E5 stretch advice

[awesomeOne]

Hey guys, I have an E5 that input in the other week so I'm going to try a stretch since I need to replace the boom and boom supports. Looking for some advice on the bits it need, gearing, pinion etc.

What I have is a stick E5 with
Castle 120 ESC
Gryphon GSR-7075 20A BEC
MKS HBL 950 Cyclic
MKS HBL 880 Tail
CGY750 FBL

I have the following blades I won in a raffle and a motor which I'm hoping to use.

Cyclone 615 Main
Cyclone 95 (or 105?) Tail
Xnova 4030 2.5Y 560 SP

I'm thinking a 12s setup with the above.

What bits would I need to buy to make all that work with a stretch. Any advice or recommendations appreciated.


Stuart
Citizen #507
   

[Chris Sexton]

That is a excellent set up. Motor and blades will work just fine. Matt has made stretching very easy, in the synergy store is a stretch kit. You want the 626 stretch kit. This will allow you to run blades from 610 to 626.

You can try the 95's but you may prefer the 105's less you increase the tail ratio. Depends on how hard you fly.


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[Chris Sexton]

I just looked. In addition to the stretch kit you will need the boom support ends and tail control rod ends as those are epoxied on and not reusable from the stock kit. 

If you decide you want to increase the tail ratio, which I recommend for headspeeds under 2250, you will need the 12t spur and the 54t spur gears. I don't have part numbers in front of me but on the synergy store search spur gear they will come up.


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[Cliff Chmiel]

may want to get new bearing and Orings  for the boom, this way you just replace boom to go back to 550

[awesomeOne]

Thanks guys.. a shopping I will go.. I was hoping I could use the   626 stuff wasn't sure. Do the standard e5 pinion will work?

Stuart
Citizen #507
   

[awesomeOne]

Can I clarify the tail blades. If I go with the 105s do I need to change the tail gearing? If so what am I looking for?

Stuart
Citizen #507
   

[Chris Sexton]

If you run 106 tails you are probably ok. Just depends on your head speed and flight style. Personally I prefer the 96mm tails and upgrading the tail ratio to 4.5:1 by adding the 12t spur gear and the 54t auto rotation spur gear.


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[awesomeOne]

Thanks


Stuart
Citizen #507
   

[awesomeOne]

Can you explain what the flight characteristics might be like with the different tail and gearing choices. I don't really understand the differences and why I would choose one over the other .

Stuart
Citizen #507
   

[Chris Sexton]

It all comes down to tail authority.  Through testing and experience, Matt has targeted 9500-10500 rpm on the tail rotors. Having variable tail ratios allows the user to fine tune the tail to keep the main rotor head speed in line with pilot needs and yet have enough power at the tail to handle even the most demanding loads.

The stock gear ratio on an E5 is assuming head speeds in the 2300-2500 range with 556 mains and 96mm tails.  With a 4.0:1 tail ratio, if the head is turning 2400, then the tail is turning 9600 rpm. 

If you stretch the model and turn the head at 2150, on the stock 4.0:1 ratio now the tail is only turning 8600 rpm which is below the ideal range.  Increasing tail blades to 106mm increases the amount of force the tail can generate and will help off set some of that.

If you increase the tail ratio to 4.5:1 (12t and 54T spur gears) now at 2150 on the main rotor, the tail is doing 9675 and we are back in the sweet spot for 96mm tails.

Obviously putting larger blades on is the easiest thing and I would certainly start there if you already have the tail blades.

My personal favorite combo for this bird as a 600 class is: 626 mains, 4.5:1 tail, and 106 tails at 2000 rpm.  LOVE IT!

[awesomeOne]

Great explanation. Thanks for the detailed write up. I'll post an update once I order,build and fly.

Stuart
Citizen #507
   

[anthony]

what effect would putting too large a tail blade on.  ie what would happen to the tail in flight with your setup but running 106mm blades, would there be an adverse effect or would it be like using too long servo arms on the cyclic so you wouldn't have the right mechanical setup ( hope I explained that well enough)
Anthony

[Chris Sexton]

what effect would putting too large a tail blade on.  ie what would happen to the tail in flight with your setup but running 106mm blades, would there be an adverse effect or would it be like using too long servo arms on the cyclic so you wouldn't have the right mechanical setup ( hope I explained that well enough)
Anthony

Yes that is a fairly accurate assessment. Larger tail blades equals more tail authority. Will manifest as similar to two much mechanical gain. 

I have ran 106 with this setup. Other than a little less gyro gain needed it flew fine. 116 at that headspeeds would likely cause issues and over gaining.


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[anthony]

is the tail target range specific to each model or is it a universal number , would the same tail speed work on a 450 as well as a 700 , obviously the gearing would need to be different for each heli , or does each heli have its own ideal range? i have a couple of other models that have been stretched and i have had to increase the tail blades to stop them blowing out and i was wondering if there is a way to determine the tail blade size before having problems
Anthony

[mike_capflyer]

That is a excellent set up. Motor and blades will work just fine. Matt has made stretching very easy, in the synergy store is a stretch kit. You want the 626 stretch kit. This will allow you to run blades from 610 to 626.

You can try the 95's but you may prefer the 105's less you increase the tail ratio. Depends on how hard you fly.


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Hey Chris,
I bought the 600 stretch kit, not the 626 kit, so does this mean I can go up to 609mm blades?  In other words, I couldn't use the Cyclone 615mm blades but I can use the Rail 606s?  Thanks for confirming what I suspect the answer to be.

Michael