This will be a very lazy building thread as I take all the time, I need to have a fun build.
PCBs will come from ZM in version with many (most) components mounted.
PSUs has also been ordered. Those will be 65V SMPS's.
Chassis has also been ordered from Modushop and a big box was in front of my door when I came home this evening (26.5 kg).
What added to the weight was the special heat spreaders to spread heat from a single device on each side of the mono block chassis.
Each chassis has 2 x 200 mm heat sinks on each side. This gives a challenge when only one device is mounted that needs both sinks.
A couple of images attached. One image shows the unpacked 10mm thick heat spreaders. Two for each chassis.
Shipment was only a few days.
Now time to think about how to mount the heat spreaders. Will have a closer look at the heat sinks to explore possibilities.
So far so good. This was the easy part just to order and spend some money!
PCBs will come from ZM in version with many (most) components mounted.
PSUs has also been ordered. Those will be 65V SMPS's.
Chassis has also been ordered from Modushop and a big box was in front of my door when I came home this evening (26.5 kg).
What added to the weight was the special heat spreaders to spread heat from a single device on each side of the mono block chassis.
Each chassis has 2 x 200 mm heat sinks on each side. This gives a challenge when only one device is mounted that needs both sinks.
A couple of images attached. One image shows the unpacked 10mm thick heat spreaders. Two for each chassis.
Shipment was only a few days.
Now time to think about how to mount the heat spreaders. Will have a closer look at the heat sinks to explore possibilities.
So far so good. This was the easy part just to order and spend some money!
there must be something funny in 'Olanda water ..... 
heatspreader - M4, Allen screws, shoot between heatsink ribs
all shown here: https://www.diyaudio.com/community/...-pt-2-n-channel-assembly-by-mighty-zm.385977/
for 400 deep, meaning 2*200, I would go for at least 3 pairs of bolts per each hsink, meaning 6 pairs per heatspreader plate
PL is not using goop between base plate and heatsink modules ( big amps)
depending how good is surface of these heatspreaders, maybe you'll need it or not
if extrusion surface is blameless (you can't feel "waves"), no goop
if you can feel them, then goop
remember, proper torque ( no need for torque meter, go wild) and split washers, as must
heatspreader - M4, Allen screws, shoot between heatsink ribs
all shown here: https://www.diyaudio.com/community/...-pt-2-n-channel-assembly-by-mighty-zm.385977/
for 400 deep, meaning 2*200, I would go for at least 3 pairs of bolts per each hsink, meaning 6 pairs per heatspreader plate
PL is not using goop between base plate and heatsink modules ( big amps)
depending how good is surface of these heatspreaders, maybe you'll need it or not
if extrusion surface is blameless (you can't feel "waves"), no goop
if you can feel them, then goop
remember, proper torque ( no need for torque meter, go wild) and split washers, as must
I will sand the heat spreaders to get a more even surface (and also remove sharp edges).
I don't have a bench drill (but have considered to get one). Maybe I can drill the holes "by hand".
It would be best if I could fix the spreaders to the heatsinks, so I drill through both sink and spreader, so I am sure the holes "match".
I have silicon carbide grains and aluminium oxide powder for leveling sharpening stones for a knife sharpening system. It is done using water and a glass plate. But glass plate is not that big.
Will check distance between ribs.......
I don't have a bench drill (but have considered to get one). Maybe I can drill the holes "by hand".
It would be best if I could fix the spreaders to the heatsinks, so I drill through both sink and spreader, so I am sure the holes "match".
I have silicon carbide grains and aluminium oxide powder for leveling sharpening stones for a knife sharpening system. It is done using water and a glass plate. But glass plate is not that big.
Will check distance between ribs.......
Devices are placed "dead center" or just a bit below horisontal line?
Heat will "travel up" caused by hot air so best to place the devices a bit below the horisontal line?
Heat will "travel up" caused by hot air so best to place the devices a bit below the horisontal line?
If I optimize........I can go higher in bias!
