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Post by treptoplax on Sept 8, 2018 18:49:57 GMT
The Treptoplax Design Bureau, as part of our ongoing campaign of resistance to the Laser Jellyfish Meta, have been doing research into miniaturized railgun drones. We're fairly happy with our current "Duck" class drones, with a nicely compact 23cm diameter, 3Kc cost, and a 5.75 Km/s railgun. (See Small carrier post for details or full design.) But probably this could be improved? We therefore are soliciting designs for compact guns. As these are intended to outrange targets with long-range weapons and minimal mobility our *somewhat handwavy and possibly wrong but we're sticking with it* scoring metric is: Projectile velocity / (frontal diameter)^2. (This turns out to have units of 1/m*s if you're being picky, which probably has some deep meaning but I have no idea what it is). Our current small railgun has a diameter of approximately 20cm and a velocity of 5.75 Km/s, for a score of 143750 - an improved drop-in replacement would be ideal. The fact that capacitors can't be stacked vertically in our experience is a pretty serious limitation, but YMMV. Most railguns we've seen have significantly superior velocity but are far larger; we'd also be interested in superior coilgun designs, though this seems unlikely. It's likely that conventional guns could beat this score by being particularly tiny; we're dubious such weapons would be viable (if nothing else, there's probably no benefit to shrinking much past the spot size of the laser beam you're trying to dodge!), but if you have a great one... |
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Post by someusername6 on Sept 8, 2018 19:46:59 GMT
No constraints on power usage for coilguns? If so,  Diameter is 9.3 cm, and projectile velocity is 4.11 km/s, for a score of 475199.4. CoilgunModule 50.0 MW 5mm Turreted Coilgun
UsesCustomName false
PowerConsumption_W 5e+07
Coil
Composition Vanadium Chromium Steel
WireRadius_m 0.001
NumberOfTurns 1
NumberOfLayers 1
NumberOfStages 200
BarrelArmor
Composition Boron Filament
Thickness_m 0.0245
Armature
Composition Magnetic Metal Glass
BoreRadius_m 0.00258
Mass_kg 0.001
Tracer Silver
Payload null
Loader
PowerConsumption_W 1.77
ExternalMount false
InternalMount false
Turret
InnerRadius_m 0.0415
Extruded true
ArmorComposition Polyethylene
ArmorThickness_m 0.005
AttachmentCount 1
MomentumWheels
Composition Osmium
RotationalSpeed_RPM 1e+05
TargetsShips true
TargetsShots true
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Post by treptoplax on Sept 8, 2018 23:32:08 GMT
Interesting! I haven't really looked at small coilguns... Though as you mention, I'm dubious about getting 50Mw on a drone that small.
The current model has 202Kw. My last attenpt to scale up the railgun gave me a 7.5Km/s x 30 cm diameter model that cost three times as much and didn't seem to be an improvement overall.
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Post by Fgdfgfthgr on Sept 9, 2018 10:57:10 GMT
348760 score for this design, not including the turret.  |
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Post by someusername6 on Sept 9, 2018 14:29:36 GMT
Here's a go with a railgun, using 202 kW of power and still firing at a reasonable rate.  Diameter is 4.48 cm without a turret (we are counting it without turrets now, it looks like?), projectile velocity is 2.54 km/s, for a score of 1066582. RailgunModule 202 kW 2mm Capacitor Railgun
UsesCustomName false
PowerConsumption_W 2.02e+05
Capacitor
Count 1
DielectricComposition Hafnia
Dimensions_m 0.02 0.17
Separation_m 1e-07
Rails
Composition Zirconium Copper
Thickness_m 0.015
Length_m 0.1
BarrelArmor
Composition Diamond
Thickness_m 0.0061
Armature
Composition Osmium
BoreRadius_m 0.0013
Mass_kg 0.001
Tracer Lead
Payload null
Loader
PowerConsumption_W 740
ExternalMount true
InternalMount false
TargetsShips true
TargetsShots true
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Post by treptoplax on Sept 9, 2018 14:47:43 GMT
348760 score for this design, not including the turret. Impressive! I've never had good luck with fixed guns, unfortunately (maybe they're better now?). Just a couple degrees of traverse is probably enough, but I should have specified a turret. |
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Post by treptoplax on Sept 9, 2018 14:54:40 GMT
Here's a go with a railgun, using 202 kW of power and still firing at a reasonable rate. Diameter is 4.48 cm without a turret (we are counting it without turrets now, it looks like?), projectile velocity is 2.54 km/s, for a score of 1066582. RailgunModule 202 kW 2mm Capacitor Railgun
UsesCustomName false
PowerConsumption_W 2.02e+05
Capacitor
Count 1
DielectricComposition Hafnia
Dimensions_m 0.02 0.17
Separation_m 1e-07
Rails
Composition Zirconium Copper
Thickness_m 0.015
