[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: [N8VEM-S100:6937] Re: Reorder of S-100 8-slot Backplane PCB



I agree with the 0.098 thickness. Having built a v2 board, it's superb rigidity was overshadowed by the difficulties with soldering some of the components. The reason that leads that do not protrude are difficult to solder is because the iron cannot contact it directy and does not get hot enough for solder to flow down around it.  I would hazard a guess at maybe half of all leads soldered in this fashion are cold down inside and will not last.  All it takes is one on the wrong pin.

Bob Bell


Sent from somewhere in the Galaxy...



-------- Original message --------
From: Crusty OMO <cru...@hotmail.com>
Date: 2015/05/04 10:51 AM (GMT-05:00)
To: n8vem...@googlegroups.com
Subject: RE: [N8VEM-S100:6937] Re: Reorder of S-100 8-slot Backplane PCB


H Todd,

I vote 0.098"....  here's why...

0.126 resulted in a board that measures 0.138

0.063 boards resulted in 0.063 to 0.064

Not sure why .012 was added to the first board, while the thinner boards only add perhaps 0.001"

IIRC, the primary complaint was the soldering of the RNets.  I have taken some pictures and measured the rnet lead length at 0.130, which is 0.008 short of coming through the board.  I haven't tried soldering any RNets to this board, I'm just wondering why the solder didn't wick into the hole?  Solder seems to like doing this everywhere else.

On one other hand, it's nice to have the pins coming out for soldering. On the other hand, it's nice to have a rigid board.  On the other hand, the S-100 connectors are quite sturdy on their own.  That's it, I'm out of hands!

I vote 0.098",  even if you add 0.012, it's still just 0.110 which allows some of the RNet Pins to come through.
It's still quite sturdy and the S-100 connectors will take care of the rest.

-Josh

 
 

 
 





Date: Mon, 4 May 2015 08:07:41 -0400
Subject: Re: [N8VEM-S100:6931] Re: Reorder of S-100 8-slot Backplane PCB
From: tacom...@gmail.com
To: n8vem...@googlegroups.com

Hi All,

Josh, that's great!  I'll wait a few days to get back any more comments people might have and then place the order.  10 boards?  That should help prices then!

As for thickness, I'm open to suggestions.  The last boards were ordered with a 0.126 inch finished board thickness (whatever the actual delivered thickness.)  Default board thickness is 0.063 inch.  Thicker boards can be: 0.079, 0.098, and 0.126.  Everyone please give opinions on what thickness is best.

John (and everyone else who requested boards) I will order enough for everyone who has made requests and more to keep on hand.

Thanks!

Todd

On Sun, May 3, 2015 at 11:22 PM, John Monahan <mon...@vitasoft.org> wrote:

Sorry Todd, same request

John

 

 

From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of Crusty OMO
Sent: Sunday, May 3, 2015 8:00 PM
To: n8vem...@googlegroups.com
Subject: RE: [N8VEM-S100:6928] Re: Reorder of S-100 8-slot Backplane PCB

 

Hi John,

Thanks,  I believe Todd is arranging to do the run...  I just polished up the board a bit.

Cheers,
Josh


From: mon...@vitasoft.org
To: n8vem...@googlegroups.com
Subject: RE: [N8VEM-S100:6922] Re: Reorder of S-100 8-slot Backplane PCB
Date: Sun, 3 May 2015 10:29:28 -0700

Hi Josh, great looking S100 V4 motherboard!  I’m traveling a lot this month (overseas) so in case I miss it please put me on the list for one board.

I have added an update to the S100 computers “Boards For Sale” section as well and will try and do a ‘proper’ write-up on this new motherboard when it arrives.

 

John

 

From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of Crusty OMO
Sent: Sunday, May 3, 2015 8:36 AM
To: n8vem...@googlegroups.com
Subject: RE: [N8VEM-S100:6920] Re: Reorder of S-100 8-slot Backplane PCB

 

The bus is routed to a 34 pin connector, so I thought it would be nice to repurpose this connector as the termination resistors, which is why I made it 38 pins.  Using 9 pin R-Nets, from both sides will reach 32 of the 34 pins.  The missing 2 pins are in the center and are wired as either +8V or GND, so they don't need termination. 

The +16 and -16 are wired to the 34 pin connector and don't need termination either, so be advised that either those traces be cut or the leads of that pin of the RNet be clipped.  I'm thinking of just not routing the +16/-16 since these power lines can easily be fed to the 2nd back plane if desired...  your thoughts?


From: bbel...@gmail.com
To: n8vem...@googlegroups.com
Subject: RE: [N8VEM-S100:6915] Re: Reorder of S-100 8-slot Backplane PCB
Date: Sat, 2 May 2015 22:06:01 -0400

I’m curious about the termination R-Nets.

I thought they would all be the same, but there are only 38 pins on each of the connectors where the R-Nets will go, so four 10-position (9 resistor) R-Nets won’t fit.  They will need a total of 40 pins.  And they don’t make 9-position R-Nets from what I can see.

 

Bob Bell

 

 

From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of Crusty OMO
Sent: Saturday, May 02, 2015 9:50 PM
To: n8vem...@googlegroups.com
Subject: RE: [N8VEM-S100:6914] Re: Reorder of S-100 8-slot Backplane PCB

 

PDF's attached for V4


From: bbel...@gmail.com
To: n8vem...@googlegroups.com
Subject: RE: [N8VEM-S100:6907] Re: Reorder of S-100 8-slot Backplane PCB
Date: Fri, 1 May 2015 21:26:16 -0400

Ah, so there is both an easier way and a smarter way to do this.

Thanks for the advice.

It works fine now.

 

Bob Bell

 

 

From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of Crusty OMO
Sent: Friday, May 01, 2015 8:08 PM
To: n8vem...@googlegroups.com
Subject: RE: [N8VEM-S100:6905] Re: Reorder of S-100 8-slot Backplane PCB

 

Bob,

It's the dreaded intermittent car noise.  Take it into the mechanic and it stops making that noise....  This is why I put a life sized mechanic in the trunk... it works like a scare crow.

So,  after you open KiCad, and before you click PCBNew, click File Open from the menu to open the whole project (schematic and PCB files).  Then PCBNew will find the .brd file from that project folder.

Cheers,
Josh


From: bbel...@gmail.com
To: n8vem...@googlegroups.com
Subject: RE: [N8VEM-S100:6903] Re: Reorder of S-100 8-slot Backplane PCB
Date: Fri, 1 May 2015 14:21:35 -0400

Thanks for your help, Josh.

Here’s what I have tried:

Running KiCAD 2013-07-07 BZR 4022 – stable.

From here, I click on PCBNew and it starts.

(It complains about some unknown project – makes no sense – I just click okay.)

I click File Open, and I get a dialog saying the current board has been modified, and if I want to discard the changes.

I answer Yes.

Then I get an Open Board File dialog.  In here, I navigate to where I have your files stored.

When I get there, it says No items match your search.  I know for sure your files are there – I can see them in Windows Explorer.

 

Wait…as I am going through this to reproduce the problem, I now see where I can change the file type.  And one of the types is KiCAD .brd.

I selected that and now I can open your KiCAD file.

I swear that was not there yesterday!

 

No more problems!

 

Bob Bell

 

 

 

From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of Crusty OMO
Sent: Friday, May 01, 2015 12:19 PM
To: n8vem...@googlegroups.com
Subject: RE: [N8VEM-S100:6902] Re: Reorder of S-100 8-slot Backplane PCB