Full size paper Orbital Transport

[gpoehlein]

Well, after seeing the thread on Bob's downscale version of the OT, I figured it was time to try my hand at a full sized version. I decided, however, not to design the whole thing at once. Rather, I decided to lay out and build the orbiter first - if I can't get it to glide there isn't a lot of sense in going forward. We'll see about the mother ship soon. Oh, and this build includes cardstock nose cones and all - the only non-paper parts are going to be the dowel rods.

Any way, I did a layout of the parts for the orbiter and printed them out on 110# cardstock. I've now cut out and done the sub-assemblies (I like to make the tubes, nose cone, and other components so that I have a complete "kit" to build following the instructions). Here is a shot of the components for the orbiter. I've just started assembly and will put up more pics as I get them.

 

[AstronMike]

This is going to be rather cool, especially if you save enough weight overall to get better performance. Now, since the glider itself should be lighter, that would be the ticket. Only thing is that since youre using a paper nose instead of the heavier balsa one you may end up having to add nose weight regardless, or trim with minimal elevon deflection.

Time for a question about cardstock types - how much does a single sheet of so called '65' and '110' weigh? I assume these weights are for a ream, which is 5000 sheets, so I came up with around 2.8 sheets of the 110 per ounce, and around 5 whole sheets for the 65. Are these numbers roughly correct? I have some unidentified stock on hand, but the 'heavy' ones are .4z each and the 'light' ones are still .35z. Seems too heavy for 65 stock...

I want to build a full sized BT80 gliding Bomarc using cardstock for as much as possible, and be able to fly this reasonably on a C6-3. Yea, seems kinda silly, but I believe its possible if I find the lightest stuff with just enough strength to hold up.

I cant wait to hear how well your full size carded OT does! Glider already looks cool with the printed parts.

 

[JRThro]

Time for a question about cardstock types - how much does a single sheet of so called '65' and '110' weigh? I assume these weights are for a ream, which is 5000 sheets, so I came up with around 2.8 sheets of the 110 per ounce, and around 5 whole sheets for the 65. Are these numbers roughly correct? I have some unidentified stock on hand, but the 'heavy' ones are .4z each and the 'light' ones are still .35z. Seems too heavy for 65 stock...

I want to build a full sized BT80 gliding Bomarc using cardstock for as much as possible, and be able to fly this reasonably on a C6-3. Yea, seems kinda silly, but I believe its possible if I find the lightest stuff with just enough strength to hold up.

I cant wait to hear how well your full size carded OT does! Glider already looks cool with the printed parts.

Mike, if this article in Wikipedia (https://en.wikipedia.org/wiki/Card_stock) is right, then 500 sheets of 20" x 26" sheets of 110 lb cardstock weigh 110 lbs. This converts to 4.231e-4 lb/sq. in, or 0.00677 oz./sq. in.

 

[gpoehlein]

I weighed a sheet of 110# cardstock and got 11.6g for the sheet. This works out to 0.0192 g/sq cm or .004376 oz/sq in. The weight comes from stiffening cardboard (gotta have that for the wing cores or they're too flimsy). I'll know after assembly what the orbiter weighs. Of course, since I print the "decals" directly on the cardstock, I do save the weight of most of the paint (just a couple coats of clear to seal the model and make it glossy).

Building a BT-80 sized cardstock Bomarc would be cool, but the larger the tubes get the flimsier they are. As a result, they need more centering rings to maintain their circular cross section. Of course, you could make those centering rings 2.58" outside diameter (cardstock is about .008" thick) and maybe 2.35" inside diameter - it would just become a rib then and would lighten the ring considerably.

 

[BobH48]

Well, after seeing the thread on Bob's downscale version of the OT, I figured it was time to try my hand at a full sized version.

Greg,

I'm looking forward to following this thread.

After doing the downscale based on BT-5, I started making the patterns for a BT-20 sized one to use 18mm motors but not a full size BT-50 model.

I never got around to finishing those patterns so this build might give me the inspiration to finish.

BTW, It's easy to change the color scheme. On my downscale I have the basic red color scheme, a green color scheme and a blue color scheme. I tried to do an orange one but orange is hard to get looking right. I think I like the green the best.

 

[gpoehlein]

Agreed on the color schemes - since I draw up the layouts in Illustrator, it is a piece of cake to select all the red items and change them to another color. I may well do the same with a green one and who know what other color - maybe purple!

 

[hcmbanjo]

Ooooh - go with the purple!
I'm looking forward to this thread.

 

[Trident]

BTW, It's easy to change the color scheme. On my downscale I have the basic red color scheme, a green color scheme and a blue color scheme. I tried to do an orange one but orange is hard to get looking right. I think I like the green the best.

I agree on the choice of green ... check out the link at the bottom of my sig. I've got a green OT, just open the Orbital Transport folder. The upscale is going to be red, since I bought some upscale decals in red years ago. But I'm really much more partial to the OT in green.

 

[AstronMike]

I weighed a sheet of 110# cardstock and got 11.6g for the sheet.

Building a BT-80 sized cardstock Bomarc would be cool, but the larger the tubes get the flimsier they are. As a result, they need more centering rings to maintain their circular cross section. Of course, you could make those centering rings 2.58" outside diameter (cardstock is about .008" thick) and maybe 2.35" inside diameter - it would just become a rib then and would lighten the ring considerably.

That seems to come in at .4z for the standard 8.5x11 sheet, which means that the few sheets of that I have on hard *are* indeed 110lb stock. Too heavy....

Can anyone weigh a sheet of 65lb stock and see if it comes in around .25ish ounces? That would work if not too flimsy.

Since Im figuring the BT80 Bomarc will come in around 3.5z or a tad higher, it will not be subjected to much flight stress. Also, bear in mind that this will use a full length internal pod, and this is what will be providing most of the rigidity for boost. It will butt up against a forward bulkhead at the end of the BT/NC joint. OF course the NC will have to be a rolled paper/cardstock nose.

The C rings and forward bulkhead will be made of Readiboard or perhaps even meat tray foam...gotta save weight. IF this all works out like Im figuring, it should glide like a champ but only after a low and slow boost.

Thanks for your assistance here.

 

[MarkII]

I weighed a sheet of 110# cardstock and got 11.6g for the sheet. This works out to 0.0192 g/sq cm or .004376 oz/sq in. The weight comes from stiffening cardboard (gotta have that for the wing cores or they're too flimsy). I'll know after assembly what the orbiter weighs. Of course, since I print the "decals" directly on the cardstock, I do save the weight of most of the paint (just a couple coats of clear to seal the model and make it glossy).

Building a BT-80 sized cardstock Bomarc would be cool, but the larger the tubes get the flimsier they are. As a result, they need more centering rings to maintain their circular cross section. Of course, you could make those centering rings 2.58" outside diameter (cardstock is about .008" thick) and maybe 2.35" inside diameter - it would just become a rib then and would lighten the ring considerably.

You could also use more than one layer of cardstock for the tube. I wouldn't suggest going all the way to seven layers like I did, but two or three layers ought to give you stiffness that is equivalent to or better than regular BT-80.