ROGOZARSKI IK-3 SP-400 size By Warbirdkits.com - RC Groups
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Dec 31, 2011, 05:08 PM
Big gov never Works
St. Martin's Avatar
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ROGOZARSKI IK-3 SP-400 size By Warbirdkits.com


Tom @ warbirdkits, just never seems to run out of obscure designs, to come up with. The IK-3 is on the more conventional side, looking like a cross between a Hurricane and a P-40-ish. It was a partial "rag", like the Hurricane.

WS- 33'10", LOA- 27'5", WA 179sq', 920hp Hispano-Suiza V-12

That puts the model at about 1" scale, with a WS of 34" and 179sq".

As with all of Toms kit's, this is a short kit. All Lazer cut parts, molded canopy and plastic cowl, inc. Bottom wing skins are provided. Full size plans are not req to build. Bottom skins are lazer marked for rib, spar placement. I suspect the Charlie Bice is still doing the lazer work. The quality shows.

I'm doing a step by step build thread. There is no manual at this time, as it is the proto kit. So far only one discrepency has shown up. And Tom will be notified. But a simple one at that.

For power I will be using a Tower Pro 2408-21. This swings a 9-4.5 SF at around 12A, for 130W consumed on a 3s 910Mah pack. More than enough power, as the AUW should be well under 16oz.

Tome sent me decals for a Slavic version. I found a colorful version of what a captured German version would look like. I think it will help in orientation. Very helpful on a camo painted warbird. And Tom has agreed to supply me with those decals. Decals supplied were of pressure sensitive mylar. I have no idea if Tom will supply these with the kit. But markings are always available on his site: http://warbirdkits.com/downloads.html For personal use only.

OK...I'll list the steps numbered to match the numbered pics.

Fuzz

(1) Bottom wing skins are in (3) pieces each side. Match the parts L&R

(2) Tape skins on seams

(3) Use these to make top skins from 1/16x3" balsa(not supplied) Note: Make left and right. And be sure to make the skins 3/16" wider at the leading edge, to compensate for the top curvature.

(4) Use aliphatic resin to adhere the panels to each other. Sep w/wax paper W

(5)Weight down till cured. (I used a piece of 3/16" glass)

(6) remove tape and sand panels. Concentrate more on the outer surface. Mark theinside surface of the top panels. Fine block sanding now, will eliminate sanding later, and the subsiquent starved horse look.

(7) Dry assemble W-2 and W-6 to the spar, and pin in place on the bottom skins. (cover work surface w/wax paper) Add remaining ribs. NOTE: W-1 is angled by spar for dihedral.

(8) Use a sliver of balsa to raise skin up to rib bottom, @ LE. CA all ribs, but avoid ail spar area. Add false LE.

(9) Remove ribs sections for ail spars.

(10) Cut (6) bearing from either 1/16" alum tube, or inner Nyrod(shown). Form torque rod assembly from 1/16" MW, 3 bearings each assembly, 3/8" long.

(11) Use a razor as a spacer to cut ribs for torque rod bearings.

(12) Cut ail spars from scrap sheet. Install TE, and torque rod assembly. Pre-notch ail LE to accept torque assembly. Add block for torque spur. Spars are seperated by T-Pins, to form a gap. This gap must match ail cut marks on bottom sheeting. Trim ribs if neccessary.

(13) No step 13...I'm superstitious. Proceed to #14

(14) Add balsa stabilizer block around torque rod, at root. Wing is then sanded to accept top sheeting. Bottom TE is tapered to almost a fine thickness. Torque bearings are med CA'd to ribs.

(15) Tack glue wash-out guage to bottom of wing. Wide part is in-board, just inside W-2. And recessed 1/2" from TE. Short guage is for under wing tip.

(16) Skins are attached using aliphatic on all ribs and spars. With the exception of the TE and false LE, which uses thick CA. Then the whole panel is weighted with sand bags.

(17) After cure, trim all sheeting with sanding block. Add 1/4" sht LE.

(18) Blend LE into surrounding wing surface. DO NOT ROUND YET

(19) Wing tip parts, (6) WT's have two blanks that have the grain in the opposite direction. Each tip consists of (3). And each odd grained WT is in the center of the assembly.

(20) Med CA wing tips in place on flat surface. NOTE: Do Not glue tip to aileron.

(21) Round LE, wing tips. Besure to match each LE in shape. On small models, different shapes can make for a funny flight...

(22) Use a T-Pin to tranfer the cut limes from the bottom sheeting to the top. Then join lines with a marker. Cut ailerons free with a brand new razor. #11 exacto's do not work well here.

(23) Mark and sand bevel in ail LE.

(24) Cut CA hinges into 3/16" wide pieces. Thats all that is needed. And, full hinges will make for a stiff function.

(25) Temp install hinges and check for smooth operatiom. Sand clearances on ail ends if necc.

(26) Cut ail servo pocket.

(27, 28) Joining the wing panels. One wing panel is flat. The other is raised 1" at the center of the wing tip. I used Gorrilla whit PU glue, to joine the panels. Centersection will be glassed later.

