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Work-in-Progress [WIP] Design Thread


GusTurbo

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Damn, I was just building a DC-3.. it's propellers don't freewheel, unfortunately.

And it's part count is 190+....

http://i.imgur.com/9lghbZI.jpg

Don't use Elevons on your props, use the flat rectangular antennae, the elevons do all sorts of horrible things to drag and your flight profile, I just got another 10ms out of the Wellington by swapping them. Also if you have CoM/CoL problems don't put wings inside, instead clip in a non-functional jet engine and move it around to change your CoM lots less drag and control problems.

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Hey columbia I have a DC3 replica that you can borrow for inspiration, here http://forum.kerbalspaceprogram.com/threads/130451-Dc-3

Ah, thanks Yukon!

Don't use Elevons on your props, use the flat rectangular antennae, the elevons do all sorts of horrible things to drag and your flight profile, I just got another 10ms out of the Wellington by swapping them. Also if you have CoM/CoL problems don't put wings inside, instead clip in a non-functional jet engine and move it around to change your CoM lots less drag and control problems.

Aww, the elevons looked better. :( Ah well, I'll try the antennae. And I guess the DC-3 is already too fast for it's own good..

Also, I've yet to try that CoM/CoL thing, but if i did, it would hinder the performance of the aircraft instead of slightly making it better. I'll give that a try.

- - - Updated - - -

Oh lord, I'm approaching 1,000 posts! I need to release a craft, quick!

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Thanks to Flipnascar for help with the bearing, decided to go a different direction. I wanted a bearing for the freewheeling props that moved faster and was more durable (sometimes you do make extreme manoeuvres even in a bomber). I have half, sorry about the Youtube vid for 15.5 seconds.

It weighs about a ton with 43 parts, but it can take high g manoeuvres but is even slower than Flipnascars.

Happy to see you got your own working... But uh one ton up the front?!?! Craft file? It seems more complicated? You can strengthen mine by adding more parts (cube struts - as an aside I really wish Squad would add circular cube struts as a stock part....). Another round of 8 radially attached cube struts and its tighter than a duck's bum. Can handle more G than the test aircraft can pull.

Oh also, yours is likely slower because it has all the extra mass. From the looks of it the fairing bases and all that are part of the prop assembly and it's just the nosewheels that are attached to the main aircraft? If you can keep the mass minimal there (the prop shaft), you'll have more luck with getting it to spin. For comparison, my entire assembly - including the trussing, weighs according to Engineer Report 0.2t, according to KER 168kg and 34 parts (for the low speed low-g variant). For the high-G, it's more parts, haven't found the definitive point at which you can stop adding struts. So that one ends up at most around 70ish parts.

Alternatively you can add the reaction wheel. I tried it with my assembly, one reaction wheel didn't make enough of an impact and then you're going down the road of needing to provide power etc etc

You can alternatively try building the prop assembly into a fairing. Have it all inside, and then you just attach a cube strut or octo strut (or anything) and offset it and the piece it connects to so that there is a gap between them that allows the fairing to pass through it. If you then support the assembly inside properly you could have an even more robust prop. But, you'll be adding to the part count like crazy, and sometimes getting it to work can be a bit finicky... And then your friend the heating bug comes along. But it will look much much cleaner than the way you've done it, and the way I've done it.

There's more info and pics on fairing bearings here.

Apologies if I'm teaching you to suck eggs, and if it comes across as completely critical. It's not meant that way, more just open up discussion to find different techniques for this.

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Happy to see you got your own working... But uh one ton up the front?!?! Craft file? It seems more complicated? You can strengthen mine by adding more parts (cube struts - as an aside I really wish Squad would add circular cube struts as a stock part....). Another round of 8 radially attached cube struts and its tighter than a duck's bum. Can handle more G than the test aircraft can pull.

Oh also, yours is likely slower because it has all the extra mass. From the looks of it the fairing bases and all that are part of the prop assembly and it's just the nosewheels that are attached to the main aircraft? If you can keep the mass minimal there (the prop shaft), you'll have more luck with getting it to spin. For comparison, my entire assembly - including the trussing, weighs according to Engineer Report 0.2t, according to KER 168kg and 34 parts (for the low speed low-g variant). For the high-G, it's more parts, haven't found the definitive point at which you can stop adding struts. So that one ends up at most around 70ish parts.

