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.

Re: English or Metric?
 

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

-dave

Re: English or Metric?
 

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.

Re: English or Metric?
 

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).

Re: English or Metric?
 

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

Re: English or Metric?
 

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.

Re: English or Metric?
 

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)

Re: English or Metric?
 

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.

Re: English or Metric?
 

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.

Re: English or Metric?
 

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:

Re: English or Metric?
 

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

Re: English or Metric?
 

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

Re: English or Metric?
 

Woops, sorry, it was 3/8, not 5/8, that was for something different that I can't think of right now.;)

Re: English or Metric?
 

: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).

Re: English or Metric?
 

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)

Re: English or Metric?
 

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.

Re: English or Metric?
 

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 [I am far from both] 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.

Re: English or Metric?
 

I totally agree with Ashley!

Re: English or Metric?
 

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

Re: English or Metric?
 

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.

Re: English or Metric?
 

I used to be wild about 1/4-20 but I've seen the weight factor. : :eek:

Re: English or Metric?
 

While I agree the metric system is "techincally" better, we didn't have the English system just to be "randomly" different. There's a lot of historical and economic pressure keeping it alive.

Re: English or Metric?
 

Wow! 5/8 bolts???? How do you ever get the robot to come in under weight?

Re: English or Metric?
 

Ok, 3/8 still seems like an excessively large bolt for a FIRST robot. I have trouble justifying 1/4-20 in most instances but I have a supply of them to use up. :D

Re: English or Metric?
 

you mean it would cost too much to change to metric?

Re: English or Metric?
 

Well, just ask NASA and their international counterparts the next time someone made a mistake using miles instead of kilometers when calculating the distance to the moon, etc. (Which by the way happened not so long ago, can't remember exactly what happened but it came down to the fact that someone put a distance in miles in a calculation where kilometers were to be put in.)

On topic: I would personally favor the metric system, but I could live with it if there would be only ONE system.

I guess we just have to live with that.

Re: English or Metric?
 

IIRC it meant they didn't put enough fuel in ?

Re: English or Metric?
 

I guess my team is odd 'cause we use both .... :)

Re: English or Metric?
 

HOT is anything but odd.

Anyways,

Denman using the imperial system would cost a lot to switch and many americans i.e. the ones who don't build stuff on a regular basis or don't know the metric system, think that its a waste of time (which it definitely is not.) Also, the US tried switching before (at least thats what I've been told) but it just kinda fell through. Not to mention the Imperial system is based on 12 (a number the ancients considered magical because it could be divided by 2,3,4,and 6.)

Re: English or Metric?
 

Yeah. hink of it this way. There are many companies that use the American standard for all their parts. Car manufactures not being the least. Trying to change to a different standard would mean that the oder cars would be hard to support, using American instead of Metric, and all their current parts would be next to useless because they need to change. That's a ton of american bolts that now don't have a home. That is a ton of wasted money in the eyes of companies. The metric system is gradually more pervasive and I think that eventually the tides will change and it will be metric (or what ever they will call it). But I don't expect it to happen in my lifetime. But it might get better.

Re: English or Metric?
 

Most of the time, 461 uses English measurements in buying parts and all that good stuff. In 2004, though, with weight problems, we switched from 1" extrusion to 20mm extrusion with metric bolts and T-nuts. As far as design of the robot goes, most people use the english system (foot-pounds, etc...), but I use metric, for the simple reason that the metric system has the Watt :D .

Re: English or Metric?
 

Globalizations is starting to take care of the English problem. Two years ago I didn't need metric tools for my job. Today I have to have them.

Re: English or Metric?
 

whatever fits...

Re: English or Metric?
 

Yes. Entire industries would have had to retool their plants to switch over to metric so there was always a lot of intertia to prevent it from happening. It's been happening gradually but more from the pressure of markets becoming global. But what we're seeing in some cases is that the English products dimensions are just being converted to convenient metric instead of being "pure". And now we just close our factories and buy the parts from Asia which already has metric in place.

Re: English or Metric?
 

They're BMWs, of course.

We use the English system, though sometimes it seems a wonder I can get some people to measure anything at all. I tried to standardize the use of #10-32 hardware, but it didn't work too well.

Re: English or Metric?
 

I know what you mean. Working in a timber yard where everyhting is in metric inches ;) (say 2" by 4" timber is actually just 50x100 mm)

Re: English or Metric?
 

All of you talking about how much it costs American (and other) companies to change and just use metric are somewhat right. But think about it what it costs to have two standards at the same time. Because you could give all your reasons why companies still use the imperial system can be given about two systems as well.

What I mean to say with that? -- If you need to have tools (and bigger tools in a production plant) in two systems, you need to pay for both. If you have screws and other material in both systems you are practically paying twice. Sure you can substitute somethings but still, it's having two system which makes the least sense.

I am not saying that it doesn't cost money to change to one system, I am just saying that it might eventually be cheapper to change than just pushing the problem away untill it comes up the next time.

--Just my two cent.

Re: English or Metric?
 

1293 uses English measurements. I can't think of anything that we consciously, intentionally did with metric (although I'm sure there's something on Ockham that was done in metric at some point)

Re: English or Metric?
 

Being I work in machine shops I have to use both. Usually when machining a part I use English measurements. But if I have to fix the machine of change the tooling I have to use metric sockets and Allen keys. But as for My robotics team, we're die hard English sytem users. the only metric parts on our bots we're a few Allen head screws. But if I'd have to choose between metric and English I'd have to say English, plus if suddenly the world switched to metric I wouldn't be able to use my vernier or micrometer :yikes: .

Re: English or Metric?
 

Just as long as you keep one system throughout a project--- i hate it when i have to keep switching from us back to metric, and metric back to us--- i can ususally get the size of something by looking at it, but that doesnt work when you start flippin systems- i have to lug in 5 different sockets in the size range to find the right one :ahh: Ford is notorious for it.

Re: English or Metric?
 

We're moving to metric, inch by inch.

Re: English or Metric?
 

Thats why you use a vernier or micrometer to measure it before going for a socket ;)

ROFL!!! *high five!!!* :D