Hammond Datasheet accuracy.

[TheWinterSnow]

I have been using the madbean library for enclosures (in Eagle) and I wanted to make they were accurate.  First I discovered that madbean's layout for the Hammond 1590B was way off from the datasheet.  I noticed the datasheet was incomplete regarding some measurements and seemed inconsistent/incorrect so I decided to pull out my caliper and measure a 1590B that I had on hand and found that the datasheet was even further off.

I discovered an almost 0.5mm difference in the wall thickness on my box from 1.9mm to 2.4mm where the datasheet claims that the wall thickness is 2mm.  That would be okay if it weren't for the other datasheet measurements that if you do the math claim the wall thicknesses are 2.525mm and 2.68mm on perpendicular walls.  My caliper measurements are showing in some cases around 1.5mm difference from my enclosure to the datasheet.  To me that seems a little further off than just tolerances, so I am curious if I am that bad the calipers or are the tolerances/datasheets that far off in your experiences?

[chuckd666]

Was yours a legit Hammond? I know that the Taiwanese remakes (or whatever they are) can differ from real ones.

[TheWinterSnow]

Bought from Mouser, inside is labled Hammond.  I don't have any reason to believe it is counterfeit.

[chuckd666]

Well yeah you'd hope it'd be a Hammond then haha. 

[davent]

And the last Hammonds i received from Digikey were made in Taiwan.

[Ice-9]

All Die cast enclosures are made with sloping walls, this is so that they can be released from the mould. When you measure the inside or outside dimensions with calipers you have to make sure the point you measure that you use the tip of the (parallel) jaws of the caliper. Cheap digi calipers are not that accurate either so measurements should be taken relative.
Unless the enclosure is made by a different manufacturer I doubt 1.5 mm difference is evident other than measuring at different heights on the sloped walls.

also bear in mind cast parts are not machined parts and have quite a bit of tolerance regarding spec'ed sizes

[TheWinterSnow]

And the last Hammonds i received from Digikey were made in Taiwan.

The 1590B boxes that I have from Mouser are marked with an "I" which I assume as Indonesia?

Maybe my calipers are way off.  Yes I did measure parallel to the top of the enclosure and matched it with the datasheets measurments.  Looking at my enclosure including the lid and the datasheet numbers it seems like the tolerances are very loose.  I even had discrepancies between measuring the wall thickness, as the datasheet claimed 2mm but I was seeing in some cases ~1.7mm and ~2.4mm.

My issue is that not only do I need to know the inner diameter of the enclosure so I don't make a PCB that is too big, but I need to know the size of the front/top of the enclosure relative to the PCB so I can make accurate drilling templates and accurate vinyl stickers.  I have found that If my drilling dimensions are off by 0.5mm than parts won't fit.  I want to be able to accurately within 150-200 microns or so have my PCB, graphics and drill template aligned.  Since I am using inkscape for my graphics I need accurate measures for my graphics that align coherently with the PCB and correctly with any drill template I create or have machined at some local machine shop.  With what seems (keyword "seems") like extremely loose tolerances makes my confidence of lining dimensions up with multiple programs a little low.

[ubersam]

Maybe madbean's 1590BB sized boxes aren't Hammond but some other manufacturer. When I used the Hammond 1590A datasheet for 1590A boxes that I got from Tayda (which were un-branded), the measurements were off by a few mm's. Same with 1590B sized boxes I got from mammoth, they measured off when referring to the Hammond 1590B datasheet. But, I found out that mammoth has their own datasheet for the boxes that they sell. Using that, the measurements sync up.

[Ice-9]

There are some Chinese Hammond size boxes available which are NOT made by Hammond but sizes will be close, the likes of Mommoth supply these I believe, and pedal makers like subdecay, among others use these. If you need accuracy then you need to make your own data sheet for dimensions or buy genuine Hammond.