I ordered 3 8’ lengths of 1" OD stainless steel tubing from Amazon and it arrived today. It isn’t perfectly straight, and I’m wondering if I need to be concerned. I’m sure the imperfections will be much less noticeable when it is cut to length (I’m planning to do the standard 24" x 24" build), but is some amount of non-straightness normal? This is a link to a video of me rolling the tubing on my countertop, which is very likely not perfectly flat and/or level:
Thanks!
No, that’s not normal. Tubing is pretty hard to bend unless they shoved it in a plane or truck under a lot of weight. Stainless is particularly rigid. Take a straight edge the whole length to check straightness. If you don’t have an 8’ straightedge (most people don’t) us a piece of string pulled tightly and check if the light shows through between the string and tubing. If so, send it back as damaged and state it must be absolutely straight.
Thanks, Mike. I’m going to send it back. Hopefully I can find something better from a local supplier.
My pleasure. That’s going to make you crazy if you use it.
I think you are completely fine. You did not buy material with a straightness certificate, they will not return it anyway. At the lengths we use I doubt it is even perceptible, if it is, just position the arc up and gravity will help you out. You have a lot more leeway than you would think. I can tell you I just grab the nicest conduit the hardware store has, always curved, and at the metal supplier they do not let you choose they pull it and load it and leave.
I know Ryan already answered this, but it seems to me that if there were a minor bow and you placed the tubing so that the high spot was in the middle between the spans, then the gravity would offset it, possibly being better than if it were perfectly straight.
Strictly speaking, nothing is perfectly straight. It’s a matter of tolerances.
As the famous woodworker Paul Sellers asks: “how flat is flat and how straight is straight?”
In school it was similar.
How perfect do you need it?
Maybe I shouldn’t have acted so quickly, but I already sent it back. It sounds like I probably would have been fine, but I found a way to get tubing a LOT cheaper, which I wouldn’t have found otherwise. My brother works as an automation engineer and has a supplier that can get the tubing at ~$3/foot; the stuff on Amazon was over $8/foot after shipping.
Thanks, everyone.
Hi Jeff,
I personally think you made the right decision. The way it was bent in your video was disconcerting to me. Anything straighter than those would be better. My personal feeling.
Re: Stainless Steel
That’s why I went with the MPCNC instead. SS tubing was really expensive here. I couldn’t justify the cost. Can you get me enough tubing for a 4 x 8 Lowrider? I’ll send money if so.
Thanks.
Mike
Sorry, Mike. I wish I could help, but my brother is doing me a huge favor helping me with this and he lives 100 miles away.