Poodle vs. LV-T30

[kBob]

I was trying to figure out why I would want to use a Poodle engine instead of a T30 even on my lander (which is a bit heavy at least until I can dump the science stuff and extra fuel). What am I missing? My tests so far show I'm making much more efficient use of my fuel with a T30 while escaping Kerban and while I haven't landed yet it again seems like the T30 is going to get me back up much easier than a Poodle.

BTW for me "clipping a poodle" means taking them outside and shaving off all the extra hair...seems to have a different meaning here.

Edited February 4, 2014 by kBob

[Taki117]

The advantage that the poddle has over the LV-T30 is that it's shorter, and has thrust vectoring (Useful for landing) The poodle is also slightly more powerful, and more fuel efficient in vacuum. (Has a higher vacuum Isp)

[numerobis]

This was discussed to death a couple months ago.

[kBob]

Thanks, I did a search but this is not a very good search engine doesn't seem to allow wild cards 3 letter words etc.

[Space Viking]

Using an unspecified type of lander as an example won't say much. It would probably be a better idea installing Kerbal Engineer Redux or MechJeb and start experimenting with how various configurations affects your craft's efficiency.

[WafflesToo]

Thanks, I did a search but this is not a very good search engine doesn't seem to allow wild cards 3 letter words etc.

I wouldn't sweat it too much. The forum search engine is a joke.

[RoboRay]

This forum, like every other forum, has an excellent search engine. You just go to Google and type in your search request followed by site:forum.kerbalspaceprogram.com.

[kBob]

I try to avoid google on principle I need to check and see if duckduckgo (which does not save anything you do) has a similar feature...but thanks anyway.

[UmbralRaptor]

The answer is that for a typical lander (or anything below about 50 tonnes), there is little reason to use the Poodle. You'll get more ÃŽâ€V and TWR out of the lighter LV-T30, you can let a command pod provide control authority, and either way you have to use the same size landing legs...

[kBob]

Umbral: Yes I'm getting that it seems other than for appearance the poodle is pretty useless (some might say the same for my real poodles), at least this early in my career.

RoboRay: Yep, duckduckgo does do that kind of search just fine, so I need to start using that: thanks for helping me stop taking the lazy way out.

[Jouni]

The Poodle is somewhat useful for upper stages and transfer stages, because it fits nicely between a 2.5 m fuel tank and the lifter stage. Smaller engines below the fuel tank would require ugly hacks, while radially attached engines are not always appropriate.

In landers, multiple small engines are usually better than one large engine. I used the Poodle in my Minmus kethane driller, however, because it simplified the design.

[kBob]

If what I'm reading is correct at least at the current version of the game mixing part size isn't really a problem (well expect if you need struts on the small engine it might be hard) and the adapters are not really needed, but I gather this may change in future. But yes, if you have the excess ÃŽâ€v, I expect it will become more useful as I go up in the tech tree. I actually kind of like the looks of putting the small engine on the large fuel tank .

[thereaverofdarkness]

The advantage that the poddle has over the LV-T30 is that it's shorter, and has thrust vectoring (Useful for landing) The poodle is also slightly more powerful, and more fuel efficient in vacuum. (Has a higher vacuum Isp)

Actually, the Poodle has only 2.3% more thrust than the LV-T30, is only 5.4% more fuel efficient, and is actually taller than the LV-T30. Add to that that the Poodle has double the mass. When you figure the amount of added mass from the engines into your fuel calculations, the LV-T30 is almost always a more efficient engine, and in the fringe cases where the Poodle is more efficient, the difference is a very thin margin.

The only benefit to the Poodle that I can see is the aforementioned thrust vectoring as well as its mount size (2.5 meters). I think that the Poodle could be fixed by at miinimum increasing its thrust to 250kN, to at least put it in line with the popular LV-909 - with the same iSP and 5x the mass, it should have 5x the thrust I think. But I would actually increase the mass of the Poodle to 3.0 tons and the thrust to 300kN to better match its large size. And finally the large landing legs need to be longer so they can be mounted around a Poodle and actually reach the ground!

