Holes position on heatsink
I'm looking for drawing that shows position of UMS holes in 5U (and 4U) heatsinks.
I do drilling and tapping myself and was not able to find dimensioning information relative to heatsink. Horizontal position is obviously symmetrical, but vertical placement seems to have some offset from center - at least on the pictures.
I'm looking for drawing that shows position of UMS holes in 5U (and 4U) heatsinks.
I do drilling and tapping myself and was not able to find dimensioning information relative to heatsink. Horizontal position is obviously symmetrical, but vertical placement seems to have some offset from center - at least on the pictures.
You can find the mounting specification here https://cdn.shopify.com/s/files/1/1006/5046/files/universal-mounting-specification-v2.1.pdf
I thought that that suet of data was linked to archive via the relevant store pages.
I know this spec, but cannot find information how to place holes relative to heatsink. In other words what are x,y coordinates of let's say top right hole.
Horizontal and vertical symmetry would be a guess, but pictures posted by e.g. @6L6 in his illustrated F5T build guide suggest that there is no vertical symmetry.
I was wondering whether such placement was intentional to make heat dissipation of MOSFETs most optimal - i.e. to move them towards center of heatsinks.
Thank you Jason. This makes the picture complete now.Here is the missing linkWe have quite some work to do on revising and polishing these specs up. In the coming months we'll redo them all into a nice looking PDF.
I drilled "fully symmetrical" pattern on my 5U before I realized (based on the pictures) that there may not be vertical symmetry.
I hope this will not impact heat dissipation much.
The vertical positioning was decided many many years ago after some consultation and what you see was the end result that tried to afford a good mix of performance and utility for the expected requirements of commonly used boards (including the fact some only have transistors on one side). If you drilled equidistant from each side it should make no practical difference.
Actual calculation of thermal performance is a hideously complicated field, but based on things I've seen on diyAudio over the years placement isn't as important as ensuring you just have a big enough heatsink and use a reliable insulator like Keratherm. In a perfect world, you'd have all transistors as perfectly far apart from each other as possible, but as with everything there are often more important things to worry about. For an excellent in depth analysis by EUVL on this topic see this Linear Audio article. Being DIY, there's nobody stopping you from drilling and tapping your own holes anywhere on the heatsink and using fly wires to sate your OCD of course At the end of the day you should do whatever makes you happy and gives you a great experience. You may sleep well at night however knowing that hundreds if not thousands of diyAudio members have built amps using these heatsinks over the years and had no problems, provided they chose big enough heatsinks.
Actual calculation of thermal performance is a hideously complicated field, but based on things I've seen on diyAudio over the years placement isn't as important as ensuring you just have a big enough heatsink and use a reliable insulator like Keratherm. In a perfect world, you'd have all transistors as perfectly far apart from each other as possible, but as with everything there are often more important things to worry about. For an excellent in depth analysis by EUVL on this topic see this Linear Audio article. Being DIY, there's nobody stopping you from drilling and tapping your own holes anywhere on the heatsink and using fly wires to sate your OCD of course
At the end of the day you should do whatever makes you happy and gives you a great experience. You may sleep well at night however knowing that hundreds if not thousands of diyAudio members have built amps using these heatsinks over the years and had no problems, provided they chose big enough heatsinks.
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Hi,
I purchased a 5u deluxe a few years back... I know the pre-drilled holes are M3, but what is the pitch?
Its hard to source metric hardware around these parts , otherwise I would have just bought a few to try out.
It's funny sometimes how such small obstacles can derail a project. That, and renovation + having a kid. Haha. Hard to say for sure what slowed down the progress .
Thanks,
Tim
I purchased a 5u deluxe a few years back... I know the pre-drilled holes are M3, but what is the pitch?
Its hard to source metric hardware around these parts
, otherwise I would have just bought a few to try out.It's funny sometimes how such small obstacles can derail a project. That, and renovation + having a kid. Haha. Hard to say for sure what slowed down the progress .
Thanks,
Tim
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It's a standard (course) thread pitch, which means for M3 the thread pitch is 0.5mm.
ISO metric screw thread - Wikipedia
ISO metric screw thread - Wikipedia
Thank you.
I'm gonna do a bulk order of all the odds and ends I will need to keep going once the house reno tapers off over the winter. This was on the list!
Cheers,
Tim
Chassis options by internal size
Apologies if this information is available elsewhere. I did a few searches and turned up nothing, but my google fu may be weak.
Because the chassis internal sizes are spread out across individual listings in the site, I created a table of all the chassis sizes available for order through the store (today at any rate). Note that, unless stated otherwise, the external sizes are minimum based on steel chassis options.
Table is sorted by internal width, depth, height.
I know most people are going to start a chassis search with dissipation and heatsinks in mind, but hopefully this is helpful, too.
Cheers.
Apologies if this information is available elsewhere. I did a few searches and turned up nothing, but my google fu may be weak.
Because the chassis internal sizes are spread out across individual listings in the site, I created a table of all the chassis sizes available for order through the store (today at any rate). Note that, unless stated otherwise, the external sizes are minimum based on steel chassis options.
Table is sorted by internal width, depth, height.
I know most people are going to start a chassis search with dissipation and heatsinks in mind, but hopefully this is helpful, too.
Cheers.
Great work.
Do you have this in Excel format that you would be happy to share? That would make it very easy to enable filtering by dimension of interest.