Sequoia 2m - Build log

[Wayne]

I love it!

I'll have to share your build with the manufacturer.

 

[thenated0g]

@Wayne ask them about cg and suggested throws too.

 

[thenated0g]

Any suggestions for how much ballast i should have at max? Assuming this is going to weigh around 1.1kg without any ballast. I had in the past remembered some percentage or calculation but cant seem to find anything on it now.

 

[Konrad]

About 50% of empty weight. But the real limit is space and being able to keep the ballasted ship at the same CG* as the empty weight.

*I like to keep the CG the same as empty or ever so slightly more tail heavy at full ballast.

Some ideas

Mefisto build (BLEJZYK)

At the Aloft Hobbies sponsored Camp & Fly at Sunset Beach get together I was impressed with the performance of the Blejzyk models. In the light to mild wind conditions that we had, they gave up nothing to the high dollar composite molded ships. It was painfully obvious that I did not have many...

forum.alofthobbies.com

 

[thenated0g]

Yes i have a definite limit of space from cg to where it will hit my electronics in the hatch. Thanks @Konrad that gives me something to aim for at least and see how much i can fit.

 

[thenated0g]

I actually have some of these i ended up not using for another project:

Hard Aluminum tube with fiberglass sleeve

Light but strong. Aluminum tubes in various sizes. Each tube comes with a form fitting fiberglass sleeve and is 1 meter long (39"). These are handy for building wing joiners.

alofthobbies.com

 

[Old_Salt]

Relative to ballast, Tungsten (and gold too) are much heavier than lead for the same volume. Lead comes in at 11.4 g/cm3 and tungsten is nearly twice as heavy at 19.3 g/cm3. This gives you more flexibility when the available volume is compromised.

One can think of tungsten as concentrated gravity if you really want to load up on ballast. Of course gold is also an option but with an obvious issue. Tungsten is used in unexpected places to adjust CG. If you have a chance to pick up a block do so. It will be much heavier than you would expect.

 

[Wayne]

Nate - I'd bet you can double the weight of that plane with lead if you like. I think there are some good threads out there on building and setting up a ballast tube. This plane has lots of room for ballast, you may beed to recalim some of the space with your servo tray you have designed, if you want to max out the possible load. But with this said, probably don't need a huge amount of lead for this plane. I'd hate to see her get torn up on a rough landing with a full ballast load.

 

[thenated0g]

Yeah ill not worry too much about it since its my first plane of this style and try to keep it light and simple. Once you get me cg i can figure out exactly where the tube will go. Does the company have a website @Wayne ? Myself and a few others were looking on line and cant find anything on this plane or company.

 

[Konrad]

As to formulas there is the FAI sporting code of 75g/dm2 The FAI sporting code uses the stab area in calculating wing area. I'd stay away for these higher loading with a thin (7%), wood veneer covered wing, especially if not using crow to land.

 

[Wayne]

Here are some photos and such for you.
Sounds like the CG is about 75mm. Some may push that back into the low 80s after some flight testing.

 

[Wayne]

couple of more.

 

[thenated0g]

Thanks @Wayne !

 

[Red]

Cool build log! I couldn’t resist and bought one too. I’m a little further behind you though, I only have one wing done. I’ll be watching your build, thanks for sharing.

 

[thenated0g]

Thats great. Second covid shot kicked my butt this week, hopefully get some work done this weekend. Im not in a hurry, mainly want this ready for sunset in may.

 

[Red]

Thats cool, I'm considering coming up too. I havn't flown there since I was a kid. BTW I skipped the shot and just got COVID lol. Luckily very mild symptoms. Hope you feel better soon.

 

[thenated0g]

Sunset is the only slope event i have gone too but its pretty awesome. Even took an extra day off from work this year so i can keep flying on sunday instead of leaving. If you need a spot to camp just post it here or on rcgroups and someone will let you stay at their site.

 

[Red]

Yeah I'm trying to talk a buddy into going, sounds like a fun time. I've raced many times north of there at Davenport. I may see if I can get a hotel.

 

[Wayne]

It is a great event! I'm starting to think we should do this one twice a year. Can't wait!

P.S. I think these planes will work really well at Sunset.

 

[thenated0g]

Yeah i think 2 years ago, last time we had it, all 3 days it was like 9mph after breakfast working its way up to 20 after lunch