KAM Aero Extra 300KK

[Dwight Macdonald]

http://kam-aero.com/specs-pricing/

This is my new psychotherapy tool ... to deal with COVID, winter ...

[Dwight Macdonald]

Actually the project started in the summer, when I noticed someone had the engine that I wanted to try on my next airplane for sale.

[Dwight Macdonald]

I built a test stand to be sure the engine is OK before getting the airplane kit.

[Dwight Macdonald]

https://youtu.be/OUQxAVtC4E8

Smooth as a sewing machine and quiet as a mouse! Just like the guy I bought if from said.

https://www.toni-clark.com/ftp/VM210Anleitung_en.pdf

[briankizner]

Impressive looking plane and motor. Hope to see it fly.

[Mezri]

Very Nice engine Dwight, :)

[Sempai-mj]

Nice plane & Engine, Looks like the test stand might take off if you rev the engine. :D

[AlixB]

Superb Dwight! I just love the song of that engine! No electric motor can ever replace that!
Congrats! I hope one day to see you fly that plane! Cheers!

[Xavier]

http://kam-aero.com/specs-pricing/

This is my new psychotherapy tool ... to deal with COVID, winter ...

You must be really sick :D:D:D
Nice plane and nice sound. I saw 2 of these planes fly in 2019 and they look great in the air. They both had a 4 cylinder so the sound was impressive too.
Looking forward to see yours.

Xavier

[Xavier]

I just went thru the Kam-Aero website and this page in particular is very interesting. http://kam-aero.com/design-rationale/ I have been thinking of designing my own Imac plane for a long time because most of the ones available are too much 3D oriented and heavy, especially the smaller ones around 80in/2m. This one seems to be well designed for precision flying. You will be a happy guy for sure :-)

[Jdonald]

Very quiet. I noticed what looks like valve covers. Stihl made an engine for bush trimmers that had a 4 stroke engine but lubricated the same as a 2 stroke called the 4 mix engine. Your engine appears to be of this design if I am correct.

[Dougf]

Hey Dwight, engine sounds amazing, should be a great combo with the plane. Look forward to seeing you fly it this summer. Are you going aluminum or carbon fiber on the gear? Hope you enjoy the build!

[Dwight Macdonald]

Thanks guys. Hopefully, it will be finished for this summer ... but that may be only a dream.

[Dwight Macdonald]

I just went thru the Kam-Aero website and this page in particular is very interesting. http://kam-aero.com/design-rationale/ I have been thinking of designing my own Imac plane for a long time because most of the ones available are too much 3D oriented and heavy, especially the smaller ones around 80in/2m. This one seems to be well designed for precision flying. You will be a happy guy for sure :-)

Yes Xavier, I'm hoping it will fly as advertised ... especially with the non-conventional engine. At least it should sound good.

[Dwight Macdonald]

Very quiet. I noticed what looks like valve covers. Stihl made an engine for bush trimmers that had a 4 stroke engine but lubricated the same as a 2 stroke called the 4 mix engine. Your engine appears to be of this design if I am correct.

Yes, it is lubricated like a 2 stroke with oil in the fuel, and also like the 4-stroke glow engines. A small container, containing absorbent material, is attached to the crankcase ventilation to catch the oil that sprays out.

[Dwight Macdonald]

Hey Dwight, engine sounds amazing, should be a great combo with the plane. Look forward to seeing you fly it this summer. Are you going aluminum or carbon fiber on the gear? Hope you enjoy the build!

I chose the carbon fiber gear option.

[Dwight Macdonald]

The kit comes in 5 boxes. 1. wood; 2. canopy, fiberglass parts (pants, cowel), gear; 3 and 4. foam wing cores; 5. tail and fuse foam cores

[Dwight Macdonald]

They recommend 3 degrees right and 1 degrees down thrust, so I made plywood blocks to accommodate this. The firewall and motorbox also needed some modification to accommodate the carburetor and intake pipes.

[Dwight Macdonald]

The motorbox is well designed with tabs that lock it together so it comes out nice and square and strong.

[Dwight Macdonald]

When I glued the first joints I used the other parts dry-fit in to hold it square.

[Dwight Macdonald]

The hardwood blocks will make the firewall more solid.

[Mezri]

Very clean job Dwight, ...At this step of the building I understand that you need to percevere to get it for this summer :D...
Very impressive;)

[Ian]

The hardwood blocks will make the firewall more solid.

