Gear Ratio for SE, OS61SX-H? + T&T slipper adjust?

[kjkelly]

I am morphing an old stock 60 into an SE by stretching the boom to 31.5" - adding torque tube, adding SE tray, CF frames etc. However, I still have the original 90 tooth main gear (10 tooth pinion - so 9:1) and a T&T CNC slipper, which seems to eat up quite a bit of the longer main shaft.

My question is what effect would a 95 tooth and 93 tooth main gear have on performance. I plan to run 680's, but am open to comments on whether it might be better to run 690 or 700. I'm learning 3D. I'm struggling to understand the impact of gear ratio change on how the OS61 will run. I suspect the 90 tooth is not the right main gear to stick with.

Also, any advice on setting a T&T slipper?

Also, I followed the directions for setting clutch pinion to main gear mesh, but it seems lots tighter than the old stock 60. How should I set that mesh and is it more important for the mesh to be tight or the main gear to be free running?

Thanks in advance for any suggestions,

Kevin

[Russ McC]

Hi Kevin,

Don’t know about the T&T slipper. As for the gear ratio, I always preferred 9 to 1 on my SEs, I have used 9.3 to 1 also but did not like it as much. This was with both an OS 61 WC and the YS ST2 61. You might want to try both and decide for your self. Your mesh should be as close as you can run and still be smooth.

[kjkelly]

Thanks Russ,

This is obviously the place to be if you're flying XCell. Thanks for the quick reply.

When you say "smooth", does that mean that when I spin the gear by hand it should have enough inertia to go around another turn on its own? ...because mine won't. It will turn freely but only go around about quarter/half turn on its own, and I fear that my mesh is too tight. Will a brand new mesh setup loosen up as it's run? I guess I'm trying to figure out if I have to take it apart and reset it

Thanks again,

Kevin

[DavidH]

Kevin

You want to set the clutch pinion to main gear mesh with just a little backlash. From your description it sounds like you have it set correctly. The gear train will become smoother once the heli is flown a couple of times.

The front pinion to crown gear mesh is important. I always pull the mainshaft and maingear up tight as possible and then tighen the collars that hold the mainshaft.
I then push the front pinion gear into the crown gear and set the mesh as tight as possible and still allow it to turn smoothly. Again after a couple of flights this will get smoother. Also make sure the front pinion is positioned on the crown gear correctly. The back edge of the pinion ( largest end), should be lined up with the outer edge of the crown gear teeth or just a little bit inside of them. Also make sure the pinion is engaged square into the crown gear.

David

[kjkelly]

Thanks David,

I have the front pinion installed as you describe. That's one place the X-Cell instructions are particularly good. I'll go fly it through a couple of tanks and let it break in

Thanks again