Compass 6HVU Stretch

[Raz0rSh4rp]

He did just redesign the Chronos head as well as design a 3-blade variant that is in testing. I'd like to see a stretch as well and I think the added thrust bearing is a good signal it is coming.

[Rob43]

At the going rate, I can't see the three blade head worth pursuing. It's interesting, but that's about the extent of it. Only one model to recover the cost. SAB has numerous models to spread the cost and recover time invested. They also control a MUCH bigger market share as well.

I'd like to understand how companies, such as Compass, make their decisions on what products to develop...? Is the objective to increase market share? Or, is it to maximize the current bottom line? The two strategies seldom employ the same tactics. For example, my company is halting all spending on things like replacing spares, inspecting current condition, and etc, for the remainder of the year. This is for this quarter's bottom line. They are deferring critical equipment inspections until next year. Then, next year, we won't have as much budget as this year, and will have this year's deferred inspections as well as next year's due inspections to complete. See where it goes?

[cycled]

Any more thoughts on where to get belts for a 650-690 stretch? I find my 550 too aggressive and heavy, and considering doing a big stretch... though it may be that the original 615mm is the sweet spot and anything larger too spongy?

[Fauropitotto]

Had a lot of difficulty finding anything "off the shelf".

You'll have to either find an existing tail belt from another heli, or shell out the cash to get something that is not commonly stocked.

Unfortunately these engineering issues like CG and the ability of the drive train to handle the higher loads of a stretch may make this a futile project.

I'm finding that if I'm not happy with how a model is "feeling" in the air, and if I can't tune it out with FBL settings on agility and other parameters, then it's best to sell the model and move on to another bird.

Otherwise instead of putting a grin on your face and reaching for it every time you go to the field....it will just collect dust.

[Raz0rSh4rp]

Did you look here for belts:

https://www.mrosupply.com/

This is where I found the belt to stretch the Warp.

[cycled]

Originally Posted by Raz0rSh4rp

https://www.mrosupply.com/

Thanks for the link. I found the following (taking a complete guess that they are compatible, based on the names):

1863
1950
1956

Presumably the first is sufficient for 650mm and the last two for 690mm (including larger tail blades). MRO aren't exactly close to me but might give it a try.

@Fauropitotto: yes, I know there are limitations. And I know what you mean about sitting collecting dust; that's what my 550 is currently doing (almost). But I love the 6HVU and there's some point in having helis which share parts.

That said, looks like there are also less 650 blades about... I guess that may change with the new SAB model.

[Raz0rSh4rp]

Be warned, they don't make it clear. There will likely be a lead time on the belts... up to 6 weeks for me

[dominator]

I just ordered a 1956 belt. I'll report back if it works or not

[dominator]

6HVU stretch complete. 1956 belt from link posted above, Logo 800xx boom, goblin 770 carbon pushrod. Just had to measure and cut a few inches off the boom and it works out perfect.

Ill follow up later with a 6hvu stretch project video im working on

The belt only took one week to arrive. They were in stock in atlanta

[Raz0rSh4rp]

Dang how far did you stretch it?

[cycled]

How do you like it, dominator? Is the head stiff enough? What size packs do you use?

[dominator]

I'm still working on it. I'm building custom lower frames to convert it into a nitro model 700. The 1956 belt stretches it long enough to fit 700s no problem. I have bushings to put on the 4mm blade bolts for 700 blades. The head and shafts are strong enough but the blade bolts will bend if you over speed 700mm blades. Ideally you could put a 7hvu head on but I'm just going to use lightweight blades and limit rpm to 2000. It's still going to be a rocket.

I'll post more details when it's complete on parts and design. But I can just swap lower frames between nitro and electric. For the electric setup I'll use a scorpion 4235 motor and I think you could get cg right with 4000mah packs. I only have 5000mah packs so it might be nose heavy. We will see

[dominator]

Here is a pic with the boom on. I should have taken one with blades as well.

[cycled]

Nice project! Not what I was expecting

Is there a simpler option, drill out the grips for 4mm bolts? Or would it weaken them too much?

[dominator]

You could probably do it with a drill press. I might end up doing that if 4mm bolts don't hold up.