Thread Tools
Mar 07, 2018, 06:43 AM
Build, crash...repeat
AleRRon's Avatar
Thread OP

Lg


Hereís what I came up with for LG. I tried a few different versions for the nose gear and settled on this one. Removable but seems very secure. Because at first I didnít have a good plan for the nose gear and changed things along the way, I had to cut away some of the nose bottom plate, shape and insert some foam to fill in the forward part, then reattach the plate and cut the slot. The wing mounted gear will be screwed in to the spar through the 1/32 plywood plates.
Sign up now
to remove ads between posts
Mar 07, 2018, 08:15 AM
Warbirds Lover
Dreamcatcher's Avatar
Quote:
Originally Posted by AleRRon
Thanks for your advice Dreamcatcher, I’ll keep that in mind.
I’ve had a lot of other things going on lately, so work on this bird has been slowed a bit. But today I hope to sand a little more and then attach the fin and rudder. I think I’ll put a coat or two of water based Minwax polyurethane to fill in the sanded pores and get it ready for paint. What do you think, MPF guru Springer?

YW AleRRon,

Our "WBPU" products have not the same name here in France, sorry... i can't help about MPF Guru Springer.

To coat the depron before painting (if a coat is needed) I use Polyfilla "sans poncage" p‚te lťgŤre melted with a few drops of water - This product looks to be a clone of the famous Hobbico Hobbylite filler that is sold in the US i guess.


The pros : Easy to use, tools only neeed water to be cleaned, easy to sand, very light weight, can be painted with any acrylic paintings.

The Cons : It gives to the foam surface a FLAT finish (great for Warbirds camo but may be not for a Piper Cherokee. It needs some coats of shinny varnish on the paint layers if you want a shinny finish.
It produce a very thin dust when sanding (i recommand to wear a mask and some old clothes)

I look forward the next steps
Cheers
Pascal
Mar 07, 2018, 09:24 AM
treefinder
springer's Avatar
Quote:
Originally Posted by AleRRon
Thanks for your advice Dreamcatcher, Iíll keep that in mind.
Iíve had a lot of other things going on lately, so work on this bird has been slowed a bit. But today I hope to sand a little more and then attach the fin and rudder. I think Iíll put a coat or two of water based Minwax polyurethane to fill in the sanded pores and get it ready for paint. What do you think, MPF guru Springer?
Minwax or wbpu will seal the foam nicely, you may want to put on a first coat, sand with 150 or 220 grit paper then do a second coat. The first coat "raises" the open cell "whiskers" and makes a rough surface that you can sand smooth (kinda like raising the grain in wood finishing). 2 coats will give a good finish usually. It doesn't add stiffness or strength though, so still dentable. Make sure you have full coverage if you are finishing with rattle can spray (both the paint and propellant eat bare foam). If you are using water based acrylics, It's not critical. They won't affect the foam, so you can get paint into the hard to sand nooks and crannies.
Mar 07, 2018, 09:27 AM
treefinder
springer's Avatar
Pascal's point about filler is important. If you use fillers the surface w/o be different than the foam, (absorption and smooth vs,open pores surface). So, you may need extra coats to match gloss and smoothness.
Mar 07, 2018, 12:04 PM
Build, crash...repeat
AleRRon's Avatar
Thread OP
I don't have those fillers so I'm going to try the Minwax. I've used lightweight spackle but it's pretty thick stuff and takes a lot of sanding. I wonder if thinning it with water would work. I'll have to experiment on a test piece.
I'm going to use an airbrush with acrylic paint
Bob
Mar 07, 2018, 02:33 PM
Warbirds Lover
Dreamcatcher's Avatar
You can try to melt your spackle with a few water.
I apply a thick first coat using a large brush with soft hairs, then i sand it with thin sand paper (600 for car boddy but without using water). I sand until i see the foam again then i apply a second layer and sand it too with 600 sand paper.
Then i apply some coats of klir from Johnson a fluid used to make the house floor shinny (klir is also know as clear / pledge/...). I spray paint with an airbrush. If i have to apply water slide decals i spray some more coats of Klir on the paint layer,
I apply decals then seal them with some more coat of Klir.
If i want a more flat render i spray Klir + Flat waterbased varnish. 50/50 give a rather flat render (good for warbirds, for example).

