ETLB Squawk Forums — Archive

Hello, I'm wondering why my page one plan (EROS 1650) show a 4 1/2" space between the "0" reference line and the first vertical piece. My table is 14', so I don't have that extra space.

Thanks!

John

I do not know why they did it that way. But its no biggie. Call the fire wall the reference if you want to, just subtract 4-1/2 inches from all the measurements.

Thanks. Turns out the fuselage will all fit on the table, but still curious why the space is 4 1/2", which doesn't seem like some random distance. Oh well! I'll post if I figure it out.

John

The various models have significant changes on the front end to accomodate various engines.  When the plans were originally drawn they chose a datum forward of the airplane so that the stations that remained the same on all models, basically all of them from the front spar carry through aft, would all be at the same point from the datum.  At least that's the case with the 1550 compared to the 1700.  Do you find that the 1650 has stations at:  41.75 / 70' / 7' 7" / 9' 4.5" / 11' 2.5" / 12' 6" / 13' 11.5"

Apparently a datum 41.75" forward of the front spar carry through was chosen.  This keeps the plans similar in most respects and simplifies drawing the various versions.  The 4 1/2" measurement you indicate will never be meaningful to you except when laying out the fuselage sides.

On the 1550 V Max this dimension is 18.5" (the heavy VW is moved as far aft as possible for balance) and on the 1700 Hi Max it is also 4.5"

Ahhh, got it. Thanks!

I have those same stations.

While I'm here, my work table drawing of the forward lower longeron doesn't seem to match the drawing. On the drawing, the RS8 and RS10 are joined and the center of that scarf joint is 30" from the reference line (12" from station 1 which is at 18"). A diagonal RS8 goes forward and up from there. On my table, the diagonal RS8 sits at the aft end of the joint, not the center. Not sure if the drawing is off or I'm doing something wrong.


John