Saturday, October 20, 2012

Hardbody How-To With Brian Meharry (Part 1)

Since the Car Model magazine building articles of the early 1970's, there have been few illustrated step by step guides that walk the reader through the process of building a slot car in plain and easy to understand English.

This series of building articles attempts to do just that, with photos and instructions by master builder and national driving champion Brian Meharry.

The "build" is a so called "hardbody" car, the type run on figure 8 and oval 1:1 and slot car racetracks around the country. As far as I know, there has never been a step by step tutorial published for building this type of slot car.

Let's check in with Brian as he starts the build...

The first thing to do is gather the parts that are needed to build the race car:

The body I'm using here is a late '90's Monogram NASCAR Ford Thunderbird. Tires are by ProTrack; 27mm in the rear, and the ProTrack solid rubber .950" x .250" x 3/32" "Jail Door" retro fronts (stock number 528). This car will be powered by the new Fast Ones Demon Motor, but you could use any of the FK sized motors such as the Trinity Evil 9 or TSR Falcon 7.

I chose the BRP threaded retro axle in the front to achieve independent rotating fronts without soldering. The gearing will be for Mid-America's Chris Dadds' "Lazy 8", and for that track I recommend 30 tooth crown with an 8 tooth angled steel pinion for better gear mesh. Add to this your favorite guide flag- in this case I will be using the Parma guide that normally comes with the FCR ready to runs since these guides are harder to break than others on the market.

All these parts should readily available at your local raceway.

After making sure the chassis is flat (in this case we are using the Precision Racing FCR jig to make sure the car is built flat and true), use a Sharpie to mark the area that will be cut out to raise the bushings. This cutout is needed to set the correct ride height.

Cut away the marked opening with a Dremel cut off disk or a nibbler. File the edges and make sure that the bushing fits smoothly into the opening. Be careful not to cut away too much material.

I still sometimes build chassis on graph paper, and use .032 and .063 brass plate under the chassis to get the right clearance, but here I'm using a jig, jig wheels, and spacers under the guide tongue to get the correct bushing height.

Next the bushings are soldered in place. I used Parma 3/32" offset bushings in the front, and 1/8" centered bushings in the rear. 1/8" bushings are offered offset as well if you want build in more adjust-ability to the wheelbase.

For this car, I'm trying these Bud Bartos retro threaded front axles. the axles are sold with lock nuts to hold on the wheels. Usually I just solder brass collars on the end of the axle, but I thought these were neat because I can drill a hole through my wheel inserts, place the nut on the outside of my wheel inserts and can remove the tires easily if there is a problem under green flag conditions.

Here's the assembled roller. The hard part of this build is now complete. I trued and cut my rear tires down to 1" diameter, and rounded the inside and outside edges on the hard fronts.

Pre-cut metal and plastic axle spacers work fine, but I like to use set screw collars on the axle to maintain spacing and gear mesh when the racing gets rough. Du-Bro makes wheel collars in various sizes including the 3/32" and 1/8" collars shown here. If you can't find them, any well stocked hobby shop with R/C parts should have them or can order them.

Here's the front end set up, with a better view of the threaded axle. I chose to use the set screw collars again. It makes it easy to adjust side play for different track conditions.

Two hours into the build now- about half done. It's a good time to check the body for fit, turns out with this body I didn't even have to trim the wheel wells. If I do cut out the wheel wells, I use Parma lane stickers as a template before I get nuts with the Dremel grinding wheel.....

That's it for now, more to come.

Stay Tuned to Slot Car News for Part Two of Brian's hardbody How-to. 

Racers also check out the Mid-America Hardbody Racing Series page on Facebook for race dates and more information.

No comments: