Shavrov SH-2
#77
https://youtu.be/30
so it can go on the tooth, so it will get up, after some more checks .. From different airfield, of course
Last edited by hipik634; 02-27-2018 at 01:52 PM.
#79
Today i went to the river and had a high speed taxi test, it tends to rotate if it hits the side float, the engine power for take off is really close call, but it will go, i just have to be careful not to tear its of to early
#81
actually the water level si quite high now due to show melting, so I imagined myself trying to recover the plane if something goes wrong I almost had the takeoff speed, so I hope all goes well on next try
https://youtu.be/uvx7
https://youtu.be/uvx7
Last edited by hipik634; 02-27-2018 at 01:52 PM.
#83
Some float planes I've had needed to get going pretty fast in order to come up on step. Be careful not to move the CG too far aft, that would be disastrous when you do get it airborne. That is why I was asking if you still plan to put the wheels on it. For my two cents I would rather see the first flights off land so you do get the CG right for flight first and then work with the water handling.
#84
The wheels are intended to be put on later, there is a problem with wheel size and dampening system. I'll stick to plan cg for the first flight. I will just go to some still water, not river for the maiden. One less factor to wind and temperature ..
#85
well, it didn't go well on maiden, I haven't been able to get it from water in flyable condition, something is wrong, maybe low engine power. I intend to replace 3542 with 3548, lets see after that.
Last edited by hipik634; 02-27-2018 at 01:53 PM.
#86
It might be under powered, it did seem to act like a slow speed tip stall. It is hard to tell from the video but if you were pulling hard up elevator I would say under powered. If you were not pulling up elevator it might be tail heavy.
That was a cool little retrieval device yo have there too.
That was a cool little retrieval device yo have there too.
#88
There are so many factors to consider especially with the motor mounted above the wing. I have a 1/4 scale ultralight with a pusher motor mounted just under the wing but like yours the bulk of the weight is below the thrust line. It was hard to get it airborne at first and when I did it porpoised up and down across the sky whenever I added power. Landings were a one chance only affair because adding power low and slow was dangerous. So I read several articles on what angle to mount the motor when most of the weight is under the motor and it can be surprising how much angle is needed. You get a rotational force that tends to drive the nose down when power is applied unless you angle the thrust line to go through the center of the mass. In your case it seems to get up on step and skim across the water fine but as soon as the plane breaks free of the water it looks like it wants to nose over forward. You are trying to pull up which causes the tip stalls and/or the nose is coming back down in contact with the water and spinning you around.
Just trying to help but you might want to do some research on thrust angle for pod mounted engines and see if the thrust angle might be your issue as much as balance.
Hang in there, I have all the confidence you will figure it out.
ps check out my U-Tube channel (there is a link in my signature below) and you will find several videos of the ultralight model with some on water.
Just trying to help but you might want to do some research on thrust angle for pod mounted engines and see if the thrust angle might be your issue as much as balance.
Hang in there, I have all the confidence you will figure it out.
ps check out my U-Tube channel (there is a link in my signature below) and you will find several videos of the ultralight model with some on water.
Last edited by BigTeeEldorado; 03-26-2017 at 04:03 PM.
#89
I added some washers under the engine mount to point it right, rechecked balance (5g off), reset the ailerons. Next try as weather allows, it might be also an issue with spinning forces from the three bladed prop, as it probably has these forces greater than a two bladed one
Last edited by hipik634; 03-26-2017 at 11:37 PM.
#91
I got it, for a while before the wings struts failed, repairable
GUYS, I am looking for RC modeller february 1997 , I have to find out, what is the projected weight of the plane. I think its way too heavy.
https://www.youtube.com/watch?v=H42iQ6lYnL8&index=18&list=PLkg3v72zblUzCgvk6UOa4TINnvVZwHV5G
GUYS, I am looking for RC modeller february 1997 , I have to find out, what is the projected weight of the plane. I think its way too heavy.
https://www.youtube.com/watch?v=H42iQ6lYnL8&index=18&list=PLkg3v72zblUzCgvk6UOa4TINnvVZwHV5G
Last edited by hipik634; 03-27-2017 at 12:25 PM.
#92
#93
sorry, not RC modeller, but radio modeller http://www.magazineexchange.co.uk/radio-modeller-magazine-february-1997-issue.html?&cat=0 but N/A
ok, this is what I will do, made a Clark-Y profiles on http://airfoiltools.com/plotter/index with higher area
I will make a bigger wing, now I have loading 100 g/dm2 after I would go to 75 , that would be much easier to fly; with required speed to take off with this loading I lost my wings
i will make it 25% bigger that will make move from 100 to 65 and all will be fine
ok, this is what I will do, made a Clark-Y profiles on http://airfoiltools.com/plotter/index with higher area
I will make a bigger wing, now I have loading 100 g/dm2 after I would go to 75 , that would be much easier to fly; with required speed to take off with this loading I lost my wings
i will make it 25% bigger that will make move from 100 to 65 and all will be fine
Last edited by hipik634; 02-27-2018 at 01:53 PM.
#95
well, after some consulations there are the outcomes:
- single wing area has to be at least 20 dm2 for the weight ratio 2600g/40dm2 = 65
- the floats wings has to be at least very close to good profile
- the profile on original plan is very unoptimal - going for the CLARK-Y
- the middle wing section of the wing - it has to be reworked - could work for 1000g but not for 2500 - will replace with a rod supported holder
- the diheral angle is too low
- THE WING HAS NO MASTER BEAM (dual beams in CG - torsion box) - have to rework it, on high load it just bends and looses lift.
I will post the plan as it will be available
- single wing area has to be at least 20 dm2 for the weight ratio 2600g/40dm2 = 65
- the floats wings has to be at least very close to good profile
- the profile on original plan is very unoptimal - going for the CLARK-Y
- the middle wing section of the wing - it has to be reworked - could work for 1000g but not for 2500 - will replace with a rod supported holder
- the diheral angle is too low
- THE WING HAS NO MASTER BEAM (dual beams in CG - torsion box) - have to rework it, on high load it just bends and looses lift.
I will post the plan as it will be available