switching from a #5 to #6
01-06-2008 | 12:06 PM
#3
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Joined: May 2002
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From: DFW
The #5's have either two or four steering ram's. The rams serve as gussets,reinforcing the transom. The 6's have approximately the same extension from the transom as # 5's on 12" extension box's. Therefore, the 6's without the 5's steering cylinders will place a greater side torque on the gimbal point of the transom. Subject to transom condition,material thickness,material type and engine power the transom may require thickening. Also, an extra knee brace may be needed. The factory gimbal studs are for a 2 1/4" transom, longer can be machined. Transom flex can be a logical mystery. When the steering cylinder/gussets are removed that rigidity should be replaced.
The bolt pattern will be different, requiring filling the old holes and drilling new ones. The old holes can be filled with a wooden dowel or high density foam rod. Either one can be driven into the hole after coating w/ Epoxy.
The 6's, with tie bar will weigh approx. 180# more than 5's on 12" box's,w/ 4 ram steering (90#/side) . The CG change may require relocating the engines,batteries and etc.
We made a couple of drill fixtures for the # 6 gimbal. The fixtures were made on a CNC mill and are spot on. The fixtures also have # 5 holes, providing for bolting the fixture to the transom and simply drilling through collets,creating The #6 bolt holes. The two fixtures are different each other. While #5 and #6 bolt circles are identical,one will create a higher X than the other.
The bolt pattern will be different, requiring filling the old holes and drilling new ones. The old holes can be filled with a wooden dowel or high density foam rod. Either one can be driven into the hole after coating w/ Epoxy.
The 6's, with tie bar will weigh approx. 180# more than 5's on 12" box's,w/ 4 ram steering (90#/side) . The CG change may require relocating the engines,batteries and etc.
We made a couple of drill fixtures for the # 6 gimbal. The fixtures were made on a CNC mill and are spot on. The fixtures also have # 5 holes, providing for bolting the fixture to the transom and simply drilling through collets,creating The #6 bolt holes. The two fixtures are different each other. While #5 and #6 bolt circles are identical,one will create a higher X than the other.
01-06-2008 | 12:26 PM
#4
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