SkyCadet's blog archive for March, 2012 - RC Groups
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Archive for March, 2012
Posted by SkyCadet | Apr 01, 2012 @ 12:07 AM | 3,320 Views
I stalled the motor back on, after putting some small 1/8" O-rings as inserts to minimize vibration from the motor. I am probably going to ultimately use a different motor, but meantime, want to use this one. It is fine, except for some reason noisy when running, and clicks when hand turned.

It runs smooth, but has a tiny bit of bearing play in it. I have a replacement on order. Need to use this one to at the very least balance the plane out.

Also, installed the 60A E-flite ESC. I opted to have it sit under the battery tray, facing flat forward. Air will spill over the whole fin area of the heat sink. Also, I used Industrial-grade velcro for the unit, and will also be putting some cable ties to use as a backup. Just in case. It sits totally solid now, but under 6+g loops, who knows?

I also used white glue on the top and bottom of the wood canopy floor - it is SOLID now. No flex at all. I also reinforced the gear on the inside with a overlay spar inside the gap where the blind nuts are. Epoxied in.

I made a side mount for the ESC's on/off switch. This sits off to the port side of the plane. It was cut from a 3/4" pice of balsa and slotted to fit against the wall of the fuselage on the battery cross member I installed, and the near furthest bulkhead ring. It should work well there. I may just leave it on, but thought I'd try it. I don't like having stuff out of the fuelage wall, and the battery compartment seemed an excellent location.

I also zeroed and adjusted the bottom wing throws and positions as a prelude to mounting the wings tomorrow.

Pics below...

Almost finished now, just mounting the radio, wings, linkages for the ailerons, and then wires! Woo Hoo!

Stay tuned, getting her done very fast now!

Posted by SkyCadet | Mar 31, 2012 @ 11:49 PM | 3,429 Views
I decided after inadvertently breaking off one of the flimsy aileron link horns, to follow another fellow who used the same thing: Dubro #189 ball links (aileron type). These normally get used inside a fuselage to link the servo horns to "L" wires, but these are a fantastic way to get a solid aileron linkage!

These use a 4-40 screw to normally lock a control rod/wire in place; in lieu, I used 3/4" cap screws with 4-40 threads into the ball link, and then used CA to fix them. I then cut off the head o fthe cap screw about 1/8" in from the head base, and smoothed off. The ball/screws then thread into 5/32 holes I drilled right next to the locations of the old horns. I trimmed the material carefully first, then used white glue and matching paint to hide the wood, where showing. I started with pilot holes of 1/16" and took my time with my Dremmel.

CA was dripped into the holes first, then a drop or two onto the screws. These then got fed into the holes, and bite WELL! Wicked the CA that may have squeezed out with a Qtip. Voila! Ball linkages on my Ailerons!

I plan to use the stock control rods, though ANY 2-56 threaded rod will also do. The links come with nylon sockets that have 2-56 threads in them, and brass couplers which can be soldered or adhered using CA after cleaning the surface of a straight rod.

See pix below for finished results!

Sky Cadet
Posted by SkyCadet | Mar 27, 2012 @ 11:27 PM | 3,118 Views
Well, finally!

I opted to use 2-56 clevices from Dubro in lieu of the stock units, with 2-56 threaded rod. I used Dynamax aluminum servo horns on my aileron servos, due to the 82MG HiTec servo horns being a bit small/short, which concerned me for the throws.

Problem was that the clevices are around 1.6mm OD. No problem! I used nylon spray tube inserted over the clevis pins to act as a shim. Perfect fit! The intial fit was a bit snug, but once moved a few times, it loosened up nicely with almost no play.

The Dubro 2-56 clevices on the aileron horns needed to be shortened by about 1/4" to fit the servo horn-to-aileron horn length at zero deflection. I used dubro 2.1mm screws on my horns, since the E-Flite stock 10mmx2mm (OD) machine screws did NOT have enough length to clamp the horn backplate to the 1/2" thick ailerons! Thanks, E-Flite! Bad planning....

