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davidzo · 12-01-2006, 01:50 PM

Also your top still looks a little risky for failures.
Also Plexiglas (Acryl) may not be the best material for the top as it can crack easily. polycarbonat is a lot better, but is less hard what evolves in problems with leaksealing at higher pressure at certain screw distances. its always better to have a little thicker top and a bigger radius to the side aroung the screws. dangerdens radius around the screw is too small, thats why those blocks often crack even when the plexi is relatively thick. Adittionally they have a really bad milling quality of the plexiparts and to not temper them long enough what makes cracking acrylic much likelier. When Plexiglas is handled in the correct way (e.g. not in dangerden way) it can still be a reliable material, its hardness is even superiour to non translucent very popular delrin(pom, acetal), what makes constructing with less screws (=better looking) easier and when it is correctly tempered it can withstand enough to last longer than every normal pc watercooling setup.
There are just a few musts and no nos that have to be allowed for:
- milling with good cooling and a special plastics bit, even better lasercutting
- at least 8mm thickness for threads and screws, better 10 or 12mm
- before tempering the surface should be flat and even and not rough like a rasp on dangerden blocks, polishing helps to make tempering more effective
- tempering should be done after all other work, the material should be handled with care at every point and should not be brought in contact with chemicals as Aceton, Benzine or other agressive chemicals used for cleaning
- never use teflon, be aware of orings which seal inside the thread or other thread sealants, only use orings which seal on the top surface, not in the thread
- use a minimum radius around corners of 5mm to prevent cracks around screws
- never use counter sunk screws in plexiglas or any other acrylic plastic
- do not use threads inside the plexiglas other than those of the barbs, better make the threads in the copper (e.g. do not use small therads with high loads)
- do not overtighten screws or barbs. sometime sit is useful to washers which spread the applied forces and do not harm the surface while tightening.

If you can maintain these important rules for use of plexiglas in PC-watercooling it won't make any problems.
A much more tolerable Material also arguable not as good loking as acrylic materials, is POM also known as delrin or Acetal. Acetal is easy to mill even without special cooling and it has superiour mechanical capabilities. its dynamic friction is really low what makes screwing in the barbs really easy, but does also make polishing impossible. you can either snadblast and oil it which makes for a nice dull black finish or you have to optimize the millingprocess that the material looks good enough when it comes out of the mill (like the swiftech storm blocks).

Think about that and oh yeah, the S939holes on your picture should be a little bigger otherwise even a tiny M3 screw woulnd't fit them and it would also be wise to add S775 and AM2 support.

12-01-2006, 01:50 PM	#6
davidzo Cooling Savant Join Date: Mar 2003 Location: Hamburg Posts: 141	Re: My waterblock design Also your top still looks a little risky for failures. Also Plexiglas (Acryl) may not be the best material for the top as it can crack easily. polycarbonat is a lot better, but is less hard what evolves in problems with leaksealing at higher pressure at certain screw distances. its always better to have a little thicker top and a bigger radius to the side aroung the screws. dangerdens radius around the screw is too small, thats why those blocks often crack even when the plexi is relatively thick. Adittionally they have a really bad milling quality of the plexiparts and to not temper them long enough what makes cracking acrylic much likelier. When Plexiglas is handled in the correct way (e.g. not in dangerden way) it can still be a reliable material, its hardness is even superiour to non translucent very popular delrin(pom, acetal), what makes constructing with less screws (=better looking) easier and when it is correctly tempered it can withstand enough to last longer than every normal pc watercooling setup. There are just a few musts and no nos that have to be allowed for: - milling with good cooling and a special plastics bit, even better lasercutting - at least 8mm thickness for threads and screws, better 10 or 12mm - before tempering the surface should be flat and even and not rough like a rasp on dangerden blocks, polishing helps to make tempering more effective - tempering should be done after all other work, the material should be handled with care at every point and should not be brought in contact with chemicals as Aceton, Benzine or other agressive chemicals used for cleaning - never use teflon, be aware of orings which seal inside the thread or other thread sealants, only use orings which seal on the top surface, not in the thread - use a minimum radius around corners of 5mm to prevent cracks around screws - never use counter sunk screws in plexiglas or any other acrylic plastic - do not use threads inside the plexiglas other than those of the barbs, better make the threads in the copper (e.g. do not use small therads with high loads) - do not overtighten screws or barbs. sometime sit is useful to washers which spread the applied forces and do not harm the surface while tightening. If you can maintain these important rules for use of plexiglas in PC-watercooling it won't make any problems. A much more tolerable Material also arguable not as good loking as acrylic materials, is POM also known as delrin or Acetal. Acetal is easy to mill even without special cooling and it has superiour mechanical capabilities. its dynamic friction is really low what makes screwing in the barbs really easy, but does also make polishing impossible. you can either snadblast and oil it which makes for a nice dull black finish or you have to optimize the millingprocess that the material looks good enough when it comes out of the mill (like the swiftech storm blocks). Think about that and oh yeah, the S939holes on your picture should be a little bigger otherwise even a tiny M3 screw woulnd't fit them and it would also be wise to add S775 and AM2 support.