Sky Ranger 40 : Old School Model Works

[Zetoyoc]

My wife is trying to keep me occupied I think. After the success of my first balsa build, I started looking into more kits to build. She suggested I make a list of kits I liked and before long I found a new kit she had ordered for me in the mail. A Sky Ranger 40 from Old School Model Works.

I am quite impressed with the packaging and quality of parts. Everything was in a separate sealed bag and taped down to the inside of the sturdy box to prevent movement and damage. It worked. Everything looked great. And when I unrolled the slightly flattened plans I saw it was a bit bigger than I had thought it was going to be. This 60" plane will be the biggest plane I have made of any kind. Exciting.



I did have one small problem, My workspace was a disaster.



Now motivated to clean it, it took some time but it finally turned into something more useful

 

[OliverW]

My wife is trying to keep me occupied I think. After the success of my first balsa build, I started looking into more kits to build. She suggested I make a list of kits I liked and before long I found a new kit she had ordered for me in the mail. A Sky Ranger 40 from Old School Model Works.

I am quite impressed with the packaging and quality of parts. Everything was in a separate sealed bag and taped down to the inside of the sturdy box to prevent movement and damage. It worked. Everything looked great. And when I unrolled the slightly flattened plans I saw it was a bit bigger than I had thought it was going to be. This 60" plane will be the biggest plane I have made of any kind. Exciting.

View attachment 175123 View attachment 175124 View attachment 175125 View attachment 175126

I did have one small problem, My workspace was a disaster.

View attachment 175128

Now motivated to clean it, it took some time but it finally turned into something more useful

View attachment 175129

I look forward to seeing your progress! I really like how the sky ranger looks

 

[Zetoyoc]

Step one. Read the instructions. All of them. Not something I usually do actually, but there were so many more steps in this kit than the last plane I built so I figured, why not. ok, I admit, I only got through the first 1/3 of it. I wanted to start.

The wing goes together in a very different way than I expected. Good thing I at least read that far. It is built from tip to root attaching the sheer webs to the ribs then putting them to the spar. OH, before that I was to make the wingtips. I actually made both at the same time so id be sure to have two different ones when I got to the second wing



Then I decided to dry-fit most of the wing and was troubled by things not lining up with the plan. Every rib I put in was a 1/16th nearer to the previous one than the plans expected. I am fairly certain I put it together correctly. not much really to mess up and any mistake I could imagine would have made the spacing bigger not smaller. So I finished out the dry buildup of the first wing and it is about 1/2in shorter than the plans.


wingtip root

At this point, I consulted the smarter of the household, my wife. She suggested I contact the kit maker. I did and was surprised to get an immediate answer via message and I completely forgot at that point that it was Sunday and he was probably not at work and I probably annoyed him with my inundation of measurements and photos. oops. But he was most gracious and I should have an answer when he is actually at work lol.

in all likelihood, both wings are off by the same amount and I suspect the drawing more than the laser cut parts. but it was a new problem for me and why not wait for a knowledgable answer. I guess ill wait for that answer and get back to the build later. now ill probably have to do chores or something to keep busy

-J

 

[Zetoyoc]

I look forward to seeing your progress! I really like how the sky ranger looks

I like it a lot as well. I spent some time today trying out a few different covering schemes on the blank plane template they provide on their site. Quite handy. It also kept me away from the dishes for a while longer..

 

[speedbirdted]

Wait, so you're saying that if I get married I can get free kits? Damn, might have to look into that!