Alternatively you can add the reaction wheel. I tried it with my assembly, one reaction wheel didn't make enough of an impact and then you're going down the road of needing to provide power etc etc

You can alternatively try building the prop assembly into a fairing. Have it all inside, and then you just attach a cube strut or octo strut (or anything) and offset it and the piece it connects to so that there is a gap between them that allows the fairing to pass through it. If you then support the assembly inside properly you could have an even more robust prop. But, you'll be adding to the part count like crazy, and sometimes getting it to work can be a bit finicky... And then your friend the heating bug comes along. But it will look much much cleaner than the way you've done it, and the way I've done it.

There's more info and pics on fairing bearings here.

Apologies if I'm teaching you to suck eggs, and if it comes across as completely critical. It's not meant that way, more just open up discussion to find different techniques for this.

It's no problem, I am no pro at bearings, I have played around with them a bit discovered a kraken drive for rovers, gave it up as a bad deal, but I have been testing some of the tanks, and while their turrets usually leave a lot to be desired, some were not completely sucky. The one I have now is slow, but very solid, with reaction wheels I can get it as fast as the low g freewheeler and it does not even quiver. I tried your ones already on the other thread, thats where I got some inspiration. But I think mine is more solid than those at the moment.

1ton is nothing to the bombers we are building, so the weight is not much of an issue, the bombers are slow though and are usually only traveling 60-90ms, I have found this is just borderline for most of the freewheeling designs to actually spin.

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Did some quick tests, fairing bearing can certainly handle the speed and the g... I just can't get it to turn. Really must get on with making some money this morning... Will tinker later when I get bored of working.

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--- Fair enough then. I'll have to add some designs to the bombers and see what can be had.

But just to clarify, it's not mass in terms of overall mass that is the issue, it's the mass of the prop assembly. The more mass that has, the harder it is for it to freewheel, and the more reaction wheels you'll need to get it to turn. So you know how you need to carry fuel to carry fuel? It could end up down that road, which again + parts + complexity. Of course, that's not to say my approach is Kraken's gift.

I will see what I can do with your Welly and Columbia's B17 later. Although I fear part counts may make it difficult and just strip 'em down to something barebones.

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Did some quick tests, fairing bearing can certainly handle the speed and the g... I just can't get it to turn. Really must get on with making some money this morning... Will tinker later when I get bored of working.

- - - Updated - - -

--- Fair enough then. I'll have to add some designs to the bombers and see what can be had.

But just to clarify, it's not mass in terms of overall mass that is the issue, it's the mass of the prop assembly. The more mass that has, the harder it is for it to freewheel, and the more reaction wheels you'll need to get it to turn. So you know how you need to carry fuel to carry fuel? It could end up down that road, which again + parts + complexity. Of course, that's not to say my approach is Kraken's gift.

I will see what I can do with your Welly and Columbia's B17 later. Although I fear part counts may make it difficult and just strip 'em down to something barebones.

Yeah I understood that about the prop weight, I was talking overall weight not being a problem, maybe it is because I am trying to turn three blades (for authenticity)

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OK with my fairing bearing and a lightweight 2 bladed antennae prop, not even a nose cone, the minimum turn speed is about 90m/s to keep it turning. That may vary with different AoA of the blades, but it does not seem to make too much difference. You will need to do a slight roll to get it started at that speed.

Download

Thats for 39 parts and .6 ton, not too bad.

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OK with my fairing bearing and a lightweight 2 bladed antennae prop, not even a nose cone, the minimum turn speed is about 90m/s to keep it turning. That may vary with different AoA of the blades, but it does not seem to make too much difference.

Download

Thats for 39 parts and .6 ton, not too bad.

I think I can bring down the weight and maybe the part count a little, off to the labs

Edited by selfish_meme
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OK with my fairing bearing and a lightweight 2 bladed antennae prop, not even a nose cone, the minimum turn speed is about 90m/s to keep it turning. That may vary with different AoA of the blades, but it does not seem to make too much difference. You will need to do a slight roll to get it started at that speed.

Download

Thats for 39 parts and .6 ton, not too bad.

- - - Updated - - -

I think I can bring down the weight and maybe the part count a little, off to the labs

Have you tried using the docking port kraken thing? The magnetism is strong enough to hold the free docking port under high g maneuvers, and I don't think there's any rotational component to the magnetism so it shouldn't stop a prop mounted on the free docking port spinning. It'd be really low mass and low part too.

EDIT: Tested and it worked, freewheeled well, but did eventually fall off and stopped spinning during turns. Still needs a lot of work.

