DierWolf
04-03-2008, 12:25 PM
This is the Trex Main Gear . the gear has a Center Hub containing the one way bearing which is
Seperate from the Gear itself, which makes it extremly easy to replace and you dont have to mess with pushing one way bearings in and out anymore, you just undo 4 screws and change the gear.
http://i83.photobucket.com/albums/j301/mark25v6/19112007125.jpg
First thing to do is to remove the entire Head from the Helicopter. there is a good guide HERE (http://www.helifreak.com/showthread.php?p=615846#post615846)on how to do this.
after this you need to get the tail drive gear out, it is possible to do this without takin the heli apart. you need to undo all the frame bolts from mainshaft backwards, and remove the tail assembly. with this done you should be able to spread the frame enough to get the shaft out.
http://i83.photobucket.com/albums/j301/mark25v6/19112007133.jpg
Remove the circlip off the top and take the gear off and remove the brass spacer, then put the gear and circlip back on.
Because we have now removed this the shaft spacer means the shaft can now rise, so i put a few little squares of double sided sticky under the top servo. For those of us with the DTS Mod (http://www.helifreak.com/showthread.php?t=68408)simply make a bracket that goes over this area thats removable but keeps the gear from moving up.
http://i83.photobucket.com/albums/j301/mark25v6/19112007145.jpg
the main gear will stop this shaft lifting completely out, this pad just keeps the shaft down to maintain a good mesh.
you can now put the shaft back in. If you have taken the frame completely apart you may want to leave it for the moment.
Motor mounts:
The mount holes in the frame needs to be elongated forward about 2mm (marked red in the photo), be carefull take your time and go easy. that way the motor can always be moved back if wanted.
http://i83.photobucket.com/albums/j301/mark25v6/19112007137.jpg
you need to then remove some material from the upper reciever/esc tray (again marked red), this will give enough room for the motor. Take off only as much as you need, red highlighted area is just for referrence.
http://i83.photobucket.com/albums/j301/mark25v6/19112007135.jpg
i removed the plastic around the motor too, you dont need to do this but the motor will rub very slightly. it seems pointless anyway, if your gonna crash hard enough to damage the motor that bit of plastic wont stop it.
ok thats the frame done if you still have it apart put it all back together now, but leave out the motor this will help getting the gear in.
as for the gear, the bearing needs to protrude from the top side about 1-2mm. this is because the tail gear in the trex has a deeper opening than the belt.
http://i83.photobucket.com/albums/j301/mark25v6/19112007130.jpg
if you dont do this the spokes on the gear will catch on the bolts on the motor mount. otherwsise the main gear, tail gear and bearing shaft go together as normal.
thats it put the new gear set in (might be tight going through the frame just push), and the head back on according to the above guide. put the shaft nut in tighten it up then rotate the head to make sure there is no binding anywhere.
if its all good drop the motor in set your gear mesh, tighten the mount screws. note tighten the front screws first, because the frame slope on the rear mounts will pull the motor back. dont over tighten any off the screws, the plastic is quite week.
thats it test again to make sure nothing is binding any where and your happy, maybe leave the blades off and spin up the motor to make sure its ok.
Final Product
http://i83.photobucket.com/albums/j301/mark25v6/19112007147.jpg
Seperate from the Gear itself, which makes it extremly easy to replace and you dont have to mess with pushing one way bearings in and out anymore, you just undo 4 screws and change the gear.
http://i83.photobucket.com/albums/j301/mark25v6/19112007125.jpg
First thing to do is to remove the entire Head from the Helicopter. there is a good guide HERE (http://www.helifreak.com/showthread.php?p=615846#post615846)on how to do this.
after this you need to get the tail drive gear out, it is possible to do this without takin the heli apart. you need to undo all the frame bolts from mainshaft backwards, and remove the tail assembly. with this done you should be able to spread the frame enough to get the shaft out.
http://i83.photobucket.com/albums/j301/mark25v6/19112007133.jpg
Remove the circlip off the top and take the gear off and remove the brass spacer, then put the gear and circlip back on.
Because we have now removed this the shaft spacer means the shaft can now rise, so i put a few little squares of double sided sticky under the top servo. For those of us with the DTS Mod (http://www.helifreak.com/showthread.php?t=68408)simply make a bracket that goes over this area thats removable but keeps the gear from moving up.
http://i83.photobucket.com/albums/j301/mark25v6/19112007145.jpg
the main gear will stop this shaft lifting completely out, this pad just keeps the shaft down to maintain a good mesh.
you can now put the shaft back in. If you have taken the frame completely apart you may want to leave it for the moment.
Motor mounts:
The mount holes in the frame needs to be elongated forward about 2mm (marked red in the photo), be carefull take your time and go easy. that way the motor can always be moved back if wanted.
http://i83.photobucket.com/albums/j301/mark25v6/19112007137.jpg
you need to then remove some material from the upper reciever/esc tray (again marked red), this will give enough room for the motor. Take off only as much as you need, red highlighted area is just for referrence.
http://i83.photobucket.com/albums/j301/mark25v6/19112007135.jpg
i removed the plastic around the motor too, you dont need to do this but the motor will rub very slightly. it seems pointless anyway, if your gonna crash hard enough to damage the motor that bit of plastic wont stop it.
ok thats the frame done if you still have it apart put it all back together now, but leave out the motor this will help getting the gear in.
as for the gear, the bearing needs to protrude from the top side about 1-2mm. this is because the tail gear in the trex has a deeper opening than the belt.
http://i83.photobucket.com/albums/j301/mark25v6/19112007130.jpg
if you dont do this the spokes on the gear will catch on the bolts on the motor mount. otherwsise the main gear, tail gear and bearing shaft go together as normal.
thats it put the new gear set in (might be tight going through the frame just push), and the head back on according to the above guide. put the shaft nut in tighten it up then rotate the head to make sure there is no binding anywhere.
if its all good drop the motor in set your gear mesh, tighten the mount screws. note tighten the front screws first, because the frame slope on the rear mounts will pull the motor back. dont over tighten any off the screws, the plastic is quite week.
thats it test again to make sure nothing is binding any where and your happy, maybe leave the blades off and spin up the motor to make sure its ok.
Final Product
http://i83.photobucket.com/albums/j301/mark25v6/19112007147.jpg