CMP Yak .50 build thread.
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From: Warner Robins,
GA
Hey guys.
Now most of you know me as strictly an electric guy...but just to prove that Im not against glow/gas planes. I decided to build a new glow plane.
After looking around the net for a while I wanted to build a .46 powered aerobatic plane. Not necessarily for 3D flying, but for general aerobatics. I wanted something I could fly at local fly-in events, and on the weekends at the field.
Recently we got a Giles from Nitroplanes.com
It works fine. So I liked the look of the yak, and ordered one. Ive heard all the mixed reports and negative comments about the CMP planes, but all of the ones Ive seen so far end up pretty nice birds. There is a swallow here, that flys great. My dad has the giles, and it maidened last weekend. He's got a little tweaking to do, but it also flys great. The yak has been widely reported as being pretty wild, and "snappy". Well Im always up for a challenge.
Im going to keep the plane as stock as possible so that if any of you decide to build one, you'll end up with the same results if you build it like I did.
Right now Nitroplanes.com will give you a $30 off coupon if you write a review on RCuniverse.com
They specifically state...they want it honest...no bull.
Im pretty well known for telling it like it is. I dont pull any punches.
So here goes.
Im going to go step by step showing how I built my yak. Enjoy!!!!
Here's what the plane looks like completed.

Step 1 - Hinging the ailerons.
Pretty straight forward task.. plain CA hinges. No mystery here. Easy to do.
Now most of you know me as strictly an electric guy...but just to prove that Im not against glow/gas planes. I decided to build a new glow plane.
After looking around the net for a while I wanted to build a .46 powered aerobatic plane. Not necessarily for 3D flying, but for general aerobatics. I wanted something I could fly at local fly-in events, and on the weekends at the field.
Recently we got a Giles from Nitroplanes.com
It works fine. So I liked the look of the yak, and ordered one. Ive heard all the mixed reports and negative comments about the CMP planes, but all of the ones Ive seen so far end up pretty nice birds. There is a swallow here, that flys great. My dad has the giles, and it maidened last weekend. He's got a little tweaking to do, but it also flys great. The yak has been widely reported as being pretty wild, and "snappy". Well Im always up for a challenge.
Im going to keep the plane as stock as possible so that if any of you decide to build one, you'll end up with the same results if you build it like I did.
Right now Nitroplanes.com will give you a $30 off coupon if you write a review on RCuniverse.com
They specifically state...they want it honest...no bull.
Im pretty well known for telling it like it is. I dont pull any punches.
So here goes.
Im going to go step by step showing how I built my yak. Enjoy!!!!
Here's what the plane looks like completed.

Step 1 - Hinging the ailerons.
Pretty straight forward task.. plain CA hinges. No mystery here. Easy to do.
#2
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From: Warner Robins,
GA
I tend to jump around, and not follow the instruction steps exactly.
I dont have the servo's and equipment for the yak yet, so Im gonna dart past some of the steps and get them later.
Step 2 - Installing the elevator.
The slot is already cut into the fiberglass fuselage for the elevator. All you have to do is remove a little covering, line everything up and epoxy in place.
First measure the entire elevator. Find center, and using a t-square, draw a line down the center of the elevator.
Now measure the front and back of the fuselage slot.
Transfer it over to the elevator, and cut away the covering. Really easy, and if done correctly, the covering will match up exactly to the plane.
Now the last pic is a dry fit. Not applying epoxy just yet.
I dont have the servo's and equipment for the yak yet, so Im gonna dart past some of the steps and get them later.
Step 2 - Installing the elevator.
The slot is already cut into the fiberglass fuselage for the elevator. All you have to do is remove a little covering, line everything up and epoxy in place.
First measure the entire elevator. Find center, and using a t-square, draw a line down the center of the elevator.
Now measure the front and back of the fuselage slot.
Transfer it over to the elevator, and cut away the covering. Really easy, and if done correctly, the covering will match up exactly to the plane.
