Yeah, I think we already discussed that 'sliced-through-the-holes' OptROM edge 
treatment (as well as the Facebook issue ;-) last summer...

@ Steve: 
Did you end up getting some of those Batten and Allen edge pins that D'Asaro 
uses, or are you using something else for the NEC etc.?

m

----- Original Message ----- 
From: "Stephen Adolph" <[email protected]>
To: "Model 100 Discussion" <[email protected]>
Sent: Tuesday, January 10, 2017 10:32 AM
Subject: Re: [M100] REX second source


> Brian - keeping it short - I am aware that, with current PCB shops,
> there is an easier way to go.  I have inventory of existing designs,
> and the existing design is validated.  Grinding the PCBs is simple
> enough, and I don't personally think it is worth a board spin when I
> have 100 or so PCBs around.  NEC versions don't need to be ground, but
> they need very specific header pins to be soldered in place.
> 
> 
> ..Steve
> 
> On Tue, Jan 10, 2017 at 9:48 AM, Brian White <[email protected]> wrote:
>> Steve, when you say you have to grind the boards, do you mean you grind the
>> long sides down to cut the 28 large through holes in half?
>>
>> That right there is a great example of what I mean by letting the
>> community/users help improve the design.
>> If the cad file were up in a git repo, or just publicized anywhere any how,
>> it doesn't have to be github, I could have told you since more than a year
>> ago, that you can get those manufactured with the holes already cut in half.
>> That's one of those whole pain in the neck steps 90% erased already, just
>> from someone else telling you something they discovered and now you can
>> incorporate it.
>>
>> You can specify the outside dimension to go right through the holes, and the
>> router will do it, and leave just the right final outside dimension, with
>> all those holes cut in half for you. That's how the figtronix boards come.
>>
>> When I build a figtronix board, all I have to do is barely sand it a little
>> just to knock down the "rat bites" (breakaway tabs), and sometimes clean off
>> these tiny little copper flags that hang off the side of some holes, left
>> behind by the way the router cuts through the through hole plating.
>>
>> But that only takes a takes a few seconds one minute and the tools are just
>> a sheet of sand paper on a flat surface. I use a cheap wood cutting board.
>> Couple swipes and it's good to go.
>>
>> pics
>> https://goo.gl/photos/i4DX5LEywTTSevQs6
>>
>> That's what I mean by you're working too hard and worrying about things you
>> don't have to worry about. I don't know how to help with 50 different things
>> abouyt the design, but I know that one thing. Somone else knows one other
>> thing, etc, etc.
>>
>> And, even though this is already better than having to grind all that board
>> down, I bet it can still get even better.
>> I *think* (I don't know), but I think you can also specify where the
>> rat-bites go, within limits. So I think it's also possible with a board this
>> small to make it only have 2 rat bites on the ends and have perfectly clean
>> contacts all down the long edges. Or you might be able to make it put 4
>> total rat bites, but with 2 on each end and none on the sides. And then you
>> can reduce the long dimension *slightly* to allow the board to fit in the
>> socket without even cleaning up the board to sand down the rat bites flat.
>> Could just break 'em off and go. No sanding at all. That's the kind of thing
>> I would research and figure out just for my own satisfaction, and then when
>> I have figured out how one does that, I'd tell you, or I'd do a submit
>> request to submit changes to the cad files. Just like if I do figure that
>> out, I'd tell FigTroniX and then the figtronix board gets that much better
>> to use.
>>
>> That's a lot of labor and manual steps totally eliminated from the final
>> design just from having users be able to contribute. You don't have to have
>> it all perfect, you just get it up there and let everyone who has an
>> interest in it help make it better over time.
>>
>> --
>> bkw
>>
>> On Mon, Jan 9, 2017 at 10:06 PM, Doug Jackson <[email protected]> wrote:
>>>
>>> Hi Steve,
>>>
>>> I agree that transferring would be work. I feel that separating the
>>> hardware and software may be the path forward, especially if the hardware
