Hi,

Inspired by boomerace's testimony of his direct drive conversion of the Birdwork's Tilde, I looked around my R/C hangar and noticed that all my wings were direct drive...and I have plenty of wings. Only my Tilde was geared.

After flying my Pop-Fly all Winter at indoor events, I knew that if the GWS motor could power that larger ship, it should work just fine on the smaller 26" Tilde wing.

My conversion took only an hour and by removing the S1 gearbox, switching to a smaller 3x2 prop, and dropping to 7 cells, I ended up reducing a full ounce from my stock 7.2oz wing.

My new direct drive Tilde was RTF at 6.2oz.

The motor was simply mounted to the spar with a rubberband. The up thrust is already designed into the spar.

Click here for a larger image.

The Tilde balanced perfectly with a 7-cell 300mAh NiMH pack up front.

Click here for a larger image.

I asked myself, "why did this plane fly better?".

I decided that the reduced weight helped to lower the stall speed and the faster speed allowed me to go further above the stall speed than the geared DX-A or S1 would allow. This tiny 26" wingspan needs a minimum speed to stay in the air. The faster speed provided better control and aerobatics.

Nice job, Boomer!

Click here for a larger image.

Thanks Greg,
Is that a mini Zagi or what!!! If you want more zip put on the Fan motor as I did! Boy does that little Jewel move then!!!! I get more complements on the little Tilde when flying it than I do on my Zagi 400X. It looks like it's going faster than the Zagi because of the size. It does glide pretty good now that the gearbox is gone.
Love that plane
boomer

Boomer,

What flight pack are you using with the ducted fan motor?

Greg,
The 7 - 300ma NiMH pack same as you.
boomer

Boomer,

I found some specs on the ducted fan motor on the GWS site in Taiwan. It does look like a good fit with those 300mAh NiMH cells at about 3amps so I ordered a couple from Todd's Models.

Greg,
Let me know how you like it. I don't have any idea on longivity but with the performance if it goes I'll install another!
boomer

I received my GWS Ducted Fan motors from Todd's Models but I've decided to hold off on putting them in my Tilde.

I flew it a few more times with the IPS direct drive motor and 3x2 prop and decided that it works very well as is. I'll wait until I burn that motor out before swapping in the more powerful ducted fan version. I currently have a GWS 2amp ESC in my Tilda and would also need to replace it with a 5amp ESC to handle the ducted fan motor's 3amp max. draw. While this may give me more performance, it will also reduce my flight time using my 7-cell, 300mAh, NiMH pack.

So, for now, i'll continue having fun flying it with the IPS motor. The lighter weight and higher speed is a noticable improvement in performance over the geared DX-A or S1 configurations.

Regards.

Hi Greg. You may not have to replace your ESC. GWSCEO has stated several times that the 2A rating is very conservative. He says that other manufacturers rate similar components at 5A. I personally wouldn't worry about 3A.

Maybe it's time I drag my Tilde back out and try out this direct-drive thing...

I replaced the balsa fuse on mine with a piece of EPP foam covered with Zagi tape and clear tape plated bottom and attached the motor directly to the hardwood fuse stick by routing a small grove to provide needed thrust angles. Weighed it with the 7-300ma NiMH 4 X 3 packs I made up and it weighs exactly 6 oz so all the changes I made put me back to within 0.2 of the same weight Greg came up with. But I do like the EPP foam keel better than the balsa since it doesn't suffer damage from landing on concrete or rock. My balsa fuse was looking pretty bad!
Greg, as far as performance you are gonna be surprised when you do try the fan motor! And mine runs just fine on the 2 amp esc.!
Tom, It's like an entirely diff. plane with the DD!!! More Zagi like!
boomer

Here is a pic of my setup ... You can see the buried receiver in the pic. No damage except I did need to re shrink wrap on one of the battery packs after my son nose dived it into the ground spliting the shrink wrap!
boomer

Ok, thanks guys. I didn't realize you could push those 2amp ESCs. I haven't measured the current yet but based upon the GWS specs, the ducted fan motor runs happy up to 3amps as compared to the 1.5amps of the IPS motor.

Hmmm...now that it is only a quick plug-in motor swap (even the connector is the same) i'll have to try it.

I don't think I'll be able to get to this for another week or so because I need to put back in all of the electronics, but I figured I'd better ask in case I can get an earlier start this weekend...

How/where do you mount your motor? I originally built the Tilde as a tractor version and I can't locate my instructions. My basswood fuse doesn't stick out much past the back of the wing. How far away do you mount the motor? If I just extend the piece of basswood can I mount the motor to that, or do I need to do something to change the angle?

How much reflex did you put on the elevons?

Tom,

The basswood has the proper angle of upthrust in it. Assuming that you build it stock originally, you need only extend the piece of basswood.

My elevons are stock too and it flies great!