New Hurricane Frame Design

[Wazzer]

Hi Guys

I have been working on this design on and off for a few months now and have decided to push it forward again, and I would really like your feedback on it.

If I get enough interest then I would consider making a few sets for other people.

I have designed a new one piece frame with direct to swash servo mounts that will accept full size servo's.



I don't take credit for any great new ideas I merely combined some of my favorite design aspects from a couple of other Hurricane frames that I liked for example direct to swash servo mounting idea from the CHP frames although modified to accept full size servo's and the one piece frame idea from the Hurricane 425. The servo's shown in th epictures are the exact dimensions of a Spektrum DS821.

I have currently built a full size prototype using acrylic instead of Carbon for trial purposes and found that the battery mounting position was slightly wrong and I could not fit the canopy properly, so the pictures attached show the revised battery position.
I will have another revised frame set cut in acrylic soon and depending on the results I have just enough 2mm carbon sheet to have a final set cut in carbon.
I will post some pictures of the 1st acrylic prototype later this evening
The Arced lines shown around the frame represent the outline of the canopy when installed. Also shown on the Heli are a pair 4100 3sell Lipos one on top of the other. These are the largest pack that I fly with so if these fit then almost any battery configuration should fit.

I have designed the frame set to be a straight swap for the standard carbon framed hurry using all the std hardware like bearing mounts etc.

Some of the components shown in the attached pictures are in Red some are Blue some are in Grey and some White. The components in RED are optional and represent std items that I have redesigned.

Items shown in Grey are std hurry components such as the top main shaft bearing block

The motor mount is shown in RED as I have modified it to accept a frame stiffener to be bolted to the back of it. Not dissimilar to Marco's STIFFY.

The lower main bearing block is shown in red as I have modified it to accept a full size main shaft bearing for the OWB shaft. the lower OWB shaft bearing block has also been designed for a full size main shaft bearing. This idea is yet to be proven as i am not sure there is enough space to allow for the thicker bearings. I have yet to assemble the OWB shaft and take any measurements.

I have further stiffened the drive line with two more frame stiffeners to try and eliminate any potential frame flex that could alter the mesh of the gears that mate with the main gear. Each frame stiffener should ideally have its own shape but to reduce the number of different parts I have reused the same component.

Also any component shown in RED could be used on a STD carbon framed Hurricane

I have shown the STD swash anti rotation bracket as this will be required on this frame.

Components shown in Blue are all new and are required when you use this frame e.g. the 120 degree servo mounts and the Frame spacers

The frame has been designed around and is shown with the Raptor / Trex600 landing skids but as we all know the Std hurry skids will bolt up with very minor mods.

So guys please let me know your thoughts.

Many thanks

Ben

[Mikej]

Very creative Ben, good work. Just a few of things that hit me ....
* That's a lot of battery hanging that far out front - are you sure that it will not muck up the balance ??
* The only down side of a single piece frame is obviously that you cannot have any "sacrificial" bits - might it not be better to have a two-piece frame with cheap and easy to replace lower sections.
* How much more powerfull does a servo have to be to be direct to swash rather than push / pull ?

Obviously a lot of thought gone into it though.

Mike.

[Wazzer]

Hey Mike

Thanks for your comments, constructive critisism is what this is all about!!

The battery shown in the drawings is a 6cell lipo same as i currently fly with, admittedly its a bit on the large side at 4100mah but i manage to get it to balance and fly fine. Some people mount their Lipos in Hurricnaes with standard plastic and carbon frames this way with both packs on the top.
My thinking behind designing it this way from the start is it helps keep the weight higher up in the frame to help make rolls more axial. Also some people are starting to use 6 cell packs as opposed to 2x3cell packs for the convenience.

The battery is also shown in a forward position and can be moved back up the battery mount closer to the motor with no problems. The battery mount itself is also adjustable for and aft so there should be n problem figuring out the best positon for correct CoG

I hear what you say about not having any sacrificial parts to the frame but i was aiming for lightness with this one. The Hurricane 425 and CHP frames didnt have a lower sacrificial frame. However I would highly recommend that you use plastic bolts or tie wraps to mount the landing gear.

To be honest i have no idea how much more powerfull the servos would need to be in a direct to swash system. I doubt weather they see much more load than the normal hurricane system due to the fact that none of the levers reduce the throw of the servo increasing the mechanical advantage. Also the CHP fram flew just great from all accounts with the smaller 9650 servos. The big dissadantage of the direct to swash system is the un balanced load seen by the servo when in comparison to a push pull system which will balance the load on the servo output spline. PLus the push pull helps to eliminate slop in the control system.
The advantage of direct to swash is initial set up and simplicity plus lower parts count and less weight. plus it moves the weight of the servo's higher up in the heli helping with the axial rolls.

The pictures of the prototype frame with canopy and battery show that the adjustment n the battery mounting tray.
This is the first prototype and you can see that on the drawings in the first post the battery is much higher up and it interfers with the canopy.
Oh and the prototype frame dosent have the Servo mounts on it yet either as I am still waiting for them to be machined.

Thanks for the interest

Ben

[Mikej]

Wow - that looks really good - nice one

The question about teh push / pull was exactly as I said - just don't know, as well as the load being one sided, presumably the aamount of force needed will depend on flying style, length of servo arms, size of blades etc..

Looking good though

Mik.

[mysticmead]

looks GREAT Ben.... maybe I could send you some Walmart cutting boards to hvae the frames made


seriously though.. let me know when you get a final design on how much a set of frames would cost...

I do have one question though.. where is the gyro mount?

[xodarap1]

Nice job Ben!

[Wazzer]

Hey mystic will be a while till i can offer anyone anything for sale!!

The gyro will be mounted in the standard position i just havent got a plate installed yet
Alternativleyit is possible to mount the gyro in the frame in the tail servo locationas long as you have a bom mounted tail servo.

Wal Mart???? it will be Carbon all the way for this Baby!!

[Hurry_can]

Hey Wazzer, will it be ready to fly this Saturday?
I am really interested to watch it

[JaggedEdge]

Way cool wazzer.. Looking forward to seeing more progress.. Keep us updated.

The plexi/plastic mock up makes me want to fly a glass version.

[chrise2]

I like the clear frames. Wonder Woman would be proud.