English or Metric?

This popped into my head just now, and most of the discussion on here is old so…
Does your team use Metric or English parts?
For those of you that don’t know the difference, English measurements are in inches and feet, Metric measurements are in millimeters, centimeters, and any other unit based off the meter.
I’m also trying to see if theres a difference between US teams and non-US teams, so please vote accordingly.

Oh lordy, lordy. Just when I hoped I would never have to deal with this topic again. Let the pummeling begin… :frowning:


i voted metric just because its so much easier.
I work in a “Lumber Yard”/“Hardware Store” and everything is measured in the metric equivelant of inches.
Eg a piece of 4x2 (inches) timber is 100x50 (mm)
and the lengths are every 30 cm , which is darn near every foot.

My team has been using the English-ish system. Its not to unusual to find Metric bolts on our older robots. We commonly use what every fasteners are laying around our lab which is why random things will be metric while other parts of the robot are English. On a past two robots we have tried to use the English system with no more than two or three different sized bolts to keep things simple when we have to fix stuff in a hurry(which is realy much too often).

There should be an option for both (albeit it is a pain in the behind to keep track of what’s what)

We’re a Canadian team that uses both, but more Imperial than metric. Since we use materials and mechanisms that rely on both systems, we have both sets of tools. As a result, our students have the distinct advantage of being able to read and use both systems, which is not something I can say for our US counterparts… not that they need to from a purely functional perspective I suppose.

There should be an option for both, and for Canadian teams, I’d argue there’s little choice but to use both. If we wanted to get components and in some (rarer) cases, materials in Canada, metric measurements would often be used by manufacturers and suppliers. But if we’re CADding or assembling the frame, we use Imperial. This is because most of the stuff we deal with still is. For example, say we need to get some aluminum stock for a gearbox from the supplier down the road. We’re much less likely to get 10mm than 1/2" stock, so we design for Imperial. In practice, most materials are still measured in Imperial in the sectors we deal with in Canada, because it makes the most sense for certain suppliers to do so (for a multitude of reasons you can probably figure out on your own). Even though the rest of the civilized world (including Great Britain, the originator of the Imperial system) theoretically uses the more integrated and straightforward metric system, Imperial is far more appropriate for FIRST teams to use in any country, not only because FIRST uses Imperial measurements in its own documents and standards, but because the industrial sector of Canada we deal with does too.

Hence, we are forced to use and know both. It’s not a big deal.

We use both. Most of the bolts we use are all 5/8", but I have to reach for the metric wrenches/alan wrenches/magic wand, too much to say one way or another. We like to use english in general stuff, like framing, because the max dimentions is in inches. I would rather use english have it the right size than make a mistake and be too tall and not be able to do anything about it. If everything was in metric, I am sure that we would use more metric, but it’s not. (and as a side note, we use 5/8" bolts because we have a huge bag of them, but it is currently running low, so we might get a different size bolt for the future)

In our shop most of our tools are English measure, so 99% of the nuts bolts and any other parts found on our robot are in English Measure. The most commonly used wrenchs on our robots is 7/16ths or 9/16ths.

We use an odd mish-mash of Metric and ANSI. Since we’re located in Canada, a lot of the stuff we get exclusively in Metric (fasteners and extrusion) while other stuff we can only get in ANSI (shafts, thicknesses of metal and Lexan, etc).

However, we think mostly in ANSI since that’s the way FIRST thinks, and we’ve all gotten to the point of doing the conversions without having to think about it.

Geez. Well, I guess it is good for standardizing but a 5/8" bolt is pretty darn big for an FRC bot. It depends on the application, but when you say “most of the bolts we use” it leads me to believe they are found in many applications, and are way overkill for lots of things. Getting some different bolts I think is a good idea.

This year, we tried to do as much of the hardware as possible in 10-24 and it worked out very well.

If there is a metric tapped hole in a part on the robot, there’s nothing we can do about that. But other than that, we do English, and this past year, standardized English (10-24).