I have not assembled one personally but I've heard some problems about there being some fitment issues with OSMW kits, particularly early production runs. Though, I'm quite surprised by the methodology of building that wing. On every wing I've ever built that needed shear webbing, I usually had all the spars installed before making preparations to put them in. Furthermore it isn't exactly necessary from a structural standpoint to have the edges of the shear webbing butt up exactly to the wing ribs - by nature all shear webbing does is convert a set of two spars into an I-beam. This helps to transfer load between the two spars, as in almost all cases the one in compression fails first. The glue joints on the spars and webbing, if you use something like thin CA, are more than strong enough to do this and them being in contact with the ribs is not required. If there's nothing else stopping you, such as the leading and/or trailing edge pieces having notches in them so the wing keys together easier, I would say place the ribs in accordance with the plans and have the shear webs have some gaps. What is strange though is that on the OSMW website, the naked sky ranger they have on display there has no appreciable gaps in the shear webbing, but then again it would only be about 1/32 on each side so maybe I'm just too blind to see them.

What will you power this with? I saw one a while ago with a YS 63 on it and the guy did all sorts of fun stuff with it. Of course a decent 40 2 cycle would sound terribleprobably be perfectly enough power, though in the age of throttles power is never something you can have too much of Or there's always electric...

 

[Zetoyoc]

Wait, so you're saying that if I get married I can get free kits? Damn, might have to look into that!

I have not assembled one personally but I've heard some problems about there being some fitment issues with OSMW kits, particularly early production runs. Though, I'm quite surprised by the methodology of building that wing. On every wing I've ever built that needed shear webbing, I usually had all the spars installed before making preparations to put them in. Furthermore it isn't exactly necessary from a structural standpoint to have the edges of the shear webbing butt up exactly to the wing ribs - by nature all shear webbing does is convert a set of two spars into an I-beam. This helps to transfer load between the two spars, as in almost all cases the one in compression fails first. The glue joints on the spars and webbing, if you use something like thin CA, are more than strong enough to do this and them being in contact with the ribs is not required. If there's nothing else stopping you, such as the leading and/or trailing edge pieces having notches in them so the wing keys together easier, I would say place the ribs in accordance with the plans and have the shear webs have some gaps. What is strange though is that on the OSMW website, the naked sky ranger they have on display there has no appreciable gaps in the shear webbing, but then again it would only be about 1/32 on each side so maybe I'm just too blind to see them.

What will you power this with? I saw one a while ago with a YS 63 on it and the guy did all sorts of fun stuff with it. Of course a decent 40 2 cycle would sound terribleprobably be perfectly enough power, though in the age of throttles power is never something you can have too much of Or there's always electric...

The way I understand it. The build method they use is thier web lock method? Anyway the idea I think is that by gluing the sheer webs which key into the rib , to the rib first is that you ensure a square buildup. It seems to work. I'll know more about the spacing issue soon. But suspect I can build it a number of ways and have it all turn out fine.
For the power... I have a few glow motors laying around but I have never flown anything but electric. Granted the saito fa50 4 stroke I have would sound good. I was considering about 1000w of electricity. Maybe a 4250 on 5s or somewhere in that ballpark. I am sure I'll get some encouragement to fly the nitro motor from some others. So who knows

 

[TooJung2Die]

I'm watching this! It's most likely the plans being off. I've come across several errors in drawings and had to make corrections. Fortunately for most laser cut kits you don't need full size plans because the parts are cut accurately. A straight line to build along is often enough.

 

[FoamyDM]

great write-up so far. Keep us informed.

 

[speedbirdted]

A 1000w motor is like extreme overkill but I guess you could do it. You'd be looking at like 200+ watts/pound The FA50 will probably fly it fine. I have a Cub that weights like 6.5 pounds and has a foot of wingspan on this, and it flies pretty happily on a crappy ASP 52 which I'm pretty sure has less power. Built right, this will have a similar wing loading.

 

[Zetoyoc]

A 1000w motor is like extreme overkill but I guess you could do it. You'd be looking at like 200+ watts/pound The FA50 will probably fly it fine. I have a Cub that weights like 6.5 pounds and has a foot of wingspan on this, and it flies pretty happily on a crappy ASP 52 which I'm pretty sure has less power. Built right, this will have a similar wing loading.

