I use machine sockets on everything.  I agree a thin-bladed standard 
screwdriver is the best tool to remove chips.
Pry one end halfway up, then the other end.  You can slide it underneath 
the chip at that point if necessary.

Ed

On Wednesday, July 9, 2014 2:32:46 PM UTC-5, Andrew Bingham wrote:
>
> Okay, I just wanted to make sure I wasn't doing something horribly wrong.
>
> The boards look so much nicer when they are done soldering before I start 
> putting in chips with the machine sockets.  And since I generally fail at 
> most things hands-on requiring neatness (I must have missed that class in 
> first grade) I like for my boards to look as nice as possible because I 
> have finally gotten the hang of making nice solder joints - after doing the 
> ECB backplane!  It's really satisfying to put it all together at the end.  
>
> Actually building all of these boards has helped me a lot with fine 
> detailed work.  I am almost feeling ready to try some surface mount stuff.
>
> Andrew
>
> On Wednesday, July 9, 2014 12:23:17 PM UTC-7, John Coffman wrote:
>>
>>  Andrew,
>>
>> I have used the machine-tool sockets for major components on a couple of 
>> boards; e.g., CPU chips, UPD7220 (ceramic), &c.  Yes, chips in those 
>> sockets are more difficult to extract.
>>
>> Before using an extraction tool, or even without an extraction tool, a 
>> thin-bladed screwdriver is probably the best.  You should ease the 
>> components up higher without bending any pins.  It practically take 2 such 
>> screwdrivers, because after one end is raised, unless you prevent it from 
>> being see-sawed down when you pry up the other end, you need to support the 
>> chip at the raised end.
>>
>> Be gentle.  Go easy.  They are fine sockets.
>>
>> --John
>>
>>
>>
>> On 07/09/2014 10:42 AM, Andrew Bingham wrote: 
>>
>> When I built my Zeta and ParPortProp boards, I used the "double wipe" IC 
>> sockets.  After reading up a bit more on the whole build process I saw a 
>> lot of reference to using "machine tool" sockets instead due to being more 
>> reliable.  So for the SBC-188 and my SBC6120 (non-N8VEM CMOS PDP-8 board) I 
>> used gold coated machine tool sockets.  I figure I will only ever build 
>> these boards once so I want the nicest product possible. (especially the 
>> SBC6120 which is no longer available at all) 
>>
>>  I made a little jig with some ESD-packaging to allow me to more easily 
>> bend the pins on the ICs to just the right angle to fit into the sockets 
>> exactly.
>>
>>  However - it seems like it is *almost impossible* to remove a fully 
>> seated IC from a machine tool socket.  I literally bent an extraction tool 
>> trying to get a 40-pin 8255 out, and ended up having to insert some tools 
>> carefully under the IC from each end and "pry" it up from below to get it 
>> out.
>>
>>  This is somewhat concerning as I go into some of my other builds - the 
>> intent of the sockets is that if I have a bum part, or I need to switch to 
>> a different logic series on a '74 chip for some reason, or say I want to 
>> take the HD6120 out of my SBC6120 board to go into a hypothetical ECB 
>> HD6120 board - the ICs will actually come out of the sockets without 
>> breaking something!
>>
>>  Am I doing something wrong?  Or are machine tool sockets supposed to be 
>> that much of a PITA to get chips back out of?  (Which I would understand 
>> since they are used in MIL-STD hardware subject to vibration environments).
>>
>>  Andrew B
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