Stuart Grasshopper Engine

[BOB BLACKSHAW 1Participant @bobblackshaw1]

[BOB BLACKSHAW 1Participant @bobblackshaw1]

Hello all, Ive got the drawings for a Stuart Grasshopper Engine and I am to make this at .65 scale of the drawing. I have a nice cast brass flywheel at 41/2 inches diameter so thats why Im doing it at .65 scale. My question is the drawing of the beam is a cross section and does not show the width of the beam. Has anyone got a measurement of the full scale beam width, I got a rough idea but the yokes that fit inside , if I make it a bit big it could hit them when the piston moves up and down.

Thanks Bob

[JasonBModerator @jasonb]

Bob as it uses the same beam casting as the other beam engine I would think it fair to assume they are the same which is 3/8" for the end and linkage bosses and 1/2" for the central one

[BOB BLACKSHAW 1Participant @bobblackshaw1]

Thanks Jason, I have that measurement , but it's the beam width from the middle, the actual size of the beam only.

Thanks Bob

[JasonBModerator @jasonb]

Sketch on a drawing and post a pic of the dimension you want. I'll measure my beam

[BOB BLACKSHAW 1Participant @bobblackshaw1]

Thanks Bob

[JasonBModerator @jasonb]

Bit tight to get the callipers in but I'm getting 39mm though could well be 1.5"

End radius is 3/8"

[BOB BLACKSHAW 1Participant @bobblackshaw1]

Very much appreciated Jason. I intend to fabricate it rather than one piece.

Bob

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