Plans For Heretics (Metric Engineering)

[shred]

As others have said, it's not so much the conversion factors-- digital calipers and DROs and calculators and all make that pretty painless, its that the materials and tools are much harder to come by in the 'foreign' units. 3mm threaded rod is as annoying to come by here as say #4-40 rod in a metric country. Yeah, it can be done, but it's so much easier to 'go with the flow', especially if you're scrounging materials.

 

[HughT]

Hi Guys,
The other method is dividing 23 by 64=.359375 which rounded off (5 and above goes to the next highest)= .35938 =.3594=.359. mm to imperial .03937*mm=imperial.
Hope this helps
Tony

Hi Tony,

The problem is not the level of decimal places - it is the dimensional accuracy I was referring to with original plans - from my own experience it seems quite common practice for the original draughtspersons to set an accuracy level when dimensioning in 'inches' to 1/32, 1/64, 1/128 or whatever ...etc etc. The majority of plans that are currently freely available tend to dimension to the nearest 1/32 of an inch which equates to 0.794mm - this can accumulate throughout the design and ends up with things not quite fitting together or in some cases not working at all. If you look at Elmers designs they are dimensioned to the nearest 1/32 of an inch.


Its not the fault of the original designer its just something that needs to be considered when converting units from these old designs.

 

[cobra428]

Sorry for my misunderstanding. The Imperial plans for the kits I bought have the dim mix all over them some even a combo of imp and mm. I have never seen what the free plans look like, just the stuff here, that people made from them.
Tony

 

[HughT]

Sorry for my misunderstanding. The Imperial plans for the kits I bought have the dim mix all over them some even a combo of imp and mm. I have never seen what the free plans look like, just the stuff here, that people made from them.
Tony

Hi Tony,

Thank you, but no apology necessary - I was not very clear in my original post. I have only seen the plans that are freely available, some museum archives and the Elmers collection!