I noticed some aluminum square bars of various lengths for sale in the mechanical product section. Does anyone know whether the holes drilled in these will match the SES hole pattern?
If these] are the bars to which you are referring, I’m not sure just how you are looking for them to “match” the hole pattern (one single hole is always a perfect match with another single hole). The bars are 1/4" on a side, with 4-40 tapped holes drilled along their lengths at the spacings indicated in the “dimensions” image link on each bar’s product page. The spacings of the holes vary with the length of bar, but they’re pretty clearly marked in the images.
Besides: both the bars and the brackets are aluminum. If you need a hole where there isn’t one, you can always drill one. 4-40 drill and tap sets can be found fairly readily from hobby shops, as it is a common thread size used in R/C cars and planes. If your local shop doesn’t carry them, they can probably order them easily enough, or you could just buy them from an online shop.
If you were referring to the channel bars ( lynxmotion.com/Category.aspx?CategoryID=96 ), then yes, they have SES bolt patterns and were designed to work with the SES brackets.
Sigh… electronic communication is such a limited medium. 
My apologies, I thought my description “aluminum square bars for sale in the mechanical product section” was clear. Perhaps I should have included a link.
Seamus - a single hole will match up with another single hole? 
I guess I always thought that the idea behind the SES concept was that everything would link together easily (without drilling and tapping) using a basic connection pattern. Now I understand that these bars are not meant to be incorporated into the SES. A pity, really, I would find them more useful than the channels.
Well that is the concept… All of the products in the SES area are infact interchangable.
I am missing something. These bars are simply used to connect flat panels at 90° angles. I don’t see how a threaded rod could be SES compatible. Now the U channels on the other hand are SES compatible.
The Aluminum Square Bars Seamus linked to are not for SES. They are too connect sheets of lexan (or any material for that matter) together… Here is an example:
lynxmotion.com/images/index/chas01.jpg
The Aluminum Channels that SN96 linked to are for SES.
We’re talking about two different types of “bar”, here.
In my original reply, I was referring to the square bars used to fasten lexan panels together at 90 degrees:
…because the original post referred to “aluminum square bars of various lengths for sale in the mechanical product section”, which is where they are listed.
The SES channels:
…which are designed specifically for use with the SES system, are listed in the SES section.
Exactly. The SES system has tubes, channels, etc., but if I want to incorporate those nice aluminum square bars I learned that I will have to drill and tap holes. I guess I am the only one thinking of incorporating straight, squared structural components such as the aluminum square bars into an SES creation. For what I want to do, the channels are overkill.
Oh no, not at all. Amateur robotics is experimental by nature. If a part suits your purpose, then by all means, use it. Nobody’s going to jump down your throat if you build a robot that uses something other than “official” Lynxmotion Servo Erector Set parts.
The SES can’t accommodate every single design envisioned by everyone. There are some cases where modifications may need to be done to get the results you want, second, there are only so many holes that a structure have before it’s integrity is compromised.
The square bars, since not part of the SES brackets, will need to be drilled and taped to your specs.
nolo contendere