>>> design is proven.
>>>
>>> My clocks use a 240mm square PCB that I source from Pcbcart. Experience
>>> has shown that they are cheaper than OSH part for volume. I normally order
>>> boards as 60 to 100 units at a time to take advantage of volume discounts.
>>> Same for parts, I have oearnt that volume discounts make sense in small
>>> scale manufacturing.
>>>
>>> After surface reflow, all of my boards go through a test and firmware
>>> loading jig. I published the design for one of the jigs on Instructables.com
>>>
>>> http://www.instructables.com/id/A-Programming-Jig-for-our-DougsWordClockcom-DeskC/
>>> this radicaly simplifies the firmware load. I am confident that I could
>>> devel op something to do the CPLD load as well.
>>>
>>> From the perspective of manufacturing capacity, my workshop has
>>> microscopes and logic analysers and grinders etc etc.. but it woud be
>>> worthwhile figuring out how to modify the design so that there was no need
>>> to rip spacers from wood, or grind boards and remove as many manual handling
>>> steps as possible.
>>>
>>> Doug
>>>
>>>
>>> On 10 January 2017 12:52:26 pm AEDT, Stephen Adolph <[email protected]>
>>> wrote:
>>>>
>>>> Doug, thanks for your note - read on...let's discuss.
>>>>
>>>> I'd be happy to put the board files on Oshpark, and place the
>>>> software, firmware, test applications in a git, but that isn't enough.
>>>> One needs to install the firmware and test the hardware afterwards..
>>>> and that assumes you can assemble a REX in the first place.  Plus you
>>>> need test jigs to do all that.  Feasible, but a significant investment
>>>> in time and learning.
>>>>
>>>> The biggest issues I see-
>>>>
>>>> * fine pitch soldering
>>>> * grinding the PCBs down so that they can be plugged
>>>> * sourcing spacers - I slab cedar strips using my table saw.... 0.050
>>>> inches
>>>> * firmware - it is stable now, but in general you must understand
>>>> RTL,VHDL and CPLD programming
>>>> * REX software is quite complicated.  it gets right in to the OS via 4
>>>> separate hooks and significantly affects boot up.  it can be a real
>>>> challenge to debug.
>>>> * Keeping ahead of changes and how they work in all 5 supported models
>>>> is a bit of work also.  One needs to have hardware examples of all 5
>>>> models to do the testing.
>>>>
>>>>
>>>> The equipment I rely on in general includes
>>>>
>>>> 1) a bench grinder/sander
>>>> 2) a 15x binocular microscope
>>>> 3) a Tek scope
>>>> 4) a logic analyzer
>>>> 5) my hardware jig(s) for installing firmware and testing the hardware
>>>> (M100, PC8201 variant)
>>>> 6) xilinx CPLD toolset (easy to get but you have to learn to compile
>>>> and install CPLD code
>>>> 7) a basic weller temp controlled iron + solder paste in a syringe
>>>>
>>>> If there were zero design changes, here are the steps to assemble a
>>>> working REX.
>>>>
>>>> 1)  assemble REX - grind PCB, hand solder CPLD, Flash, power supply,
>>>> clean.
>>>> 2)  install firmware - using Xilinx tools and known good firmware
>>>> binary, install binary image into CPLD.  REX mounted in test jig.
>>>> There are 3 firmware versions. M100, T200, NEC.
>>>> 3)  test REX - run stand alone test software on appropriate Model T /
>>>> rework failed units.
>>>> 4)  install application
>>>> 5)  final test
>>>>
>>>> Further development of REX is more involved obviously.  Maybe at this
>>>> point future development is limited to software only, and it may be
>>>> safe to assume the hardware and firmware are fixed.
>>>>
>>>> Anyhow, as I said, it is feasible to transfer this to someone, but I
>>>> feel like it is a fair bit of work to transfer as well!
>>>>
>>>> Steve
>>>>
>>>> On Mon, Jan 9, 2017 at 8:26 PM, John R. Hogerhuis <[email protected]>
>>>> wrote:
>>>>>
>>>>>  I think the only fundamental problem right now is availability, since
>>>>> Steve
>>>>>  has been busy with real life. Rex is not something you can just git
>>>>> clone
>>>>>  and make. Part of it could be, of course.
>>>>>
>>>>>  Component ordering, fabrication, assembly, test, order taking, shipping
>>>>> is
>>>>>  the current issue.
>>>>>
>>>>>  -- John.
>>>>
>>>>
>>>
>>> --
>>> Sent from my Android device with K-9 Mail. Please excuse my brevity.
>>
>>
>

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