Using bicycle's frame as heatsink for the Phaserunner

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Using bicycle's frame as heatsink for the Phaserunner

Post by thunderstorm80 » Oct 17, 2017 1:53 am

Hi,
One of the great advantages of the Phaserunner is it's low weight, but when you add a big heat sink you kind of negate that. Especially when you have such a huge heat sink beneath your legs. (the bike frame)
I would have liked to use the frame as a heatsink, but the frame is hydroformed - so it doesn't have any symmetrical cross section parts which you can match with any existing market heatsink: For example, you can find a heatsink which is intended to wrap a circle or even ellipse, but as the frame is neither one of those, you will not have full contact but only at some points.
Rubber is excellent for expanding the contact area, but rubber is heat insulator... In fact, every solid which is flexible is heat insulator.
The last idea I've had, is to create an intermediate&sealed volume between the body of the Phaserunner and the frame, which would be filled with some sort of cooling fluid - but those are only effective when they come in large volume and being pumped around in a cooling/heating circulation.

Does anyone has an idea, or did use his bicycle frame for this purpose, with success?

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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by dustNbone » Oct 17, 2017 3:24 am


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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by ferret » Oct 17, 2017 3:43 am

thunderstorm80 wrote: Rubber is excellent for expanding the contact area, but rubber is heat insulator... In fact, every solid which is flexible is heat insulator.
The last idea I've had, is to create an intermediate&sealed volume between the body of the Phaserunner and the frame, which would be filled with some sort of cooling fluid - but those are only effective when they come in large volume and being pumped around in a cooling/heating circulation.

Thunderstorm,
check out this table of thermal conductivity of common materials:
https://www.engineeringtoolbox.com/ther ... d_429.html
Rubber and other solid materials which are relatively bad heat conductors still conduct heat better than air.
In fact many of the TIM materials (Mica, Silicone, grease...) are considered insulators when compared to good heat conductors such as metals.

Large volume/circulated Liquids (and gasses) cool by convection. Heat sinks cool by conduction (and are cooled themselves by convection).
If you fill volume between the body of the Phaserunner and the frame with liquid it would still transfer heat very effectively even without large volume and being pumped around.
http://mechanicalbuzz.com/methods-of-he ... -1073.html

TL;DR: practically any material that will fill the air gap between the controller and the frame will improve cooling.

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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by Chalo » Oct 17, 2017 11:47 am

Funny 21st century problem you got there. Straight round tubes made the best bicycle frames 100 years ago, and it's still true today. It's not very hard to thermally interface with one of those.
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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by Drunkskunk » Oct 17, 2017 1:27 pm

I'm not sure how much effort you want to put into this, but you can cast a formed heat sink in aluminum with not much more than some wax, a BBQ grill, some old beer cans.

Simplified, the process would be something like:
-cover the Phaserunner and frame with masking tape. Then tape the Phaserunner to the frame where you want it, make sure you tape it well to seal all around it.
- pour melted wax into that space and let it harden
-remove the wax casting and clean up the shape with sandpaper.
-Mix sand and a small amount of motor oil until you get a thick sand paste. it doesn't take much oil.less oil is better, it just has to be able to hold it's self together.
-Stick the wax casting in an old soup can or something similar. Pack the sand around it tight but leave the top exposed.


melting aluminum is easy, but finding which system you want to use is a bit tricky. google Melting aluminum. there are a lot of ideas, and you'll have to decide which is right for you. In essence, a leaf blower, a BBQ grill, and a soup can is all you need. A graphite cruicable would be helpful, and is in the $20-$30 range. You can melt scrap soda and beer cans, or just buy some aluminum ingots to melt.

-Pour the aluminum onto the wax mold. the molten aluminum will displace the wax and fill in the space in the sand.
-When it cools, clean up the casting with some sandpaper, and you'll have a form fitting heat sink.... on the 3rd or 4th try... :mrgreen:
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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by wturber » Oct 17, 2017 5:33 pm

Why not a small finned heatsink and a fan = like from an old CPU? I think air movement matters more than heatsink mass.

Another idea would be to wad up and smash aluminum foil to fill the gap between PhaseRunner and frame.

Lastly, wouldn't the heat sink idea require you to remove the frame paint for the best thermal conductivity? Yuk!
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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by spinningmagnets » Oct 18, 2017 1:26 am

"DIY phaserunner heat sink" (several examples shown)
https://endless-sphere.com/forums/viewt ... =3&t=82196

For this one, I clamped two thick square-bars together and drilled-out the center with a hole-saw. I drilled from both ends towards the center, then separated them and halfmoon-filed the slot. Of course the size of this aluminum mass was way overboard, it could be much smaller and still help quite a bit.