(28, 29, 30) While that was curing, I assembled the below wing Glycol cooler. Does a reasonable simulation. I like the grill. Lazer cutting makes a lot of things doable. I tapered the inside rear edge, to better give the look of sheet metal.

The fuselage is well along. I'll post tomorrow when done. Amazing... I started on this 5:00am this morning. A pretty fast build. I will be using silkspan and lacquer for the base finish.

Fuzz
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Jan 01, 2012, 06:10 AM
Registerd Beaver
Smokin' Beaver's Avatar
Sub'd. What an ineresting plane - looks a bit like Dewoitine 520 to me.
Nice one Tom, where did the inspiration come from?

Phil
Jan 01, 2012, 07:00 AM
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danrc's Avatar
Subbing in!
Jan 01, 2012, 07:25 AM
Big gov never Works
St. Martin's Avatar
Hi guy's, your right Phil, it does look like a Dewoitine. I'm liking the looks of this, more and more. Like to have one big enough for retracts. The wing is quite thick, in the wheel area. And make it fabric/built-up in the rear. All I would need is the plans blown up and ribs, and make a stick/bulkhead fuselage.

Fuzz
Jan 01, 2012, 07:36 AM
Registered User
JIMA's Avatar
I give up. What nationality was this airplane?

Jim
Jan 01, 2012, 01:04 PM
Big gov never Works
St. Martin's Avatar
Yugoslavia,Jim.
Jan 01, 2012, 04:03 PM
Cajun-American
Boogie_'s Avatar
Cool little bird Fuzz. ...and Tom.

Quote:
I used Gorrilla white PU glue, to join the panels.
I love this stuff.
Since I've started using this glue I've just about given up on epoxy for high stress glue joints, and very lite compared to epoxy.
There is a learning curve to using it so it don't make a mess though.


J
Jan 01, 2012, 05:07 PM
Big gov never Works
St. Martin's Avatar
Your absolutely correct, Julian. I only use the amber for skinning cores, because of the working time. The white goes much faster and with less expansion. Here's a tip tho...if you can, wrap the joint with masking tape, such as the wing joint. Just remove the tape after about 30min. It sticks to tape well.

Well..I did not get to work as long on the IK-3 today. Only thing leftis to install the elevator pushrod and finish sheeting the top aft fuselage. I need to edit the instructions and pics sequence. Just to late tonite to do it all.

But the hatch came out real nice. Will save time in batt access. But F-3 is in the way for that operation. So, I will have to remove the F-3 cross member, after adding a few cross member supports.

Fuzz
Jan 01, 2012, 06:13 PM
Manzano Laser Works
TomJacoby's Avatar
Quote:
Originally Posted by Smokin' Beaver
Sub'd. What an ineresting plane - looks a bit like Dewoitine 520 to me.
Nice one Tom, where did the inspiration come from?

Phil
Hi Phil,

The profile appears to be very close to a Hurricane.

Inspiration? I like the unusual, and this one certainly fits that description! This history of this aircraft and the Royal Jugoslavian Air Force at the outbreak of WWII are pretty interesting. I think they only had a half-dozen in flyable condition to hold off the entire might of the Luftwaffe!

Tom
www.warbirdkits.com
Jan 01, 2012, 06:17 PM
Manzano Laser Works
TomJacoby's Avatar
Quote:
Originally Posted by St. Martin

(10) Cut (6) bearing from either 1/16" alum tube, or inner Nyrod(shown). Form torque rod assembly from 1/16" MW, 3 bearings each assembly, 3/8" long.

Fuzz
I got lazy and just built in a real cheap, light servo in each wing panel. Probably doesn't weigh much more than the single servo plus torque rod setup...

-tom
Jan 01, 2012, 06:21 PM
Registered User
JIMA's Avatar
Very interesting. I did not know Yugoslavia had an air force much less one with some original designs. Thanks for the info Fuzz.

Jim
Jan 01, 2012, 06:24 PM
Manzano Laser Works
TomJacoby's Avatar
Quote:
Originally Posted by St. Martin
So far only one discrepency has shown up.
Fuzz
Was it the radiator?

Today (New Year's Day) I sanded the wing assembly for my IK-3. I'm a sloooow builder, so you'll probably have yours done before I get much more done.

The cowl will need to have the lower air scoop cut in. It's tough to see in the photos and drawings online, so I will add a sketch of the scoop to the plans.

Info about the Rogozarski IK-3 here: http://en.wikipedia.org/wiki/Rogo%C5%BEarski_IK-3

-t
Jan 01, 2012, 06:29 PM
Registered User
JIMA's Avatar
It looks unusual with a rather small fin and rudder. Cool project. I like to see lesser known airplanes. You can only build so many P51s and P-40s before they become boring. Ok maybe not the P-40s. LOL.

JIm
Jan 01, 2012, 08:02 PM
Registered User
D-Rock's Avatar
Wow, what a cool unusual model! Looking forward to seeing this one shape up.

D-Rock
Jan 01, 2012, 09:22 PM
Registered User
nice, I like s400 warbirds. Rogozarski looks like mix Hurricane and MS 406


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