Re: Solid Wood F1D Motorstick

From: <rbharlan_at_comcast.net>
Date: 11 Jul 2015 08:22:06 -0700

I guess I'd better jump in here. I would guess that having my bearings break off the motor stick is mainly due to not putting the right tissue over it and getting enough glue on it. Esaki is too closed to let glue get through it fully. Lightweight silkspan is the right stuff to use, paying attention to getting the grain to go across the bearing. I usually use about a 1/4" square piece and lightly glue it to the bearing's wider surface (.040 or .050, depending on bearing) after lightly gluing the bearing to the motor stick. After the glue is dry, put some glue between the silkspan and the tube, against the bearing. Then use a piece of wire, or the hypo tube of the glue gun to press the silkspan tightly into the corner between the tube and the bearing. Add some glue to the slikspan that may not be attached to the tube (on the same side) and work it against the tube. Repeat for the second side of the bearing. Then put a final coat of glue over everything.
 

 Another thing I do for braced sticks is to loop the tungsten around the bearing and glue it to the cap on the stick. Also add glue all along the wire where it touches the cap and bearing.
 

 One advantage of the aluminum bearings over the wire bearings is that side thrust can be built in by slanting the bearing. No bending is required. I straight piece of music wire about 2" long, in the bearing, can be sighted along the stick. If it points to a spot about 1/4" to the right of the end of the stick (stick inverted), there will be about 2-3 degrees of side thrust. This is very general, of course and more precise aiming may be needed.
 

 As for boron attachment, the key is some elasticity added to the boron. CyA a thin piece of FAI rubber or a thin rubber band to one end of the boron (boron already has glue on it). Then glue to the end of the stick for half an inch. Support the stick between two thick straight edges (even balsa will work). pull the rubber a little and tape it to the bench. Slip a piece of balsa under the boron that extends past the end of the stick and thick enough to put the boron right on the stick. Move the boron so it is straight on the stick. Then use a little acetone every two inches to tack it to the stick. Then do the same between tacks. Finally, use acetone to secure the boron all along the stick. Then break off the boron at the end and add glue to the ends to be sure it doesn't come loose.
 

 Ray

Received on Sat Jul 11 2015 - 08:22:07 CEST