Awesome start to your project Dwight.... and I thought you bought that engine as a fan installed on a bench to keep us warm in the summer :)

All joking aside, I'll be following your project with eagerness.

One question, when you build the mounting blocks for the engine, do you install soft mounts or vibration isolators? I was wondering about this, I thought I read somewhere that when you go 4-stroke or higher engine displacements (>60cu.in.), isn't the airframe structure absorbing more impulse / impact vibration?

[Dougf]

They recommend 3 degrees right and 1 degrees down thrust, so I made plywood blocks to accommodate this. The firewall and motorbox also needed some modification to accommodate the carburetor and intake pipes.

Hi Dwight,
Thanks for the great photos showing your build process. Couple of questions:
What are you using to cut your hardwood? Is it a band saw? Also are the thrust angle blocks planed to the right taper or just two different thicknesses and shimmed if needed...couldn't tell from the photo with the engine installed. I have a scroll saw that is hard to cut straight lines with, was thinking of upgrading to a band saw, hence the first question. Thanks Doug

[Dwight Macdonald]

Awesome start to your project Dwight.... and I thought you bought that engine as a fan installed on a bench to keep us warm in the summer :)

All joking aside, I'll be following your project with eagerness.

One question, when you build the mounting blocks for the engine, do you install soft mounts or vibration isolators? I was wondering about this, I thought I read somewhere that when you go 4-stroke or higher engine displacements (>60cu.in.), isn't the airframe structure absorbing more impulse / impact vibration?

The engine instructions recommend mounting it directly on the firewall or with the metal standoffs they provide. It is supposed to give very low vibration if mounted solidly.

[Dwight Macdonald]

Hi Dwight,
Thanks for the great photos showing your build process. Couple of questions:
What are you using to cut your hardwood? Is it a band saw? Also are the thrust angle blocks planed to the right taper or just two different thicknesses and shimmed if needed...couldn't tell from the photo with the engine installed. I have a scroll saw that is hard to cut straight lines with, was thinking of upgrading to a band saw, hence the first question. Thanks Doug

I use a compound mitre saw for all my straight accurate cuts. I find it very tight and accurate. It needs some help to hold small pieces of material though. I use a guide block and double-sided carpet tape to hold the small pieces. For rough, curved cutting I use a scroll saw.

[Dwight Macdonald]

The landing gear plate is supported with oak rails that are glued and screwed in.

[Dwight Macdonald]

The side formers are also plywood.

[Dwight Macdonald]

Need to reinforce the structure where firewall and center tray were cut to make room for the intake system.

[Dwight Macdonald]

Try not to add too much weight.

[Michael O'Bree]

No doubt another masterpiece in the making - thanks for sharing, Dwight.

[Dwight Macdonald]

I'm very behind on my posting!

[Dwight Macdonald]

The muffler with the "Y" apparently gives more power because the alternating exhaust from each cylinder helps the flow of the other.

[Dwight Macdonald]

The parts will need to be silver soldered together.

[Dwight Macdonald]

The Y exhaust system is slightly heavier.

[Dwight Macdonald]

The fuselage sides are built next.

[Dwight Macdonald]

The sides are covered with 1/8 balsa.

[Dwight Macdonald]

The pieces of 1/8 sheet are glued together with carpenters glue. The frame is glued to the sheeting with thick CA.

[Mezri]

WOW...Very Nice progression ...Thanks for the photos

[Michael O'Bree]

Looking good, Dwight.

I hope we see it fly at WIMAC before the City decides to put a walking trail through the middle of our runway :unhappy:

[Florin]

This airplane is huge. I can't wait to see it in the air!

[pauldaigle]

Hope it is STAL looks a bit big for the runway at WIMAC :D

[Dwight Macdonald]

Thanks guys. It's a bit bigger than my Extra 330 that I fly these days, but similar weight ... so it should be no problem to land and takeoff at WIMAC. It will have a nicer, more scale, sound.

[Dwight Macdonald]

This completes the wood frame part. The rest is all foam covered with balsa.

[Andrew Fernie]

Interesting perspective in the photo. It makes your Extra 330 in the background look like a little toy!

