Car Building Clinic Tips

Presented By Paul Karczewski

 

Use an HO scale ruler and car.  Multiply the HO scale length by 1.5 to get the length in inches for the car you will build.  If you have a forty-foot car, multiply 40 by 1.5 to get 60 inches.  The car you are building will be 60 inches long.  One inch in 1:1 scale is equal to an eighth of an inch in 1:8 scale.  3" would equal 3/8".

 

A welder is also an excellent tool to have.  If you don't have the money to purchase one get together with a group of people from your local club and buy one as a group.  Set up your rules as to when it can be used, etc and the cost becomes extremely affordable.  Use a MIG welder instead of a flux-cored welder and your welds will be much cleaner.

 

A basic frame that almost any car can be built from can be made from 1" x 2" box tubing, 1" square tubing and 1" angle iron.  Start with the 1" x 2" box tube for the backbone one to two inches longer than the length your car will be.  This allows the couplers to stick out past the car.    The two cross members above the trucks are also 1" x 2" box tube centered 8" from the end.  I recommend and use Mountain Car Co. trucks.  As such I also add a 3" piece of 1"x 2" tubing on each side of the backbone.  These are what the frame rides on.  Note that some trucks such as Tom Bee trucks require an additional 3/8" plate below that as well.  Check with your trucks supplier to see what they recommend for height.  Depending on the length of your car you will want to add one or more cross members made from 1" square tubing.  Next, use 1" angle iron for the perimeter of the frame.

 

 
Stirrups can be made from a 1/8" x 1/2" x 8" piece of steel stock.  Mark off 1-1/2", 1-1/2", 2", 1-1/2", and 1-1/2" respectively.  Bend the metal up vertically on each end of the 2" center in a vise.  Clamp the vertical side at the 1-1/2" mark.  Grab the vertical piece 1/2" from the end with a pair of pliers and twist AWAY from you ninety degrees.  Clamp the other vertical piece in the vise, grab 1/2" down from the end and twist TOWARDS you ninety degrees.  This ensures that the twists rotate in opposite directions.

 

 

For stake pockets 1" channel can be used.  Layout a series of marks evenly spaced down the sides of your car for stake pockets.  Be sure to leave room at each end for the grab irons.  Apply a weld bead on each side of the stake pocket for a secure hold.

 
For grab irons use 1/8" brazing rod.  Center punch your locations.  Using a #30 or 1/8" drill bit drill the holes and then insert the grab iron.  Point the welding gun at the center of the rod sticking through the side and tap the trigger.  The resulting button weld will hold the grab irons in place very securely. 

 

 

If you want a walkway under your brake wheel you can use expanded metal.  Weld two small angle brackets below the brake wheel plate and tack-weld a piece of expanded metal to them.

 

1/2" square tubing can be used for ribs.  Drill 3/8" holes in a row and plug weld them from the backside.  Start at the edge of the hole and then drop down into the hole following the edge of the circle.  Using a flap disk grind the weld smooth.

 

 

 Small detail pieces can be attached using Loctite 330.  This can be purchased through suppliers such as McMaster-Carr.