RE: Picorare Build Thread
 

Tending to put off the stab mounting as much as I can, I went ahead and got it mounted this evening. I'm feeling pretty good about its 3D positioning with respect to the fuse and levelness with respect to the wing. I find anhedral stabs are tricky to get right as you can't rely on a level to compare it to the wing - it has to be done by triangulation so to speak. I hope it'll still look good to me tormorrow because I've also made the fillets between the stab and the fin.

Other than that, I sorted out the wing bolts and replaced the 6-32 for 10-32's as I didn't have any 8-32's. The stab mount and fillets brought the airframe weight up to 12.5 oz. Hopefully another 1/2 oz for the FW and some tri stock and we'll be done!

Motor should be here Tuesday so I should be able to get the build wrapped up either Tuesday or Wednesday. The only remaining details left involve the tuck lines and the canopy/fuse front shape which require the FW to be installed.

A few final touch-ups and sanding and I should be able to get get her into some colours!

David.

RE: Picorare Build Thread
 

Good news! The motors arrived and they seem quite nice. I spun one up the other day and a gut feeling tells me they should pull the Pico along nicely. What remains to decide is what to do with the second one!

I was a little over ambitious with my 8-32 standoffs. The motor X-mount just passes 4-40 bolts so I had to devise another system. It also becomes quite tricky to get an allen key to the lower two mounting bolts so what I did is mount the motor by reversing the bolts and using lock nuts at the X-mount. Basically, I passed 4 x 1-1/4" bolts from behind the FW and put washers on either side of it. I then slid some copper standoffs 7/8" long and tightened the X-mount onto the protruding bolt ends with the lock nuts. I added some blue thread lock to the lock nuts and to the various motor bolts including those that mount the motor to the X-mount and those of the prop adapter.

In order to clear the balsa nose rings, the motor sits back from these about 1/4" and a spacer on the prop shaft locates the spinner backplate at the correct position. The shaft itself actually has the core threaded to allow a small Allen bolt to secure the cone of a small spinner. I'm not sure what the thread size is nor what spinner would work with this but I plan to use a light electric GP spinner either with a plastic cone or an aluminium one. For the latter, the shaft threads might actually be useful.

In short, I feel the dimensions of this motor were the right way to go from a built standpoint. I also prefer the standoff FW mount to a nose ring front mount (i.e. inrunner) particularly because there isn't great strength built into the nose ring section of the model even though I doubled on the nose ring balsa backers. We'll see how it fares from a power plant standpoint.

Attached are some pics of the motor mounted on the FW which has been drilled out to allow air back over the battery and ESC. Next I'll install the assembly into the nose.

David.

RE: Picorare Build Thread
 

An hour or so later...

I got the motor mounted and backed with some tri stock. Perhaps a little more in the front and some along the bottom behind the FW to strengthen the nose section and with a little final sanding to the fuse and canopy we'll be ready for some finishing!

Here's the motor mounted. As can be seen, the front of the can actually ends before the balsa nose ring backers. The prop shaft just allows a beefy nylon washer to be threaded on to it and provide enough length for the spinner backplate, prop hub (APC 8x6E), prop washer and prop nut. Bigger props with thicker hubs might be a problem as there might not be enough thread.

However, I don't intend to use a prop any longer than 8". If anything, I might use a 7x6.5SF or similar.

David.

RE: Picorare Build Thread
 

Great job David you have a winner there, now put some colors on it.
Whats going to be the scheme on this beauty ?

Mine is going slow but steady :D !

RE: Picorare Build Thread
 

The beauty of electric power is that you can drop a couple of lead weight bags on the model atop a stand, mount a prop and blow some serious air around the basement at 1 am! :D (But lets keep it under 300W shall we!?)

... so that's exactly what I did. Hoping to not wake the kids, I thought I might get a tach reading off the APC 8x6E on 3s. I made sure things were nice and tight and spun the little 28mm up... scary. Good job I turned the model so that the papers were far away in front of it otherwise they would be all over the office [:-].