[Dwight Macdonald]

The next step is to cover the foam parts with 1/6 balsa using West System epoxy. The 4' x 4" sheets are edge glued with carpenters glue then sanded. The sanded sheet is sprayed with hair spray, sanded lightly and the process repeated. The hair spray seals the wood so the epoxy doesn't soak in to keep the weight down. The wood is then coated with a thin coat of epoxy, spread with a key-card. The epoxy-coated balsa sheet is held in place against the foam part with a couple pieces of masking tape, some toilet paper is placed around the whole thing for air flow and it is placed in a vacuum bag inside the shuck with some weight on top. The pump is set to pull about 7" of vacuum overnight.

[Dwight Macdonald]

The edges will be trimmed and sanded later to fit with the other parts.

[Mezri]

Super Shape...Interesting, the vaccume...Very good result...I need to play with it in the future builds...Thanks for the Photos.

[Dwight Macdonald]

As usual, I'm behind on my posting ...
This is the last foam part on the fuse.

[Dwight Macdonald]

There will be a lot of trimming around the landing gear area.

[Dwight Macdonald]

This is the fin and rudder. They will be cut apart later.

[Mezri]

Taking shape...Very Nice:)

[Dwight Macdonald]

I installed the stab tubes with 30 min epoxy, but should have use gorilla glue because the epoxy cured too fast.

[Dwight Macdonald]

The servo mounting system was installed with gorilla glue.

[Dwight Macdonald]

The balsa skins are prepared.

[Dwight Macdonald]

The skins are laminated onto the foam as before.

[Dwight Macdonald]

The wings are done similarly.

[Dwight Macdonald]

Two servos per aileron.

[Dwight Macdonald]

Important to keep the wing flat while gluing the parts imbedded in the foam. My pictures are not quite in order. A temporary strip of balsa is added to the leading and trailing edge prior to balsa skin vacuum bagging to prevent crushing the foam edges.

[Dwight Macdonald]

I weighed the pieces of balsa for the wing sheeting so the stronger more dense wood is in the center where the wing tube is.

[Dwight Macdonald]

The balsa sheeting pieces are only 48" long so an extension is required at the wing tips.

[Dwight Macdonald]

Fiberglass cloth is added to reinforce the wing beyond the end of the wing tube. It is nice to have slow curing epoxy for lengthy lamination step.

[briankizner]

Beautiful work. With all the ready to fly planes these days, we don’t often see craftsmanship.
……And it looks like old fashioned encyclopedias still have a purpose.

[Dwight Macdonald]

Thanks guys!

A trial fit of the wings and stabs makes it look more like a plane. Some alignment is necessary prior to gluing the wing and stab tube sleeves.

[Dwight Macdonald]

Installing the wing roots.

This is actually where I am with the build now.

[Mezri]

Toujours un Plaisir de voir des photos de l'évolution d un projet ...Merci Dwight.:)
Always a pleasure to see pictures of the evolution of the project...Thanks Dwight.:)

[Dwight Macdonald]

The build season is back! Time to catch up with my posting ... trimming the wing roots.

[Dwight Macdonald]

Wing leading and trailing edges.

[Michael O'Bree]

Always fascinating to follow...thanks for sharing.

Pace yourself though, unless you plan to start another project....who knows when we will finally announce the end of "the pandemic" :eek:

[Mezri]

Very Nice :smile:

[Dwight Macdonald]

Thanks guys!

Razor plane and sanding block are used to trim the excess from the wing leading and trailing edges. I round the leading edge later, after the final alignment of the wing and stabs in their fuselage mounts.

[Dwight Macdonald]

The stabs are attached by tabs on the ply roots. Hard points are installed on the fuse so the tabs will have a solid place to bolt onto.

[Michael O'Bree]

So Dwight, how did you find time to read at least 20 volumes of The American Peoples Encyclopedia ? ;)

[briankizner]

Most people think encyclopedias are useless in the internet age. Congratulations to Dwight for proving them wrong.

[Dwight Macdonald]

Nothing like turning a model build into an academic project!

[Dwight Macdonald]

The incidence of the stabs are set and an alignment pin is installed.

[Dwight Macdonald]

The rudder is cut away from the fin, edges are sanded true and the balsa hinge lines are glued on.

[Dwight Macdonald]

The hinge holes are drilled with a template and the angles are planed and sanded.

[briankizner]

Going to be a beautiful airplane.

