Updating and Old design _ TutorII

[Dennis Toth]

Guys,
Now that I have the building board clear I wanted to do an update on my electric profile a kit bashed Tutor II. This was my first venture into electric stunt, I liked this ship because it had a deep over wing fuse section that allowed me to include a cutout to mount the battery through the fuse and back over the wing to correct the CG without adding weight. This worked fine but does put the vertical CG a little high. All in all it has been a fine ship and over the past three years I have learned a lot about electric power with it.

The ship has a few short falls that I think can be corrected to make it a more competitive profile machine. To me the big weakness is the thin aft fuse section that allows considerable twist to the tail section. This causes the ship to kinda go all over in the wind. To strengthen this I plan to add a new aft fuse outer skin from 1/64" plywood. I intend to add formers over the existing skin and increase the aft section to 1/2" all the way back (it is tapered to 3/8" now). I will use a little curvature to hopefully add stiffness and reduce the fuse drag a bit, also going to reduce the height about 1/2".

The other annoyance I have had with this ship is in the wind. It has a very long tail moment (18" hinge to hinge) it seems to want to turn around a point pretty far back of the CG. Normally, I will try to move the CG back a bit then reduce the flap movement relative to the elevator.  The current ship has a stab/elev that is 17% of the wing area. I will do a new stab/elev that is 23% to 25% of the wing and to get the corner a little better shorten the tail moment to 17" (H to H) around were current ships are.

Lastly, I will add some removable cowl sections (similar to the ones Tom Morris has on his profile) to cover the battery and wiring. With luck I should be able to hold the current weight, maybe even reduce it a bit if I can get it to complete the pattern on a 3300 mah pack (11.5 oz vs 12.5 for the current 3900 mah pack).

Anyone make any similar or other mods to the Tutor II that work?

Best,        DennisT

[Dennis Toth]

Guys,
Just to finish this off in case someone searches mods to Tutor II, I completed the mods and stiffened the fuse with 1/64" ply and added formers along the rear half of the fuse that increase the width to 5/8". It worked very well the ship is crisper in the corners with the shorter tail moment (17" vs 18.5") (hinge to hinge for easy way to measure changes, not actual aero moment) and 24% stab/elevator. The stiff rear fuse greatly reduced the twisting and keeps the ship tracking in the wind (the original fuse is very thin at the back and very weak in twist which causes the ship to wander up top in the wind). With these mods the Tutor II is a pretty strong ship.

Best,        DennisT

[Tom Niebuhr]

Like I have said many times. Why go through all the work and still have a profile. It would have been easier and faster to build a simple box fuselage using the same wing. It will fly much better too.

[Tim Wescott]

I've been tempted more than once to build an Ugly Stick for stunt.  It should be a quick build if you don't try to put lipstick on it during the final finish phase.

[Dennis Toth]

I did the rebuild out of need. I needed to have a profile for the upcoming contest. The original was a little unpredictable in the wind. Also, don't have to much room on the rack. For me it worked out, really like the way it fly's now.

Best,    DennisT

[Dennis Toth]

Finally got a chance to do some flying with the revised ship. I have been trying to use 4S 3300 mah packs instead of 3900 mah packs, this save about 1 1/2 oz. Problem was that the 3300 pack was strong until about the first loop on the clover. I have found some Zippy 4S 3700 mah packs that are thin and only about 3/4oz heavier than the 3300 mah TP packs at 1/3 the price. I flew them today and all the mods worked great. There was a bit of a breeze so it was a good test to see how the ship handled the maneuvers up top. It was just as I hoped for, no kitting, presented nicely and traced solid. All in all a success.

Best,     DennisT