inches or metric?

The design of other, logistical features, such as documentation, parts lists, supply sources, and instructions.
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JiB
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inches or metric?

Postby JiB » Sun Jan 02, 2011 5:28 pm

It looks like a lot of users here are from the USA, a country that has still not converted yet from the medieval units they inherited from the British. That is very unfortunate, as it is hard to cross that divide from either side: Imperial size tools, bolts and screws etc are hard to get in the rest of the world, while it probably is just as hard to get metric sizes in the USA.
The obvious solution is to make two parallel designs: one in imperial and one in metric. The downside of that is that it takes more work to convert from one to the other and might require knowledge that the other side does not have (readily available), like what size of bolts are easily available: do you substitute a M6 or a M7 for a 1/4" thread?
I can only point out that this is a potential problem, I do not have an easy solution for it either.

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beermkr
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Re: inches or metric?

Postby beermkr » Sun Jan 02, 2011 10:21 pm

I think parallel designs is the absolute way to go.
Mike Pensinger
Chief Brewer, The River Company Brewery, Radford, VA

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Awesomeness
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Re: inches or metric?

Postby Awesomeness » Mon Jan 03, 2011 8:50 am

I think a lot of the decisions of the design will hold true for either units. For instance, the design of the linear bearings, whatever it is, should be able to be similarly replicated in either.

I do agree that one of the tough parts is "normalcy conversion". Here in the US a 1/4" bolt is extremely common, and every toolkit comes with tools to tighten one. I have absolutely no idea what the common metric equivalent of that size is, that you would run into on a daily basis in the UK.

That said, I don't know if parallel designs are really possible, without ending up with two very unrelated machines. It seems to me that serial is the only way to keep them very close. One team designs a part for their machine in one units, and the other team copies that part into their units translating for "normalcy". Maybe we're saying the same thing, and it's just semantics though.

Just out of curiosity, which bolt is a more normal metric equivalent of a 1/4"? M6 or M7?

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beermkr
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Re: inches or metric?

Postby beermkr » Mon Jan 03, 2011 4:17 pm

I interpret what you are saying as a parallel development. I see your serial thought but if you are doing each part as we go then we end up with full machines at the end (or really close to it.

On that thought I think that the base table is the first place to start as it defines a lot of other dimensions.
Mike Pensinger
Chief Brewer, The River Company Brewery, Radford, VA

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Keith
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Re: inches or metric?

Postby Keith » Mon Jan 03, 2011 8:31 pm

To answer Awesomeness's simply question; (and this really is as basic as we need to get with this issue of imperial and or Metric), I simply put 2 rulers together or I use a ruler and a micrometer.... 1/4" is closer to 6mm then 7mm on my rulers and micrometer so therefore is DO ALREADY use EITHER for the same purpose.

I honestly thaik that we need to design this machine with the capability of being built with whatever is availble in the country where it is going to be built!

We only need to that if 3/4" MDO/MDF/Plywood is used it is interchangable with 18mm or if avaiable 19mm material. If the plans call for 1/4" and only M6 is availble the that is what should be used, however we can and I believe should RECOMMEND what we believe is the most suitable size.

However I believe that if a builder used M7 bolts instead of M6 it would not seriously affect the machines performance if the MDO/MDF/Plywood available is 19mm+ in thickness. However I would think that a M6 bolt would be better suited to 18mm MDO/MDF/Plywood.

I firmly believe our final design should simply state what is "recommended" in the way of materials, materials types, Thickness nuts & bolts etc etc etc.


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