CNC Heli CF Frame

[kimthepilot]

Hi All,

I'm thinking of upgrading to the CNC Heli CF Frame. I'm wondering what people's experiences are with it. Thanks!

kimthepilot

[bandit.r]

too heavy? ... 200grams

[Luvmyhelis]

I love the things. For lots of reasons. One, it gets rid of all body flex. And half the vibes that creates. Next, it perfectly lines up the mainshaft bearings. Unlike the plastic body where core shift effects everything. And more significantly if you understand what this means, it quiets the entire heli down.

Next, the tail boom clamps are awesome. No more boom slippage, ever! And, the cyclic servo support is the strongest in the industry, and it opens up the body so you can actually bloody work on things. Like being able to oil the tail gear drive setup.
Yeah, they are heavier. I will weigh the one I have coming in for a guys build I am doing on thur/fri and post up the exact weight on it.

One thing to think about when using these. You have now surpassed the entire Eflite/Trex/Titan/Protos, and many other 450 shells in overall quality. This removes the heli from being called a B400 if you upgrade the electrics. Pretty much turns it into a full quality custom.

[bandit.r]

I remember that the stock is 80 grams and cnc is 200?! But I'm not sure ... what I'm sure is that I have to stop following you Luv!!..

[Luvmyhelis]

Originally Posted by bandit.r

I remember that the stock is 80 grams and cnc is 200?! But I'm not sure ... what I'm sure is that I have to stop following you Luv!!..

[Cailid]

The cnc frame doesn't have guide pin where the tail boom goes in to stop it from rotating.

[Bee_random]

IMHO.

cnc GF frame is stronger than CF.

cnc frame is weaker around the motor mount - crash damage.

Bearing alignment is a tiny tiny difference.

Boom clamp is suitable for cf booms, but the cf may require roughing up and a little loctite to get a solid clamp. Same goes for the cnc tail (not a good buy IMHO)

Will you notice the improvement? Only if you add a scorpion motor, decent servos and a quark gyro.

THEN you have the best FB 450 size heli out there.

Would I get another? No. It's real pretty on the shelf, but that is likely the biggest benefit, maybe until I can fly a LOT harder than I do now.

[Luvmyhelis]

Originally Posted by Bee_random

IMHO.

cnc GF frame is stronger than CF.

cnc frame is weaker around the motor mount - crash damage.

Bearing alignment is a tiny tiny difference.

Boom clamp is suitable for cf booms, but the cf may require roughing up and a little loctite to get a solid clamp. Same goes for the cnc tail (not a good buy IMHO)

Will you notice the improvement? Only if you add a scorpion motor, decent servos and a quark gyro.

THEN you have the best FB 450 size heli out there.

Would I get another? No. It's real pretty on the shelf, but that is likely the biggest benefit, maybe until I can fly a LOT harder than I do now.

Not only is the cf frame weaker around the motor mount, but in crashes is also weak in the boom support area. They drilled big friggin holes right in the middle of the boom support area? Why? So here I double up the CF panels. And also reinforced the motor mount with more cf overlays.

And yes, the fiberglass version is much stronger. Problem is. I think they discontinued the thing sadly. You are correct bro. The cf body needs extra work to make it rule here. Glad you posted this and popped me out of my cloud.

[Bee_random]

All info gathered from you, Scott and a wee bit of experience.

Just checked and you're right, looks like no more GF. Bummer. I do have a few spares fortunately.

[scott s]

It is only weaker around the motor mount when you get carried away with the file so a scorp fits. I have bashed both mine stretched into the pavement and never ever broke the frame in that location. Now as far as weight the bit of extra is so well worth it. Sorry to say guy's but bearings slipping in the stocker frame and all the flex coherent in the stocker it is not worth it. 400 plus flights on my original stretch fbl and I started the fbl craze here HA! Ya just need to lay back and build it correctly. The cnc frame will not die as first hand info is it may be updated for 14mm dia booms also and that will keep you all building for ever!.

[kimthepilot]

Thanks for the input everyone! Based on what I read, I get the impression it will be a worthwhile upgrade for my FBL B400. Here's a current pic of the heli.

[bandit.r]

has anyone weighted the cnc frame?

[madmorgan]

only bugaboos i have had with mine so far is the boom wanting to rotate and one of the servo mounts for cyclic was drilled and tapped wrong. other than that its nice and blingy.

[Luvmyhelis]

Originally Posted by bandit.r

has anyone weighted the cnc frame?

Aw, rats!

My laptop crashed on me thursday. Just got it back earlier today. And a new carbonfibre frame showed up saturday for a heli I am building for someone. Sadly I totally forgot to weigh this and it is now fully assembled.

Oh man, sorry!

[bandit.r]

Weight fully assembled then.
My 400, with sonix head, G5 tail, scorpion and savox servos weights 652 grams. Only the frame is stock.

[Luvmyhelis]

Interesting. My stretched fbl version with the Carbonfibre frame came in at roughly 660 grams plus or minus a few last week. That is with 600 skids, raised tail, stretched boom and all without the battery. I need to more accurately measure this obviously since something must have been off with my scale.

[bandit.r]

The CF frame weights about 140grams. the stock one is only 60.
We'll see after some mods ...
I want to move the front servo as Luv did and put a decent battery holder.

[bandit.r]

Studying the first mod. The servo is slightly touching the main shaft. I have to move it about 0.5-1mm forward.
Hei Luv any suggestion?

[Luvmyhelis]

Yes, mine is just a few thousandth of an inch from tagging my main shaft also. You have to get it close so the servo link has room to clear the motor. I had to move mine back twice to get the clearance I needed. Also, like Scott I have never lost the area where the motor meets the frame in the single bolt hole. But I have totally trashed one body in a 80mph faceplant about 2 years back. Now I just use carbonfibre and brace up the motor mount area just as a precaution.

The weight penalty is minimal overall compared to the multiple advantages. Incredible frame stiffness, open areas in which you can access the bearings and parts for oiling. And to be vain. The looks!

Also, out of the close to 6 to 8 thousand people who have purchased the Sk720 with its vibe log feature. Our little B400 built here on this B400 forum posted the lowest vibe logs they have ever seen! What this means is the frame itself is structurally superior, and when it is assembled correctly it has the ability to lineup and support the moving parts precisely.

I just did a 6s stretch build here and abandoned it due to inherent body flex as scott s mentioned. Plus the difficulty in accessing any of the interior parts durning the process after the case is assembled on the plastic version. And as Scott mentioned, the upgrade is well worth it.

[bandit.r]

Have you made a custom motor flange? I'd like to install the Align slanted gears and I need to move the motor about 1-2mm ahead.