Buying : Making Rivarossi Crankpin Screws for HO Locomotives
Thurs 10-1-2026 2:37 p.m.
Finding Rivarossi HO steam locomotives in good condition is becoming more difficult. Finding salvageable steam locomotives (that is, rebuildable cores) is difficult. It is also difficult to find tenders and even more difficult to find trucks for tenders. There are modelers and merchants who like to work on Rivarossi steam locomotives. However, rebuilding, repair and fabrication skills are often lacking and appear to be declining. Unfortunately, many salvageable locomotives are torn down for parts. Over-all, supplies are diminishing as well as the quality of parts.
Faced with the lack of availability of locomotives and parts for locomotives, I have been forced to repair everything I can and also make many Rivarossi replacement parts. It is time consuming but there are few options. On the bright side, it is my opinion that almost any Rivarossi steam locomotive or Rivarossi part can be rebuilt, repaired or fabricated. Even locomotives where the zamac (zinc alloy) chassis has zamac rot, zamac cancer or zinc pest can be repaired (that is, breaking / cutting the chassis if necessary, aligning the pieces, applying super glue and reinforcing the break areas with tin can strips / super glue).
Many times, I have purchased Rivarossi steam locomotives with dangling side rods because the hex head crankpin screws and washers have been removed. The washers underneath the crankpin screws are absolutely essential for ensuring that the brass hex head nuts in the drivers and crankpin screws are tight. Without the washers, the crankpin screws will come loose.
Recently, I found out how to make my own Rivarossi crankpin screws of varying lengths (that is, the shoulder length and the threaded length). I start with Chinese-supplied M1.6 Phillips head screws which are 3 millimeters long and made from stainless steel (that is, metric M1.6 screws or 1.6 millimeter maximum thread diameter screws or 0.063-inch diameter screws). I compare the Chinese screw to the Rivarossi crankpin screw and cut the screw to length with a pair of diagonal pliers. Then I use a fine-tooth jeweler's file to remove the burrs on end of the fastener. Next, I tighten up the threaded section of the screw in a jeweler's vise. Now comes the trick. I wrap sewing thread around the threaded portion of the screw to create the shoulder feature found on the Rivarossi crankpin screws. Holding the sewing thread wrapping tight, I apply some super glue to the sewing thread to hold the sewing thread windings in place (similar to what is done to hold the eyelets in place on a fishing pole). The sewing thread winding needs to be slightly smaller in diameter than the hole in the side rod. If the shoulder is too short, I can always add a few more thread wraps / super glue. If the diameter of the shoulder is too large, it can be reduced with some careful filing with a jewelers file.
It is possible with use that the thread and super glue will wear. In that case, cut off the worn sewing thread and super glue with a modeling knife. Then wrap the M1.6 screw with fresh sewing thread and super glue.
I make my own crankpin washers from aluminum can lids. A 0.065-inch diameter hole can be drilled in the aluminum can lid material. Cut out a piece of can lid with the hole and mount it on a jeweler's rat tail file. Use a pair of childeren's scissors (narrow blades) and trim the piece of aluminum to create a disk.
I also make my own Rivarossi crankpin bushings from 0.005-inch thick brass sheet stock. Use the formula Circumference = Pi (or 3.14) x the outer diameter of the Rivarossi crankpin bushing. Measure the length of the Rivarossi crankpin bushing. Cut out a 0.005 thick rectangle of brass (that is, the circumferential length x the length of the Rivarsossi bushing). Roll up the flat strip with a jeweler's screwdriver shaft as a mandrel or use a pair of Kadee coupler pliers for shaping.
I also can make my own slotted prop shafts using rolled-up bushings or tubing. Replacement plastic drive tubes can also be made from square brass tubing. I use a worn-out Rivarossi motor armature to swage the ends of the drive tubes.
Now there is no need to be robbing salvageable Rivarossi locos for parts!
Regards,
ag01
