BlackHorse SU26m 55cc COG problem

[AKfreak]

So are the elevator servos in the tail. I asked to see the exact setup so I can make recommendations. Knowing the CG point is one thing, shifting weight is another. I would just use the wing tube at my CG point, then pull all the gear and move stuff until I got my cf perfect. 1 gram on the tail is worth 3-4 grams at the nose.

I just went through measuring a Yak 54 with unknown CG, it was. 1/4 of an inch from the wing tube dead center. I too was tail heavy. By the time I was CG neutral, the plane was 19 1/2 lbs for a 50cc plane. For a sport plane that cool, but for a 3D monster that's horrific. I ditched the project, as wing loading was too high for what I consider to be a good 3d plane. Yes it flys, buy it was like flying a school bus.

 

[aviator2002]

Here is a link from the distributor... and the probable reason why you haven't heard of it is that not many have bought them !! I've flown some of their smaller planes over the years but never one of there... it cost approx $620 (£390 sterling / €490)

Hi Ron
I also have this model and wondered if you had sorted out the CG and if you have flown it yet.

Regards
John

 

[3dmike]

Hi Ron
I also have this model and wondered if you had sorted out the CG and if you have flown it yet.

Regards
John

In case you don't see this [MENTION=3324]ron_owens[/MENTION] I tagged ya so you'll get an email.

 

[aviator2002]

In case you don't see this @ron_owens I tagged ya so you'll get an email.

Not quite sure what that means as the only email I got was to say you have tagged me??

 

[3dmike]

Not quite sure what that means as the only email I got was to say you have tagged me??

When you want someone to know that you have a question specifically for them you can use the @ sign plus there user name and it will email them to let them know they have been mentioned. Like this example. Hey [MENTION=3994]aviator2002[/MENTION] how's it going?

I was just letting Ron know you have a question for him. Sorry for the confusion.

 

[aviator2002]

Thanks for that 3Dmike I am a bit of a novice as regards forum talk??

 

[3dmike]

Thanks for that 3Dmike I am a bit of a novice as regards forum talk??

No problem! I just want to see you get your question answered!

 

[ron_owens]

No problem! I just want to see you get your question answered!

John,
after much checking and re-checking, I went with the COG 143mm back from the start of the MAC. It took off ok, but the landing was anything but nice.. seriously tail heavy. Managed to get it down in one piece. Started adding some lead to the nose. Not much of an improvement and second landing was worse. Broke off the UC and broke the prop.

Due to other commitments, I wasn't willing to spend any more time on it...and I had just bought a Pilot Sbach 111cc !!! Much better quality package...

I have the Sukhoi to my friend Nigel who did some serious work on it. He build a new engine box around 3 inches in front of the original. He also moved all the batteries as far upfront as possible.
It's not the best plane in the world !!!!
It now flies but all the mods have left the UC too fr back and it "Noses over " very easily !
Here's a video I took yesterday of it flying...
[video=youtube;1C96rCxBHQ0]https://www.youtube.com/watch?v=1C96rCxBHQ0&feature=youtu.be[/video]

 

[aviator2002]

Hi Ron
Very interesting video? I know this kit is not the best quality but when I got mine I thought I was going to do well at a cost of £299.99 for a model of this size but the first thing that put me off a bit was the hinge method as my elevators especially are not as solid as they would have been using Robart type and I think that will be the first mod I make after the test flight, I have mass balanced the elevators as I don`t want to induce any flutter. My engine is a ZDZ 60 sitting on standoffs which are about 60 or 70mm long I forgot to measure them before fitting the cowl today. Having now got it ready to maiden I think it balances around the stated 143mm or just in front, if I pick it up with the larger of the two wing tubes it noses down a bit so I hope it will be ok for the first flight at least then take it from there. We have a tarmac and grass runway at the club site so hopefully I won`t have the nose over problem unless I have to land on the grass. Depending who is on the field when I take it for the maiden I will try and get some flying shots and maybe a video to post on here. Do you have any expo programed?

 

[3dmike]

Looks like you may have to get different landing gear for it... gear that swoops forward. :-(