Anyway, it fit great. When storing the wing (I was planning an out of town trip for two days, and need to mount my electronics inside the fuselage now before hooking up the wings), the horn on one of the servos hit my hand and snapped off the aileron! This is the one that hooks to the second wing-set horns. Glad it happened now! I guess I'll have to do an upgrade like many here now, before flying... VERY weak lateral strength.

So, a few more fun things to do before flying. Glad that this happened now - no fun having ailerons fail in mid flight... The servo horns fit great. VERY robust with MAYBE 1/2mm or so of play. smooth motion though. I like this Dubro and metal servo horn upgrade - much more beefy. I left the Nylon 82MGs on the rudder and elevator though, and used the Dubro clevices and 2-56 threaded rods like on the ailerons. I like this - easy to set up and adjust...

Stay tuned...

Posted by SkyCadet | Mar 23, 2012 @ 10:29 PM | 3,480 Views
I just finished painting the prop. Just put it on lightly to test fit everything.

Looks great, I think...

Tru-Turn 2.25" spinner, MAS 12x6x3-blade. Standard spinner, electric conversion kit to mate to a 5mm shaft with collet. Painted gloss black on spinner, yellow on cup for cool effect!

Posted by SkyCadet | Mar 23, 2012 @ 07:29 PM | 3,264 Views
I finished the cowling today! I used graphite epoxy to stiffen the backside of the faux-engine parts and then used semi-gloss white/black paint to make a steel grey mix applied with a toothpick into the grooves on the faux-cylinder heads and mounts. Just enough to look like an engine, but not so much that it looks too "new"

I also blackened the firewall and seams where the cowling and battery cover sit, as well as the battery cover where it has black on the topside. Makes a cleaner look to the model!

See pictures below. Now, onto finishing the wings and wires, and then battery system!

Almost ready!!!

Posted by SkyCadet | Mar 23, 2012 @ 12:37 AM | 3,997 Views
I carefully cut out the slots between the faux-radial engine! Whew. A fair bit of precision work to look nice. I plan to use some graphite-epoxy to strengthen the engine spars and radial cylinders a bit more. I smoothed the job with a polishing wheel and my dremmel to remove any burrs and to remove sharp edges. Looks great!

Now, to paint the interior flat black and then epoxy into the cowl. I plan to paint yellow tips on the prop, then mount it. Getting there every day!

Sky Cadet
Posted by SkyCadet | Mar 21, 2012 @ 08:46 PM | 3,220 Views
I did a slight mod to the Pitts battery cover: A magnet, 10mmx3mm was mounted flush-wise to the 10-o'clock position as viewed from the front. The magnet holds a small 4-40 socket screw that was mounted in the middle of the front battery cover rib.

This holds the cover with a SNAP! and is just tight enough to prevent the cover form flying off. Mine was pretty good anyway, but I wanted to make sure before placing the cowling on. Now, the cover is as close to ideal as I can get it!!

Just trimming the final bits off the Faux-Radial plate, then gluing to the cowling.

Posted by SkyCadet | Mar 20, 2012 @ 07:32 PM | 3,072 Views
Hey everyone!

Finally! After a long hiatus, some other-hobby related activities, and such, I am almost ready to finish this plane.

Mounted the motor, tail section, and just finishing the battery/ESC install before popping the wings on, the wires, the prop, and up we go!!

Meanwhile, a few construction additions and notes:

I decided to run 4S 3700mAh lipos topping out at 320g each. That should give me over 16 mins of cruising flight time, with some excellent left over capacity for some aerobatics. The firewall mount for the 900Kv RC Timer 770W motor was also touched up with dilute 50% white glue (WeldBond) to add some strength, and the cowl mount blocks were too, after being positioned with 6-minute epoxy.

As can be seen again in one of the photos attached, the battery tray was extended and lowered by about 1" to accomodate a wider range of batteries.

My Tail wheel was rplaced by an eBay special - it is 1/8" taller, and i used the wire hardware from the kit, and a mounting block for the tail wheel with dual collets to avoid rudder stress. The mains will be 2.25" Hangar 9 wheels in lieu of the stock wheels/pants. I personally do not like wheel pants due to excess drag issues when landing on grass. My gear struts were also pre-drilled near the top with a 1/8" hole to prepare for mounting the flight wire kit I bought for this model!

Stay tuned, no several months waiting this time!!!