i understood what you wanted to say while i was posting :p

As a tip, you're going to want to keep that layer VERY thin, because those small holes are very restrictive, and they will be even more restrictive if they're deep.

Think along the lines of "paper thin".;)

ok i got that, the problem is that if i am going to make 7 holes, i have to forget about making a hole round the slit for the thread of the barb to fit in so that the water does not escape.

so the only option that remains is to make a block with 2 o rings?? one between 2nd layer and base and the other between top and 2nd layer.

are there any other options???

Why don't you just solder a short piece of 1/2" copper pipe, instead of trying to thread a hole for a barb? The 1/2" pipe should have an ID of 12.7mm .

If the tops of the fins contact the under side of the top I see no advantage to holes over a single slit. They will only increase friction = increased head loss, for no gain in cooling. I also like the idea of a 5/8" barb, and drill it out to boot. Anything to maintain max flow until inside the block where the head loss can be traded for increased cooling. You could even insert a bit of copper 1/2' tube (or 1/2" joiner tube/fitting the true OD is just under 3/4" with those but this would only help if running over sized lines), then sodder in place. Disadvantage with that is they don't come out real easy for testing changes, but another possible way to go.

I do very much like the idea of a slightly inlarged opening for the center 3 channels. This could be done with a very small roto saw cutter. But I can see a couple of concerns in doing this.

1) you don't want to decrease the flow in the outer channels by much.

2) I'd start out with only about a 20% increase per inner channel to start with. You can open it later if you wish as you are testing.

3) A narrowing of the slit overall will be needed if a very large increase in the center slits is done. This of course to maintain velocity.

edit: I see Ben posted ahead of me on the copper tubing idea. I really like the idea/advantage of higher flow gained useing copper tube as inlets/outlets to blocks as opposed to barbs. Keeps head loss at a mimimum where it does nothing to improve cooling.

edit (2) for better clarity on the sizing of copper tubing to use.

because i wanted plexy top, to be visible, but if not possible i will go your way :cool:

and also thank you blackeagel for you help. i found them very interesting and helpful

I have to agree. Scrap my idea. :D

In that case... You could glue a PVC fitting to the top. The PVC will be white or grey. If you want a clear fitting: www.usplastics.com

i can arrange something between the 2. because with your idea i can control the flow of the channel :)

to be sincerierly i had that idea before i draw the top, but you know what, it never came to mind that i could change the flow over the channels using it.

you are genius:drool: even you bigben :drool: and Blackeagle :drool:

thank you all

i had a new idea. i could use 1/2" or 5/8" barb and then use a reducer with one end wide as the 7 holes (a little bit more) and with the other end to fit in the barb. what do you think?

one question for you machinist, does there exist any xyz table for a drill press?? i mean the table itself moves up and down not the drill press itself

I agree with the idea of just bonding the tube in place with a epoxy, I would still use copper tube for the thin walls. Would suggest you use a but of 200 grit sandpaper to rough up the part of the tube to be bonded into the plexi top.

If you want to use clear as BB said another couple sources you could check.

www.mcmaster.com At this one the platics are in the raw materials & springs section of the first page.

www.delviesplastics.com This ones good only if you intend using acrylic.

Would suggest use of polycarbonate (Lexan) instead of acrylic, it's worth the extra cost as polycarb is about 30X stronger than acrylic.

I have not seen one before. Doesn't mean they do not exist though.

A xy & Z or just a xy tool? I havn't see a 3 way moving set up.

XY's can be had at shops selling milling equipment.

I know that it might be a stupid question, but I'll ask anyways: why?

Probably so he doesn't have to hold down the drill press handle and try to run the xy table at the same time. Some drill presses do not have a lock to hold it down. Mine doesn't. Using handwheels is a lot easier when you can have a hand on each x and y wheel at the same time.

you guessed why :drool:

so i actually did some work, that's why i took so long to post.

i found a way to use a z axis and not change the direction of where the xy table would look (i don't know if u understood this bit)

i hung a car's jack (or jag: don't know how to spell it) at the bottom of the table and when i would need to change the height, i can first open the nut at the rear of the table then change the height using the jack and then tight the nut again for security.

on the other hand, i am still not decided what xy table i am going to buy: i saw this link what do you think??

do you have other sources??

thank you

another thing that i modified before will start milling was the outlets positions. because i had to increase the size of the input, the 3 barbs did not fit near each other :eek: so i had to remodify the drawing again

If your drillpress is like mine, to lock the z axis you could do like I did. Should be more accurate.

actually i posted my reply to this thought on your thread because that is the one i saw first. when i tried that method, the z axis never locks up accuratly, far away. mabye your drill press is somewhat differente, at least i hope so

so here is an update of my design. i increased a channel on each side as you suggested my but in the last channel there are only 3 holes and in the one before the last i reduced it from 7 to 5.

now do you know where the fu** i am going to find a barb either plastic or al, better plastic having a thread of 22mm??? the inlet is preffered to be 5/8" or 1/2"

any help and any comments???

Thank you for your help :dome:

no help?? :cry: :cry: :cry: :cry: :cry:

you mean barbs like this?

they can be had from most hardware stores, look in the micro irrigation section.

but does there exist something of the sort of this size?? (see picture) with an input of 5/8" or 1/2" or i will need to use a reduce. [in the picture i am assuming that the width of the plastic where the thread is found is 2mm]

something more, those any body else know a good link for an xy table better than the one i showed you.

actually i think that the one you showed me fits exatly my needs :).

thankx volenti