Monogram McLaren M6A project, part 2
NOTE: This article picks up where our earlier article on modifying this car leaves off. See that article first at http://www.electricdreams.com/Slot-Car-Collecting-and-Racing-News/slot-car-tech-news/deja-vu/ before starting on the modifications described in this article.
A while back we published an article on how to modify a Monogram McLaren M6 CanAm car to get the body down lower over the chassis and enhance the cars performance. Since then we have decided that there is room for more improvement, so we built a second car to try more ideas. One feature of the car we found annoying the first time around was the motor brush housing that sticks up from the top of the FC130’s endbell. This made it more difficult to get the rear of the body down where it belongs. However, the FK130 motor doesn’t have that problem. As you can see in the photo below, the FK130 is completely flat on top. which will allow the body to be lowered more easily. The FK130 fits into the same length and width as the FC130 but requires modifications to the mount. We had some Falcon motors floating around the Tech Department, so we decided to see what it would take to fit one into the McLaren chassis.
The can end of the motor mount would be unchanged, while the endbell end would need considerable modification to fit the FK’s smaller bushing housing and make room for its lead wire tabs, which come straight out of th end of the motor instead of on top as on the FC.
This photo shows the original FC130 installation (l.) and the new FK130 installation. To get from one to the other we needed to fabricate a sleeve for the motor mount. We CA glued a length of Evergreen Styrene 5/16″ od plastic tube inside a length of 3/8″ od tube. When the glue set we cut a slice off the end, made a small flat spot in one side, and had a perfect adapter to allow the FK130 shaft bushing to ft snugly in the mount. We discovered, however, that the mount for that end of the motor was thin enough that it didn’t really offer enough surface to glue the adapter to. We could foresee the adapter coming unglued from of the mount under the stress of snapping the motor in or out. So, we dug through the junk box until we found an old broken chassis with an intact FC130 mount built into it. (This, friends, is why you should always save your broken chassis. You never know when you may need part of one for a kitbash project.) We cut out the FC130 endbell mount portion of the chassis and trimmed it so it could be CA glued in place outboard of the original endbell mount, effectively doubling its thickness and providing lots of gluing surface for the adapter. With the everything glued in place we cut the notches for the FK130 lead wire tabs and still had a more than adequately strong snap-in mounting for the FK130.
The car’s original anglewinder pinion easily transferred over tho the shaft of the FK130. A little adjustment of its position on the shaft gave a smooth, quiet gear mesh. We installed a Slot It guide up front, and replaced the original lead wires with Professor Motor lead wire and eyelet connectors, which fit easily but snugly into the guide. With the axle assemblies snapped back in place the car was ready for body installation and track testing. We used on-track testing to determine the optimum magnet installation for the more powerful FK130. After trying a number of combinations we settled on two Professor Motor PMTR1030 1mm bar magnets CA glued to the bottom of the chassis as shown below.
This magnet arrangement looks a little odd, but it works well, and only delivers a reading of 310 grams on our Magnet Marshal, a quite moderate figure. With the Falcon motor, Maxxtrac M28 tires, and this magnet fit the car is fast, highly drivable, and runs just fine on a single Scalextric C996 power pack per lane. Of course, you can modify the magnet arrangement to deliver more or less downforce, but the very low clearance under the chassis doesn’t leave enough room for thicker magnets unless you recess them into the chassis, which will not be easy to do.
Here’s the completed chassis from both left and right sides. And if you are racing against other owners of Monogram McLarens…
is the view of it they will most likely get.