Howdy folks....

I'm building this Carden 40% for John Wondra.... He was good enough at Tucson to walk away with a kit! Thanks to Carden for donating the prizes too!

Many of you may know me as the 3D Foamy guy.... I've been just enjoying flying and family since JohnVH bought the business, and also doing alot of building. I'm doing it for hire in my free time.... so If you like what you see here, let your friends know.

So on with the build!

First of all.... This is a community build. I REALLY want to hear from you if you have a cool idea for a change, or a better way to do it. This is the first Carden I have built.... so please type away!

First Impressions.... I love the simplicity of the Carden kit. They lack any laser or CNC cutting, but that frees up my creativity to "kit Bash" as we used to call it. I calipered each part to redraw in cad for the lightning holes.... and was VERY surprised that the precut plywood parts commonly measured to the tune of 7.0005 and 9.001, and 3.0000.... I was very impressed at that. so even though it lacks the burned signature of a laser... Dennis is the man when it comes to table saws!

I build on a custom building table that has 16 jack screws on the bottom to get everything perfectly level. I made a custom set of aluminum jigs that are bolted to the table with 1/4-20 bolts to align the top and bottom of the stick sides. They all get aligned over the plans with an aluminum level and locked in place. Both sides end up exactly the same this way.


There are going to be some really cool stuff going on in this build.... I've got a long list of upgrades and mods that are gonna get pullout out. It's an all out bling airplane for John. He's working hard to take on Kyle Wyoshnis this year in IMAC...

All the vertical 3/8" sticks come precut to length... this makes it go pretty fast. These are all glued in place with good ole "Non CA" Each one gets squared up to the top stringer with the cut down yellow quick square.

I protect the plans with a sheet of thick mylar before I start building... Works well cause the glue doesn't stick!

Nothing like a good joint....

I moved the forward stick back to sandwich the wing rotation pin plate. I also drilled them out for the custom wing pins/bolts you'll see later on.

NOTE: You should move the rear stick forward.... I messed up here. The F-3 Former needs to get bonded to the front stick... I had to add a vertical 3/8" Sq to the end of that to get a glue surface. I just gained 6 grams!!!!

Both sides get the cross bracing sanded to shape, glued in, then sheeted with the 1/8" balsa. I tack glue the 2 sides together and do the final edge sanding on the sheeting so they match perfectly.

Lots of sheeting on this baby... Nice thing is that Dennis edge trues all the sheeting in the kits. I simply taped the pieces together and used white wood glue to edge join. A few longer parts like the bottom deck and wings get butt joints to extend the 48" sheeting. I alternate these, so that its like a brick wall, instead of a solid break in the sheeting all in one place.

Iv'e had sheeting crack when getting it around the tighter corners... so I edge glue it early on, wet the outside and weight it down in the shucks to "Mold" the balsa to shape before final glueing. It will sit for a week or so... and end up dry.

My trusty helper assists in weighing each sheet on the gram scale....

I match all the sheeting up to the application. Decks and hatches get the light stuff. Stabs and vertical gets the next step up, and the wings get the most dense (read strongest)

Above and beyond that, I separate the stab and wing sheeting into 2 separate matched stacks... so that the right and left halves are with in a gram of each other....

the lightest sheets were 18g for the 48x4x1/16 stock and the heaviest are 29 grams

The most common complaint about the Cardens are their weight.... 40+ is the going rate if you don't take time to build light.

John is what we call a "3D ****" so minimum weight is a necessity. We fly at 500-2500 above MSL... so were not going to take it to the extreme end of lightened up.... but close. LOL... if you only know what is in store.

John tends to need a hangar rash friendly airframe.... so were keeping the skins solid on the sides, stabs, and wings. This could have saved about 10 oz if they were cut away like Ivan Christensen does.... but then it invites objects to poke through that pretty covering.

In the quest to save weight, internal structure has to be drastically lightened up. The kit has solid aircraft ply (read strong, but heavy) for all the formers, plates and motor box structure. I drew all the parts in CAD to do the layout of the holes.... Then paper templates are 3M77'd (lightly) to the wood and it's all cut out by hand. The corners get radiuses with a forstner bit, then the "dots" get connected on the scroll saw. Everything gets a light sanding and the process starts over on the next part.

The motor box sides alone were taken from 23 oz down to 10.5 oz with the cuts shown in the pics. I still have to finish cutting the rest of the box parts out.... well worth the time and effort! Waynr G. and Ivan C. have 300+ and 100+ flights on Cardens with the same basic cutout setup... and then some more on the fuse sides.... defiantly a strong plane!

My trusty helper is always doing quality check for me..... she says I "boodin an a-pain daddy"

And this is what another hour on the scroll saw gets you....

I drew the coutouts up in CAD and can share the .PDF file with anyone wanting to make their building a little easier.... just PM me with your e-mail address and I'll send it off. it's on a 36x36 sheet that Kinkos will print for a couple bucks.

I Feel the end of the scroll sawing nearing!!!!

At last the lightning is complete..... Some light sanding on the parts and assembly can start.

I should mention that I talked to Dennis today. (What a great guy!)

We discussed the lightning holes that have been made similar to mine.... His blessings are on them, with some conditions.... to make a long discussion typable... If you are rough on your planes... AKA, still working on that landing thing... or like to do a hard harrier land.... you may be at a higher risk to a fracture in the motor box area... so added awareness in pre and post flight checks need to be made.

John is an EXCELENT pilot, and lands on the numbers (smoothly) consistently... so we have no issues with the slight loss in "crash resistance"

Because the weight savings are well worth it!

Proofs in the pudding.... or on the scale.

There is 27oz of wood on that scale. All from the motor box and the formers. Yes it takes some time... but I just made up for a set of cans.... "free of charge" in the weight department.

In case you missed it on the above post....

I'm all about sharing the love... so if you want the .PDF for these motor cutouts... send me a PM with your e-mail address. Thay are all on a single 36x36 sheet printable at Kinkos.

One last comment about the motor box lightning....

The hole are designed to be used only with cans... Reason being that there will be a mid plate that spans the entire length of the motor box from F-4 to F-1. This plate forms the tunnel for the cans. This adds alot of structural integrity back to the box as well as tensional rigidity. I would leave at least another 1/2" of material on the cutouts if using mufflers with no plate.