550 CFS question with Gearing

[skigolfmike]

There were questions raised in another thread about gearing. I've been doing some research since I am getting close to flying and I want ot make sure I have the right pinion. I'm looking for 1900-2100 for headspeed. I have the CFS kit with the 1500W 1100kV motor upgrade. ReadyHeli says to run a 22 on it. However, even with the 60T main front spur gear, that's 2600rpm by their headspeed calculator.

My questions are what is the front main gear on this kit, 42T, 50T or 60T. How can I tell? From experience does anyone know what the gearing for this motor should be?

I need to find out so I can order the correct gear(s).

Thx!

[mysticmead]

the stock gear is 42T

[mysticmead]

using their ready heli calc... a 50T with a 14T pinion on the 1100kv motor with 6s battery would give you the head speed you're looking for.. keep in mind.. that the calcs are NOT perfect. they are just a guideline and that calc does not take into consideration that you might be using a 20T OWB

I prefer this calc instead because of the extra gearing choices you can make http://ezfly.se/hscalc.htm

this one shows that using the stock gearing... 42T first, 19T OWB, 61T main with the 1100kv stock gaui with 6s and 13T pinion gets you the head speed you are looking for..

[skigolfmike]

What motor and gear are you running, and what headspeed are you getting?

I just got off the phone with ReadyHeli support and they told me to run a 22T pinion with that motor and I would get about 2300 headspeed. They told me the number to use in their headspeed calculator is 68. I have no idea how they come up with that number.

In theory, running a 42/19 on the front is the same as running a 135 main gear. a 50 would be a 160 and a 60 would be a 193.

What I'll have to do is set the throttle curve at 0-0-0-0-0, put the throttle at 1/2 stick, 0 pitch, and bump up the throttle curve until I get 2100 rpm. if I get it between 60% - 80% throttle, all is good. If I get it at like 30% - 40%, then I need a different pinion. I should know tonight.

[mysticmead]

none yet :D

[Stallion]

@skigolfmike

The pinon you have from ReadyHeli is a 0.6 Module that means that every teeth is 0.6 mm appart. you need the 68T Front Main gear for that pinon!

The standard pinon with the stock 42T Front Gear would be a 14T or 15T Pinon and they are Modul 0.7.

I hope that helps!

[skigolfmike]

I was thinking about that. I was told to buy the .6 pitch pinion, so maybe I already have the 68T main. (Although, looking at the pics, I think not.) If not, then I'm going to have to order something, either pinions or a Revco 68T main.

With the .6 gears a 22T pinion would be around 2200 rpm.

[concept1]

stock gear is 42t, and it is black .8mod, the revco gearing is a white gear and it is 68t .6mod, the teeth are much finer (smaller) a 21t revco pinion is about the same as a 13t stock pinion. I assume you would have the stock gearing if you just bought the kit! if it has black plastic gears then all you need are either a 13 or 14t pinion! us guys who are running the revco's do so only because when the kits first came out the stock gears were not strong enough for higher power motors, but Gaui has changed the gear material and the new gears are just fine.

[skigolfmike]

I've called ReadyHeli 3 or 4 times about this now. I tell them I have a stock CFS kit and they say the Revco 21T-22T .6M pinions will work with the stock kit. I will find out for sure tonight when I get home.

I have looked online everywhere and I cannot see where Gaui makes a 68T, .6M front main gear. Let's just say I am skeptical.

With the stock 42T front main and the 1100kV motor I'd need a 13T-14T stock pinion.

[skigolfmike]

Let's just say I am skeptical. and I was right.

The CFS kit comes with a stock 42T, .8M pitch front main gear. The Revco pinion gears I got are .6M pitch and are for the 68T Revco front main gear.

So, I called ReadyHeli and explained what happened. I had made a purchase based off their advice and it was incomplete. Anyway, I explained it and, IMO, they made it right. Sad part is I have to tear down the Heli to change the gear, but I would have had to do that anyway. Just would have been sooner than later.

So, I have blades and I can setup the collective and cyclic. then I'll tear it down in preparation for getting the gear.

[mcnabbwr]

So the correct setup for the stock kit would be 14 or 15T Pinion?

[skigolfmike]

13T to 14T with the stock 42T front main gear.

[mcnabbwr]

Thanks

[skigolfmike]

Actually, changing the Front main gear isn't that bad. Take off the motor mount off the top of the shaft, loosen the 2 set screws holding the main gear hub on the shaft, pull the shaft down to clear the gear and hub and slide the gear and hub out the side of the frame. To replace, do the opposite. Takes about 5 minutes to make a gear change.

If you want to try using other headspeed calculators than the ReadyHeli Gaui calculator, figure 135T main for a 42, 160T main for a 50, 193Tmain for a 60 and 218T main for a Revco 68.

For a head speed of 2200rpm with the 1100kV upgrade motor and the 42T front main the pinion would be a 14T, for a 50T it would a 16T pinion, for a 60T it would be a19T pinion and for the 68T it would be a 22T pinion.

[vicrc]

I totally agree with the post below. I would also stick with .8 module instead of the smaller .6 Revcos as the teeth are bigger. There is nothing wrong with the Gaui OK gears on a carbon frame. You can also go 13t pinion with 42T if you think the 50T and 14T will not give you enough pop!

using their ready heli calc... a 50T with a 14T pinion on the 1100kv motor with 6s battery would give you the head speed you're looking for.. keep in mind.. that the calcs are NOT perfect. they are just a guideline and that calc does not take into consideration that you might be using a 20T OWB

I prefer this calc instead because of the extra gearing choices you can make http://ezfly.se/hscalc.htm

this one shows that using the stock gearing... 42T first, 19T OWB, 61T main with the 1100kv stock gaui with 6s and 13T pinion gets you the head speed you are looking for..

[skigolfmike]

The smaller .6M pitch gears should be fine. From experience smaller pitch gears run smoother and quieter if setup right. Getting the gear lash right is the key. It's just a little more work because there is less room for adjustment.