Of course no tach reading - not enough contrast, but I think it's in the 12K range. Now, if I could only remember how much a piped 15 pulls on an 8x6. Frankly, a piped 15 on a 26 oz model sounds like something I'm not fit to fly. But I still suspect that this e-setup will have the Pico flying vertical straight out of my hand! [8D]

According to Dualsky Calc, we should be spinning at 11,250K with 34 oz of thrust and a pitch speed of 103 km/h :D Amps at 27.8A and input power at 309W.

Sweet!

I might have to drop to an 8x3.8SF (248W) or an 8x4E (231W). A Graupner 8x6 CAM prop pulls 274W - another longer flight option.

For fun I uploaded a spinup of the motor as a Quicktime file. Right click and save as Pico Motor Runup.mov

Hey guys, I just noticed that PDF uploads are now supported on our forum! Cool. No more switching extensions and they should show up as an icon now.

David.

RE: Picorare Build Thread
 

Thanks Rafa!

Colours? White with... Soon we'll find out!

By the way, I should have mentioned that after a 30 sec spinup on the 8x6, the presumed 28A run left the motor warm (the motor is rated at 22A eta_max). I was able to leave my finger on it and the battery was barely warm. The 56A ESC didn't seem to change in temperature one bit. Heck, I might just leave that ESC in there at the cost of 1/2 oz - at least until I get an appropriate one. A couple of 20-25C 3s packs would be nice although the 15C's seem fine.

David.

RE: Picorare Build Thread
 

That is awesome. I'm curious to see how she flies. I wonder how it compares to a Brio or similar.

RE: Picorare Build Thread
 

Thanks Tim!

Little classic pattern planes are cool. [8D] But I haven't flown a classic in this size yet (my Deception 10 remains on ice... but the sun's coming out). Brio? I'll have to give QQ a call and ask him to take the Pico for a spin - then we'll know. :D

BTW, be sure to check out Raindave's UFO 66% build. That'll be a nice one too!

David.

RE: Picorare Build Thread
 

In other news, I quit sweating the tuck lines (it's a bit like sculpting clay...) and got down to some covering!

The wing bottom is done. White MK base with Insignia Blue EK trim - it worked. Some details to tidy up around the front fuse section on the wing.

Wing top will be different... somewhat.

Weight gain from the covering on the bottom half was around 0.6 oz which is great. This should yield a finished wing at around 7.5 oz and an airframe in the 15 oz range - not bad for a 40" model with fully sheeted airfoiled surfaces. But I know David will do better with his UFO... ;)

David.

RE: Picorare Build Thread
 

I almost forgot.

I spun up the 28-34-1460 on an APC 8x6E this afternoon. On a 15C 3S pack I was able to get an idle of 1,800 rpm and WOT of 11,500 rpm which should be in the 35 oz thrust range. Back of the envelope gives me ~105 km/h pitch speed. Some 20-25C packs might be in order.

David.

RE: Picorare Build Thread
 

David,

I spent all day at the field flying yesterday (I was there at 7:45 AM, flew until 7:30 PM, and left after the fireworks about 10:00)! 14 models flown, several maidens or first in a long time. The jet jocks were there too. Some day ...

You definitely want the highest C rating you can afford, and the largest pack as well. The idea is to keep the voltage as high as possible. I had several flights on the Gulfstream (propped with 6x5.5E APC) and the SF props are definitely better than the E for this size. Heat and vertical performance go hand-in-hand, it seems. The 7x5SF was much nicer, a little slower flying, but up and down lines had more consistent speeds. Long vertical lines were possible, but the motor was pretty hot afterwards.

We were playing with wing loading vs. battery size on another plane, flying one designed for 2000's with a 3500 instead. It's worth the 2 MPH landing speed increase! If you got the room, pack in the electrons!

Andy

RE: Picorare Build Thread
 

Andy,

That's great news! It sounds like a wonderful day.

