Fusion 360 help please.

[Dr.Al]

It's not a great drawing is it? Not that I'm surprised having seen some datasheet dimension drawings...

I agree with the 5.24 though.

The least useless most useful drawings seem to be the ones on pages 8 & 10. Those shows the mounting holes as being 2.6 mm in from the bottom edge of the PCB (or possibly the module, it's not that clear). If we assume it's from the PCB bottom edge, then as we know that the PCB is 75.8 and the mounting holes are 70.6, we can work out the offset as (75.8 - 70.6) / 2, which corresponds with the 2.6 mm in from the edge.

With mounting holes 2.6 mm from the edge of the PCB, the pin offset from the mounting hole is 7.84 - 2.6 which is 5.24 mm.

I think the drawing assumes that most of those dimensions are centred on the centre line, but it would be nice if it stated it explicitly rather than relying on assumptions.

 

[ajlelectronics]

....The drawing states a size for the module (75.95mm) and a size for the PCB (75.8mm)

Yes but they are referenced from the bottom line, so not symmetrical. The display itself is 0.15 above the PCB. Doing a crude calliper measurement on the holes shows a small discrepancy top and bottom, so I wonder if the holes are centred on the display, rather than the PCB? That would cause an error of 0.15.

 

[ajlelectronics]

The least useless most useful drawings seem to be the ones on pages 8 & 10. Those shows the mounting holes as being 2.6 mm in from the bottom edge of the PCB (or possibly the module, it's not that clear). If we assume it's from the PCB bottom edge, then as we know that the PCB is 75.8 and the mounting holes are 70.6, we can work out the offset as (75.8 - 70.6) / 2, which corresponds with the 2.6 mm in from the edge.

Indeed, however if that is true, then where is the alignment error coming from? I am starting to believe that the 70.6 is centred on the display, rather than the display's own PCB.

5.24 is the 0.15 in error of course, so it is probably me! I will have a go with that dimension tomorrow.

Thank you both.

 

[ajlelectronics]

....The drawing states a size for the module (75.95mm) and a size for the PCB (75.8mm) (the screen probably overlaps the PCB slightly). It also states mounting holes are pitched at 70.6mm - everything is assumed to be centred.

Therefore the holes are (75.8-70.6)/2 = 2.6mm from the PCB edge, making the first row 7.84-2.6 = 5.24 from the hole centre. The size of your PCB is irrelevant since the holes must align you need to position your connector from the hole by the same distance.

I think that you are both quite right, now I have had half an hour to think about it away from the problem. Thanks for taking the trouble to look at it for me.

 

[ajlelectronics]

It's not a great drawing is it? Not that I'm surprised having seen some datasheet dimension drawings...

I agree with the 5.24 though.

The least useless most useful drawings seem to be the ones on pages 8 & 10. Those shows the mounting holes as being 2.6 mm in from the bottom edge of the PCB (or possibly the module, it's not that clear). If we assume it's from the PCB bottom edge, then as we know that the PCB is 75.8 and the mounting holes are 70.6, we can work out the offset as (75.8 - 70.6) / 2, which corresponds with the 2.6 mm in from the edge.

With mounting holes 2.6 mm from the edge of the PCB, the pin offset from the mounting hole is 7.84 - 2.6 which is 5.24 mm.

I think the drawing assumes that most of those dimensions are centred on the centre line, but it would be nice if it stated it explicitly rather than relying on assumptions.

I have done some tweaking by eye and the figure that makes it visually correct is 5.390mm

 

[Misterg]

I have done some tweaking by eye and the figure that makes it visually correct is 5.390mm

If you have a model of the module that you trust, you don't need to measure anything - just position the module where you want it to be and align the features in your design to it (for example, you could use a projection of the connector pins to position PCB pads in a sketch in your design).

 

[ajlelectronics]

If you have a model of the module that you trust, you don't need to measure anything - just position the module where you want it to be and align the features in your design to it (for example, you could use a projection of the connector pins to position PCB pads in a sketch in your design).

I don't know if I can trust it. As pointed out, the datasheet is dreadful and real life measurements cannot (here) be made accurate enough. It's a .step file supplied by the display manufacturer and merged with my PCB design from EasyEDA Pro. I think I will have to go with my gut and get the boards made once finished. Worst case, the connections will just become flying leads.

 

[ajlelectronics]

I have found an interesting conversion tool for PCB design. It will convert between most of the industry standard packages' files (as well as EasyEDA standard to Pro). That would have helped me last week if I had known of it!

Format Converter | EasyEDA Pro User Guide

prodocs.easyeda.com

 

[ajlelectronics]

Work continues on the RTTY modem. I have learned a fair bit now both the Fusion and EasyEDA packages. I am quite pleased with my transformer 3D model, my only niggle is that the appearance didn't change for the top of the bobbin, it is all supposed to be the same white plastic colour.

 

[Hood]

It is because your windings go right to the top so are basically sharing the same top surface as your insulator plate or whatever you call it.
You can still make it white but it still doesn't look correct because of the coil and insulator sharing the same plane.

 

[ajlelectronics]

It is because your windings go right to the top so are basically sharing the same top surface as your insulator plate or whatever you call it.
You can still make it white but it still doesn't look correct because of the coil and insulator sharing the same plane.


View attachment 478845

Right thank you, it makes perfect sense now!

 

[Hood]

If you shorten the coil to 7.5 it looks correct.

 

[Hood]

You actually want to shorten the coil to 7mm and then move it up 0.5mm so both top and bottom of the coil are in the correct position with relation to the insulator.

Having said that the way you have drawn them seems a bit strange, looks like you have drawn them in different positions then moved to where you want, personally I would draw every part in the position it was meant to be then if you wanted to lock them all together use "as built joint" (shift + J) to do so .

 

[Hood]

Actually the joint wouldn't work as you have done them as bodies.

 

[ajlelectronics]

You actually want to shorten the coil to 7mm and then move it up 0.5mm so both top and bottom of the coil are in the correct position with relation to the insulator.

That is what I have done.

 

[ajlelectronics]

Actually the joint wouldn't work as you have done them as bodies.

I wanted to apply different appearances, so couldn't if they were all one body, which is why I built it as separate bodies.

 

[Hood]

I wanted to apply different appearances, so couldn't if they were all one body, which is why I built it as separate bodies.

You can still build in place but have separate bodies.

 

[Hood]

That is the beauty of extrude, you have a drop down to give all options.

 

[ajlelectronics]

You can still build in place but have separate bodies.

Yes, I got myself a bit confused clearly! However with your kind assistance as well as @Misterg I am getting things done and learning a lot. I really couldn't have achieved that on my own so you have my grateful thanks.

I am struggling with something a bit more involved with errors multiplying, but will have a good go at it first!

 

[Hood]

Yes, I got myself a bit confused clearly! However with your kind assistance as well as @Misterg I am getting things done and learning a lot. I really couldn't have achieved that on my own so you have my grateful thanks.

You learn as you go, I have been using Fusion a few years now and still learn every day.