X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 06 Jan 2006 20:56:30 -0500 Message-ID: X-Original-Return-Path: Received: from wind.imbris.com ([216.18.130.7] verified) by logan.com (CommuniGate Pro SMTP 5.0.6) with ESMTPS id 915565 for lml@lancaironline.net; Fri, 06 Jan 2006 13:39:54 -0500 Received-SPF: none receiver=logan.com; client-ip=216.18.130.7; envelope-from=brent@regandesigns.com Received: from [192.168.1.100] (vsat-148-63-101-227.c002.t7.mrt.starband.net [148.63.101.227]) (authenticated bits=0) by wind.imbris.com (8.12.11/8.12.11.S) with ESMTP id k06Icntv028909 for ; Fri, 6 Jan 2006 10:38:55 -0800 (PST) (envelope-from brent@regandesigns.com) X-Original-Message-ID: <43BEB930.8000004@regandesigns.com> X-Original-Date: Fri, 06 Jan 2006 10:38:40 -0800 From: Brent Regan User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.2) Gecko/20040804 Netscape/7.2 (ax) X-Accept-Language: en-us, en MIME-Version: 1.0 X-Original-To: Lancair Subject: Re: Fast-Ons et al. Content-Type: multipart/alternative; boundary="------------030306060508070704080506" This is a multi-part message in MIME format. --------------030306060508070704080506 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Mark and Lisa make a good point, that a proper crimp is easier to accomplish than a proper solder joint. By proper crimp I am talking about a four lobe crimp on a tubular wire receiver using a M22520 ratcheting crimper ($200 - $500) NOT a "B" crimp on a stamped contact using a $20 pliers type crimper. If you must use a connector, using MIL spec pins and crimper are the safest options. If you need to make a connection that will remain connected for most of the life of the airframe then solder and heat shrink will yield the lightest, cheapest, and reliable connection. The ability to suspend a 5 Lb. weight, while entertaining, has little relevance in the evaluation of the suitability of a connector system. Static loads don't fail connectors. Corrosion, thermal cycling and vibration (with its friends fatigue and fretting) are the long term culprits. The very design of the Fast-On invites moisture to come and stay a while. If Fast-Ons were such a great value, wouldn't you see them in late model cars or avionics? Having stirred the connector pot, how about this: The only wire you should use (except coax or proprietary cables) is MIL 22759 (single wire) or MIL 27500 (shielded) and you should only use thermal strippers (hot blade) to strip the insulation. Never use PVC insulated wires, including wire that may be included as part of some products, and never use sharp edge strippers. PVC has a lower melting point than Tefzel (used in the MIL wire) and sharp edge strippers often nick the wire's conductor strands. These nicks form stress concentrations that, with vibration and the copper's work hardening, lead to mechanical failure of the conductor. Reliability is a product , in part, of attention to detail. Regards Brent Regan --------------030306060508070704080506 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit Mark and Lisa make a good point, that a proper crimp is easier to accomplish than a proper solder joint. By proper crimp I am talking about a four lobe crimp on a tubular wire receiver using a M22520 ratcheting crimper ($200 - $500) NOT a "B" crimp on a stamped contact using a $20 pliers type crimper.  If you must use a connector, using  MIL spec pins and crimper are the safest options. If you need to make a connection that will remain connected for most of the life of the airframe then solder and heat shrink will yield the lightest, cheapest, and reliable connection.

The ability to suspend a 5 Lb. weight, while entertaining, has little relevance in the evaluation of the suitability of a connector system.  Static loads don't fail connectors. Corrosion, thermal cycling and vibration (with its friends fatigue and fretting) are the long term culprits. The very design of the Fast-On invites moisture to come and stay a while. 

If Fast-Ons were such a great value, wouldn't you see them in late model cars or avionics?

Having stirred the connector pot, how about this:

The only wire you should use (except coax or proprietary cables) is MIL 22759 (single wire) or MIL 27500 (shielded) and you should only use thermal strippers (hot blade) to strip the insulation. Never use PVC insulated wires, including wire that may be included as part of some products,  and never use sharp edge strippers.  PVC has a lower melting point than Tefzel (used in the MIL wire) and sharp edge strippers often nick the wire's conductor strands. These nicks form stress concentrations that, with vibration and the copper's work hardening, lead to mechanical failure of the conductor.

Reliability is a product , in part, of attention to detail.

Regards
Brent Regan





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