Heatsinks

edited May 2015 in IET Formula 24+
Hi
Does anyone know how to get cylindrical Heatsink right round the motor body, I have seen a picture of the one we need on a Greenpower kit car motor but I don't know how to upload it to the forum,

Thanks

Comments

  • Also as another question, how is it that on videos of F24+ some cars are much much faster than others even if they don't have great bodywork compared to the ones they go flying past?
  • Can you post a link to the heatsink photo? Teams have machined heatsinks from aluminium or copper billet, or fabricated from aluminium sheet. For cooling we use a large computer type heatsink clamped to the motor backplate and two computer fans controlled by a thermal switch blow air over the motor if it reaches 50C. The fans are 12V 0.15A so they're connected in series, the current is less than 1% of the car's power budget and probably runs for less than 25% of a race.

    Any links to the videos you've seen? You can't make an aerodynamically inefficient car "fly", the Greenpower motor simply won't produce enough power and you'd flatten the batteries very quickly.
  • You can certainly make an unaerodynamic and incomplete car fly if you're willing to flatten the batteries quickly.

    We ran Electric Boogaloo without bodywork at the Goodwood test day and were only overtaken once all day (Jet almost got us but we dove into the pits) however we were discharging the batteries in ~40 minutes. We were using the session primarily to test the powertrain and the steering, both of which we needed to be running at full speed to fully exercise.

    If we were actually trying to make a full race distance, we'd have to knock at least 5mph off our speeds, if not more. Once the bodywork is finished (the ongoing saga for us) we should be able to run faster and further.
  • And so you will!!
  • Zachy2110 I'm not sure if those heat sinks you mentioned are sold by GP anymore but I stand to be corrected. I don't see them on their shop web page. They were originally made by Electroad and sold through GP as part of the modular series of car components (i.e. Trug). I know I had the last three from Electroad directly as they were no longer being supplied to GP. We use them on FR-6M & FR-5M and I have one left over for the GP kit car we are about to build (so we can take part in the KitCar Final!). FR-2 uses a fully encased heatsink machined from a solid billet of aluminium......a work of art that someone kindly made for us....anodised gold too!

    CC
  • Hi

    I contacted greenpower about the heatsinks but like you said they no longer sell them. Do you know foremarke if the are any blueprints to make the heatsink again?
  • Not that I'm aware of although I could ask Michael at Electroad. I'll see what he says.
  • Further to above, no drawings exist. He says that he made them by cutting the square sections from bulk pieces of heat sink material and then drilled out the center on one to allow the motor shaft through and then four holes in the corners to attach the four retainer springs. The wrap around material for the motor body he apparently had specially manufactured for him.

    CC
  • Ok thanks for asking, and I will see what we can do at our school. I did reply to you the other day but I didn't press the post comment properly so sorry for that,

    Thanks
  • You can buy/find old heatsinks with circular cutouts in their centre for a thermistor, which you can put the motor spindle through. Can't work out what ours are from, but we've got 2 or 3 in the shop somewhere.
  • Have you sorted the heat sink. It maybe ours you saw online. We had it made to order at the local college on a cad/cam system. Will chase drawing if you want ?
  • No we haven't sorted them out yet JohnDean, but if you could find the drawings that would be great, If you send them to my email address zachary.mariner@aim.com that would be brilliant,
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