Image

Image

Image

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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by rberger » Oct 20, 2017 1:38 am

Drunkskunk's proposed solution of molding your own aluminum heatsink with a BBQ sounds so awesome!! Someday I will have to try that!

But in general, How much of a win is it to add a heatsink to the Phaserunner? How much current draw from the battery do you need to make it worthwhile?

For instance my dual 52v battery pack / BMS is rated at at total of 50Amps safe continuous output and 80Amps peak. Would that ever allow the Phaserunner to heat up enough to make it worth a heat sink? I have it mounted on the bottom front boom of my trike and it should get some good airflow.

The Phaserunner page says: "The continuous current capability without additional heatsinking is typically 45-50A" which seems to be a no for my situation.
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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by thunderstorm80 » Oct 20, 2017 1:02 pm

rberger wrote:Drunkskunk's proposed solution of molding your own aluminum heatsink with a BBQ sounds so awesome!! Someday I will have to try that!

But in general, How much of a win is it to add a heatsink to the Phaserunner? How much current draw from the battery do you need to make it worthwhile?

For instance my dual 52v battery pack / BMS is rated at at total of 50Amps safe continuous output and 80Amps peak. Would that ever allow the Phaserunner to heat up enough to make it worth a heat sink? I have it mounted on the bottom front boom of my trike and it should get some good airflow.

The Phaserunner page says: "The continuous current capability without additional heatsinking is typically 45-50A" which seems to be a no for my situation.
You are confusing between battery current and motor phase current. They are not the same. The manual talks about phase currents.
With proper heatsink you can achieve a steady state of 70A phase current. (from the specs)

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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by thunderstorm80 » Oct 20, 2017 1:07 pm

spinningmagnets wrote:"DIY phaserunner heat sink" (several examples shown)
https://endless-sphere.com/forums/viewt ... =3&t=82196

For this one, I clamped two thick square-bars together and drilled-out the center with a hole-saw. I drilled from both ends towards the center, then separated them and halfmoon-filed the slot. Of course the size of this aluminum mass was way overboard, it could be much smaller and still help quite a bit.
Building such a massive heatsink is like reinventing the wheel - I can just buy a regular rectangular heatsink with fins, fix it to the PR with the M4 bolts and some thermal paste, and that's it. The whole point is finding a way to connect the already existing heatsink (the bike frame) with the PR... :D
And, even if I build one - the frame geometry is not a circle, nor an ellipse, but a constantly changing shape due to the hydroforming build. The cross-section geometry of the frame is already different even beneath one extreme of the PR to the other.

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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by thunderstorm80 » Oct 20, 2017 1:09 pm

Drunkskunk wrote:I'm not sure how much effort you want to put into this, but you can cast a formed heat sink in aluminum with not much more than some wax, a BBQ grill, some old beer cans.

Simplified, the process would be something like:
-cover the Phaserunner and frame with masking tape. Then tape the Phaserunner to the frame where you want it, make sure you tape it well to seal all around it.
- pour melted wax into that space and let it harden
-remove the wax casting and clean up the shape with sandpaper.
-Mix sand and a small amount of motor oil until you get a thick sand paste. it doesn't take much oil.less oil is better, it just has to be able to hold it's self together.
-Stick the wax casting in an old soup can or something similar. Pack the sand around it tight but leave the top exposed.


melting aluminum is easy, but finding which system you want to use is a bit tricky. google Melting aluminum. there are a lot of ideas, and you'll have to decide which is right for you. In essence, a leaf blower, a BBQ grill, and a soup can is all you need. A graphite cruicable would be helpful, and is in the $20-$30 range. You can melt scrap soda and beer cans, or just buy some aluminum ingots to melt.

-Pour the aluminum onto the wax mold. the molten aluminum will displace the wax and fill in the space in the sand.
-When it cools, clean up the casting with some sandpaper, and you'll have a form fitting heat sink.... on the 3rd or 4th try... :mrgreen:
That's a really nice idea, but I think that even that wouldn't be accurate enough so I would probably just go with a regular rectangular heatsink (such as from an old CPU) and get over with it...

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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by thunderstorm80 » Oct 20, 2017 1:11 pm

Chalo wrote:Funny 21st century problem you got there. Straight round tubes made the best bicycle frames 100 years ago, and it's still true today. It's not very hard to thermally interface with one of those.
Not when you have hydroforming geometry: The cross-section at any part of the frame along it's length is not fixed.
All my bikes are modern, so all have that geometry.

