Hi guys
Is it possible to weld heatsink together and still have fully functional thermal dispation? I’m using these heatsinks
http://cgi.ebay.com/HEATSINK-ALUMIN...ryZ31489QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
Is it possible to weld heatsink together and still have fully functional thermal dispation? I’m using these heatsinks
http://cgi.ebay.com/HEATSINK-ALUMIN...ryZ31489QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
The quality of aluminium welding has very much improved.
For good strength the melted mother material has to be thoroughly mixed with the weld, a strong weld also has good thermal crossing. That leaves the welding material that has to be homogenous.
The aluminium parts i welded 30 years ago with argon-arc had joints that looked like spongecake.
MIG and TIG welding have been so much improved that an aluminium weld can be stronger than steel welds nowadays.
Thermal transfer of welded aluminium can be good, depends mostly on the skill of the one doing the TIG welding.
The TIG welding on my boat was done by a photo-welder, i could never weld like that.
You can google for an article called: Why Aluminium ?
(originally by D.Boon of Vripack yacht design for Palmer&Johnson Yachts/Wisconsin)
For good strength the melted mother material has to be thoroughly mixed with the weld, a strong weld also has good thermal crossing. That leaves the welding material that has to be homogenous.
The aluminium parts i welded 30 years ago with argon-arc had joints that looked like spongecake.
MIG and TIG welding have been so much improved that an aluminium weld can be stronger than steel welds nowadays.
Thermal transfer of welded aluminium can be good, depends mostly on the skill of the one doing the TIG welding.
The TIG welding on my boat was done by a photo-welder, i could never weld like that.
You can google for an article called: Why Aluminium ?
(originally by D.Boon of Vripack yacht design for Palmer&Johnson Yachts/Wisconsin)
Hi
I am also considering welding some small heatsinls together.
I have used chemical metal on other alloy items and it has worked. I am planning to try chemical metal om some heatsinks and I am hopeful.
On some others with machined faces I am planning to use acrylic glue as used in the aero industry - although I think this will only work to fasten two machined faces together.#
Don
I am also considering welding some small heatsinls together.
I have used chemical metal on other alloy items and it has worked. I am planning to try chemical metal om some heatsinks and I am hopeful.
On some others with machined faces I am planning to use acrylic glue as used in the aero industry - although I think this will only work to fasten two machined faces together.#
Don
Banned
Joined 2002
I’m building an Aleph-X 100W . Using this scematic: http://www.kk-pcb.com/alephx.html
I have four heatsinks per channel-2 power transistors/heatsink. After about one hour they will get to hot, over 60 C. If I use one more heatsinks/channel I think it’s going to be enough. But the problem with this is how to spread the heat between the heatsinks. I tried to mount them side by side VERY tight but that wasn’t nearly enough. So what’s left? All can think of is:
Either welding them together or mounting them with think aluminium plates.
I have four heatsinks per channel-2 power transistors/heatsink. After about one hour they will get to hot, over 60 C. If I use one more heatsinks/channel I think it’s going to be enough. But the problem with this is how to spread the heat between the heatsinks. I tried to mount them side by side VERY tight but that wasn’t nearly enough. So what’s left? All can think of is:
Either welding them together or mounting them with think aluminium plates.
Banned
Joined 2002
hehe-speaking of welding...jacco vermeulen said:
yacco-can you point me on some handy webb source...friend of mine need new paddle for entirely new setup (new engine+Z-foot) for his 6m boat ; problem is that almost entire boat is DIY made,and few local guys asks too much cash for calculations........
so-in short-how to calculate paddle parameters-.......?
sorry for off topic
btw-copper spreader is way to go
Zen Mod said:
[Way off-topic On]
Zen-raper,
i suppose you mean the boat has an engine and a Z-drive and you need to know what kind of screw is needed ?
If so:
The screw type depends on the outgoing RPM, speed of the boat (engine power), torque, and allowable screw diameter. A cavitating screw is required for a planing or semi-planing hull.
