Non SS Tubing Question

So about a year ago I planned on building a MPCNC and purchased some 1" OD tubing from Summit Racing. But I’ve changed my mind and want the ability to have 4x8 capability and want to build a Lowrider 3 instead. Unfortunately the tubing I purchased was not stainless steel and is only 7 feet lengths. My two questions are can I paint this tube or just clean it very well and keep it oiled to avoid rusting? My other question is has anyone joined tubing together for the long axis? Either by welding or some other means? Thanks.

If you have 2 7’ lengths you have more that enough for a LR3. Use EMT as your Y rail as its perfect for that.

I actually have 3 7ft sections. But I thought emt wasn’t recommended for the LR3?

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Depending on the outside diameter of the DOM it could be good

Actually a LowRider can be made with EMT, although if I remember right, the X gantry can be done with larger EMT than is recommended for the long Y rail.

You can use a couple of your larger 7’ tubes for the X gantry (their length will need cut down), and you can buy some smaller, affordable EMT for your long Y rail.

Consult the build docs for specific sizes and to double check my advice!

I use non-stainless 1" OD steel on my LR3. It’s fine. I have tool wax, but have not actually applied it.

Of course, I live in a dry climate. Your mileage may vary.

The LR3 can be made with 1/2" conduit for the Y rail (this is what I use as it was all 1/2" comduit in the first beta release) and as this is the least expensive option I recommend it. The smaller diameter also leaves a gap between the conduit and table, so it doesn’t trap chips. 3/4" conduit, 25mm or 1" tube can also be used here.

The first beta release had 1/2" conduit as the X rails, too, but this proved to allow twisting of the beam, so a bit sturdier was recommended. By general release time, 3/4" conduit, 25mm and 1" versions are available.


I built my first MPCNC with 1" steel pipe because I couldn’t find stainless. I cleaned it with WD40 initially and occasionally would reapply WD40 if I noticed any rust spots developing. It worked fine. I bought stainless when I built the MPCNC Primo because I was able to find a source at the time.

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Let’s clear up these terms. EMT is measured by inside diameter. 1" EMT is way too big (because it can fit 1" inside it).

1" OD tubing from a metal supply store is probably what you have. It is steel, but not stainless. That should be fine.

The two concerns are rust (which we don’t have in Colorado, but I have heard of it before) and the seam having a weird shape. You can just turn it so you aren’t riding in the seam. You can protect it from rust with wax or oil or anything you use for your other iron or steel tools. Anything wet (like a lot of oil) is going to collect a lot of dust. Johnsons paste wax is commonly used on table saws for this purpose (and it doesn’t contain silicone. Silicone can affect wood stains).


I use this on the table saw that stays in the garage, after coming out in the spring and seeing rust on the bed. (Turned put to be a spill which caused it.) Still the wax also helps stuff slide when applied.

I had intended to apply it to both the Primo and LR3, but so far I haven’t. I did see a couple rust spots on the Primo after hanging a damp towel over one of the rails, and forgetting it overnight.

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