Simon, the thing is that he’s blind, and has to sense how to get the screw in the hole with the wire loop already in place (where it essentially does what tweezers do supporting the screw ‘upright’ once bent… but he can’t see to confirm that the loop is ‘square’ to the block.)
What I’m beginning to think is that he might practice with a set of roundnose pliers to form a reliable loop in solid or tinned stranded wire, then flat pliers to where the loop is in plane with the block when the wire is brought to it. If he then puts a dab of conductive grease (or dielectric grease as used for aluminum house wiring) on the loop it will hold the screw as he goes in to secure the wire, enough that finding the slot or x does not pop it out and turning as above to find the start of the thread doesn’t ‘derail’ the screwdriver fit.
Then the challenge is greater than I thought. If your approach does not work, I would reconsider using the Atlas accessories if the screws do not remain in place. There must be a better technical solution that allows someone with a disability to connect these wires.
I could probably obtain some petroleum jelly somewhere; my main concern there is to make sure that the substance I get would not be too harmfulif I touch it. Perhaps a reversible glue would be a good idea. MicroMark has been coming up here and in other areas of Model RR, and I learned yesterday about a “Micro Screw Starter,” which can be bought for either a Philips or Slot screw. I plan to order one in a day or so. MicroMark also has an item called “parallel pliers” on which the jaws remain parallel at all times. On tinning the wires, I have not figured out a good way to do it to the right degree without sight; I usually get too much solder so that the wire is too stiff and thick for this application. That’s why I am using only solid hook-up wire for the wiring to the track switches, with a short length of a stranded wirepair running from the power supply to the beginning of the line of switch controllers. I now use the small spade connectors which Atlas sells specifically for their control boxes, and they help because I can slide a spade under the screw AFTER I have it started and on its way down. I have heard of “tinning pots” for tinning wires, but I wouldn’t dare set up one and have a well of molten solder around. I may eventually power the switch motors with DC from a “home-brew” setup which would deliver only a short pulse when a switch button is pressed, no matter how long it is held. I nearly “got in trouble” one night when I was doing some wiring where my arm had to lie across part of the control panel. After a few seconds, I happened to hear the AC buzz and realized that I was resting on a controller. No harm came because I immediately turned off the power pack. I thank you and others who have commented on my dilemma. I’ll certainly contact MicroMark about some items, though I don’t want a print catalog because it wouldn’t do me a lot of good.
I think I will order that tool at the Amazon link along with something from MicroMark so that I can deal with the Philips or the slot screws. Some of my Atlas controllers come with Philips heads, and some came with slot heads. To solve the problem of the occasional dropped screw, I ordered three packs of those screws from Atlas (you get 12 screws in each pack for around $3, I believe). Also, I definitely plan to move to a capacitive-discharge circuit, which I believe is essentially the “home-brew power circuit” I mentioned in another message. Since I have not been reading model railroad-type magazines, I had never heard of that circuit; in a way, then, I sort of “reinvented the wheel” on a small scale. Another advantage of such a circuit using DC is that it would more easily lend itself to a degree of automation done over solid-state technology using power transistors to operate the switch motors. As one of you said, that type of circuit can save many a switch motor! I’ve never fried one; but one night years ago at a friend’s layout, a switch got stuck on and we began to smell smoke. By the time he had located the “smokin’ switch motor” it was fried, and the plastic housing was melted! I thank all of you who have given me suggestions on how to deal with those screws. Sometime I might post a tip on a way to reliably identify 'Common, Straight, and Curve wires on an Atlas switch machine if you can’t see the colors. I had no sighted help available, so I had to device a technique for identifying those wires once I took a switch out of the box or had to reconnect one when I installed new wiring. It’s not too hard if you have the track switch where you can touch it as you work.
You are correct. Original brass plated common screws became zinc plated. Those are American thread and interchangeable. Later Phillips head screws are different thread. You cross thread the older units if you use the later screws.
I believe there are also two versions of the Phillips head screws. The screws with very slightly smaller heads do not seem totally interchangeable with the very slightly larger headed screws.
When production moved to China the Atlas component quality went way down in my view. The moulding holding the captive nuts is very poor in recent product.
at one time you couls buy straight blade screwdrivers that had a fixed outer layer, with a spring loaded rotating inner straight blade … the difference between these two [in angle] would hold a straight screw slot screw in place on the end of the screwdriver …to install these, the inner portion would lock straight, and then unlock [with the fingers] to hold …
i still have some of these [i think two] but can’t find them at the moment to see if they had brand names stamped into them … i think they were in both 1/4 and 1/2 inch for sizes …
Probably the easiest way is to start by dipping the wire end in flux, then melting chips of solder against the wire until you can still feel the strands when cool but the end is reasonably inflexible and keeps a ‘set’ when bent into a loop with round-jaw jeweler’s pliers. The alternative is to tin the wire heavily after fluxing, then repeatedly heat it and pull it through something like a wire brush or solder braid which removes the surface excess but not the solder that has wicked between the individual strands.