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How to install cooling fan for RX18?
Posted: Thu May 14, 2015 4:45 am
by atcttge
Hi all. I'm new to all this RC stuff, so please bear with me. Thanks.
I've read that HL RX18 boards can burn when over stressed. To prevent it from happening, a cooling fan is installed. I've looked around on how to install a cooling fan to an RX18 board, and while I've seen where to install it and what modifications are to be done to the box, I don't see how the cooling fan is electrically connected to the system. By that, I mean where do you connect the wires of the cooling fan? I've read that some prefer to connect it in such a way that when the tank is powered on, the fan already is whirring, so I guess the connection is somewhere near the battery before the on switch...? Also, is there a need to install resistors and other stuff? And what voltage is required for the fan?
My tank is a HL 1/16 Leo2A6, and I'll be receiving my HL M1A2 sometime next month, so I'm going to put cooling fans for both tanks.
Additionally, I'm not much of a smoke feature guy, so I'm looking to removing the smoke machine entirely and relocating the RX18 board there where the engine vents are so as to help facilitate ventilation with the cooling fans (in the Leo, I hope to find a couple of small fans so I can make use of the round vents on the hull top as intakes). I wonder though if such placement is bad since it's near the motors where heat can possibly build up and whether the magnets of these motors will have an effect on the RX18.
Thanks in advance!

Re: How to install cooling fan for RX18?
Posted: Thu May 14, 2015 9:17 am
by Tankbear
To be honest I think your wasting your time. I've run fan less rx18 in heavy tanks with upgraded motors with out any problems.
I think the early rx18 when first released might of had issues or people thought because was in a plastic box it might over heat. But I've never had one fail because it got too hot.
Re: How to install cooling fan for RX18?
Posted: Thu May 14, 2015 12:54 pm
by MichaelC
I am with Tankbear also. RX-18 is cheap enough that even if it does burnt, you can easily replaced it. However, if you are installing a fan, in addition to the power wiring, you will also need to drop holes on the cover so that air is actually moving thru the unit. All that effort really is not worth it since I don't think it does anything at all. Fro all the Taigen 2.4Ghz unit that comes with the fan, I usually just remove them completely and never had a problem.
Re: How to install cooling fan for RX18?
Posted: Thu May 14, 2015 1:17 pm
by RobW
As Michael notes, the fan can only move air around the enclosure. Poorly fitted fans can actually cause more problems (the motor gets hot...) by trapping warm air in certain areas.
A more effective (if somewhat overkill) method would be to buy a metal hull, and connect the hot bit (which bit of the board needs cooling?) to the lower hull with a heat pipe.
Re: How to install cooling fan for RX18?
Posted: Fri May 15, 2015 12:07 am
by atcttge
Oh I see. I had the impression that the RX18 had a heat issue and needed a fan to cool things down especially when upgrading the motors.
I just realized I failed to describe my tank and why I asked about the cooling fan in my initial post above.
My HL Leo2A6 currently uses a 3-shaft hi-lo steel gearbox with motors that came with it, metal tracks, metal idlers, and metal sprockets. I've read that if an HL tank has those metal upgrades especially the tracks, a cooling fan is recommended to have on the RX18. I'm planning to upgrade the motors so it runs faster. It's because of those upgrades that I was thinking of adding a fan in order not to fry the RX18.
Problem with getting an RX18 replacement is that it's not easily available here in the Philippines as there is no supplier. I would have to resort to the internet to order a replacement and that could mean a month (at least) or more for a replacement to arrive (reason for such long delay is our post office and customs where mailed matter can take forever to be cleared).
So, with that added information that my tank is running metal tracks, metal sprockets, and metal idler, plus with the intent of upgrading to stronger motors, is a cooling fan still recommended?
Re: How to install cooling fan for RX18?
Posted: Fri May 15, 2015 10:12 am
by Tankbear
If your worried take the plastic top off the RX18 this should help let heat escape but I do think the fan came about because of mis-information.
Like i say maybe the early versions did have problems but all the boards I have had Rev 7 printed on the circuit board and I had no issues.
Also the previous electronics did not come in a plastic case and had a big heat sink on, so I would think somebody thought hold on a minute this new RX18 has no heat sink and is a little plastic box that is going to over heat which makes logic but with out any proof. And the internet been what it is people agree on the logic and forget there is no proof of it been an issue even after 5+ years and lots of users sharing the experience.
I don't want to sound like I'm telling you not to do just some times not all the information available is correct.
So back to your original question. I would remove the electronics from the plastic box and mount on PC stand offs so doesn't move around in the tank, get a 40mm fan and mount it at one side so blows air across top and bottom from the side and connect the fan wires in to the power lead going to the RX18.
Ian.
Re: How to install cooling fan for RX18?
Posted: Fri May 15, 2015 2:35 pm
by atcttge
That's good to hear, Tankbear! I hope I won't need a fan. I have yet to open the box of the RX18. I'll do so tomorrow, take a photo of it, and will be posting it here so that I know what version this board is.

Re: How to install cooling fan for RX18?
Posted: Tue May 19, 2015 6:52 am
by atcttge
I opened up the RX18 and saw Rev5.1 printed on it. What's the latest revision of the RX18? Is it still 7?
EDITED to add photo from the internet:
That's exactly my RX18 board found in my Leo2.
Re: How to install cooling fan for RX18?
Posted: Tue May 19, 2015 12:32 pm
by Tankbear
That looks to be the 2.4ghz control unit (newer than rx18) so I'm not certain what the latest revision is for that.
Re: How to install cooling fan for RX18?
Posted: Tue May 19, 2015 12:50 pm
by MichaelC
If it is the 2.4 then you don't need to worry about external fan. Can you send a picture of the cover and also of the radio ?