The Optimist

(Stock Electric Propeller Vehicle Showcase): Bringing power to the people!

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Hello all,

I have recently been spending way too much time learning to build stock supersonic propeller planes in KSP 1.4.3.

My goal is 400m/s. The best achieved so far is 377 m/s (mach 1.068) in sustained level flight at 335 m altitude. This is with stock aero settings. MUCH higher speeds are possible by playing with the stock aero settings in the debug menu, particularly the lift/drag ratio. Therefore I have posted screenshots including the debug menu settings.

Developing these things requires a significant effort in testing. Even fine adjustments to pitch, position of blades and many other variables, can radically change performance or affect stability.

Specs of "Spinner 377":
  • 23 tons
  • Part count 186
  • Total 60 large reaction wheels in 2 contra-rotating engines
  • Total 60 RTGs
  • Bearings: Stayputnik and M-1x1 structural panels
  • 4 x elevon 3, 8 x elevon 4

Spinner 377 is still experimental. When the project is complete I will upload the craft to Kerbal X. Meanwhile, please enjoy these images of the craft in flight and in the VAB:

 

Spinner 377
zVR5HBn.png

 

fUszs4A.png

 

gRqu2mj.png

 

UndDdI2.png

 

WfH12Hv.png

 

T4cWeYx.png

Edited by Tyr Anasazi
imgur sucks

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Update: This craft is soon to be Spinner 400 as today it is flying sustained level flight speed in the high 390's!

FFvbZrl.png

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Looking for examples of re-dockable propellers, I found only Rade's rather complex Duansoar.  I made a minimalist general-purpose electric-prop, with pitch varying 30° to fully feathered, to accommodate different atmospheres. (at KerbalX)bearing.jpg

A pair of shielded docking-ports can be used repeatedly, because shielding then opening each port resets its docking function, without the need to move >1 meter away.  The pair or ports weighs a lot, though.  I used a claw instead.

From Collide-O-Scope we can see that the claw has a spherical collider that moves forward when it is armed. I let the claw grab the flat surface of the reaction-wheel to stow the prop, and  clipped a small antenna into the claw to be exposed and act as a jewel bearing when the claw retracts .   Thermometers around the spherical collider of the claw keep that end centered.   The far-end bearing is a standard antenna in a ring of RCS balls.

I did enable 'part-clipping-in-editors' so I could put a de-coupler on the same node as the claw.  It seems that the last part attached to a node determines how much of the node's surface is covered for purposes of computing drag, so I was careful to put the claw on last.  I used the medium size reaction wheel, for it higher torque-to-weight ratio, and with no fairing I have one medium-size cross-sectional area as flat-plate drag.    It goes a speedy Mach 0.21 at Eve sea level.

Edited by OHara
kerbalx link

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On 7/15/2018 at 10:16 PM, OHara said:

Looking for examples of re-dockable propellers, I found only Rade's rather complex Duansoar.  I made a minimalist general-purpose electric-prop, with pitch varying 30° to fully feathered, to accommodate different atmospheres. (at KerbalX)bearing.jpg

A pair of shielded docking-ports can be used repeatedly, because shielding then opening each port resets its docking function, without the need to move >1 meter away.  The pair or ports weighs a lot, though.  I used a claw instead.

From Collide-O-Scope we can see that the claw has a spherical collider that moves forward when it is armed. I let the claw grab the flat surface of the reaction-wheel to stow the prop, and  clipped a small antenna into the claw to be exposed and act as a jewel bearing when the claw retracts .   Thermometers around the spherical collider of the claw keep that end centered.   The far-end bearing is a standard antenna in a ring of RCS balls.

I did enable 'part-clipping-in-editors' so I could put a de-coupler on the same node as the claw.  It seems that the last part attached to a node determines how much of the node's surface is covered for purposes of computing drag, so I was careful to put the claw on last.  I used the medium size reaction wheel, for it higher torque-to-weight ratio, and with no fairing I have one medium-size cross-sectional area as flat-plate drag.    It goes a speedy Mach 0.21 at Eve sea level.

Clever prop design, I like it.  Really like the low part count.  What's the top speed?  150 m/s?

A question - does that horizontal stabilizer need to be that big for balance?  It's seems over-large.  I bet if you throw a nose cone on the end of that reaction wheel (and offset it to clear the bearing) you could reduce the drag a bit more.  Throw the 'chutes in a Service Bay just aft of the COM for even more drag reduction.

Edited by HalcyonSon

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prop1.jpgYes the horizontal stabilizer helps lift the mass of the engines, which is placed all near the props.

One could move some of the engine components forward where the empty tapered fuel tanks are, where it looks like the engine should be, but then the moments of inertia are more like a wobble prone cigar and might need stronger bearings. The flying-saucer-like distribution of the rotating mass here is easy on the bearings.

This is a slow and forgiving aircraft. Top speed 100m/s at 10km altitude.  Maybe 120m/s on Duna. (If you want fast, of course, look two posts above.)

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11 hours ago, OHara said:

prop1.jpgYes the horizontal stabilizer helps lift the mass of the engines, which is placed all near the props.

