KSP Community CubeSat

[MBobrik]

Or, for a more professional (And complicated) option, SolidWorks.

It's free like sketchup ?

[Newt]

Well, about Solidworks, though I am sure it is a valuable tool, it looses out to Sketchup in the vital area of cost. And it is easier to learn than other free 3d software (Blender for instance), albeit more basic. (Anything, is better than drawing in MS paint:rolleyes:).

As for price, the value I cited may have also included the cost of labor, which we are not dealing with here, and other similar cubesats may also circumvent with volunteers. And placeholders certainly make the total cost value a number to eye carefully. It will change very much in the future.

About the computer, the Raspberry Pi is not going to be on all the time, and mostly will deal with data transmission and gathering, won't it? It will remain off most of the time, so power concerns about it can be limited.

MBobrik: I think that the URL's for spreadsheets that you linked need to be switched.

[MBobrik]

MBobrik: I think that the URL's for spreadsheets that you linked need to be switched.

What's wrong with them ?

[Newt]

The torquer sheet comes after the weight volume title, and vice versa.

[Nicholander]

I just download SketchUp and made a model of our CubeSat:

Is there anything I forgot to add to it?

Edited December 14, 2014 by Nicholander

[Newt]

That looks like sketchup to me, Nicholander.

Do you mean of all the things decided, or all the things needed? I would say your model need to have batteries, maneuvering control of some sort, solar panels, et cetera. But, I guess it has the essence of the design as I know it. (Opening a new scene in Blender).

[Nicholander]

*Facepalm* Sorry, I meant to put SketchUp. Anyway, I'll add those things and then show you.

[Nicholander]

I tried it again, missing anything?

[Newt]

That looks mostly fine to me. Are you basing it on actual proportions or general guesses?

I threw together a quick Blender model based on your image, but I guess that I need an imgur account or something to that effect to post pictures here.

[Nicholander]

Guesses, actually. But I did make it a 10 Cm Cube, and the Solar Panels are 10 Cm x 10 Cm too.

[MrOnak]

I tried it again, missing anything?

http://i.imgur.com/38qH1yt.png

- The comms equipment is virtually on the opposing side from the antenna. While certainly not impossible you can simplify the overall design if you get those two closer together.

- you'll need to heat at least the moss and the batteries - place them so that they share a wall with the heating element in between.

- with all electronics in one half of the satellite and the other half being mostly air, meeting the centre-of-mass requirements of the spec might become tricky. Same due to the batteries being far out.

- are you not using magnetorquer rods? Shape looks unusual

- having the magnetorquer so close to your electronics might cause problems on the latter, but this is a guess

Edited December 14, 2014 by MrOnak

[deljr15]

As for modeling of the cube I have a full Solidworks Professional seat that includes simulation. I am willing to make models for our components.

Example item available from CubeSat Shop.

I see some problems with this design and some nice bits. The launcher interface would be nice to copy. The pads coming off the bottom and top have me puzzled. Maybe to separate the various cubes. I need to find the standards for cubesat frames to know for sure.

After posting I found this link:

http://2.cubesat.org/images/developers/cds_rev13_final.pdf

I will be reading thru this for a bit.

I have an idea in my head for the experiment indexing mechanism that I want to get drawn up. It has been a busy week at work.

Anyway my services are available. And if we go the Solidworks option. Their may only be a small handful of us that can edit, but anyone can download the eDrawing Viewer from Solidworks and view measure and spin any Solidworks model

Edited December 14, 2014 by deljr15
Added link

[Nicholander]

- The comms equipment is virtually on the opposing side from the antenna. While certainly not impossible you can simplify the overall design if you get those two closer together.

- you'll need to heat at least the moss and the batteries - place them so that they share a wall with the heating element in between.

- with all electronics in one half of the satellite and the other half being mostly air, meeting the centre-of-mass requirements of the spec might become tricky. Same due to the batteries being far out.

- are you not using magnetorquer rods? Shape looks unusual

- having the magnetorquer so close to your electronics might cause problems on the latter, but this is a guess

1. Okay, I guess I can change that, but it has to be below the Moss Monitoring equipment, which has to be below the moss.

2. Wait, how is that possible to do? If I add a new heating component, it can't be connected to the moss, because it can only be on the bottom, and the Moss Monitoring Equipment is there! But it can be next to the batteries.

