hllywdb

I figuered this would be the place to post this one as most of us have owned at least one or a few Kaos planes in the 60 or 40 size, maybe even the smaller 1/2A ones too. I haven't seen any 25 size Kaos planes which is surprising as it is a great size to toss into the car for a quick trip to the field, or for me, finding a space to tuck it in next to the trainers to give me something to sneak in a quick flight in between training sessions.

I couldn't find any 25 size info out there, so I ended up scaling down a 60 size Kaos, or at least that was the plan. When scaling down you end up with a lot of odd sizes on things like spars, LE, TE, etc.. Plus I didn't see a need for 20 ribs on a 25 size plane. So I ended up re-drawing most of it from scratch. Since it is such a classic design, I stayed with all other scale dimensions including airfoils. I also stayed with Joe's 2 peice leading edge and sheeted trailing edge. Some things need to be respected.

I went back and forth between a 42" and 45" wing size and decided to scale it to 42" which would give a great flyer with a 25LA and all the performance you could want with a hot 25 and a pipe. I plan to keep adjusting the plans as I build and work out any bugs that come up, but am including a jpg of the 1st set of plans.

I got all parts laser cut and started by sanding the ribs, laying them out, gluing the spar doublers and gluing the ply landing block doublers on.

hllywdb

Since the TE is tapered from the root to the tip, I needed to measue and slice it first, then sanded it down to final size. Since it is sheeted over, it is not super critical.

doxilia

My Feedback: (3)

Bill,

fun thread and nice job on the plans. In recent years there has been some interest in smaller versions of the classics. I have been very keen on them.

At 42" and a 25 engine you'll have a little rocket on your hands! I suspect that if built light, it could even fly nicely on a hot 15. One of the old OS FP 20's or a 21 might also do nicely.

I built (but haven't quite finished) a 40" Deception (recently active thread) which I expect will be overpowered with a ST G23 but there is no pudding nor proof as of yet...

I look forward to your build,

David.

hllywdb

Thanks Dave,
I love the classics as well. I recently finished a 30" Dr Jekyll with a Norvel 061 and a 36" Integral with a 074 Norvel over in the 1/2A forum.

On to the build. I added building tabs to 3 ribs on each side as long as I was re-drawing anyway. The tabs are on the top of the ribs as I am building the wing flat upside down.

Once the 3 tabed ribs are in first, I glued in the LE and TE to get them aligned correctly.

hllywdb

Next I added the rest of the ribs after trimming them to fit and glued them in place.

Once dry I fit and glued in the top (bottom) spar.

At this point the airfoil looks so fat compared to all the thin airoils I've been building lately!

R_G

My Feedback: (1)

Very COOL, hllywdb! This should be fun! [sm=thumbs_up.gif]

Nice job on the plans! What software package do you use?

RG

hllywdb

Thanks RG,

I have an old version of Turbo Cad, and just downloaded the new DraftSight, but I drew this one up in Illustrator and exported as a CAD file.

I epoxied the landing gear block in and then cut the front sheeting glued down the front edge.

doxilia

My Feedback: (3)

Hey Bill,

I have a set of plans that I drew in Illustrator (CS5) and would like to have them laser cut. I have exported as a regular DXF file but I discovered that things like line color and certain objects are distorted (e.g., circular or oval cutouts) into multi-faceted shapes (e.g., pentagons). Any suggestions on how to go about the export to obtain a proper file?

TIA, David.

hllywdb

Hi David,
My first guess is a version compatibility issue in CS5. I always save mine all the wqay back to Illustrator 3 format before exporting. This should resolve the compatibility issues between CS and DXF.

doxilia

My Feedback: (3)

Bill,

Thanks, I'll give that a shot. It appears also that the line weight needs to be sufficiently large (e.g., 0.25 pt) in order for color information to be retained in the export. I was asked to set the line weight at 0.003 pt as I suspect this is the laser width. If I keep lines at that weight, all exports show up as white on black.

But enough on that and back to your build thread.

Thanks again, David.

hllywdb

Hi David,
.25 should be fine, I have had issues with wood burning a bit at .75 but it gives it a more antiqued look for the older style planes

hllywdb

Next step was to finish glueing the front sheet. The 1/16 was still a bit stiff even after wetting it with hot water, so I needed to clamp and weight the straight edge down to get a good hold.

AndyKunz

David,

Ask your cutter what he uses to drive the laser. Some use laser etchers and prefer the drawing in Corel or Illustrator, while others use engineering-level lasers and they work off DXF/DWG files. I have a friend in Canada who uses an etching-type laser to cut parts for boats. E-mail me if you need to know how to contact him.

Andy

doxilia

My Feedback: (3)

Hey Andy,

I've been in an email nightmare for a month or so (all systems down type of thing) and haven't gotten a chance to reply to your email.

I'm actually discussing with the very person you mention (Derek). He's been great and we were set to have a cut done last February but one thing led to another and I didn't get around to finishing. Things are actually now finally done and he's waiting for lumber to arrive to cut the kit.

