Dad's Workbench...

Started by Wingnutz, February 26, 2013, 11:34:22 PM

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Wingnutz

Okay, so I'm proud of my soon to be 90 dad...he's still building model airplanes! In an earlier post about his DH89 Dragon Rapide (finished last month), I made reference to our Monday pub lunches which he buys while I feed him model airplane kits, parts...and help out with electrical stuff. At the rate he's building I'd be way behind if costs were tallied! Photos are of his latest, a Macchi M5 Fighter, Flying Boat (seaplane) and Schneider Cup racer...and another beautiful biplane. Last picture is the jig he built to get the wings aligned.
Anybody got plans for an Avro Anson Mk I or II? He wants to do one of those next! Failing that he'll settle for a Waco YMF, Waco ARE or Aeronca C3...beauties and the bathtub!
DOWN WITH GRAVITY! UP WITH LEVITY!

Andy Hoffer

Hi Bill:

So wonderful that your dad is sharp and active at 90 and that you share a strong common love for RC aircraft.

I hope we will get to meet him at TEMAC this summer?  Maybe a family portrait?!

Cheers!

Andy Hoffer

Ededge2002

Great work!  The old hands still got it!! 
Yea 400W/lb should about do it.. But wouldn't a nice round 500 be better?

Gregor77


piker

Very nice, Bill... and Bill's Dad!

As you know, Bill, I have the same kit, but I'm not that far along.  I have the top wing mostly done and the fuselage boxed up, as your dad does, but that's it.  I'm inspired seeing these pictures.  It'll be sweet little flying boat.  I hope we can see it at the lakeside this summer!

Robert

Wingnutz

Hi Rob,
I'd appreciate your thoughts on motor choice. We've picked an e-flite Park 280 because it's light, has a kv rating that's high enough to get some thrust out of the small prop this model demands AND I can't find an inexpensive substitute from HK in the same weight/kv range. It's rated for around 100 w on 3S and we're thinking a 6x4E or 6x5E prop which is close to the max diameter this model will allow. We expect the finished model to come in at 12-15 oz. with 850-1000 mah 3S on board.
I still agonize over motor/prop choices so any input from you experienced types would be appreciated.
DOWN WITH GRAVITY! UP WITH LEVITY!

piker

Well, I'm certainly no expert at choosing motors these days.  I still go by the simple watts/pound approach and find that has never failed me.  The Kv value only comes into play when considering extremes like F5B and Nooners (and EDF) where optimum performance is the goal  ;D

The Park 280 seems like a good choice to me.  It'll let you swing the prop you want to swing, will easily give 100 w/lb, which will be WAY over kill for this plane, and it's nice and light.  How can this be wrong?

The vast number of motor options available these days seems to make it harder to select a motor, but as long as you know what power you want (ie. watts/lb), the limit on prop size, if any, and a general idea of the type of motor (Kv - slow with thrust vs. pylon racer fast) then any one of the motors that satisfy that will be fine.  In otherwords, unless you're looking for/ require for competition an optimum set-up, don't worry about it too much.  These days we have the luxury of being a bit off   :)

What do the rest of you say on this subject?

Robert


Wingnutz

Rob,
Thanks for making me feel more confident about the factors to consider when making a motor choice. I think I've been doing pretty much what you outlined. Helps to have experienced RCers' advice.
Jeff,
That's certainly a short list candidate. Thanks for taking the time to find it and point it out.
DOWN WITH GRAVITY! UP WITH LEVITY!

Wingnutz

Settled on Jeff's recommendation for motor and ordered from HK. In the meantime, building has continued. Here's a few more pictures as the build progresses taken after this week's visit to the pub.
DOWN WITH GRAVITY! UP WITH LEVITY!

piker

Such an interesting building project.  The framed up flying boats have so much character.

BTW, is the tail made from Depron, or is it covered with white covering already?

Wingnutz

#11
Quote from: piker on March 12, 2013, 10:51:51 AM
Such an interesting building project.  The framed up flying boats have so much character.

BTW, is the tail made from Depron, or is it covered with white covering already?
Rob,
Both...horiz stab is traditional stick and Coverlite but rudder is depron as dad decided to increase its size and created a unique air rudder driven water rudder... Sorry I missed that detail in the photos. He wants to fly it from water but the RCGroups thread for this model isn't  complimentary on the small (Dare) version in the water. Time will tell.
DOWN WITH GRAVITY! UP WITH LEVITY!

Wingnutz

#12
We had another pub lunch today, so the photos show the progress on Dad's Dare Macchi M5 over the last two weeks. The deck(fuse top) has been added and the balsa stained with Minwax. The pilot figure (re-worked Star Wars action figure from the dollar store) has taken his seat and the dummy engine (Isotta Fraschini I think) painted and temporarily fitted. The motor and ESC (en route from HK) will both fit here so in addition to the aileron servo wire, there are going to be two more wires from the fuse to the motor platform...we're still trying to figure out how to hide them. The bottom wing and bottom of the top wing have been covered with Coverlite, chosen to try to keep the weight down.
We're hoping it'll be ready for TEMAC's Schneider Trophy 100th Anniversary event.
DOWN WITH GRAVITY! UP WITH LEVITY!

piker

Wow!  Looks so nice!  And that pilot is perfect.  Great work adapting an unconventional pilot.  It looks better than most RC specific pilots.

sts41

Hi Bill...I am crunching the numbers for the Motor/Prop/Battery. And if you can get the eflight park 280... Go with the 6X3 prop and you should have a perfect setup:

Here are some of the important numbers...

Power:        70 watt
Thrust:        13.4 onces
Current:       6.71 A
RPM:            13500
Mixed flight time about 13 minutes at 850 mA 3S battery...

Anything bigger than 3.5 on the 6X3 calculates to a Thrust Stall. If you can find the 6X3.5, you will get a bit better performance, but with the  weight to thrust ratio of the 6X3... should be way more than enough.

I use the Castle Creation calculator and I find it to be easy to use and understand... It didn't have the Eflight Park 280, but I just added the numbers from Horizon site. I find it very accurate, but nothing beats testing.

http://www.ecalc.ch/motorcalc.htm?castle&lang=en

Hope that helps
Steve