Minor crash during the maiden of my second scratch-built balsa plane, the Tail Dancer

[Hogster]

Nothing too serious fortunately. This was on the fourth flight after the maiden (the maiden took place about 10 minutes before this flight! :p). A glitch sent me slightly nose-down towards the ground (I was only about 10ft up), and I overcompensated waaay too much, making the plane cartwheel on the ground .... not violently (as it was only flying along very slowly), but still fast enough to create this small amount of damage.

The motor breaking off the mount was something I wasn't too surprised at. The GoBrushless motor doesn't come with any means of connecting it to anything, so I just had to improvise by push fitting the end of the stator-mount into a piece of aluminium tubing I found, and then CAing it in place. Not surprising that it came off ..... it actually came off MID FLIGHT on the 3rd flight! :eek: Made for a hairy landing I tell ya! :o

The whole tailplane also snapped off .... again something I wasn't really surprised at ... it was butt jointed with CA to the fuz. :rolleyes: In itself this method wouldn't have been too bad, as the CA would have wicked its way into both pieces of balsa, but I reckon the fuz already had hardened CA on it ... and CA doesn't stick to CA very well.

http://hogster.rchomepage.com/dancer/minor_crash_1.jpg

http://hogster.rchomepage.com/dancer/minor_crash_2.jpg

http://hogster.rchomepage.com/dancer/minor_crash_3.jpg

Moral of this crash: CA isn't infinitely strong! Don't use it on joints with small surfaces areas, particularly those that need to withstand a lot of force ... like a motor mount! :rolleyes: Also, don't overcompensate, or at least use more expo on the control surfaces! :p

Will be fixing it shortly. :)

See this thread for more details of the plane:

http://rcgroups.com/forums/showthread.php?t=271515

[ashdec87]

Good looking plane!!

I've never seen a motor like that. Definetly something new to me. Would epoxy work??

Ash

[Hogster]

Well here's the video of the flight! The crash occurs right at the end:

Maiden flights of the Tail Dancer! (http://hogster.rchomepage.com/dancer/dancer_maiden_4-9-04_3ivx.avi)
21MB, VLC (http://www.videolan.org/vlc) recommended for viewing

Enjoy! :)

ashdec87 - how do you mean? You've never seen a brushless motor before? Or you've never seen the bell directly attached to such a large folding prop? ;) It's certainly the first time I've seen a folding prop attached directly to a CDROM-style brushless motor ... certainly goes well though, which is the important part! :D

I had thought of epoxy too, and it may have worked, but I'm currently working on a new super-duper method of mounting the motor - piccies soon of course! :)


Oh yes and I finished repairing the tailplane mount last night - here's how:

http://hogster.rchomepage.com/dancer/tailplane_repair.jpg

I cut back the SolarFilm over the joint, and firstly CA'd the tailplane back onto the fuselage. I then separated the two plys from a piece of toilet roll, and cut some thin (10mm wide) strips from one ply. I then laid these strips over the fracture, and soaked the area (and the strips of toilet paper) with thin CA. This is similar to the process of fibreglassing (I imagine), where the toilet paper is acting as the webbing, and the CA is acting as the resin. I then sanded the joint and recovered it with two layers of SolarFilm. You almost wouldn't know that it had broken! :)

[Hogster]

Motor mount is now repaired ... and here's how! :) Instead of gluing the bevelled part on the stator-mount directly to the aluminium tube, I've abandoned using the tube altogether. I sadly can't remove the tube as it's SERIOUSLY glued to the plane with CA! :p So here's an idea my Dad came up with:

http://hogster.rchomepage.com/dancer/new_motor_mount_1.jpg

I cut out a rectangle from some thinnish copper sheet. I then drilled a snug push-fit hole for the bevelled part of the stator-mount, together with a slot for the wires to pass through. I then put a rim of solder around the outside of the hole in this plate (on the side of the plate that would face outwards), as well as putting solder around the widest part of the stator-mount. I then placed this copper rectangle onto the stator-mount, and heated the whole area with a small blow-torch (with my fingers crossed that it wouldn't screw up the bearings or stator!). The solder from each piece flowed together and tadah, the two pieces are held together! I then drilled four clearance holes in the corners of the copper rectangle, and four pilot holes into the firewall at the front of the fuselage. As the firewall is only made of balsa, I used a cunning technique to give the screws something more dense to grip onto ....

I screwed this new mount to the fuselage normally, and then took the screws out. I then put a drop of thin CA onto each of the holes and allowed it to set. Then, when I screwed the mount back on, the self-tapping screws I used tapped their own thread into the CA, making a really firm joint! Works superbly! :)

I finished it off by painting it white. Here're two more snaps:

http://hogster.rchomepage.com/dancer/new_motor_mount_2.jpg

http://hogster.rchomepage.com/dancer/new_motor_mount_3.jpg

All looking absolutely spiffing! :D

But sadly ... it wasn't to last. :( See here:

http://rcgroups.com/forums/showthread.php?p=2596886