One could move some of the engine components forward where the empty tapered fuel tanks are, where it looks like the engine should be, but then the moments of inertia are more like a wobble prone cigar and might need stronger bearings. The flying-saucer-like distribution of the rotating mass here is easy on the bearings.

This is a slow and forgiving aircraft. Top speed 100m/s at 10km altitude.  Maybe 120m/s on Duna. (If you want fast, of course, look two posts above.)

Makes sense...  Are the antenna/ RCS ball bearing stronger than all RCS ball bearings?  My all- RCS ball bearing can get temperamental when things wiggle, probably because there's not much overlap in the hit boxes.. It seems that the type you've used might have an advantage because of the longer hit box of the antenna.  

Low and slow prop planes are a lot of fun to fly, provided they are maneuverable and sturdy.  Much more forgiving trainers too.

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I like having an antenna (cylinder) as the axle of the bearing, and don't yet see any downside to that.  Its lower impact tolerance  has never been a problem for me.

In this case the central antenna was an obvious choice because the prop shifts a bit axially, back when the claw presses to grab it, forward when it thrusts.   This prop, though, is easy on the bearing; I have a version with and antenna in a cage of 8 antennas and only once shook even that bearing loose.

Edited by OHara
spelling

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11 hours ago, OHara said:

I like having an antenna (cylinder) as the axle of the bearing, and don't yet see any downside to that.  Its loser impact tolerance  has never been a problem for me.

In this case the central antenna was an obvious choice because the prop shifts a bit axially, back when the claw presses to grab it, forward when it thrusts.   This prop, though, is easy on the bearing; I have a version with and antenna in a cage of 8 antennas and only once shook even that bearing loose.

An all-antennae bearing?  Yeah, I can see how that would work a lot better for fore-aft movement.  The hit box is at least twice as deep as the RCS ball hit box.  Probably easier to visualize the placement too compared to the thermometer with it's funny little legs.

 

I really need to fire up KSP again and play with this some more.   Trying to finish the Baldur's Gate series first!

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Has anyone built a rover wheel powered stock electric prop?  I believe I've seen a tank turret built on this concept, but I can't get the rpm I need for a prop.

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On 9/14/2018 at 2:59 PM, HalcyonSon said:

Has anyone built a rover wheel powered stock electric prop?  I believe I've seen a tank turret built on this concept, but I can't get the rpm I need for a prop.

@AzimechI believe has made one, but for a boat, not a plane.

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2 hours ago, Azimech said:

Interesting design.  I'm curious how you managed to keep everything aligned.  I've tried several different bearing designs and rover wheels.  Mostly the shaft jitters itself out of the motor and blows up on the runway.  When it does stay together, I can't get enough traction from the rover wheels to spin the shaft at more than a crawl.

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1 hour ago, HalcyonSon said:

Interesting design.  I'm curious how you managed to keep everything aligned.  I've tried several different bearing designs and rover wheels.  Mostly the shaft jitters itself out of the motor and blows up on the runway.  When it does stay together, I can't get enough traction from the rover wheels to spin the shaft at more than a crawl.

Oops. That's asking for more than a thousand words. Currently RL keeps me occupied. And this topic will be addressed when I start broadcasting with Twitch.

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Wow, guess I shoulda been coming here all this time i was looking for a new bearing on my props. I'v tried the Standard thermometer/RCS props, Girder/stayputniks and RCS bearings but i never would have thought about an Antenna but eventually they all fail at some point (actually i havent tested the girder prop much).

I'm a replica builder on KerbalX and i try to focus on low part count craft and i think that antenna bearing would fit pretty well with my needs, could one of you show me the spacing and such for building one of these things?

 

by the way if you're interested, myself, holidaytheleek and HB stratos are going to have a stock prop air race, no set date yet but let me know if you're interested

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@Phantomic

I usually use the stayputnik/1.25m fairing combination, mainly because it is almost unbreakable and because the fairing occludes the engine parts. The other combination is linear RCS/solar panels bearings, these seem to work slightly better than thermometers, while being only slightly bigger. But these bearings can break if you do some sharp maneuvers or if the propeller is spinning to fast.

Regarding the spacing of the parts I would recommend you to get the Collide-o-Scope mod. This will allow you to see the exact collider shape for any part, which allows you to precisely position the parts of the bearing.

I might be interested in the race, but I would need to know if there are any rules, like the number of engines or reaction wheels allowed. As you've probably seen few people have managed to build prop planes that can go faster than Mach 1, with the @Tyr Anasazi holding a speed record with a Mach 2 capable plane. Also you might want to invite @SuperHappySquid into the race he is one of the best when it comes to building the stock propellers.

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23 minutes ago, _Rade said:

@Phantomic

I usually use the stayputnik/1.25m fairing combination, mainly because it is almost unbreakable and because the fairing occludes the engine parts. The other combination is linear RCS/solar panels bearings, these seem to work slightly better than thermometers, while being only slightly bigger. But these bearings can break if you do some sharp maneuvers or if the propeller is spinning to fast.

