Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Scott Davies

#16075

VME Assemblies | 24 April, 1998

I realize this is a SMT forum, but I have another problem related to electronics assembly and hope there will be someone out there that can save my life (this time). We build quite a few VME assemblies to which we attach a SAM board. Fairly standard. We use round standoffs to support the SAM board and also to provide a ground. The standoff is round and we are now putting a patch- lock screw throught each end. However, the standoff resists the patchlock screw and must be held. It is not acceptable to have the standoff scratched. So how do you do this? I thought delrin pliers would work, but they didn't. You can't use pliers with metal teeth, either. So does anyone have any ideas as far as hand tools go? Where can I find pliers to accept a round standoff?

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Greg Curler

#16078

Re: VME Assemblies | 27 April, 1998

| I realize this is a SMT forum, but I have another | problem related to electronics assembly and hope there | will be someone out there that can save my life (this | time). | We build quite a few VME assemblies to which we attach | a SAM board. Fairly standard. We use round standoffs | to support the SAM board and also to provide a ground. | The standoff is round and we are now putting a patch- | lock screw throught each end. However, the standoff | resists the patchlock screw and must be held. It is | not acceptable to have the standoff scratched. So how | do you do this? | I thought delrin pliers would work, but they didn't. | You can't use pliers with metal teeth, either. | So does anyone have any ideas as far as hand tools go? | Where can I find pliers to accept a round standoff?

Scott, What about non-locking screws with a thread-locking sealant (loctite)?

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Scott Davies

#16079

Re: Re: VME Assemblies | 27 April, 1998

| | I realize this is a SMT forum, but I have another | | problem related to electronics assembly and hope there | | will be someone out there that can save my life (this | | time). | | We build quite a few VME assemblies to which we attach | | a SAM board. Fairly standard. We use round standoffs | | to support the SAM board and also to provide a ground. | | The standoff is round and we are now putting a patch- | | lock screw throught each end. However, the standoff | | resists the patchlock screw and must be held. It is | | not acceptable to have the standoff scratched. So how | | do you do this? | | I thought delrin pliers would work, but they didn't. | | You can't use pliers with metal teeth, either. | | So does anyone have any ideas as far as hand tools go? | | Where can I find pliers to accept a round standoff? | | Scott, | What about non-locking screws with a thread-locking sealant (loctite)? We tried Loctite before and had some quality problems. *Not* with the Loctite, but with how it was used. Sometimes globs of Loctite were poured onto single screws, and other times no Loctite was used at all. (That's tough to visually inspect). We were trying to put a new product on the market that had purple finger prints or loose screws. Not impressive.

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Dave

#16076

Re: VME Assemblies | 27 April, 1998

| I realize this is a SMT forum, but I have another | problem related to electronics assembly and hope there | will be someone out there that can save my life (this | time). | We build quite a few VME assemblies to which we attach | a SAM board. Fairly standard. We use round standoffs | to support the SAM board and also to provide a ground. | The standoff is round and we are now putting a patch- | lock screw throught each end. However, the standoff | resists the patchlock screw and must be held. It is | not acceptable to have the standoff scratched. So how | do you do this? | I thought delrin pliers would work, but they didn't. | You can't use pliers with metal teeth, either. | So does anyone have any ideas as far as hand tools go? | Where can I find pliers to accept a round standoff? Scott: Two ideas come to mind: 1. change the stand-off round to to a hex shape 2. if you must use the round shape, go to Sears, buy a "robogrip" and a pack of the platic inserts that fit over the plier teeth to prevent scratching finished surfaces. Dave

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Scott Davies

#16077

Re: VME Assemblies | 28 April, 1998

| | Where can I find pliers to accept a round standoff? | Scott: Two ideas come to mind: | 1. change the stand-off round to to a hex shape | 2. if you must use the round shape, go to Sears, buy a "robogrip" and a pack of the platic inserts that fit over the plier teeth to prevent scratching finished surfaces. | Dave I thought about the hex standoffs, but can't use them because we're putting them thorugh a connector and can't easily drill out a hex-shaped hole. The "robogrip" idea sounds good. I tried melting shrink tubing over other pliers already, but had poor results. Maybe the Sears product will hold better. Thanks.

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