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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by wturber » Oct 20, 2017 2:16 pm

thunderstorm80 wrote:
Chalo wrote:Funny 21st century problem you got there. Straight round tubes made the best bicycle frames 100 years ago, and it's still true today. It's not very hard to thermally interface with one of those.
Not when you have hydroforming geometry: The cross-section at any part of the frame along it's length is not fixed.
All my bikes are modern, so all have that geometry.
I think Chalo understands that. I think he's making the point that not only do the modern, complex, hydroformed shapes offer little or no real advantage, they also complicate something that would have been simple if 100 year old round tubes had been used.
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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by Triketech » Oct 20, 2017 9:40 pm

Unless you expect to run over about 2000 watts continuously you won't need a heatsink. I've run mine at 1500 watts for extended runs and it barely got warm.

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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by spinningmagnets » Oct 20, 2017 9:57 pm

Building such a massive heatsink is like reinventing the wheel - I can just buy a regular rectangular heatsink with fins, fix it to the PR with the M4 bolts and some thermal paste, and that's it. The whole point is finding a way to connect the already existing heatsink (the bike frame) with the PR...
Rather than me starting small, and then make larger versions in steps, I preferred to make one as large as was convenient, using methods and materials that are readily available, then cut it down in steps. I would recommend an aluminum plate that is roughly the size and shape of the stock baseplate, then halfmoon-file a shallow cylindrical depression to mate it with the seat-tube.

If you do add an additional baseplate and mount the PR vertically, perhaps make it a little longer on the top and bottom to facilitate attachment options.

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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by Epyon » Oct 20, 2017 11:11 pm

wturber wrote:
thunderstorm80 wrote:I think Chalo understands that. I think he's making the point that not only do the modern, complex, hydroformed shapes offer little or no real advantage, they also complicate something that would have been simple if 100 year old round tubes had been used.
Hydroforming offers many advantages. Aesthetics is the top one, but it offers structural advantages as well. Weight savings if done right and better weld interfaces. In hardtails, yeah it probably doesn't offer much beyond looks, but on suspension frames you get some great designs that probably couldn't be accomplished with straight tubing.

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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by Chalo » Oct 21, 2017 12:02 am

Epyon wrote: Hydroforming offers many advantages. Aesthetics is the top one,
I think you mean the only one.
but it offers structural advantages
Nope.

Study what a truss is and why it works. No trusses in the engineering world ever have curved struts. It defies the purpose of a strut.
Weight savings if done right
Nope. See above.
and better weld interfaces.
Maybe. But was that a problem with round tubes? I don't think so.

Hydroformed frames serve marketing wankers who are trying to distinguish their product and persuade people to spend more than it's worth, but they don't serve anybody else. They always mean more material to do the same job, or the same amount of material to do an inferior job. And of course they don't accept mountings with nearly as much versatility.
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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by Epyon » Oct 21, 2017 12:25 am

but it offers structural advantages
Nope.

Study what a truss is and why it works. No trusses in the engineering world ever have curved struts. It defies the purpose of a strut.
Weight savings if done right
Nope. See above.

I think you're only imagining vertical forces, where a straight triangle shines. Bicycle frames are subjected to much more than that. I'm not talking curved tubes so much as contoured or flared tubes.
and better weld interfaces.
Maybe. But was that a problem with round tubes? I don't think so.
With multiple tube joints and machined pieces, yes it definitely is a problem.
Hydroformed frames serve marketing wankers who are trying to distinguish their product and persuade people to spend more than it's worth, but they don't serve anybody else. They always mean more material to do the same job, or the same amount of material to do an inferior job. And of course they don't accept mountings with nearly as much versatility.
[/quote]
It's just evolution (or something). Much like putting an electric motor on a bicycle.

I trust my modern hydroformed downhill frames far more than most from the past. I broke many (frames and bones). I've even accepted the dark side that is carbon.

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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by rberger » Oct 23, 2017 3:18 am

Looks like thunderstorm80 was correct and I was mixing up Battery Current output capacity and Phase Current. And now that I've got my trike all set up and tried to go up my big hill (1500 ft rise in 2 miles) I seem to be getting the Phaserunner into thermal cutback. (All the details of my trials and tribulations at the forum entry Power "Sag" when going up a long hill. But not overheating. Turned out I wasn't overheating the motor but was overheating the Phaserunner.

So now that I realize I really need a Heatsink, and I'm minimally mechanically inclined, I'm looking for a heatsink I don't have to fabricate myself (even though the BBQ Aluminum forge sounded like a hot idea!). I can probably drill some holes, but that's about it. I'm also not clear as to how much heatsink I need.