Thanks for the battery pointers. I think I'll keep the 15C packs for the T-6 which doesn't need as much punch. I'll have to look for some affordable good 25C packs.

As far as capacity perhaps bumping up to 2500 mAh. As long as it stays under 28 oz we should be golden.

I noticed that the SF props pull more current. I'll have to see what's available that will keep the power up.

David.

RE: Picorare Build Thread
 

Andy,

The 8x6E seems to keep the motor at its optimum power output without overheating (static...). I see the following choices for SF props that might be suitable:
[ul][*] 7x6[*] 8x3.8[*] 8x6[*] 9x3.8[*] 9x4.7
[/ul]
The 8x6SF will probably exceed the motors amp rating by quite a bit (8x6E seems to be about max). What props do you suggest trying? The motor is rated at 22A eta_max and 30A peak.

Thanks, David.

Edit:

Dualsky Calc actually states the motor should pull 22A @ 248W on the 8x3.8SF and 28.9A @ 320W on the 9x4.7SF (11K+ rpm). Would the latter be excessive? Maybe not provided WOT is properly managed. Smaller props don't seem to pull enough electrons (or are they holes? :)).

RE: Picorare Build Thread
 

It depends on your goal. Just adding watts doesn't add performance. You may get to climb vertically longer with a large diameter prop with lower pitch, but is that true to the airframe? Personally I think that would be more appropriate for the modern flying whales than a classic.

I would go with a higher-pitch prop to get the airspeed up and fly it more like old (real?) Pattern.

The SF props may pull more amps but you get a lot of thrust for it due to the wider chord. Thrust isn't all you need, though, you need pitch speed as well. I need the SF props on my Gulfstream because of the fixed gear. A 7x5SF trimmed to 6.5" seems to be what is best for my setup.

And yes, 320W is way more than the motor is going to like for very long, and more than the airframe is going to need up front.

I have to put a cooling air intake on mine now.

Andy

RE: Picorare Build Thread
 

Andy,

it sounds like from an APC standpoint, the 8x6E might be the right choice on this airframe with this motor. Otherwise it might be interesting to try the 8x3.8SF and the 9x3.8SF perhaps cut down to 8.5". I've never cut down an electric composite prop and I'm not sure what the best way to do that is but it sounds like it might be an interesting option.

Granted, it strikes me as though the 8.5x3.8SF would produce nicer verticals, slow the model down a tad but probably yield a more modern style to the model compared to the 8x6E. I'll give them a try when she's flyable.

David.

RE: Picorare Build Thread
 

I got a little further this evening. Considering it was a national holiday south of the border (and mum's birthday ;)), not too bad.

I'm either getting a little better at the compound curve thing with MK or TF's new formulation is making the material easier to stretch and fold over. I can never quite get a perfectly horizontal material cut on the tips even with single edge blades (I need to improve on that technique), but all in all I'm quite happy with how the wing covering is coming along. The wing tips are actually wrinkle free (1/2 hour each of iron time). The rest also worked out fine although I always dislike the appearance of covering over glass cloth. I wasn't about to paint the center section on this one though and the glassed area is not visible except for a small section underneath.

Now I just need to get my hands on the trim colours to finish the wing. I'll probably move on to the empennage next.

The wing stands at 6.9 oz. The top trim and aileron cover will probably bring her up to ~7.2 oz.

David.

RE: Picorare Build Thread
 

Nothing too exciting to report tonight but got the first shade of colour on - gotta keep the momentum up. Picked up some flicks to watch with "my dearly beloved" so it'll be a night of non-cover.

Those a little more familiar with Tipo trivia might start to recognize an emerging pattern. Anyone care to guess what colour(s) is/are missing on the wing?

David.

RE: Picorare Build Thread
 

So, after a night off for a soiree with the "wee kitchen" (old fashioned Irish term of endearment for one's wife), I got back to the job at hand.