I have 3M lapping film down to 0.3 micron. If I worked both surfaces and had access to vacuum (to avoid oxidation), then heatsinks and spreader could be cold welded together. But back to realism......I will even the surfaces of the spreaders. Have not checked heatsink surfaces yet.
I have 3M lapping film down to 0.3 micron. If I worked both surfaces and had access to vacuum (to avoid oxidation), then heatsinks and spreader could be cold welded together. But back to realism......I will even the surfaces of the spreaders. Have not checked heatsink surfaces yet.
I keep going back & forth on whether to do this (add the M4 bolts) for my Sony VFET build once I get the chassis. The lapping, drilling & tapping of the bracket requires disassembly of Papa's handiwork & so I hesitate.
no, if you're careful
I did it simply because I wanted to replace puny silicone TO3 pads with olde mica+goop
but, again, that's my OCD in the work, majority of Greedy Boyz are totally happy, even seeing SITs glowing in the dark
https://www.amazon.se/dp/B005OQEK9W?psc=1&ref_=cm_sw_r_apin_dp_KKVRJ0TGKZZZT95FVZ8C
High quality, resonable price, more than good enough for home use in my opinion.
Well. Perfect for straight as an arrow drilling jobs in them fine heatsinks 🙂👍
Naah, not really free free. But close enough in the really good sounding high fidelity context 😎
The Bosch PDB40 is exactly the one I have considered. It gets fine reviews.
Does the laser pointer work or is it more a "gimmick"?
With bench drill it is nice to know exactly where the drill bit hits.
Free hand you have a punch mark the drill bit "catches".
Does the laser pointer work or is it more a "gimmick"?
With bench drill it is nice to know exactly where the drill bit hits.
Free hand you have a punch mark the drill bit "catches".
I would say that the laser pointer is good enough for woodwork, but with higher precision work as drilling heatsinks, i always punch mark first, to avoid the drill bit to dance around or drift away.
Ok, I need to learn bench drill technique on how to hit an exact point when the item to drill into has been fixed and secured.
It would be nice to have some X and Y axis adjustment?
It would be nice to have some X and Y axis adjustment?
That kind of x-y clamped and adjustable precision is only attainable in very expensive professional equipment.
But even they, the professionals with high end drill presses, punch marks first. Because no matter how stable the drillpress, the thin drillbit can flex away.
But do you then fix the item to drill into after the drill bit has "hit" the punch mark?
So, you move the item with one hand and the other hand on the "drill press handle"?
So, you move the item with one hand and the other hand on the "drill press handle"?
No need to clamp in my opinion. I placed a thin protective rubber sheeting on the drilltable. To avoid scratching the heatsinks.
Then i punchmarked for drill bit guidance and calmly freehanded the drilling process.
Result: More than Close enough for cigarr 🙂👍
Then i punchmarked for drill bit guidance and calmly freehanded the drilling process.
Result: More than Close enough for cigarr 🙂👍
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OK!
What I like with pure freehand is that you can fix the item 100% first and then hit the punch mark.
Now 3, 4mm bits are so small so safety is not a big issue with those bench drill. But with large bits like 10mm or larger then if the bit "dicks" into the item it rotates very fast so you can cut yourself. I have heard that a bench drill can be dangerous tool if the item is not fixed 🙂 But again with 3, 4mm bits it should be ok.
What I like with pure freehand is that you can fix the item 100% first and then hit the punch mark.
Now 3, 4mm bits are so small so safety is not a big issue with those bench drill. But with large bits like 10mm or larger then if the bit "dicks" into the item it rotates very fast so you can cut yourself. I have heard that a bench drill can be dangerous tool if the item is not fixed 🙂 But again with 3, 4mm bits it should be ok.
It’s not that hard to do without a bench drill. The best way to do it is by making the punch mark, drilling it with a smaller bit like a 1.5mm and than drilling it with the 3 or 4mm bit. You don’t need to go full depth with the 1.5mm bit, it’s just to help with the alignment of the bigger bits with the punch mark. That way you will be dead center.