3. Okay, I guess I can do something about that, but the Moss has to be on the top.

4. I didn't know how a magnetorquer looked like, sorry.

5. Well, if that's true, there's nothing that can be done anyway, I mean, the whole thing is jam-packed with electronics!

deljr15, great! That SolidWorks stuff will help, good!

[dharak1]

Th magnetorquer would take up a bit of space on each of at least three walls all on different axes so that it could rotate the X, Y and Z of the cubesat if I'm imagining right because quite a while ago K^2 said we would line the edges of the frame with the coils giving us 3 10x10 cm coils.

[Newt]

We should probably be somewhat easy on Nicholander; this would seem to be his first ever model in this software, and it was put together pretty quickly. But it is helpful to look at nonetheless. It really is such a small space that the magnetorquer needs to be either up against the computer or the cameras or the radio or all of them really, 10cm^3 is tiny.

I have been wondering about the heating system. Might not the computers/magnetorquer not only heat up the satellite, but bake it if we are not careful? I am uncertain that we will need something specific to keep the thing warm, considering the hardware we have already. We might really need to be looking for where to put the radiators.

[MBobrik]

Anyway my services are available. And if we go the Solidworks option. Their may only be a small handful of us that can edit, but anyone can download the eDrawing Viewer from Solidworks and view measure and spin any Solidworks model

It needs not be either-or. I am reasonably sure Solidworks can import at least some formats Sketchup can export, and vice versa. So anyone could make his component in Sketchup, and then we would integrate it together in Solidworks.

I have an idea in my head for the experiment indexing mechanism that I want to get drawn up.

Me too. Curious about your idea.

[Newt]

It needs not be either-or. I am reasonably sure Solidworks can import at least some formats Sketchup can export, and vice versa. So anyone could make his component in Sketchup, and then we would integrate it together in Solidworks..

No it does not. It is to me looking as though we may well be able to transfer files between Sketchup, Solidworks, and Blender (which I use). We just need to test it and see.

Edited December 14, 2014 by Newt
sepling, si fidicutl

[Darthwahl]

Hello everyone, Wow, I'm surprised I have not come across this thread until now. I have been interested in working on a Cubesat project since the beginning of the program, and I feel there is real possibility here with this group of dedicated folk. As far as what I can bring to the table:

-Solidworks Modeling

-3D Printing (Mainly SLS Nylon, which would be most useful for this project)

-Basic electrical engineering knowledge

-Years of experience in designing and working with 3D printed components for aerospace

There is more info on my background and capabilities on my Linkedin profile https://www.linkedin.com/pub/hunter-wahl/9a/230/b38 and my design portfolio http://www.coroflot.com/HunterWahl/portfolio

I am willing to donate time and resources into the initial design phase in order to prep the project for it's crowd-funding phase. This is really exciting! Let's get it into space!

[MrOnak]

First of all @Nicholander & @Newt: I wasn't attaching Nicholander and sorry if my post came across like I did. Having a 3d sketch is helpful to find flaws. I was merely pointing some of those out. The sketch will very likely go through dozens of iterations while hardware is being decided on so changing the sketch is inevitable.

1. Okay, I guess I can change that, but it has to be below the Moss Monitoring equipment, which has to be below the moss.

2. Wait, how is that possible to do? If I add a new heating component, it can't be connected to the moss, because it can only be on the bottom, and the Moss Monitoring Equipment is there! But it can be next to the batteries.

3. Okay, I guess I can do something about that, but the Moss has to be on the top.

These three sound like the moss has to be on one end of the satellite? why is that? I'm guessing to maximize the artificial gravity? Well my point is, heaters take space, mass and use up precious electricity. Having two on board is something I'm not sure you can afford. Even more so since you have high demands on the spin rate, indicating a lot of power going to the magnetorquers.

4. I didn't know how a magnetorquer looked like, sorry.

They come in all sorts of shape actually. one even roughly fits the box shape that you sketched: http://www.cubesatshop.com/index.php?page=shop.product_details&flypage=flypage.tpl&product_id=102&category_id=7&option=com_virtuemart&Itemid=69&vmcchk=1&Itemid=69

Despite its looks its a full 3-axis control system.

You also get solar panels with integrated torquers (clyde-space and others) and the "classic" torque rod http://cubesatshop.com/index.php?page=shop.product_details&flypage=flypage.tpl&product_id=75&category_id=7&option=com_virtuemart&Itemid=69

5. Well, if that's true, there's nothing that can be done anyway, I mean, the whole thing is jam-packed with electronics!

