Sanda Models Mach 2 carbon (Set Up ?)

[Konrad]

For the tail, I'm pretty sure we sold you some of the KST 215 or the Daviga 213 servos. They are both the same size. Anyhow, they are my go to servo for tails, they are nice and fast, and plenty of torque for the tail. They should be a pretty close fit to the holes in the servo tray in the Mach 2.

I don't think many of these planes have sold in the USA, so you may have some fun finding anyone that has built one. But, there is nothing to different from your other moulded gliders. It should go together pretty nicely with the exception of that tail linkage. We now order our planes from Sanda with the linkages already installed. If you like, I can see about getting a new joiner from Ivan, but it might be a while before it would arrive.

I'm at a loss as to why there haven't been many of these sold in the USA. OK, most videos on Youtube show the Mach II being a sedate flier. But today is the second time I've taken out the Sanda Mach II. It was a blast! I was flying her like I stole her. I have to be honest in gliders size does matter. At 2.4m she out flew the much smaller 1.9m Mefisto. Not as much as one might have thought. But this was because I had her set up without ballast, she still out rolled and basically out flew the Mefisto with her 265 grams of ballast doing everything that did not need rudder input. (I think the Mefisto has stronger rudder responce).
Now with the 90° flaps the Mach II actually was a bit easier to land than the smaller Mefisto. (The Mefisto only has about 65° flaps).

The winds were a bit lighter than they have been for most of the week at 12mph to 14mph. It was because of these lighter winds that I thought the larger more efficient 2.4 wing un-ballasted might work well, and it did.

While the wind speed might have been down a bit the lift was strong as witnessed by the dozen parasailers in the air.
I need to finish the mini-Mach! And maybe acquire some more Sanda kits.

 

[Konrad]

Well today I finally had conditions that warranted ballasting the Mach II, not only ballasting but fully ballasted. With all 10, 53gram (by my math that's 0.53 KG) lead slugs there was absolutely no trim changes! It really is nice to find a designer that has the same ideas as myself as to what is a proper Center of Gravity. (I’m really looking towards finishing my Sanda mini-Mach). I was setting up for the ISR when I made this last flight. Being as I wanted to stay out of the way for the guys who were readying themselves for the race. I only made a quick test (re-maiden) flight.

As I had changed a lot of parameters this really was more of a maiden than a test flight. The engineer in me would rather change one thing at a time and test the results. This time I change the servo arm biasing a bit further aft to get a bit more downward bias to the rear flippers. I also shortened the rear control arms by moving the soldered on spherical balls 3 mm closer to the hinge line, for more throw. I also changed the V tail weight in the program so that the surfaces didn’t bottom out prematurely, if both the rudder and elevator command was given for extreme movement. I got lucky everything worked out. I think I'm really close to being finished with the building and trimming of the Sanda Mach II. I’m really liking her!

All the best,
Konrad

 

[Konrad]

Got in four more flight with the Sanda Mach II at the "Slot". We were going to do some 60" M.O.M. racing but due to lack of participation the day turned into a fun fly. The conditions were almost perfect, we had 35mph winds often time going to 45mph with gusts over 50mph.

These condition warranted being fully ballasted with 0.53 Kg of lead. I'm now getting comfortable with the Mach II as I've had her out about ten times. This was the first time I didn't change anything from the previous outing. I can now do consecutive rolls from one end of the hill face to the other. Inverted flight is very comfortable, even more so if using a bit of reflex.

The airfoil does respond well the camber changing.

I will say that the only real flight complaint I have is that the rudder is rather weak. I had some issues with stall turns. Also slow rolls were a bit of a problem as the 90° points needed rudder inputs but the rudder response was dead. The Mach II is not a freestyle glider.

Landing are a joy and with the wing tips up out of the way with the 3 break polyhedral there is less chance of damaging the wing tips.

Now as we were suppose to be flying a 60" (1.5 meter) race there were a few 60" racer in the air with me. I have to say I was a bit surprised at how well these little ships flew against this Mach II having to give up almost a full meter of wing span. The Mach II was faster but the little Sunbirds were quicker. That is the Sunbirds reached their top speed sooner than the Mach II. It took the Mach II a bit longer to stretch her legs. But once moving you could see the advantage of the longer 2.4 meter wing.

All the best,
Konrad

 

[Konrad]

Earlier in this thread I had a concern with the floating joiner and how the wings attached to the fuselage.

Yesterday I was using this Mach II as my entry into F3F flying. I was using more ballast than I would normally use while sport flying trying to gain speed. This combined with my lack of familiarity with the Mach II (I only have a dozen flight on her) and the landing site. I made a few less than graceful landings. One gallingly bad landing had the Mach II performing a wicked ground loop swinging 45° each way as the wing tips touched the ground. I heard a loud snap and knew I broke something! Upon close examination I saw that the wings had parted from the fuselage about 2mm and that all the tape used at the fuselage to wing joint had failed in tension. That was the extent of the damage!

