I wanted to center the engine mount between the fins. One motor tube would be centered, the others would fall evenly between the other fins.Look closely at the base of the yellow fin.
The engine mount was slid in place - no glue yet.
A small pencil mark was made at the center of the fin. Another reference tick mark was made at the middle of one motor tube.
The engine mount was removed.
A ring of glue was applied inside the tube just below where the upper plywood ring would end up.
The engine mount was slid in place.
TIP: About 1/4" out (before the engine mount tubes were even with the BT-60 mainframe) the motor mount was twisted until the tick marks lined up.
By twisting the mount (at the last moment) that inside bead of glue is evened out into a smoother fillet.
Inserting the mount and twisting into position does take some planning.
Don't use too much glue inside the tube. Use enough to allow the mount to be slid into position. White glue shrinks and a large bead of glue might "pucker" a ring around the body tube where the glue was inside.
Check to see the tubes are even. The back side of a ruler was pressed on both ends to be sure.
Some more white glue was added at the rear joints.
I have to admit I don't understand your reasoning. You put epoxy fillets on the fins, but used something else (you don't say, but I'm assuming white or yellow glue) to install the engine mount. The standard 30 minute hobby epoxy I use is almost like grease until it begins to set; using it to install the engine mount gives me gobs of time to get everything straight.
ReplyDeleteHi Chris,
DeleteThe glues I use depend on the model and my mood.
The Ranger clone got epoxy on the fins. I felt the fins needed a stronger bond. Smaller models get Titebond M&TG fillets, larger models get epoxy. The width and radius of the fillets are wider on larger models.
I do use epoxy on engine mounts more often now that Elmer's has changed it's formula and a coupler or engine mount can lock up before it is slid into position.