An Adequate Substitute for 3mm Rigid Tubing (US-Only)

[Phoxtane]

For some improvements on a previous model, I knew I would need a decent amount of 3mm rigid tubing - but I didn't know yet how much I would or how long the pieces would need to be. Since buying genuine rigid tubing can get expensive fast, and I would likely have to cut it up into various lengths that wouldn't end up being used, I decided to find an alternative.

I found 1/8" (3.175mm) OD nylon tubing on McMaster-Carr which seems to work well enough for what I need. Unfortunately, McMaster-Carr only ships to addresses within the United States (for us little people, anyway), so this substitution is only available to those in the US.

Below is an image of the tubing after I opened the package and cut a medium-length piece for comparison purposes:

 

Below is a comparison between the substitute tubing (middle) and official Lego tubing (bottom), with a black 1x16 brick for comparing color:

 

McMaster charges 29 cents per foot for this stuff, and sells it in lengths of 25, 50, or 100 feet. I ordered a 25ft roll, and it cost me $7.25 (with minimal or no shipping costs - McMaster is a bit weird with their invoices).

As for how well it works as a substitute for genuine Lego tubing, it's perfectly adequate for my purposes! My tubing is black, which matches Lego black almost perfectly. It does have a much smoother and glossier surface than genuine tubing, but in my opinion that makes it match the surface of a fresh brick better than the real stuff. It feels a bit softer and certainly more flexible than genuine tubing; however, it's not nearly as soft or flexible as the silicone pneumatic tubing. The internal diameter is much larger than the Lego tubing, resulting in much thinner walls than the Lego tubing. This probably explains why it's so flexible, but it also means it will be more prone to kinking or collapsing on itself.

It snaps in and out of clip pieces a bit more easily due to being softer than the real stuff.

Another thing to note is that there's information printed onto the tubing itself. It does ruin the look, but thankfully the text can be cleaned off with an alcohol wipe.

Overall I'm quite pleased with this stuff. Apart from black, McMaster supplies it in blue, green, red, yellow, and gray (none of which I needed so I can't comment on how the color matches to their corresponding Lego colors). Oddly enough, the gray is only available in metric, at 3mm, so it may be too small.

Here's the link to the McMaster page: https://www.mcmaster.com/standard-plastic-and-rubber-tubing/=60fa861250244b82b607a2f2a3d13811k0yhfgb7

As a side note, McMaster-Carr is weird to order from - you have to create an account, then go into your account settings and put in card information that orders will charge to. At that point, you're free to order as much as you want. They then send a confirmation email, send an invoice shortly after that, ship your items the day after, and the charge shows up on your card about five days later.

I'm baaaaack. I graduated college and moved halfway across the US to the East Coast for a job, and even have cats to knock stuff over for me instead of doing it myself.

[dr_spock]

Welcome back.  For a moment there, I thought you were going to use your 3D printer filaments and bend to shape with a heat gun.  Aren't cats great? 

 

[1963maniac]

Hey, thanks for sharing this information!

[ecmo47]

Looks like the 1/8th inch comes in 5 colors: red, yellow, blue, green and black. Grey appears to be offered but only in 3mm. Thanks for that link!!

 

[knotian]

I have used single solid conductor wire as a substitute for the tubing. Added advantage is that it will hold a curve due to it's solid interior. Try Lowes or HD.

[1963maniac]

6 hours ago, knotian said:

I have used single solid conductor wire as a substitute for the tubing. Added advantage is that it will hold a curve due to it's solid interior. Try Lowes or HD.

That sounds like a good idea too. I have yet to try making a marble run. I bet it's tricky to get that tubing just right.