Instruction manual

O-rings, and the shim(s). Apply a little grease to each side of the shim(s) and reinstall all items except the

dowel pin.

NOTE: Concerning step AF@ below, it may be necessary to loosen the lower main shaft block #115-18 to

allow the main shaft to slide into the bearing easily. Re-tighten the bolts after the main shaft has been

tightened.

E. Slide the autorotation unit into position and slide the main shaft downward. Align the holes within the #0866-

12 retaining collar, the sleeve on #0866-6 and the lower main shaft hole. Note: that the #0866-12 retaining

collar has one large hole and one small hole. The large hole is for insertion of the #0840-6 M3x20 dowel pin

and the subsequent #0057 M4x4 socket set screw. The small hole is for removal of the pin using a 1.5mm

Allen tool or similar device. Insert the #0840-6 dowel pin as shown in drawings 3D. The pin should easily

slide in far enough to allow installation of the set screw. If not, then there are two possible causes and various

steps to cure the problem:

1. The pin may not insert fully due to an obstruction within the collar. Remove the collar and trial fit

the pin. Look for any metal debris lodged in the Asmall hole@ side of the collar. If any exist, use a

1.5mm tool to push the debris out.

2. The pin may not insert fully due to misalignment of the holes in the related parts. The main shaft

hole is suspect here. The easiest solution is to run a sharp 0.120” (3.0-3.1mm or #31) Drill bit into

the assembled retaining collar, sleeve and main shaft. This will deburr any offending hole and will

not harm anything. The drill will stop automatically as it reaches the small hole on the opposite side

of the collar and is too small to harm the M4 threads at the inlet.

Reinstall the pin followed by the #0057 M4x4 set screw with a very small amount of Loctite (on the set screw

only).

Note: The sprag bearing should be cleaned and re-lubricated periodically (approximately every 50-75 fights).

F. The main shaft must now be adjusted and secured at the middle bearing block. Select one #0059-1 M2.5x6

socket head bolt, apply a little Blue Loctite and insert an M2 Allen tool. Rotate the lower main shaft split

collar (#0875-1) for access to the threaded hole and install the bolt, leaving it loose and the tool in place. Pull

upward on the main shaft while pressing downward on the split collar. Tighten the bolt. Check the gear mesh

during a full rotation of the main gear. If the gear mesh is Anotchy@ and tight throughout the 360 degree

rotation (and the tail rotor bevel gear is confirmed to be correctly positioned as per Section III Step 1C) then

an adjustment is required. This can be accomplished by either adding a shim ring as per section III step 5D or

slight repositioning of the #0232 bevel gear. The shims are the preferred method. If the gear mesh has only

one or two small tight spots during a full rotation, nothing is required as they will break-in quickly.

G. To avoid loss and prepare for final adjustment during a later step, select the remaining #0059-1 M2.5x6

socket head bolt and temporarily install it in the upper split collar, move the unit up to the upper bearing block

and lightly tighten.