with little in the way of problems.

As it was explained to me, the longest "spans" in the design are the side-to-side supports and he wants them to be shouldered by the uprights. The front to rear supports can [and will] shoulder on one piece of steel, but the longer spans are to be shouldered by two. That's what the man is paying for, so that's what he'll get. I will definitely run the "round horizontal" to "square vertical" idea by him and see what he thinks about having only the vertical steel members exposed. I haven't done much "pipe welding," but, if it's set up properly in the first place, I think that I can manage it. Regardless, I'll let the thread know :grin:
 
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Make sure you post pictures! This sounds like an interesting project, I'd love to see how it turns out!
 
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