Having used the suitcase connectors to wire my nearly 5 year old layout, I read the "Making the DCC Suitcase Connection" article that arrived today with interest. For those on the forum awhile, we've seen prior threads that have discussed the need for choosing and installing these correctly (mentioned in the article), as well as a fair percentage of members who would not risk using them due to potential reliability issues (vs a soldered connection).
I'll add a couple of comments to round out what I took from the article:
a) A potential important detail on one 3M ScotchLok, #558, is a likely typo on what AWG wire sizes can be used. The article states the range is 22-18AWG. (This connector is designed to handle the same wire range in the "run" as well as the "tap".) The Mouser product number is 517-558 and lists the AWG range as 22-16AWG, confirmed by the related 3M datasheet (link is on the Mouser page). The reason I point this out is that this part contains the nice feature of dual connection "teeth", which should roughly halve the reliability risk vs. a single tooth connector. This was important to me, as my smaller 5'x9' layout needed only 16AWG buses, and I could use this dual tooth connector. Larry notes that the #905 IDC is the most commonly used in smaller scales, designed for 18-14AWG runs and 22-18AWG taps. But those are single tooth connectors. So I'd conclude to use the dual tooth 558 if the bus wire is thinner (16 or 18AWG) than the 14AWG that the 905 can handle. Larry does emphasize to choose the right connector, and I'd add to look at the spec sheet to ensure it is properly described by the seller.
http://www.mouser.com/Search/Refine.aspx?Keyword=517-558
b) Something I'll add is to ensure one buys a reputable product. My first buy was a too good to be true item on EBay. It was listed (and the box labelled) as a "Scotch-Lok" vs the 3M "Scotchlok" (TM). It was a box of 100 for about 9 cents per connector, vs the 3M item at 27 cents from Mouser. It was deceptive, obviously, and not even the same design (e.g., not dual tooth). I'm glad I discovered that (and returned them for spite) before wiring the layout with unknown quality knock-offs.
c) The article does not discuss the question of stranded vs solid wire. That seems to be driven by the preferences of the individual rather than whether one is better than the other in terms of reliablity because of using IDCs. For instance, I used 16AWG stranded for the bus wires as many reported it was easier to route under the layout than the stiffer solid wire. I used 22AWG solid feeders as I thought the bent end of the solid feeder would be easiest to solder to the web of the rails. Whether one type or the other is significantly better than the other for IDC connection reliability was beyond my understanding but I'd hope that is a secondary issue.
Paul
Modeling HO with a transition era UP bent
I agree with Peahrens: I, too, used the 3M #558s with a 16AWG bus and 22AWG feeders. No problems after 4+ years. Layout is a doughnut 8'-4" x 11'-6".
Dante
peahrens b) Something I'll add is to ensure one buys a reputable product. My first buy was a too good to be true item on EBay. It was listed (nd the box labelled) as a "Scotch-Lok" vs the 3M "Scotchlok" (TM). It was a box of 100 for about 9 cents per connector, vs the 3M item at 27 cents from Mouser. It was deceptive, obviously, and not even the same design (e.g., not dual tooth). I'm glad I discovered that (and returned them for spite) before wiring the layout with unknown quality knock-offs. c) The article does not discuss the question of stranded vs solid wire. That seems to be driven by the preferences of the individual rather than whether one is better than the other in terms of reliablity because of using IDCs. For instance, I used 16AWG stranded for the bus wires as many reported it was easier to route under the layout than the stiffer solid wire. I used 22AWG feeders as I thought the bent end of the solid feeder would be easiest to solder to the web of the rails. Whether one type or the other is significantly better than the other for IDC connection reliability was beyond my understanding but I'd hope that is a secondary issue.
b) Something I'll add is to ensure one buys a reputable product. My first buy was a too good to be true item on EBay. It was listed (nd the box labelled) as a "Scotch-Lok" vs the 3M "Scotchlok" (TM). It was a box of 100 for about 9 cents per connector, vs the 3M item at 27 cents from Mouser. It was deceptive, obviously, and not even the same design (e.g., not dual tooth). I'm glad I discovered that (and returned them for spite) before wiring the layout with unknown quality knock-offs.
c) The article does not discuss the question of stranded vs solid wire. That seems to be driven by the preferences of the individual rather than whether one is better than the other in terms of reliablity because of using IDCs. For instance, I used 16AWG stranded for the bus wires as many reported it was easier to route under the layout than the stiffer solid wire. I used 22AWG feeders as I thought the bent end of the solid feeder would be easiest to solder to the web of the rails. Whether one type or the other is significantly better than the other for IDC connection reliability was beyond my understanding but I'd hope that is a secondary issue.
Scotchloks are made for solid, stranded, or both. You should always make sure that the model number being used is compatible with your gauge and type of wire.
There are Scotchloks and there is everything else. I will only use Scotchloks, no matter what the application. If I can't get or don't have Scotchloks on hand, I solder the connection.
I use a pair of parallel jaw pliers, whose jaws remain parallel throughout their entire travel. It is important that the jaws press the blade only straight down and do not put any offset pressure on it.
CG
Stick with the 3M product, absolutely. I've tried various 'generic' versions and they were one and all absolute junk.
Disclaimer: This post may contain humor, sarcasm, and/or flatulence.
Michael Mornard
Bringing the North Woods to South Dakota!
I used T connnectors (suitcase style) from my local Napa Auto Parts store 7 years ago plus and have had no issues. Several layout owners in my area have also used them with no issues.
Raised on the Erie Lackawanna Mainline- Supt. of the Black River Transfer & Terminal R.R.
Where can I find suitcase connectors I tried Lowes and Home Depot today and no luck.
Thanks
Bill
Amazon? Search by the model number, like "3M 905", not "suitcase connector" for best results. They seem to have boxes of 50 of the various types for about $15.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Lowes has some but their search doesn't respond to IDC (insulation displacement connector) properly. Try Hillman or Ideal connector, then look through the hits to find the suitcase connectors. Try the same thing with HD.
No idea if these brands are up to par for IDCs.
CentralGulfScotchloks are made for solid, stranded, or both. You should always make sure that the model number being used is compatible with your gauge and type of wire.
As CG notes, the suitability of a certain 3M IDC for stranded, solid or either type wire can be important. I'm not certain I even checked that out when I chose mine, and don't know if any of the sizes we might use are only for one type of wire, such that one might choose poorly basis only AWG.
The "data sheet" I found on the Mouser listings details AWG specifics but not wire types.
http://www.mouser.com/ds/2/1/EMD%20IDC%20Brochure%208040233-29202.pdf
But once you have one you want to consider basis AWG needs, you can check the specific data sheet for a given 3M IDC by googling "3M Scotchlok (xyz)". Then choose the multimedia.3M.com link that will be in the list. These data sheets are for the specific item and show the wire type. Examples for #558 and #905 follow:
http://multimedia.3m.com/mws/media/984606O/scotchlok-electrical-conectors-idc-558.pdf
http://multimedia.3m.com/mws/media/137035O/3m-scotchlok-self-stripping-elec-conn-905.pdf
Might as well be sure to get it "right" when you choose. You wouldn't want hindsight on a poor choice after wiring the whole layout.