[Dwight Macdonald]

The forward bottom deck is cut out to make room for the landing gear plate.

[Dwight Macdonald]

Before attaching the balsa laminated foam parts to the wood frame, I decided to paint the surfaces in the engine and muffler area to prevent oil from soaking into the wood. To keep all the vapor and paint overspray out of my workshop, I made small paint booth ventilated with a fan exhausting out through an unused wood stove chimney. The paint booth will also be useful when I paint the cowl, wheel pants and area around the canopy.

[Dwight Macdonald]

The foam parts are glued on with Gorilla glue.

[Dwight Macdonald]

I should have covered the entire seam with masking tape to prevent the Gorilla glue from foaming out ... it would have saved some sanding.

[Dwight Macdonald]

The front of the fuse is capped off with 1/4" balsa.

[briankizner]

Meticulous work

[Mezri]

Very Nice...Thank You For the Photos

[Dwight Macdonald]

Next is capping the bottom of the rudder and fitting the turtle deck around the fin.

[Dwight Macdonald]

The turtledeck is glued in place with Gorilla glue.

[Dwight Macdonald]

Trial fitting the hatch parts and the cowl.

[Mezri]

Very nice...going better...I think Its a good satisfaction when you have rudder and stab. glued in place (correctly :D)...
Congratulations:)

[pauldaigle]

The guy should have been a dentist :-)

[Dwight Macdonald]

Working on the hatch.

[Dwight Macdonald]

Glassing the hatch front to strengthen the area at the front of the canopy.

[Dwight Macdonald]

This post should have been before the last one.

The canopy is glued on with structural epoxy.

[Dwight Macdonald]

The cowl is glued to the ply mounting rings with structural epoxy.

[Dwight Macdonald]

The exhaust pipe on the left side will need to be shortened before I silver solder them together, because it is touching the cowl.

Finally, my posts are now up to date! This is where I am actually with the build ... not sure if it will fly this summer ... possibly in the fall ...

[Dwight Macdonald]

Some baffles are added to direct the airflow for better cooling.

[Dwight Macdonald]

The stabs in the shucks are marked for cutting of the elevators at the hinge lines. The stabs are rough cut with a hacksaw blade then sanded accurately using a jig system.

[Dwight Macdonald]

The ailerons are done similarly. Balsa is then glued on the accurately sanded surfaces with Gorilla glue. The balsa is then planed and sanded flush to the wing surface.

[Dwight Macdonald]

The hinge line balsa blocks are glued on square then bevelled later.

[Mezri]

Very Nice to see the project back :)

[Dwight Macdonald]

The edges of the balsa blocks are trimmed and sanded flush. The hinge pin holes are drilled with a guide jig.

[Dwight Macdonald]

The hinge blocks are beveled using a jig system.

[Dwight Macdonald]

The ends are capped with 1/8" balsa and trimmed.

[Dwight Macdonald]

Lots of end capping.

[Dwight Macdonald]

The balsa sheeting is removed to expose the servo mounts.

[Dwight Macdonald]

The control horns mounts are installed using plywood and dowels

[Dwight Macdonald]

The control horns and servos are test fitted. The hinges will be glued after the covering is done.

This is actually where I am now, working on the servo and control horn mounts. The covering and fiberglass parts painting will be next. I will need to decide on a color pattern soon. The covering material was purchased a while ago.

:)

[Dwight Macdonald]

For the covering, I marked the line edges with pieces of tape then used tracing paper to get the curved parts identical on each side.

[Dwight Macdonald]

Also getting the wheel pants and cowl ready for painting.

[Dwight Macdonald]

Finishing around the muffler area before covering.

[Dwight Macdonald]

Monokote time!

[Xavier]

It looks great Dwight. It is motivating to see your work. I have a few projects I should get back to. Thanks for posting.

[Mezri]

Very Nice, looks like a multicolour covering...Interesting to see technics...never did that.

[Dwight Macdonald]

The colors are overlapped about 1/4"

[Dwight Macdonald]

The next step will be to paint the fiberglass parts.

[Dwight Macdonald]

I used color match car paint ... slightly expensive ...

[Dwight Macdonald]

Lots of masking tape.

[Dwight Macdonald]

Can anyone guess where I am copying the color scheme from ... with one color change from something else to red?

[Dwight Macdonald]

This is about where it is now at.