Have a nice evening !
Mar 15, 2018, 02:08 PM
Build, crash...repeat
AleRRon's Avatar
Thread OP
Sorry to keep everyone waiting. I've had some other duties lately and unable to spend much time on this project. Actually also trying to learn CAD so I can produce plans for this and for other planes I have in mind.
Anyways, I've been sanding and sealing the foam- pictures aren't helpful for that. Soon I'll do some masking and airbrushing. Any suggestions for paint scheme?
Mar 16, 2018, 10:24 AM
Scale RC Plane Lover
julescrafter's Avatar
my piper cherokee wingspan 1100 mm
I love this plane, so easy to control also can do aerobatics

Mar 16, 2018, 04:07 PM
Build, crash...repeat
AleRRon's Avatar
Thread OP
Looks great! Is that scratchbuilt or factory built? Does it have ailerons and flaps or just ailerons?
Mar 17, 2018, 09:14 PM
Scale RC Plane Lover
julescrafter's Avatar
Quote:
Originally Posted by AleRRon
Looks great! Is that scratchbuilt or factory built? Does it have ailerons and flaps or just ailerons?
Thanks, it's scratch build from 3 mm polyfoam board (depron like foam) with no flaps. It's just 650 gram no need flap.
Jun 03, 2018, 06:50 AM
Build, crash...repeat
AleRRon's Avatar
Thread OP
I know itís been a long time to get to the finish with this plane, sorry about that. Too many things...

Got all the electronics and pushrods installed and everything moves and works as expected. But the C.G. seems a little forward, can anyone advise?

Itís a 6Ē wing root and the C.G. falls at 1 1/4Ē behind the LE with a 1000 mA battery. With 2 lead weights taped to the tail the C.G. moves back 1/2Ē. The plane design with the battery compartment doesnít allow for shifting battery position.

Tell me what you think!
Jun 03, 2018, 07:53 AM
treefinder
springer's Avatar
I would probably fly it as is just to see how she performs. (Relying on the old saw nose "heavy flys poorly, tail heavy flys once") though I would first try a power off glide test into some tall grass to insure there isn't a serious issue. If you have some tall grass or weeds near, it is a low risk way to see what you should expect on glide.

I always hate to add non productive weight, but the half inch gets you to 25% which would be my first try target, so you could glide test both conditions. Regarding the lack of aft room , it is only foam, so you can cut and glue in "extensions " to the pocket. I don't know how many times I remodeled plane's fuse insides to get CG right!

Good luck with first flights, she is a beauty!
Jun 03, 2018, 08:56 AM
Retired CAD guy
birdofplay's Avatar
I agree with Springers' comments

From the 3rd Pic in your last post,
It Looks like you could improvise some wiggle room for battery placement ( fore - aft )
Also, The ESC looks lonely and the RX appears to be behind the CG, just a tad.
Jun 03, 2018, 11:39 AM
Build, crash...repeat
AleRRon's Avatar
Thread OP
The battery compartment is on the bottom, in front of the wing LE, as designed. But there is room for the battery up on top instead, near where the C.G. ought to be. Iíll play around with it to see if I can get C.G. at 25% of chord.
Alternatively I may be able to carve a pocket into the foam in the aft portion of the existing battery compartment to move the battery back a bit. But thereís a few things coming up from the center wing spar; servo extensions and the wing-securing rubber band That I have to stay away from.
Jun 03, 2018, 12:01 PM
treefinder
springer's Avatar
Either way will work, of course. I have several planes where I slide the Lipo into the compartment then forward or aft and keep it in position with a piece of foam sponge or block foam. Makes a nice, secure retention


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Piper Pawnee 33% or 40% Piper Cub? behour Fuel Plane Talk 6 Jan 16, 2012 11:38 AM
Help! Moding Kyosho Piper Cheroke Minium omer921 Electric Plane Talk 2 Dec 22, 2010 05:25 PM
Discussion Herr Piper Cheroke set up tips fasteststang 1/2A Planes 2 Apr 27, 2009 07:49 PM
Discussion kyosho cheroke/4ch post your mods b36roxs Scratchbuilt Indoor and Micro Models 6 Dec 24, 2008 11:07 PM
Discussion Piper J-2 Cub vs. Piper J-3 Cub Inverted Schizo Giant Scale Airplanes 9 Jan 16, 2007 04:32 PM