Heisler Frame Construction Part IV
 Nelson Riedel, Nelson@NelsonsLocomotive.com
Initial 2/22/2007, last updated 02/23/2007

The fabrication of the frame bolsters, bolster brackets and boiler supports are described in this page.  The design details for these parts are at Frame Design I and .Frame Design III .

 

Bolster: The step in fabricating the bolsters was to cut notches in the ends of the 1.25" X 2.5' bars and to weld on 3/16" thick bar stock for the pads.  The bars after these operations are shown above.

The next step.  was to mount the bar and angle on each end.  Each bar and angle is held in place by a pair of 6-32 FH screws.  A weld bead is then run along the seam on the top where where the plate joins the bar and also along the  the seam on the bottom where the angle joins the bar.

After the welding the bolster was mounted in  the 4-jaw chuck as shown on the right.   The lathe was then used to turn the bar thickness down to 1.213  thickness.  The slope in the pads was also turned at this point.  The final step was drill the center hole and turn a shallow recess for the cylindrical shoulder.       

 

The photo above shows the bottom of the finished bolster after the turning operation. .The shoulder will be held in place by the shallow recess in the center.. 

The photo above shows the bottom of the finished bolster.  The cylindrical shoulder is held in place by a couple 10-32 screws.

This is the top of the front bolster.  The weld bead between the end plate and the top of the center bar had been ground down until it essentially a fillet typical of a casting.  

 

This is the top of the rear bolster.  Note the recess in the top which insure that the top of the bolster pin and associated retaining ring will be below the top the bolster.   Also note that length of 1/2" angle that is screwed to the back of the bolster.  The top of this angle is positioned  1/8" below the top of the bolster.  so that the floor of the electrical compartment which it supports will be even twith he top of the bolster      

Bolster Brackets: These brackets are made of 3/16" bar stock and 1/8" angles.  A bevel was ground into the edges where the two pieces join and then a weld bead  was run down the joint..  The photo above shows one of the brackets just after the welding operation.    The weld was ground flat and the  surface finished  on the belt sander.       The photo below shows the finished brackets.

 

Boiler Supports:  The finished boiler supports are shown in photo above.  The front  and  rear supports are simply  notched pieces of angle.  The side supports shown in the middle of the photo were made of plate and bar stock silver soldered together.  Brass FH screws were used to hold the pieces in position during the soldering operation.  The screw heads are visible on the right support which is positioned  with the plate on the top --- the normal position.  The screw heads will be against the bottom of the frame side and not visible.   

Finished Frame:  The following photos show various parts of the finished frame.    

The front and rear boiler supports are not mounted yet.  Only a few of the screws holding the bolsters, saddle and sill have been installed since it likely that the frame will have to be disassembled several times before the locomotive is finished.

The photo on the right is the front top.
This is the bottom of the front.
This shot shows the stiffeners and brackets  at the front.  Note  that many screws are missing.
This is the top view of the rear of the frame.  The plate between the sill and the bolster is the floor of the electrical compartment.  
This shows the under side of the rear of the frame.

 

This is the nearly finished frame.   The front and rear boiler supports must be attached and holes must be  drilled for the engine mounting hardware, the front sill and probably a lot other things.    The frame at this point weighs 90 pounds. 

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