Hi Jeff and Andrew, thanks for the tips.
Do you mean screwing bolts on heatsink and fixing the heatspreaders using washers and nuts?
Last edited:
Install the studs/set screws in the heat sink and attach whatever to the heat sink with nuts. No wear/damage to the aluminum threads this way.
This also helps where a tall capacitor blocks access to the bolt/screw head. A spanner can remove the nut/s
Why are you guy's not using clamping bars. You can use bigger diameter screws. Much easier to tap as well.
IMHO good idea if you often need to replace/exchange the transistors e.g. during test phase...
BR, Toni
Another option is to use a tap that "forms" the threads rather than cuts them.
These work well in Aluminium, no chips and the tap is less likely to break, not weakened by chip clearance slots.
Should be available in your country or easy to send in a plain envelope for mail order.
Best wishes
David
Something like this?Osg Tap, Right Hand, Thread Forming, M4, 0.70mm Pitch, Cobalt, Bright Finish - | eBay.
Looks fine but very expensive option!
Last edited:
The drill size for a thread forming tap is bigger than the drill size for a thread cutting tap.
You will need to find out what drill size to use for the material you are working with.
Aluminiums are quite different formulations and I suspect this affects the drill size.
You will need to find out what drill size to use for the material you are working with.
Aluminiums are quite different formulations and I suspect this affects the drill size.
Thread rolling taps are better for sheet metal. In blind holes they are more prone to stick. They do form a tough smooth thread though.
I'm not sure if Sowa will ship to Greece but they have a good selection of aluminum taps and a reasonable priced. SOWA - Homepage
I'm not sure if Sowa will ship to Greece but they have a good selection of aluminum taps and a reasonable priced. SOWA - Homepage
Yes - that's a good alternative to standard screw tapping ...
I will try using this one: gewindebohrer.de - BAER HSSE-TIN Forming Tap M 3 x 0,5 - DIN 371 with oil grooves 34TD70320601
You will need a
- 2.8mm drill for M3
- 3.7mm drill for M4
- 4.65mm drill for M5
BR, Toni
Last edited:
I can't see any reason for heatspreaders removing when transistors fail.😉
BTW. My country not included in his shipping catalog but i see very expensive shipping cost for such a small thing
Last edited:
Not those parts some posts ago - especially designed for blind holes.
But one must use oil during forming the tapping ...
BR, Toni
I was just looking at the ones you posted the link to. They look a lot higher quality than the versions I've been using. I've only used Sowa/Chinese junk to date. Notice the ones you linked to are for high speed power tapping only.
Looks like i have another option when the drilling is between fins (no blind holes required).
Attachments
Last edited:
I suspect this is only if you push the limits, they list stainless steel - which is extremely difficult.
For Aluminium I have never seen a "power only" limitation.
That's a sensible option too.😉
Best wishes
David
Last edited:
I don't trust myself to get one hole in the right place let alone two or more so I just have Modu do it 😉 in my case, it is money well spent.