I'm wondering if something like a relay heat sink along the lines of
3 phase relay heatsink sm.jpg
3 phase relay heatsink sm.jpg (36.53 KiB) Viewed 791 times
https://www.amazon.com/dp/B01A9VUFGS could be used? Not clear how wide that middle part is though if it would fit on the boom or fit the Phaserunner.

Or could I use one of these basic heat sinks
generic aluminum heatsink sm.jpg
generic aluminum heatsink sm.jpg (20.81 KiB) Viewed 791 times
, mount the fins against the boom (no wrap around or any real thermal coupling to the boom) and the phaserunner to the bottom flat plate?

Any other suggestions for the fabrication challenged?
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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by wturber » Oct 23, 2017 2:35 pm

I would suggest an approach like this - including the fan. A good flow of air probably matters as much or more than the heat sink design.

Image

The plate that mounts this to the frame is just a piece of aluminum bar that was cut with a hacksaw and had holes drilled in it for the stand-offs and holes drilled for mounting to the water bottle cage mounts.
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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by rberger » Oct 28, 2017 3:55 pm

Just for the record I had found what seems to be the perfect heatsink at HSC Supply Surplus Electronic Parts store.
PR on Copper Front View sm.jpg
PR on Copper Front View sm.jpg (103.64 KiB) Viewed 658 times
Doesn't really use the frame as a heatsink much though. But it has a 100mm long x ~50mm wide copper plate that I attached the Phaserunner to with thermal paste and tie wraps (for now) and it seems to be working great.
PR Tie wrapped to HS Front Side Gd sm.jpg
PR Tie wrapped to HS Front Side Gd sm.jpg (70.83 KiB) Viewed 658 times
I was able to go up my big hill without Thermal Rollback for the first time using this. It wasn't a complete test as my human motor pooped out a few times and had to take 3 rests. But before I couldn't do that without several Thermal Rollback incidents.

If I find its still gets overheated, I can add a fan.
PR on Copper w Fan Front View sm.jpg
PR on Copper w Fan Front View sm.jpg (109.32 KiB) Viewed 658 times
Any suggestions on how to make the fan automatically turn on at some specific temperature without adding a computer? Are there any 12V thermo switches or something that I could mount on the heatsink?
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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by wturber » Oct 29, 2017 1:29 am

There are a few 12v thermal relays on Amazon. You might also try a thermally controlled case fan. The thermal sensor regulates fan speed, but does not turn the fan on and off.
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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by amberwolf » Oct 29, 2017 2:24 am

Yes, for those just go to a computer store and get one of the case (or CPU) fans that has a built-in thermal sensor. These often spin at a very slow rate (silently) whenever powered on, but spin faster the hotter the sensor gets. The sensor is usually a little green "blob" sitting in the airflow near the fan motor. That's probably good enough, if you have it sucking air off the heatsink, rather than blowing onto it.

If you want it to react more to the heatsink temperature you can disconnect the little blob and solder some extension wires to it, then put the blob on the heatsink itself, close to the PR. Sometimes these fans have the sensor already separate to do this with (so it can be put on the CPU heatsink, for instance).

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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by loopdiggakid » Dec 30, 2017 10:46 pm

I used to be in the R/C scene a while back and now i'm also in the works of purchasing the phaserunner for my own build. I thought I would share this incase one might want to try and incorporating this on their own build as what seems you may be able to place around the frames tube. If you place 2 side by side (would make it 96x48mm) they should work as the phaserunner's dimensions are 99x33mm.

hwa86080130/p279175
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Here is the link where to purchase

https://www.amainhobbies.com/hobbywing- ... 30/p279175

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Re: Using bicycle's frame as heatsink for the Phaserunner

Post by LewTwo » Dec 31, 2017 6:22 am

As an alternative to Drunkskunk's idea there are certain low melting point metals that might be of use: Wood's metal, Rose's metal
https://en.wikipedia.org/wiki/Wood%27s_metal

This stuff is expensive (about $16 per pound) but I should think less than a pound would be required.
https://www.rotometals.com/roto158-190f ... loy-ingot/

I should think that a casting mold could be made around the frame with something a simple as modeling clay, wood, Plaster of Paris or paper mache. The low temperature metal can be melted with hot water and poured into the mold. After it is cooled , remove the mold and you have a form fitting chunk of metal to go between the frame and the PR.
Sample Mold(788).png
Sample Mold(788).png (74.34 KiB) Viewed 264 times
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