Erm... according to the sketch it is 50% full of air actually. But as said I didn't do the math whether the magnets would actually disturb the controllers. If the moss chamber will be round as in the sketch then the corners might have enough space for torquerods.

I have been wondering about the heating system. Might not the computers/magnetorquer not only heat up the satellite, but bake it if we are not careful? I am uncertain that we will need something specific to keep the thing warm, considering the hardware we have already. We might really need to be looking for where to put the radiators.

If your microcontrollers heat the whole satellite you're in trouble. They won't get warm. The thing is, most off-the-shelf electronics is specified to work between -40°C and +85°C, give or take. Since your sat is spinning you most likely won' exceed the +85°C. But you very possibly might dip below -40°C.

The batteries don't like to be below freezing, that makes heating them during the night cycle pretty much mandatory unless you're constantly drawing so much power that they keep themselves warm.

Since you want to study the growth of moss I'd assume that it helps with growth if it is kept above freezing as well but I'm clueless about biology so I'll leave that to others .

Bottom line (by gut feeling only!) is I wouldn't worry about radiators until thermal modelling indicates you need them.

The pads coming off the bottom and top have me puzzled. Maybe to separate the various cubes. I need to find the standards for cubesat frames to know for sure.

First they prevent scratching / destroying the solar panels when the cubesats are stacked inside the P-POD.

Second, two of the bottom pads typically have springs to separate the CubeSats from each other after leaving the P-POD.

Third, at least one of the other two is required to have a switch that disables the sat when pressed down, to prevent the sat from "doing things" in the time between pulling the remove-before-flight pin and being pushed out of the P-POD.

The solidworks model is great by the way! are the panels individual pieces by any chance? I'm wondering whether its possible to export them as individual .stl files for 3d printing.

Edited December 15, 2014 by MrOnak

[vetrox]

Oh wow! How have I missed this!!!!! I would love to help but the only skill I really have for a project like this is the ability to weld XD

You guys need to get a website sorted for this sort of project if you guys are serious (Im only on like page 20 so far) so people can donate and get updates XD

[Newt]

Solidworks is looking, to me, to be the best option; there would appear to be several formats that we can import and export between (I am not certain of all of their capabilities) between the different software we have been discussing, but importantly, we have access to simulations, through delijr15, above and beyond what we otherwise would have access to. That alone, might be reason to go that route, for those simulations will be likely very valuable in analyzing our satellite's behavior, and thus designing it better. If we can edit it in other software, that would be great, but I think the access to those simulations should be paramount.

Greetings DarthWahl and Vetrox! Glad to have you onboard.

[deljr15]

I took some time at lunch today to sketch up the indexer mechanism. Here are some photos.

More shots with it placed in the "CubeSat Shop" frame

The hole indexer has a estimated mass of 14g without samples. The main body is 6061 (aluminum) with brass bushings and a 1045 (steel) sleeve to be hardened.

I still need to add the mount and drive.

Another note the sample "Bubbles" are there for concept. We also will need some grommets on the holes. When we have a decided sample container I will update.

Second Edit: The "Bubbles" are 3cm in dia

Edit: As usual all files are available on my server. Message for login

Edited December 16, 2014 by deljr15

[MrOnak]

I really like that design! Simple, light, and probably doable without lubricants, which is kind of important.

Its probably even possible to extend the part of the axle that goes toward the wall such that you can fit a heater and the batteries behind the dishes. Again, that way you'd help balancing and heat up both things that need heating the most with a single heater.

What I mean with balancing: If I remember correctly the center of mass must be within 3cm of the center of volume. By putting the battery outside helps counter-weighting (is that a word?) the electronics that might be on the other opposing wall.

Edited December 15, 2014 by MrOnak

[Nicholander]

Good model deljr15! How often will you be able to have access with SolidWorks? (Or was that made in SketchUp?) Anyway, I'l try to revise my SketchUp model again, I'll tell you the results.

[deljr15]

Good model deljr15! How often will you be able to have access with SolidWorks? (Or was that made in SketchUp?) Anyway, I'l try to revise my SketchUp model again, I'll tell you the results.

That was in Solidworks. Mon-Fri I can work at lunch and or stay late. One of these days ill get it set up at home.

Edit: There is more I want to respond to but it will have to wait until tonight when I get home

Edited December 15, 2014 by deljr15