As you say, I believe he uses Corel to produce the final file for the laser. My plans and files are in Illustrator which I keep getting better at especially with the new bells & whistles in recent versions (CS5). Illustrator can export DWG/DXF files with various options but the export is not intelligent when it comes to vector shapes such as circles and ovals. Unless these are multi-point objects (i.e., essentially non vectors), they export as octagons. Interestingly, things like airfoils and other curves don't pose a problem. In any event, he has a working file now so I should have some kits at the door sometime in the near future!

David.

AndyKunz

Glad to hear you got it resolved. Dereck is an OK guy.

Andy

hllywdb

Hey David,
Did you ever finish the Deception build? It looked gorgeous so far. Don't make me get this in the air before yours

On with the build. Finished sheeting the bottom of the wing and added the cap strips. Then flipped it over and added the servo rails in between the ribs. Being ADHD I have the other half going already. If only CA didn't take so long to dry!

doxilia

My Feedback: (3)

Hi Bill,

well at my present stalled pace, you probably will get yours done before I do. I should be able to get back in the shop in a couple of weeks or so. I have 4 smaller models on the bench including a Super Pacer, the Deception and a Mystic that all need to be finished. This doesn't include a Tipo and a Calypso which are in similar stages... I guess I won't be starting anything new this winter.[]

Keep up the good work!

David.

P.S. In a month's time you will be having fun with your K25 in the air while I will be shoveling snow off my front porch. Still, the sun is shining today.

hllywdb

I used to live in the north east David, just leave the gear off and land in the snow.[8D]

Onward. I added the shear webs. None for the first rib as I am using a full width dhiedral brace with the holes drilled for the wing dowels.

Then glued down the front of the top sheeting. I also altered the plan again and added a lite ply dowel brace up against the inside of the LE. Maybe it's overkill but with the thin 2 piece LE a bit of reinforcement can't hurt.

JeffH

My Feedback: (43)

You should offer a laser short kit of this

hllywdb

Hi Jeff,
Have to see how it flies first[8D]

But it may make sense as I think David may be right, it will probably fly great with a hot 15, an FP20 or LA 25 or even an FS 30, and really smoke with a hot 25 which would make it quite versital and a classic to boot. Having that big a range of power plants makes it work for anything from a 1st low wing, to aerobatic fun plane, or an all out barn burner. We really do have a lot of engines available to us right now that would work.

hllywdb

Finished the sheeting on the 1st wing half. Added a little filler (just mixed some alpha glue with micro ballons) Still need to make the wing tip blocks and add the 2nd LE piece after a bit of trimming and sanding. I'm out of balsa blocks so I will need to make another trip to the LHS.

Updated plans copy too.

hllywdb

Ok,
Got the front leading edge glued on. I like 2 piece leading edges, it just makes the sheeting/LE transition so much smoother and easier to build straight.

Here is a close up of how the LE is put together, you lap the sheeting over the 1st piece then trim/sand even. Then the 2nd piece overlaps it all.

I then traced out the tip outline on the balsa block for the wing tip. I see lots of shaping and sanding in my near future!

As long as I'm on the build, I have to give some credit to kdubose from this group for working with me on the planning stage of this one. It's great to bounce stuff off someone else when you start drawing and planning. Thanks Kirt!

AndyKunz

My son's 42" Gulfstream (a little less draggy than a Kaos) has been clocked at 100 MPH on the straight and level, and it's heavy (32 oz) with an E-Flite Six Series motor spinning a 7x5.

A 25 up front on a 42" Kaos, even a half-dead one, will be overkill!

Good thing throttle is on a stick instead of a toggle switch! You're gonna need it!

Andy

hllywdb

Andy,
Are you insinuating that with my Norvel 25 on a tuned pipe I need to make extra sure I get good adhesion on the covering?

doxilia

My Feedback: (3)

I have to agree with Andy's assessment.

I think a 25 or anything larger would be overkill on 42". A 4 stroke 30 would be interesting but probably too heavy - reason for which those small 4s engines were by enlarge discontinued. Having said that, the weight of a ST G23 is essentially the same as a ST G15 (power plant options for the 40" span Deception). I plan to use the 23 on a muffler on a 36 oz model (ideally - we'll see about that).

David (Rainedave) built a 66% UFO (43.5" span) for which he was considering a piped Enya X25. He later decided that it was bringing up the wing loading too much and fell back to a lighter HB 21. His thread is here:

http://www.rcuniverse.com/forum/m_8860320/tm.htm

I wish he was around to finish his build. I feel that the ideal engines for the Kaos 42" are light and in the 15 to 21 size range. An old vintage 23 such as the ST G23 would probably also be OK. A hot ST X21 would make it ballistic but then again so would a Cox Conquest 15 or the infamous Rossi 15 RE pylon engines (throttle questionable on engines like this). Then there is also the K&B 18 Aero which I believe is still in production. Manufacturer claims 1.15 HP on a pipe with 30% fuel.

Marian used a hot RE HP 15 (if I recall correctly) on a 15 sized 42" span 40 oz Peppermint Pattie. His thread is here:

http://www.rcuniverse.com/forum/m_7663424/tm.htm

David