I have to admit it was near 3am when I wrote that and I did look at 1000w motors. But the setup I listed turns out to be only about 800w which is actually the minimum suggested but the maker. I was looking for at least a 1:1 thrust to weight ratio based on an assumed final weight. Id like to use this to start learning a few more aerobatic maneuvers and wanted a bit of panic power reserve , you know, just in case

 

[Zetoyoc]

Distractions will sure sneak up on you if you let them.

I can't wait to get back to this build. It will be soon. My issue with the rib spacing was resolved several days ago. I just got distracted with a bunch of flying and sorting through piles of plane parts and bits I found at a sale a few days ago.
I have to say it was quite refreshing to get a nearly instant response from the kit manufacture with help for my questions and concerns. I have only started this build but can say I am impressed with both the kit and the service from Old School Model Works.

-J

 

[BATTLEAXE]

Distractions will sure sneak up on you if you let them.

I can't wait to get back to this build. It will be soon. My issue with the rib spacing was resolved several days ago. I just got distracted with a bunch of flying and sorting through piles of plane parts and bits I found at a sale a few days ago.
I have to say it was quite refreshing to get a nearly instant response from the kit manufacture with help for my questions and concerns. I have only started this build but can say I am impressed with both the kit and the service from Old School Model Works.

-J

This is going to look awesome and I cant wait to see you fly it. Are you thinking of a transparent covering or a solid?

So jealous of your collection

 

[Zetoyoc]

Progress has been made. I have most of half of a wing done It has gone together fairly well so far. There is a bit more to do and consider with this model than my last one. I think I'll move on to the second wing half before I finish this first one. Mainly I am left with the shaping of the leading and trailing edges and plan to use a plane but I should probably sharpen the blade on it and I am procrastinating that job

 

[speedbirdted]

A technique I learned for shaping wing leading/trailing edges is to cut a "negative" for the leading edge shape out of hardwood then coat the inside of it with sandpaper, which will then sand the leading edge to a constant shape. Typically you only need one, making more with finer and finer grits of sandpaper is not useful as this sanding can be done by hand with paper or blocks.

 

[TooJung2Die]

That's a sturdy looking wing construction.

 

[BATTLEAXE]

A technique I learned for shaping wing leading/trailing edges is to cut a "negative" for the leading edge shape out of hardwood then coat the inside of it with sandpaper, which will then sand the leading edge to a constant shape. Typically you only need one, making more with finer and finer grits of sandpaper is not useful as this sanding can be done by hand with paper or blocks.

Man that is brilliant, would never have thought of that. Yet it is probably a balsa hobby standard which for the most part I know nothing of. Buy it does totally make sense to just make a form of the shape you want and run that.

I really want a balsa more and more now

 

[speedbirdted]

I really want a balsa more and more now

In my mind, it's a perfectly reasonable excuse to drain your bank account

 

[BATTLEAXE]

perfectly reasonable excuse to drain your bank account

No opposition here

 

[Zetoyoc]

A technique I learned for shaping wing leading/trailing edges is to cut a "negative" for the leading edge shape out of hardwood then coat the inside of it with sandpaper, which will then sand the leading edge to a constant shape. Typically you only need one, making more with finer and finer grits of sandpaper is not useful as this sanding can be done by hand with paper or blocks.

That is a good idea. I have used that on other projects but hadn't thought to apply it here.

In my mind, it's a perfectly reasonable excuse to drain your bank account

I may be addicted already. I have only completed one balsa plane so far. but already have a few other kits either on the shelf waiting. or in the mail on the way. not to mention several estate sales partial or crashed planes I have now to fix and refurbish. I am not sure what ill do with all the leftover foam board I have now lol

 

[Zetoyoc]

Both wing halves are now mostly done. Really not much to show. They look almost the same so pictures would be a bit redundant. I do have a bit more sanding and shaping to do and hope to join the two tomorrow. I did have to wet the trailing edge balsa and weight it down overnight to try to straighten it. It is made from laminating two thinner sticks together and I missed the bow in it. My attempt seems to have worked.


I am really looking forward to working on the fuse. Anything but wings. Good thing it wasn't a biplane this time