Now the last pic is a dry fit. Not applying epoxy just yet.
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From: Warner Robins,
GA
Step 3 - Installing the Rudder
First you have to slot the fuselage. The slots are not pre-cut in the fuselage, so you'll have to cut them. The back of the fuselage is balsa which makes cutting the hinge slots easy.
The manual tells you to install the tail wheel at this time. I plan on using a different tail wheel assembly out of preference, so I skipped this section. The manual shows how to install the stock tailwheel and is pretty self-explanitory. So basically cut the slots and use CA hinges to install the rudder.
On my model the counterbalance on top of the rudder required some trimming to make it fit correctly. It was too large.
First you have to slot the fuselage. The slots are not pre-cut in the fuselage, so you'll have to cut them. The back of the fuselage is balsa which makes cutting the hinge slots easy.
The manual tells you to install the tail wheel at this time. I plan on using a different tail wheel assembly out of preference, so I skipped this section. The manual shows how to install the stock tailwheel and is pretty self-explanitory. So basically cut the slots and use CA hinges to install the rudder.
On my model the counterbalance on top of the rudder required some trimming to make it fit correctly. It was too large.
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From: Warner Robins,
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Step 3 - Installing the wings
In reality, there isnt much to do here, but it is a critical part. The holes for the anti rotation/incidence pins are already drilled in the wings, but not in the fuselage. The fuselage has little molded divots where the holes are "supposed" to be drilled. DONT USE THEM!!!! They are close, but not dead on accurate. I found them to be up to 1/16" off. If you use them, most likely you will end up with one wing at a different angle...which equals....rolling tendancy and never tracks right. Since you cant re-drill the holes in a fiberglass fuselage...you'd better get it right the first time.
Here is how I did it.
First install the pins into the wings. Make sure when you epoxy them into place that they are EXACTLY 90 degrees to the wing root. You may have to trim the holes to get the pin to set just right.
Next take the little eye screws and using a dremel, cut them so that it forms a hook. If you dont do this, you cant get the spring on later.
Epoxy EVERYTHING in place...including the eye screws.
Now measure and draw a line directly down the exact center of the wing root on the fuselage. Slide the wing tube into the fuselage, and slide the wing onto the tube. Line everything up, and mark the fuselage where the pins are. Then drill the holes in the fuselage. Check, double check, and triple check everything...if you screw this up...your hosed.
Once everything is drilled out, then attach the wings, and install the spring. Check everything for alignment.
In reality, there isnt much to do here, but it is a critical part. The holes for the anti rotation/incidence pins are already drilled in the wings, but not in the fuselage. The fuselage has little molded divots where the holes are "supposed" to be drilled. DONT USE THEM!!!! They are close, but not dead on accurate. I found them to be up to 1/16" off. If you use them, most likely you will end up with one wing at a different angle...which equals....rolling tendancy and never tracks right. Since you cant re-drill the holes in a fiberglass fuselage...you'd better get it right the first time.
Here is how I did it.
First install the pins into the wings. Make sure when you epoxy them into place that they are EXACTLY 90 degrees to the wing root. You may have to trim the holes to get the pin to set just right.
Next take the little eye screws and using a dremel, cut them so that it forms a hook. If you dont do this, you cant get the spring on later.
Epoxy EVERYTHING in place...including the eye screws.
Now measure and draw a line directly down the exact center of the wing root on the fuselage. Slide the wing tube into the fuselage, and slide the wing onto the tube. Line everything up, and mark the fuselage where the pins are. Then drill the holes in the fuselage. Check, double check, and triple check everything...if you screw this up...your hosed.
Once everything is drilled out, then attach the wings, and install the spring. Check everything for alignment.
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From: thiruvananthapuramna, INDIA
i have purchased a cmp yak 50 as my first aerobatic model. going to build the same with a os 46AX powering the same. will post some pictures soon.