Regarding the spacing of the parts I would recommend you to get the Collide-o-Scope mod. This will allow you to see the exact collider shape for any part, which allows you to precisely position the parts of the bearing.

I might be interested in the race, but I would need to know if there are any rules, like the number of engines or reaction wheels allowed. As you've probably seen few people have managed to build prop planes that can go faster than Mach 1, with the @Tyr Anasazi holding a speed record with a Mach 2 capable plane. Also you might want to invite @SuperHappySquid into the race he is one of the best when it comes to building the stock propellers.

If mr. superhappy squid is squiddy, he's said he didnt want to do it at the moment.

Has collide-o-scope been updated for 1.5.1? i used to use it a bunch in my 1.4.5 game

the only rules i have at the moment are keep it under 400 parts and the classes are 20 wheels and below then unlimited, turbos would be judged on speed rather than "horsepower" if you will

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36 minutes ago, Phantomic said:

If mr. superhappy squid is squiddy, he's said he didnt want to do it at the moment.

Yea that's his forum name here.

1 hour ago, Phantomic said:

Has collide-o-scope been updated for 1.5.1? i used to use it a bunch in my 1.4.5 game

It was updated, works great.

1 hour ago, Phantomic said:

the only rules i have at the moment are keep it under 400 parts and the classes are 20 wheels and below then unlimited, turbos would be judged on speed rather than "horsepower" if you will 

Is that 20 small wheels per plane or per engine?

For additional rules I would recommend to make the cockpit a required part, otherwise the drones would have unfair advantage over manned planes.

There should be some rule or maybe 2 separate classes for the different propeller blade configurations.

for example plane with this prop blade config (ignore the rotors)

pR8vDu0.png

will have a considerable speed advantage over a same plane with prop blades arranged like this:

VrYOpqx.png

Also maybe there should be some rule to limit the maximum diameter of the propeller, because bigger props will have a speed advantage provided you have enough reaction wheels to spin the prop at full speed.

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6 minutes ago, _Rade said:

Yea that's his forum name here.

It was updated, works great.

Is that 20 small wheels per plane or per engine?

For additional rules I would recommend to make the cockpit a required part, otherwise the drones would have unfair advantage over manned planes.

There should be some rule or maybe 2 separate classes for the different propeller blade configurations.

for example plane with this prop blade config (ignore the rotors)

pR8vDu0.png

will have a considerable speed advantage over a same plane with prop blades arranged like this:

VrYOpqx.png

Also maybe there should be some rule to limit the maximum diameter of the propeller, because bigger props will have a speed advantage provided you have enough reaction wheels to spin the prop at full speed.

good point, though i think a 2 engine class would be necessary, not sure about the probed vs.manned because most of my props are manned with command seats seen here jlellXw.png

now i understand how you guys on the forums build, powerful enough to use the stock parts but builders like me who make lightweight designs tend to use less wheels, hence the 20 and under class.

 

Mainly i wanted to do this to drive innovation, and add more rules as it's necessary, get people thinking outside the box

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Thing about the probe core vs. manned, is that the plane with a small okto probe inside the fairing will be about 1t lighter and it will also have less drag compared to the plane which would have to use the cockpit.

Ta4eoUx.png

for example this thing can go 218m/s at low altitude, but if you where to remove the cockpit and just control it via the probe core maximum speed increases to 228m/s.

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8 minutes ago, _Rade said:

Thing about the probe core vs. manned, is that the plane with a small okto probe inside the fairing will be about 1t lighter and it will also have less drag compared to the plane which would have to use the cockpit.

Ta4eoUx.png

for example this thing can go 218m/s at low altitude, but if you where to remove the cockpit and just control it via the probe core maximum speed increases to 228m/s.

I get that, if it becomes a serious trend i will set a rule. right now i have one guy using a probe and he'll be in the 20 and under class because he's using one of my engines. everyone else is using pilots

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tuiyf65.png

That feel when your first prop takes off for the first time. 

smAnP7h.png

Here we are cruising at about top speed, which is barely controllable. It stalls at like 25m/s, to give you an idea.

But still, it works.

8 Elevon props (clipped into each other for looks), 8 small SAS wheels, 6 RTGs on a 5.5ton frame.

More will come, especially if I want to race against some of the more experienced people in this thread.

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Anyone found out practical ways to miniaturize landing gear drive?

Edited by Pds314

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10 hours ago, Servo said:

tuiyf65.png

That feel when your first prop takes off for the first time. 

smAnP7h.png

Here we are cruising at about top speed, which is barely controllable. It stalls at like 25m/s, to give you an idea.

But still, it works.

8 Elevon props (clipped into each other for looks), 8 small SAS wheels, 6 RTGs on a 5.5ton frame.

More will come, especially if I want to race against some of the more experienced people in this thread.

are you using a fuselage/stayputnik bearing or is it still a thermo? if yoi'd like, send it to me on discord and i could do some experimenting, maybe find a better prop

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Thought that I would try and re-join the club :)

I think i'm the only person going back in time with these designs rather than forwards!

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