English is simply much easier when all your machine tools go by thousandths of an inch.

Also, metric hardware is EXPENSIVE here in the states and harder to find. For price, a bag of 10 metric washers (like M6 I think) might be like $1.80 when a bag of 25 1/4" washers (just the same for FRC purposes) is like $1.99. And if you get into nice black oxide allen head screws/bolts (like shcs or button head) then the price REALLY goes up. Also, at least at my LHS, the metric screws come in wierd quantities, like 3 to a package. :confused:

At the local “hardware” shop (more of an ironmongry imho) they sell it in both. and you can usually get about 100 washers for that price lol

45 uses metric bolts, but measure with english. Ya, I know it sounds wierd, but atleast now I know what M3 and M5 means! :slight_smile:

Woops, sorry, it was 3/8, not 5/8, that was for something different that I can’t think of right now.:wink:

:Warning, slightly off topic:

Ok, just have to share this fun story about english and metric.

My father and I had gone into Radio Shack to get some cords to hook up my uncle’s speakers (and to reassure everyone, no I did not actually touch anything) and the salesguy approached us when we walked in. We told him what we wanted and he said that all he had was the 30 ft. cables (very expensive), but they were the best, so buy those. He was rather overly self confident, so I preceded to walk around the store and find the 8 ft. cables that we wanted and bring them over to my father. My dad said that these were the ones we were looking for to which the salesman replied “Oh yeah, we have those but they’re no good for anything but tying down your trunk. Besides, the 30 ft. cables are English, the ones your daughter has are metric, American bought speakers won’t work with them.”

My father promptly put everything down and walked out of the store.

Sorry for going off topic, just thought of that the second I saw this thread.

On topic, I think we use metric tools, but English for the lengths of materials and stuff (like, 2 by 4’s).

We used mostly US Standard on our robot… We tend to “borrow” stuff from various companies we work at, and since the company i work for and two of the engineers work for only use U.S. Standard sizes its easier for us to grab a few US Standard nuts or taps if we need them for the robot.

Then again we’re a scrappy team and we use whatever we find laying around so if it’s metric we’ll figure out a way to make it work (if it dosen’t fit just use a bigger hammer)

We try to use English as much as possible. We’ve also gone as far as standardizing screws. If you’re not using a hex socket 6-32, you’d better have a good reason.

I am not sure what we use – I dont pay attn.

One thing though, I dont understand why Americans have to randomly be different. Isnt it bad enough we are all “fat” and “rich” psh * But anyways back on topic… Since I have grown up mostly with english I use that most. But I wish I was better with metric. It is so much easier and it just makes so much more sense! I like the base number 10. Its simpler. Instead of 12 inches = 1 foot blah blah ew! Haha

Anyways. Thats just my opinion.*

[quote=“Ashley Christine”]
I am not sure what we use – I dont pay attn.

One thing though, I dont understand why Americans have to randomly be different. Isnt it bad enough we are all “fat” and “rich” psh * But anyways back on topic… Since I have grown up mostly with english I use that most. But I wish I was better with metric. It is so much easier and it just makes so much more sense! I like the base number 10. Its simpler. Instead of 12 inches = 1 foot blah blah ew! Haha

Anyways. Thats just my opinion.

I totally agree with Ashley![/quote]

If it’s metric we just drill it out and re tap it. One of our engineer mentor cringes every time we do it.

Well, your survey was lacking in a few options. We’re certainly a US team and our last robot had BOTH English and Metric parts. The metric parts were in the chassis in that it was constructied of 20 mm T-slot aluminum members to save weight over the minimim, that I could find, 1 inch English sections. That required that we use 5 mm and 3 mm threaded fasteners in the chassis contruction and to fasten parts to the chassis. However, the rest of the robot was constructed using English unit materials since those are sooooooooooooo much easier and cheaper to come by in the US.