Edited by BlueCanary
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Have you tried using the docking port kraken thing? The magnetism is strong enough to hold the free docking port under high g maneuvers, and I don't think there's any rotational component to the magnetism so it shouldn't stop a prop mounted on the free docking port spinning. It'd be really low mass and low part too.

EDIT: Tested and it worked, freewheeled well, but did eventually fall off and stopped spinning during turns. Still needs a lot of work.

Trying to stay away from the docking ports, they get way too squirelly

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Lighter, but not less parts and not really superior in any way. Wanted to try out the elevons to see if rotating elevons created as much drag as static ones. On the good side it rotates faster. On the bad side, before it starts rotating the elevons cause severe control issues, and it's worth noting the throttle is full and that plane is usually capable of somewhere north of 180m/s in close to level flight. But with elevons 90m/s <- see Columbia

VigilantPointlessCooter.gif

Not sure whats wrong with the gif, maybe it takes a while to become visible, you can see html5 video here

Edited by selfish_meme
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Lighter, but not less parts and not really superior in any way. Wanted to try out the elevons to see if rotating elevons created as much drag as static ones. On the good side it rotates faster. On the bad side, before it starts rotating the elevons cause severe control issues, and it's worth noting the throttle is full and that plane is usually capable of somewhere north of 180m/s in close to level flight. But with elevons 90m/s <- see Columbia

http://zippy.gfycat.com/VigilantPointlessCooter.gif

Not sure whats wrong with the gif, maybe it takes a while to become visible, you can see html5 video here

So I spent about 30 minutes playing with yours. And have to say, I'm impressed. It's solid as a rock. I cannot however get it to rotate below 50m/s (playing around with prop pitch - it seems a flat out 45 degrees works best. I also turned it into a five-bladed prop but no idea if that made any difference...)

I think a freewheeling prop is the wrong job for this bearing. This should be the bearing for a tank's turret. I'm very tempted to rebuild the sentry gun I was playing with yesterday to use your variant of the faring bearing.

I threw five prop bearings onto the worst flying pos thing I've ever managed to stick together. Outer engines are single torque wheel powered. "Low-G" variant was fine up to 130 [?]m/s. High-G, solid as a f'kin rock.

Freewheelers - High-G variant started to spin around 30m/s... Low G around 50m/s.

Unfortunately on this test aircraft, your bearing just wouldn't stay put. I tried adding more cube struts but it was already at 300 parts so I was on a losing battle. I cannot wait for 64-bit...

Should probably take a more scientific approach... but I didn't.

EghXqU5.jpg

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So I spent about 30 minutes playing with yours. And have to say, I'm impressed. It's solid as a rock. I cannot however get it to rotate below 50m/s (playing around with prop pitch - it seems a flat out 45 degrees works best. I also turned it into a five-bladed prop but no idea if that made any difference...)

I think a freewheeling prop is the wrong job for this bearing. This should be the bearing for a tank's turret. I'm very tempted to rebuild the sentry gun I was playing with yesterday to use your variant of the faring bearing.

I threw five prop bearings onto the worst flying pos thing I've ever managed to stick together. Outer engines are single torque wheel powered. "Low-G" variant was fine up to 130 [?]m/s. High-G, solid as a f'kin rock.

Freewheelers - High-G variant started to spin around 30m/s... Low G around 50m/s.

Unfortunately on this test aircraft, your bearing just wouldn't stay put. I tried adding more cube struts but it was already at 300 parts so I was on a losing battle. I cannot wait for 64-bit...

Should probably take a more scientific approach... but I didn't.

http://i.imgur.com/EghXqU5.jpg

Azimech or sgt_flyer might have better versions, I remember them using similar bearings.

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Voyager 1 and 2 has come a long way since I last posted here, I've finished the Star 37E, and now I finished the Centaur D1-T! I've also given a few Kerbpaint recolors, which makes it more like the real one, but I don't think craft compatibility is removed without kerbpaint, which is a plus.XaZWO6A.png

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My current nightmare... I started out making a small 4 engine tanker but it didn't send up enough fuel to LKO so this eventually happened...

EkI8lh8.png

It uses basically a mid engine design so that the COM doesn't shift much as the tanks empty.

Still needs a lot of tweaking and polish before it is stable though and I don't really have the time or inclination at the moment to finish it.

Just wondering if anyone else has already made a monster reusable tanker that they could share a craft file for me to save me the headache?

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