So I have to give Mo credit (post#9) for the save! I was using the hockey tape to attach the wings and it worked great. Both as a seal and as a mechanical fuse to protect the airframe against my landings.

Wing Tape for Moldies

Clear wing tape (aka hockey tape) allows you planes color to show through while holding your wings in place. This tape has good tack strength but is still easy to remove. Leaves behind no sticky residue.For use with moldies only, not recommended for plane

alofthobbies.com

All the best,
Konrad

 

[Konrad]

As I mentioned earlier I used my Sanda Mach II carbon as my entry into F3F.

Flew my first F3F race 7/28/2019

Flew my first F3F race at Thornton Beach this Sunday. Well, tried too, what a blast! I hadn’t planned on flying. I came out to help run the race and was talked into racing. While not as exciting (read scary) as Man On Man racing it was very rewarding. Now before I go on any more I need to...

forum.alofthobbies.com

While I may have embarrassed myself on Sunday the Mach II did not! She is a sweet easy handling robust 2.4 meter ship. The Mach II is not an F3F ship, her ballast compartment is too small and limited to the fuselage. For roll stability many F3F ships place their ballast in the wings. While I'm sure the Mach II would have looking more stable in roll if I could add ballast to the wings. In reality she looked very comfortable running the ridge with what little ballast I could fit in the fuselage (530 grams).

My Mach II is a carbon lay up and as such is rather stiff. This showed dividends as there was no flex that I noticed in the hard turns.
I think this is the first time I've had a model with a HN-1037 airfoil. I was impressed at how fast she was when I finally found the lift zone.

I wish somebody had some video of how fast she looked when I was properly flying the course. All the videos I see of the Mach II show her as a slow sedate flier. While she is good at the low speed side of the flight envelope she is no slouch when she picks up her tail and runs the ridge.

All the best,
Konrad

 

[Wayne]

Very nice - you should ask someone to grab video next time.. Can be helpful to critique your own flying after the heats..

 

[Konrad]

At this stage of the game I'm painfully aware of where my short coming are when it comes to racing. If I get better I might try to make promotional videos of the Mach II.

Yes, I use video to get information to improve many aspects of sports or other activities.

 

[Konrad]

Stupid! Stupid! Stupid!!!

Yep, you guessed it I lost my Mach II this afternoon. This was my favorite sport ship. 2.4 to 2.7 meters is a very nice size. So I fly it a lot. Today was a great day at Mussel Rock, big air lift. I haven't sport flown in months so I was a bit excited to out with all most nobody around. In My rush to put together the Mach II a forgot to tape the wings ons. I keep forgetting that tape as used on most of these molded gliders isn't done for just aerodynamic reasons but that the tape holds the wings on! I was having a blast ripping up the sky at full ballast. doing a lot of rudder work. Well, all that yawing of the fuselage slid a wing out of the pins. With one wing dead I could not crow. I had enough control to be able to fly the Mach II into the hill and not put anybody in harms way. But with only partial control I wasn't able to properly slow the Mach II down prior to hitting the ground.

Well, I shattered the fuselage snapped the joiner and holed the wing. Tomorrow I'll do a postmortem on the model but its not looking good. This was just a stupid way to loose a great $550 sport glider, all for the want of 5 cents of tape!

 

[Hank GB Z]

Konrad,

Sorry you lost a nice glider. Maybe OpenTx should come out with a pre flight check list screen. Then when you program a model the check list will read off the requirements. Ballast, check, CG, check, tape, check. As our models get more complex this will start to become a safety issue.

Hank

 

[Konrad]

Check lists are great. I had thought about taping the wings but talked myself into thinking that it was a performance issue not a safety of flight issue. (STUPID!!!)

Well after sleeping on it. It doesn't look that bad in the light of a new day.

There is no damage to the spar or wing boxes. The fuselage still has all the datums intact. The servo tray and elevator mount are loose but not broken.

The only loss is the carbon joiner. It should only cost $20 to replace it. If I can't get a replacement it should be easy enough to fabricate a replacement wing joiner.

So it looks like the repair of the wing will be rather easy using what is shown here.

Skin repair of molded models (60" glass and rohacell racer)

It pains me to admit this in front of everyone, but I damaged my little 60" moldie racer. The good news is I don't think I damaged the main spar. You can see that the wing skins are showing damage. At the flap hinge line both the upper and lower skins are showing tension damage. A head of the...

forum.alofthobbies.com

 

[Wayne]

Oh no!!