changing 3.85 to 4.5 ratio

[Blade120]

Any of you guys running the old 4.5 gear ratio on your 600 pro? was interested in changing the gears out but wanted to get some input on how its working for you guys. If you could list the parts that I would need to revert back to 4.5 from 3.85 that would be a big help. Looking at running slower head speed.

[ranchhand]

You will have to slot the frames a little to get a good gear mesh. Here are the parts, I like it so far.
MOD 0.7 TAIL GEARING
Bearing Shaft: H60139A
Autorotation Gear: H60020A
Torque-Tube Gear: H60121

[Blade120]

Thanks for the reply could you explain where the frames need to be slotted to get the mod to work? thanks again

[helicocrasher]

What you want to achieve is to move the complete tail boom case forward by about 0.5mm, to get a tighter meshing. So the 4 screw holes on the left the 4 for screw holes on the right plus oval holes for the tail boom positioning need to be elongated towards the front.
The exact amount of sloting the holes you need to determine by checkin the gearmesh. 0.5mm was fine with my 600 Pro. Slotting is definitely required I know from experience. Withouth the tail drive can fail under higher load - not nice

[ranchhand]

The holes that the boom block bolts to. You can get away with drill them out to 4mm and then either slot were the tab from the boom block goes or trim some off of the boom block tab it's self.
I used those aluminum cup washers to help spread the clamping force out to cover the larger holes.
I just used a dremel and slotted the all the holes.

[Blade120]

Great info appreciate it, will give this a shot

Sent from my DROID RAZR using Tapatalk 2

[Mike A.]

This will work too right? And this one is supposedly stronger.

http://shop.align.com.tw/product_inf...oducts_id=4911

[ranchhand]

Originally Posted by Mike A.

This will work too right? And this one is supposedly stronger.

http://shop.align.com.tw/product_inf...oducts_id=4911

Yes they will, I'm using them. They are really out of round though and I don't know how much stronger they really are, having such small teeth.
But you can be them from Align Trex Store, any order over $25 has free shipping, so if you get two sets or one of each, front and rear there's no shipping charge.
KDE is still working on a set also, but it's becoming quite a challenge trying to CNC them. Align is just thremo or injection molding them and that's why they run out so much.

[Stevin]

since I have changed to the original gear ratio I have so much more confidence in the heli. I can whip tight knife edge funnels feet off the ground with no fear! DO IT! I dont kno what align was thinking when gearing the tail

[Stevin]

oh yea and im running
2150-2250

[RaymondJ]

How was the tail when running the suggested 2500 HS from the manual? I just bought one but didn't even think about the tail ratio when I was reading the specs before ordering. I'll probably just try all the settings from the manual and see how she fairs up. I'll also probably stand about 100' away from my 600 running 2500 hs

[Mike A.]

Originally Posted by chronic

How was the tail when running the suggested 2500 HS from the manual?

Personally I've found 2300 to be a good speed where the tail is completely solid. Doing very fast and steep funnels the tail holds perfectly. I've never gone up to 2500.

[RaymondJ]

Cool, thats good to hear. Im going to be running 3300s so i would prefere more then 3 minutes of flight time

How is the tail in wind? Thats my other enemy is the wind here can make a good tail struggle to hold.

[Mike A.]

Originally Posted by chronic

. Im going to be running 3300s so i would prefere more then 3 minutes of flight time

How is the tail in wind? Thats my other enemy is the wind here can make a good tail struggle to hold.

With my 3300 packs I do 5min flights using about 70% of the capacity of my packs.

It's pretty common to have a decent wind blowing in my area, once I started flying at 2300 it's been solid. I flew it for a while at about 2100 and during hard funnels it would blow out.

[phranticness]

I can barely do a funnel, they are ovaled, ugly. But, I was nervous about having a tail blow out anyways. 75% of my flying is in the backyard, over a walnut orchard, not a lot of room to save it when something happens.

I used a set of edge 105's I had laying around and I confidently run 2000/2150/2300. No other mods. I'm just careful with take-offs and landings.

[Stevin]

when I was running stock gearing I found 2400 to be the number that I had faith in. 2300 will do the job but if you have some packs that are getting tired be weary towards the end of the flight.