Length_m 0.1
BarrelArmor
Composition Diamond
Thickness_m 0.0061
Armature
Composition Osmium
BoreRadius_m 0.0013
Mass_kg 0.001
Tracer Lead
Payload null
Loader
PowerConsumption_W 740
ExternalMount true
InternalMount false
TargetsShips true
TargetsShots true
Oh, interesting. That's only a little higher velocity than my chemgun flavor of this drone, but it's quite small, and one could easily reduce the power requirement with a lower rate of fire. |
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Post by someusername6 on Sept 9, 2018 15:06:39 GMT
Here's a go with a railgun, using 202 kW of power and still firing at a reasonable rate. Diameter is 4.48 cm without a turret (we are counting it without turrets now, it looks like?), projectile velocity is 2.54 km/s, for a score of 1066582. RailgunModule 202 kW 2mm Capacitor Railgun
UsesCustomName false
PowerConsumption_W 2.02e+05
Capacitor
Count 1
DielectricComposition Hafnia
Dimensions_m 0.02 0.17
Separation_m 1e-07
Rails
Composition Zirconium Copper
Thickness_m 0.015
Length_m 0.1
BarrelArmor
Composition Diamond
Thickness_m 0.0061
Armature
Composition Osmium
BoreRadius_m 0.0013
Mass_kg 0.001
Tracer Lead
Payload null
Loader
PowerConsumption_W 740
ExternalMount true
InternalMount false
TargetsShips true
TargetsShots true
Oh, interesting. That's only a little higher velocity than my chemgun flavor of this drone, but it's quite small, and one could easily reduce the power requirement with a lower rate of fire. I guess I really like relatively high power small guns. Or that I find them interesting to design. It might come down to how large / heavy is your power source, and what is the spot size of the lasers you are going against -- doesn't make sense to miniaturize it past that. |
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Post by Fgdfgfthgr on Sept 10, 2018 1:53:24 GMT
Conventional guns are going to get it. Score 340099.904347 with a turret!  |
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Post by treptoplax on Sept 10, 2018 3:21:21 GMT
Conventional guns are going to get it. Score 340099.904347 with a turret! Wow, I'm going to have to look that over carefully. I thought I had tweaked my chemguns pretty thoroughly but I never managed a velocity much over 2Km/s. Power requirements will be trivial obviously... I had a model of this drone in that size with a lousy 10mm gun that was used mostly as a submunition from small drone carriers, but this might be significantly more useful. |
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Post by AdmiralObvious on Sept 10, 2018 3:37:23 GMT
I'm probably going to be prevented from uploading for a week to so, but I had a fairly high velocity chem gun getting almost up to 3.4 km/s.
There's no requirement for bore size or projectile mass?
I was originally trying to replicate the 7mm Browning MG, and it turned into that.
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Post by Fgdfgfthgr on Sept 10, 2018 4:00:34 GMT
Got over 154000000 from coilgun, but you are probably not going to like it...
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Post by someusername6 on Sept 10, 2018 4:39:09 GMT
Got over 15000000 from coilgun, but you are probably not going to like it... I am suspicious that the optimal score for this is going to be 'make the diameter as small as possible, and then maximize the velocity for that diameter, even if that is under 100 m/s'. But please post it. |
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Post by Fgdfgfthgr on Sept 10, 2018 4:46:17 GMT
Sorry for it only gets up to 1440000... I missed typed one more 0...  |
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Post by treptoplax on Sept 10, 2018 4:52:51 GMT
I'm probably going to be prevented from uploading for a week to so, but I had a fairly high velocity chem gun getting almost up to 3.4 km/s. There's no requirement for bore size or projectile mass? I was originally trying to replicate the 7mm Browning MG, and it turned into that. I don't really care about bore size, only total diameter (with turret). Since this is intended for a drone that mostly targets laser mirrors and/or radiators, projectile mass doesn't matter much either. Currently I have two useful models of this drone around; one with a 1g/5.25Km/s railgun for anti-laser work, and one with a 4g / 2 Km/s chemgun for killing anything with meaningful armor. The railgun model has 2x101Mw Apophis reactors, and the other has a smaller 16Kw reactor derived from an old Tessfield design. The problem with the chemguns in the anti-laser role in my experience to date, beside lower velocity, is that they tend not to have as much ammo and are more accurate than my railguns (useful for drilling through armor, less so for fire at a mass of laser mirrors from 800Km). |
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