[Dispatcher]

I've used the Poodle in order to retain more strength in the assembly of diameter 2 multistage rockets and when Career doesn't offer more choices. However, when comparing it with the LVT 30, the LVT 30 tends to outperform it. As mentioned above, the Poodle also has vectoring (gimbaling). You can see a comparison of maximum altitude and 50% non fuel mass between engines here:

http://forum.kerbalspaceprogram.com/threads/67403-Graphs-of-Engine-Comparison-Flights?p=949688&viewfull=1#post949688

When I have more engine choices unlocked, I seldom use the Poodle, if ever. Your tastes may differ.

[kBob]

Seems the consensus, here and in the thread referenced above, is that the poodle isn't very useful, sounds like the engineers need to go back to the drawing board (or cut the price by half?), real poodles are unhappy with their name sake.

Looks like it would be easy enough to change this it's in the ...\kerbal space program\game data\squad\parts\engine\liquidengine2-2 folder and the parts.cfg looks easy to edit, notepad will do--the thrust and mass are easily found. The lander legs would be another problem. I may do this once I've gone though the stock parts in my first career. If anyone does let us know what you think of it.

Yep, I just changed the title to read "Standard Poodle" worked fine.

[numerobis]

It's your copy of the game, so edit the part.cfg as you will. Of course, don't use modded parts in a challenge against others!

[Jouni]

The only benefit to the Poodle that I can see is the aforementioned thrust vectoring as well as its mount size (2.5 meters). I think that the Poodle could be fixed by at miinimum increasing its thrust to 250kN, to at least put it in line with the popular LV-909 - with the same iSP and 5x the mass, it should have 5x the thrust I think. But I would actually increase the mass of the Poodle to 3.0 tons and the thrust to 300kN to better match its large size. And finally the large landing legs need to be longer so they can be mounted around a Poodle and actually reach the ground!

The Poodle is already powerful enough for a vacuum engine. It's more or less the same as using 4 or 5 LV-909 engines, with the added benefit that it often allows simpler and cleaner designs. The real problem is that by the time you need that much thrust in vacuum, you probably have access to nuclear engines, which are much more efficient in most cases.

[Pecan]

Here I was thinking that loving '30s was my "guilty secret" ^^ They're included in the demo version so before I started using Travert's mass-optimal charts I assumed they were superceeded by things like the poodle and felt a bit guilty about using clusters of them. Even then I was using the bi-,tri-, quad- adapters to place them since I didn't know the strut trick.

They're still the engine I try to find an excuse to use; when Nuclear is just too heavy and 48s too underpowered ...

[ThinkOutsideTheHangar]

Use the poodle. If your ship is too small for that, then use the LV-909.

[kBob]

What's the strut trick? (I only have the basic strut's available not those I beams I've seen, so maybe I'm not where I can use it yet, but I got a ship going to Minmas, finally and can land so maybe soon!).

[Pecan]

All I mean by "strut trick" is using the Cubic Octagonal Strut to make a cluster of engines either under or radially on another part. No idea where that strut comes in the career tech-tree but you can use it to attach just about anything to anything else anywhere and it's massless in flight - although listed as 0.001 in the VAB/SPH. IE; You can usually only put 1 engine under a component but the editor happily allows you to put several struts there (use symmetry!), then you can attach an engine to each strut using the same symmetry. 4 x 48-7S engines will fit nicely under a single 1.5m part, without clipping, for instance. Even if they weren't massless their combined mass is less than a quad-adapter for the same job.

Edit for below: Yes, the adapters do look better and the mass difference isn't THAT huge - ~0.1t per adapter. There's also the niggling feeling that using struts is 'cheating' even if the editor allows it. It is a handy way to do things though - your game, your choice :-)

Edited February 6, 2014 by Pecan

[kBob]

Ah got it...something to look forward to though I kind of like the way my tri-adapter engine mounts look...still function before form.