Don't think you'll find much information on the web, the boatbuilding business is very conservative, and many parameters are emperical.
[Way off-topic Off]
copper heat sinks
Hi,
The guys talking about the copper heat sinks have a valid point.
Some years back I worked on a Ling 8016 power amp used in the vibration business. It had 860 output transistors on 16 output cards. Each TO3 package was mounted to a copper bar, and on the back of the bar was a small water pipe.
The whole amp was cooled by street water.
When cranked up to full power (about 80kw) we never had a heat related failure of the parts.
A few times when other heavy water using devices were running we did trip a safety when enough GPH coulden't get through the amp.
There are a lot of surplus heat sinks on the market. Taking an existing one and choping it to fit is always an option. Or go the micro processor route and have individual fans blowing across each heat sink.
Good luck on your project
Mike aka Jack Crow in Kuwait
Hi,
The guys talking about the copper heat sinks have a valid point.
Some years back I worked on a Ling 8016 power amp used in the vibration business. It had 860 output transistors on 16 output cards. Each TO3 package was mounted to a copper bar, and on the back of the bar was a small water pipe.
The whole amp was cooled by street water.
When cranked up to full power (about 80kw) we never had a heat related failure of the parts.
A few times when other heavy water using devices were running we did trip a safety when enough GPH coulden't get through the amp.
There are a lot of surplus heat sinks on the market. Taking an existing one and choping it to fit is always an option. Or go the micro processor route and have individual fans blowing across each heat sink.
Good luck on your project
Mike aka Jack Crow in Kuwait
GW,
Good question.
Now you show up my ignorance of the rest of the world.
In the US there are companies that buy up scrap and surplus military and industrial electronics.
Some items end up on web sites of used gear.
The one that I use is called MPJA and they are in Florida USA.
They have all kinds of stuff. Good people.
When I was last down there, I ran into a few wharehouse operations that did the same thing.
Care to guess who diden't think to get a business card.
At times like this, Google can be your friend.
Do you know anybody with a good machine shop with a three axis mill? Sometimes known as a Bridgeport. A guy good with that tool can make some amazing parts, and convert surplus parts to a new requirment.
Where I used to work we had one there. Our operator modified an old heat sink to fit a 10 watt class A Brick RF amplifier. Made a 'flat' area for the brick, drilled, tapped and countersunk the mounting holes. A thing of beauty.
I gather your building a 'one of a kind' unit this is not too bad a way to go.
As for locating chunks of metal, there are scrap dealers that trade. Again back home if I needed a block of aluminum or steel, it's a look in the phone book for the nearest one.
Are you near any kind of industry? Perhaps someone who has a small machine shop can be of help.
Expensive but worth it.
Much luck
Jack Crow aka Mike in Kuwait
Good question.
Now you show up my ignorance of the rest of the world.
In the US there are companies that buy up scrap and surplus military and industrial electronics.
Some items end up on web sites of used gear.
The one that I use is called MPJA and they are in Florida USA.
They have all kinds of stuff. Good people.
When I was last down there, I ran into a few wharehouse operations that did the same thing.
Care to guess who diden't think to get a business card.
At times like this, Google can be your friend.
Do you know anybody with a good machine shop with a three axis mill? Sometimes known as a Bridgeport. A guy good with that tool can make some amazing parts, and convert surplus parts to a new requirment.
Where I used to work we had one there. Our operator modified an old heat sink to fit a 10 watt class A Brick RF amplifier. Made a 'flat' area for the brick, drilled, tapped and countersunk the mounting holes. A thing of beauty.
I gather your building a 'one of a kind' unit this is not too bad a way to go.
As for locating chunks of metal, there are scrap dealers that trade. Again back home if I needed a block of aluminum or steel, it's a look in the phone book for the nearest one.
Are you near any kind of industry? Perhaps someone who has a small machine shop can be of help.
Expensive but worth it.
Much luck
Jack Crow aka Mike in Kuwait
Banned
Joined 2002
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.