[davidmc36]

Originally Posted by BK1

Hi,

Long overdue- I am finishing my Cessna and plan to maiden it this week. I have a quesiton regarding the wing struts that run fomr the wing to the fuse.

Does anyone know if these are structural or a scale finish. I will be removingthe wing to put it in my van and I think the struts will become loose after a few trips with putting them on and taking them off....ot does anyone have a good solution for this.

Thanks!!

Looking at the manual it shows #4 X 5/8 screws called up to hold them on. I can't imagine that being extremely structural in nature. I have the kit version and whoever built it put brass inserts into the fuse and wing blocks to take 6-32 screws. Likely a bit of overkill there. Checking out my wing and handling it and based on how it mounts on the fuse, my opinion is that it would fly just fine without the struts.

I actually somewhat question the idea of the builder to beef up the strut attach screws. This summer I had a poor landing attempt with my Kavalier and hit the wing quite hard. One of the nylon bolts snapped off and the other threaded block broke out of the fuse. At first look the threaded blocks look to be attached in a flimsy way. But maybe that was a good thing. Overall the damage was quite minimal. During flight, even in very gusty conditions, there was never a question of the construction being robust enough to hold the wing on the fuse.

With the beefed up screws on my struts I sort of shudder what it may turn out like if I had a similar wing strike. (Knock on wood) It would likely rip the blocks right out.

[BK1]

Thanks David, I plan to maiden it this week without the wing struts..I iwll let you know it goes!

It is a good looking plane all put together, I am running 6S x 2 5000 mah...shoudl fly for awhile.

[davidmc36]

Originally Posted by BK1

Thanks David, I plan to maiden it this week without the wing struts..I iwll let you know it goes!

It is a good looking plane all put together, I am running 6S x 2 5000 mah...shoudl fly for awhile.

Looking forward to hearing how she flies for you. I hope to be out in a week or so with mine. Just putting on the finishing touches of the electric conversion. Needs a bit of work on the back window and finish some battery straps.

Finally found some decent prop adapters. Was in the LHS and saw some OS electric motors in the box. Their prop adapters actually have enough thread to put on a 15 or 16 inch prop and spinner backplate. Ordered a few of them to outfit this bird and have some for future projects. I just may try one of the OS motors for the Telemaster this winter.

[stegl]

Mine is the kit built version and remember that before I started it that someone had written up a report on the kit version ( in a magazine... don't remember which one) and after their first couple of flights found that there was cracking on the main spare at the wing center joint; thats one big wing..... They then recommended all kit builders to use the struts as being functional so I mounted plywood blocks with 6-32 blind nuts in the wing and fuse. It wouldn't look very gracefull... falling from the sky with the wings folded.


The arf version has an aluminum piece in with the main spare support- joiner I believe so I would think this has something to say.

[davidmc36]

Originally Posted by stegl

Mine is the kit built version and remember that before I started it that someone had written up a report on the kit version ( in a magazine... don't remember which one) and after their first couple of flights found that there was cracking on the main spare at the wing center joint; thats one big wing..... They then recommended all kit builders to use the struts as being functional so I mounted plywood blocks with 6-32 blind nuts in the wing and fuse. It wouldn't look very gracefull... falling from the sky with the wings folded.


The arf version has an aluminum piece in with the main spare support- joiner I believe so I would think this has something to say.

Thanks for passing that along!! Could save somebody a world of grief!!

What do u think of the 16 x 6 prop?

[stegl]

Originally Posted by davidmc36

I have two props and spinners set up. 15X8 two bladed and 15X7 three bladed (I wanted a 15X8 three but that was all they had at the LHS). I found a 16X6 Zinger in my prop box. Do you think that is a bit too fine pitch for this bird on the Scorpion 4020-14? Running 5S. Have not done any current tests yet.

What is the acutual max motor rpm with the 16x6 prop ?

[davidmc36]

Originally Posted by stegl

What is the acutual max motor rpm with the 16x6 prop ?

I haven't had a chance to spin it up yet. It only has a 1/4 inch hole and am not sure if I want to ream it out to 5/16 for the prop adapter if it is going to be too fine. I may want it for something 1/4 inch in the future.

I remember a small Cub I had a few years back and was messing around with props. Ended up trying a finer one on it and the result was just barely off the ground but too little airspeed and it ended badly.

The prop that came off the .61 was a 13x6, but that would have been turning buckets more RPM.

[stegl]

Originally Posted by davidmc36

I haven't had a chance to spin it up yet. It only has a 1/4 inch hole and am not sure if I want to ream it out to 5/16 for the prop adapter if it is going to be too fine. I may want it for something 1/4 inch in the future.

I remember a small Cub I had a few years back and was messing around with props. Ended up trying a finer one on it and the result was just barely off the ground but too little airspeed and it ended badly.

The prop that came off the .61 was a 13x6, but that would have been turning buckets more RPM.

I guess you answered your question.... Yes rpm is very important when going down into finer pitch props. Been there done that. As I posted in another forum before somewhere. Electrics can produce tons of torque at lower rpm to turn those bigger higher pitch props and fuelers needs to get the rpm way up to get any sort of power. In other words (in most cases) electrics work well when the pitch goes up at lower rpm than fuelers but they need the pitch to keep the airplane flying at this lower rpm.

[davidmc36]

Originally Posted by stegl

I guess you answered your question.... Yes rpm is very important when going down into finer pitch props. Been there done that. As I posted in another forum before somewhere. Electrics can produce tons of torque at lower rpm to turn those bigger higher pitch props and fuelers needs to get the rpm way up to get any sort of power. In other words (in most cases) electrics work well when the pitch goes up at lower rpm than fuelers but they need the pitch to keep the airplane flying at this lower rpm.

Cool, good insight. I don't think it will be worth it to drill the hole out for this application. First one to try will be the 15x8 two bladed and since I have the 15x7 three I will bench test that too and compare.

[stegl]

AND when doing the actual testing with what you will be running in an aircraft Always get a current draw with a watt meter... don't want to be running short on the electric fuel...
Had a great morning; flying the 182 this morning. Did some full power climbs with the 16x8 APC...8300 rpm.... 52-53 amps full power and used 20% out of a 4500 6S pack in 5 minutes run time. Find that it seems to be the prop for me. Maybe next time I will take it out, I will try the xoar 16x8 and see how that works out.