Here’s how I add grab irons…
I drill the mounting holes using a No. 79 (.0145″ diameter) drill. I find this size to be a little more forgiving than a No. 80 (.0135″ diameter) – forgiving in that the slightly larger diameter gives me the feeling that it is stronger to resist breakage. But, they do break; with experience breaking drill bits becomes much, much less frequent. It is a case of acquiring a feel doing it.
The model in this post is the excellent Westerfield #11852 CB&Q XM-23 single sheathed box car kit. The casting had all the starter holes molded in place and it was an easy matter to drill them out. I set my drill bit to protrude .100″ from the end of the pin vise. The one-piece body construction causes the holes at the corners to be blind, so the wire grabs need to be shortened to fit.
The kit supplied straight grab irons were a good match for the pitch of the holes on the sides of the body. I use a jig to trim the ends to length. It is a piece of styrene strip .100″ thick. I drill two holes the pitch spacing of the grab iron legs, insert the wire and trim the length using flush cutting pliers. Lastly, with the wire still in place, I file the cut ends to take way the small burr on each.
Then it’s easy to just insert the wire into a pair of holes in the body. I set the depth of the wire using a piece of .040″x.100″ strip styrene.
A .100″ deep hole and a .100″ wire leg set at .040″ from the body means .060″ wire engagement inside the hole.
These box cars had an odd half-drop grab iron at the bottom position – one end is like a normal drop grab while the other is a straight end. I made my own from Tichy .0125″ phosphor-bronze wire. First, I bent the wire into a 90-degree shape by eye using needle-nosed pliers.
Next, minding the orientation of the drop, I held the short end by the jaws of needle-nose pliers – the wire is held in-line (or co-linear with the main axis of the tool) with just a bit of the bent end extending from the very end of the jaws. To bend the drop, I use the tip of a slim modeling file and shove it against the exposed wire in the correct direction.
Lastly, I bent the length of the wire to a 90-degree bend. I used another kit-supplied straight grab iron and held it with the needle-nosed pliers along with the wire I’m bending to get the right length. The length of the legs were trimmed using the fixture described above.
Here is a view of one side completed and jigged to depth. No glue is applied yet.
Unfortunately, for the ends, the kit-supplied straight grab irons were a little too short, so I made new ones using a simple fixture. I took two pieces of .100″x.100″ strip styrene glued together – this makes the inside width of the desired wire. I glued strips of .015″x.040″ strip to be guides to hold a piece of .0125″ wire bent.
I use a length of .125″ styrene angle to hold the inserted wire as I bend it. I bend it as much as I can, finishing the 90-degree angle with needle-nosed pliers.
One leg of these grab iron wires will interfere with the wire already inserted on the body sides. This end is trimmed with a jig (.060″x.100″ styrene strip) so that only .020″ is engaged into the hole when the grab is set to be .040″ from the body.
The end wires are made this way, including another half-drop grab iron at the bottom position. Here they all are positioned prior to CA’ing.
Gluing the wires in place is super easy by brushing Thin CA (see Category: QUICK TIP/BRUSHING THIN CA and USING THIN CA). I use a thin round pointed brush (15/0) to apply the Thin CA right at the joint of where the wire enters the hole, being careful not to get any close to the strip styrene gauges. After glue sets, the gauges are slipped out and I’m done.
I actually find this kind of work relaxing.