Protecting PB-NUK from overheating

[Foxster]

I use at least one PB-NUK on just about every craft I build. Trouble is it seems always to be the part that overheats and explodes first. 

I have tried all kinds of placements and clipping but the heat seems to get to it somehow anyway. 

I usually don't want to add  a service bay just for a PB-NUK but that's about the only way I have achieved some protection. 

Anyone have any tips to help keep PB-NUKs from overheating on ascent and descent?

[Snark]

You said "clipping".  Be advised that clipping makes no difference to drag or heating.

If you attach a part to the outside of your rocket, the game considers it to be on the outside of your rocket.  Using the offset tool to physically clip it "inside" the rocket doesn't actually do anything other than the looks.  It will still cause drag and experience heating, the same as if it were attached on the outside.

The only way for it not to count as being on the outside of the rocket is to actually be inside, which means either in a cargo bay or a service bay.

If you have a craft that has "projecting" parts on the front end (e.g. the front end is wider than the back end, as is typical for reentry), then they will shield things behind them from heating, though not from drag.  So for example, if you've got a Mk1-2 command pod, which is 2.5m on the bottom but only 1.25m on the top, and it's reentering wide-end-first, then a PB-NUK that's located near the top so that it's in the "shadow" of the wide end would be protected from heating.

[bewing]

I'll have to retest it sometime soon, but I think snark may be mistaken in this case -- at least partially. The last time I looked at the aerogui drag for an LY10, when it was clipped its drag was lower than when it wasn't.

But besides playing with radiators, I don't know any answer to the OP's question. I play career mode, and those PB-NUKs don't come my way too often.

[Foxster]

Thanks for the thoughts. 

I was aware of the clipping issue. I meant I place the PB-NUK on the rear of a tank (hoping this means it is occluded by the tank) and then clip it up inside the tank for neatness. Doesn't seem to get occluded though.   

[StrandedonEarth]

Odd, I haven't had any problems with the NUKs. I always just put them on the side of the spacecraft, turning them 90deg so they are vertical and flush with the skin, not sticking straight out. Do you have heating cranked up in settings?

[Foxster]

Nope. Just stock settings. 

It obviously doesn't help that they have such low max temp of just 1200. 

Don't you find them being the first item to reach max temp?

Just tried mounting the PB-NUK on a small radiator panel and enabling that. Worked well, couldn't get it to overheat. Problem then is that the radiator is very draggy. Doesn't matter how you mount it it remains draggy because of the way that KSP models all parts as being transparent to drag except for same-sized parts directly coupled. 

Edited June 18, 2016 by Foxster

[fourfa]

I've had the same problem with a few other 1200 temp parts.  Micro landing legs, RCS blocks, etc.  For a Mk2 cargo bay spaceplane, RTGs at the front of the cargo bay attached to the cockpit explode, at the rear is fine.  For any spaceplane at all, I will always have a service bay for things like this (usually at CoM with all my RCS thrusters protected inside) because drag.  

For rockets - ironically, the tank next to the main engine often seems to be the coolest part on the whole ship.  Try there...

Edited June 18, 2016 by fourfa

[Signo]

Put it "inside" and attach it to a cubic.

[Foxster]

1 hour ago, Signo said:

Put it "inside" and attach it to a cubic.

Can you explain a little clearer?

[Signo]

I noticed this a few versions ago with a Eve ship - it will not completely solve the problem but it will give you some edge.