got the plans printed out and cut for the fuse due to the wing having a longer chord than the original I had to add about 4 inches the the monoblock 2 to the front section and 2 the back section. So the area for the battery and rx and servos will be quite large, once I have things verified I will be bringing up my wireless camera for some video shots just have to figure out some PowerPoint for the video recicver while at the field

hi foaminator,can u tell me the size of the wing span and the fuse in inches for the tuffyn in post 1

Look at the first PDF at the bottom of Post 1 on page 1, it is 42".

Sorry, I should have looked at the picture closer, looks like it is a baby version. Will leave response to the designer and keep my big mouth closed.

Ron

Originally Posted by RonR214

Look at the first PDF at the bottom of Post 1 on page 1, it is 42".

Sorry, I should have looked at the picture closer, looks like it is a baby version. Will leave response to the designer and keep my big mouth closed.

Ron

hey ron tony has been busy with his work for the past while, I call him about once every two months, just to keep him in the loop :-) any ways what's your comment

jim

Jim, I was replying to post 512 which was an error on my part. The picture looks like a smaller version.

Ron

hello everybody,

I would like to buidl one of those planes but I have som questions....

I've been reading the hole post and you guys talk about the CG but I don't really understand where exactly it is and in hte plans is not so clear so could you help me with that.... I already downloaded the one of 24" but you says tat measures are different so that the reasion for my question....
another questions is about my setting I already have an small motor so I don't know if that one could work on my project this are the spec of it.

http://www.hobbypartz.com/86ma01-2205-1400kv.html

but here there is a mikstake becuase according to hobbypartz it goes until 2s but in fact it runs pretty good on 3s so do you think it could work on the plane????

thanks for your comment and help...

cesar

The Tuffy Trainer.pdf file in post #1 shows the CG location as 2.75" back from the leading edge, that is what that quartered circle mark is used for. I snipped that part of the image and attached it.

Jack

thanks for the remark jack,

but my question is precisly that when I printed out the plans I measured it and the main wing is almost 24" (23" 3/8) to be exact) and not 42" as teh plans says... so that is my question if the real WS measures about 24 inches where would be the CG them????
and for my motor question:

http://www.hobbypartz.com/86ma01-2205-1400kv.html

but here there is a mistake becuase according to hobbypartz it goes until 2s but in fact it runs pretty good on 3s so do you think it could work on the plane????

cesar

Originally Posted by c_mar76

thanks for the remark jack,

but my question is precisly that when I printed out the plans I measured it and the main wing is almost 24" (23" 3/8) to be exact) and not 42" as teh plans says... so that is my question if the real WS measures about 24 inches where would be the CG them????
and for my motor question:

http://www.hobbypartz.com/86ma01-2205-1400kv.html

but here there is a mistake becuase according to hobbypartz it goes until 2s but in fact it runs pretty good on 3s so do you think it could work on the plane????

cesar

how did you print the plans remember you must have no scaling ticked in adobe when you print
jim

hi jim,

I downloaded the one that jack in his post #145 posted :

Tuffy Trainer - 24" and 33" Wing Span Plans, without grids

Hi all,

Here are the 24" and 33" plans with the grids removed.

Again, I think those are right and OK, please post it here if there are any faults in them.

NOTE !! On any and all of these scaled plans, any dimensions noted on the plans will not be right any more. And the scale will not be right either, it cannot be used for determining dimensions any longer.

Files
Tuffy Trainer_WS24 pdf
Tuffy Trainer_WS24_tiled pdf
Tuffy Trainer_WS33 pdf
Tuffy Trainer_WS33_tiled (69.8 KB) pdf


I downloaded the TT WS24" and when I printed out I did it at 100% and that was the result WS 23"3/8 that is the reason of my question....

The Tuffy 24 and 33 plans were made by scaling the 42" plans to other sizes. So the dimensions noted on the drawings will not be right after the scaling.

If the scaling is done right (same percentage on both x and y axis, the ratio of the re-scaling will be the same everywhere on the drawing. The 24 was scaled to ratio of 24:42 or a factor of 0.571 so 1" becomes 0.571" and 2.75" becomes 1.57" and that should be the new CG location for the 24" plane.

On the plans that have been scaled down and have the 1" grid on them, the grid has not been scaled down but should measure 1" per grid square. And the grid tick marks are each 1/10th of an inch.

If you look at the image I have zoomed in on the CG location on the plan that was scaled from 42" to 24" and there are a little more 15 1/10th" tick marks from the leading edge to the CG point and that is the approximate CG location for the 24" wing.

But don't lose track of the fact that various build details can change the CG location, don't think of the 1.57" (about 1-5/8" or 39.9mm) as more than a starting point. When you fly it you want to adjust the CG location until the plane flies best.

All kinds of strange things can be made to happen when you print a plan. If the grid square does not measure right one of your printer settings is scaling the drawing. If there is no grid square, a known dimension like the wing span should measure the right size.

Jack

"..and for my motor question:

http://www.hobbypartz.com/86ma01-2205-1400kv.html

but here there is a mistake becuase according to hobbypartz it goes until 2s but in fact it runs pretty good on 3s so do you think it could work on the plane????..."

If the specs are right it could work. It is a 33 gram motor and should be able to handle an input power of 90 Watts or so as them claim for it. They says it is OK for 11.1V and that would be 3S. So at 11.1V it would be drawing about 8A 90 Watts.

You can see some test data on a motor of similar size, weght, and Kv here:

Suppo 2208/14, 1460 Kv motor - http://www.flybrushless.com/motor/view/27

And that will give you an idea as to the prop choices you have and the thrust you can expect from them on 2S and 3S packs. It is all going to come down to the weight of your plane when you get ready to fly it. You want a minimum thrust of 0.33:1 for basic flight in still air, 0.5:1 would be OK for more sporty flying in higher winds, and as the thrust to weight ratio goes up the more weight you can haul and the higher the performance will be.

Jack

wow jack,

thanks a lot for yur coments and help now everything is pretty clear for me... so now I have only one thing to do... STARTTTT....
so I'll be posting pictures of my progress..

again thanks a lot for your help jack..

César

hi jack,

there is another question about the motor angle could you please help me with that... about how many degrees of tilt should be the motor?????

1-1/2 to 3 degrees down and half of that to the right is usually about right. I get it by putting washers between the motor and firewall.

Usually something like this number of washers on the four screws of the "X" mount (as seen from the pilot's seat).

-4----1
xxxxxx
-2----0

When it is right the nose will not pitch up when you give it throttle, instead it will accelerate and climb level. And it will turn left as easily as right.

Jack