Although I started a little late (and am also working a little too late into the night), I managed to get the stab & elevators a little further than the state of the wing - the latter has ailerons that remain to be covered.

It actually took me 4 hours to measure, re-measure, cut, and apply all 24 pieces of covering to the stab & elevators. And there are 8 pieces still left to do (I wish I had those colours but, alas, I don't yet)! That brings the simple trim scheme on the horizontal empennage to a total of 32 pieces of covering [:-]. The wing, since it doesn't need separate pieces on each side of the rudder as the stab does has a piece count of 2 less - 30 pieces.

Hopefully I'll manage to keep the fuse piece cut down a tad! Here are some update pics.

David.

P.S. Weird, the photos "bubbled" on upload. The covering doesn't look all bubbly as seen in these pictures. I've seen this happen before on other threads though - it's probably jpg compression which is worse on rich saturated colours (e.g., red).

RE: Picorare Build Thread
 

Absolutely Amazing work there David!!
I love to see perfectly covered tips
Can't wait to hear how she flies


DM

RE: Picorare Build Thread
 

David,

thanks for the words of appreciation and your interest in the build thread. I like the idea of perfectly covered tips - hopefully on every build we inch a little closer...

I actually learned something new about covering on this job. It shall be tested next round :D.

I'm starting to have "maiden flight dreams"... I found another great park even closer to my place!

David.

RE: Picorare Build Thread
 

Today was a rather long and tiring work day but I wanted to get something done.

I sorted out the rudder linkage which I was unhappy with. I ended up going with a "standard pattern" approach using a 1/2" dowel insert in the rudder drilled out for a 4-40 bolt which will have a pair of eyelets on each side for the P-P linkage. I just have to decide how long a screw to use.

I also managed to get some covering on the fin post and the fuse bottom rear and spent some time figuring out the fuselage trim scheme on the plans. I'll have to make a template for the colour trim as this will be the trickiest to apply.

After covering the fuse bottom and nose, I'm also hoping to cover the sides, fin and top in three pieces total. The fuse side and fin piece (one per side) will be cut according to plan trim sketches and a stab cutout will be made in each piece as if one were cutting balsa fuse sides.

The top piece is a little trickier as it will have a gull-like shape which I'll have to measure and cut with some care.

I'm hoping some of you might have already guessed what she's going to look like!

David.

RE: Picorare Build Thread
 

David my Pico had a similar rudder linkage altough wasnt PP sistem, I used a 4 / 40 screw 1" long, eyelet ended almost half the way on screw after installed.
Maybe this can give you an idea of screw lenght you need.

Waiting for maiden report, you'll be amazed with this missile.

RE: Picorare Build Thread
 

Rafa,

thanks for your feedback. That sounds about right - setting the control moment about 1/2" out from the rudder; in my case, on each side. A 4-40 bolt 1-1/4" in length should do nicely and should provide adequate precision as well as torque.

Maiden is hopefully a couple of weeks away - will depend on the hours I find to finish her up as well as the arrival of some electric juice!

David.

RE: Picorare Build Thread
 

Flying surfaces are done!

Now that her colours are on, some of you Tipo fans will probably recognize the scheme - De Facto Tiporare.

The camera doesn't render the colour properly but it's the red/orange/yellow rainbow scheme that is actually used by the 1982 Great Planes box model! Although the GP box and instructions are not in colour (hence no way to really tell), there is one source - the GP 1982 catalog.

I've wanted to build a Tipo with this scheme for 25 years... now, she's finally here - almost.

Applying the scheme to the fuse will be more akin to tensor calculus compared to the flying surfaces - they were a walk in the park!

Current airframe weight is 13.9 oz - she should come in at 15-16 oz finished. So the AUW will be in the 26-28 oz range.

David.

RE: Picorare Build Thread
 

David,

What is that yellow?

It's neat to see it come alive. Nice concept. And you're weight is right on the money. Good job!

I wish you lived closer, I'd love to see it fly in person!

Andy