Are fans required?

[mechanicalbrain]

Are we required to use the fans to cool the victors? I have another idea that would make the fans redundant and a waist of power. I'm wondering if I take a robot to the inspectors, and its devoid of fans, will they flag it?

[Cuog]

They may flag it but your best bet is that when you remove the fans be careful not to damage anything so that if they flag it you can just put the fans back on to make them happy for the competition

[coastertux]

Oops...I am stupid.
I didn't read the post right.

[phrontist]

Originally Posted by coastertux

If you remove the fans, your Victors will overheat and burnout.

Uh...

Originally Posted by THE FIRST POST

I have another idea that would make the fans redundant and a waist of power.

[Adam Richards]

Originally Posted by mechanicalbrain

I have another idea that would make the fans redundant and a waist of power.

Just make sure it isn't anything potentially hazardous to electronics like water cooling, as those pipes might burst, or something like liquid hydrogen, since if that were to spill (like the containing vessel cracking), field and/or robot damage will occur.

[Joe Ross]

I think <R55> disallows this for last year. We'll see what this year's rules hold.

[mechanicalbrain]

Originally Posted by Adam Richards

Just make sure it isn't anything potentially hazardous to electronics like water cooling, as those pipes might burst, or something like liquid hydrogen, since if that were to spill (like the containing vessel cracking), field and/or robot damage will occur.

I'm holding off on showing my idea until competition but I will say that none of that is an issue. My idea in itself is completely legal. I'm not sure how the R55 rule applies though, could you elaborate?

[Tristan Lall]

I hope that this isn't some crazy idea to hook up phase-change heatpipes, or worse, a liquid cooler, to TO-220 heatsinks. That would be rather difficult. Now, a very massive heatsink might work, given enough conductivity and surface area, but it might be difficult to secure to the FETs; plus, you'd trade weight for electrical power consumption.

But ultimately, like Joe says, <R55> doesn't seem to allow it.

[mechanicalbrain]

OK so I went back and realized what people were seeing, and realized I needed to clarify. I'm just wondering if I can run the victors without the fans on them (no modifying of the victors will be done). I assure everyone my idea isn't some crazy crackpot idea, it's actually very common if rarely known. I'm not modifying the victors in any way just running them without fans. I'm sorry I can't be more specific with my idea but it has to wait until build season.

[Richard Wallace]

Originally Posted by mechanicalbrain

I'm holding off on showing my idea until competition but I will say that none of that is an issue. My idea in itself is completely legal. I'm not sure how the R55 rule applies though, could you elaborate?

I would interpret <R55> as disallowing any modification of a Victor. Removing the fan is a modification. I can't find a rule that requires connecting the fan 12V and GND leads, though. So I guess you don't have to use the fan, but you still can't take it off.

As a side note, the fan serves a necessary function apart from cooling. It partially shields the FET tabs (which are electrically common to the Drain terminal) from metal objects that might cause them to short-circuit to each other.

[Al Skierkiewicz]

Mech,
To answer your question in a round about fashion. The fans are sometimes shipped separately from the Victors so removing them does not truly modify the Victor. However, the controllers need the fans for operation and to protect the warranty. Although I have seen teams with alternative methods of cooling, nothing works quite as well as that little fan on the top. There is very little heat generated by the FETs when they are fully turned "ON" but the transitions do generate heat, so when operating at less than full speed, some heat will be generated. An ideal, non electrical, fix would be a large heatsink out in the open. However, the tabs of the FETs cannot be electrically tied together and the added weight would be significantly heavier than the fans. For the most part, the fans do not consume that much current. If you wire them to the power input of the controller, they will indicate that the controller is powered, and since they run whenever the robot is powered, they will precool the
FETs before the match starts. If you still have a question, that you don't want to reveal your thoughts, please PM me.