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1  Bitcoin / Bitcoin Discussion / Re: State of Florida attacks Bitcoin on: February 14, 2014, 07:56:19 AM
Is buying stolen CC numbers a crime? Using the numbers would be but would possession of the numbers be illegal?

2  Bitcoin / Hardware / Re: [Work in progess] Burnins Avalon Chip to mining board service on: September 10, 2013, 01:03:41 AM
I am in support of this idea. From reading the Avalon details on the 55nm it should be only a case of substituting the 110nm. Of course nothing is ever that easy and we will not know for sure until the full specs are released on github
3  Bitcoin / Hardware / Re: [Work in progess] Burnins Avalon Chip to mining board service on: July 06, 2013, 11:10:57 PM
Anyone know if there is electrical insulation (thermal interface material) between the heat sink and the board?

4  Bitcoin / Hardware / Re: DIY water block to suit Klondike K16 and Burnins 20 (Bitburner?) on: June 27, 2013, 11:38:31 AM
3) Thermal insulation? Maybe not Smiley

opps my bad Cheesy
5  Bitcoin / Hardware / Re: DIY water block to suit Klondike K16 and Burnins 20 (Bitburner?) on: June 27, 2013, 05:03:46 AM
I have some questions before I can accurately model the board:

1) What is the thickness of the silicon?
2) What is on the under-side of the board?
3) How are TerraHash, yourself and others expecting to transfer heat from the components, through the silicon, to the aluminum heat sinks? Thermal pads, paste?
4) What material covers the avalon chips and why can't heatsinks be attached directly to them?
5) This is only a single layer board with no trace or components on the under-side or internal layers?

1) the K16 eagle files have been posted, with the Burnin we don't know yet.
2) PCB flat with though hole pads
3) Most likely thermal insulation interface material, silicone sheet possibly, going to see what Burnin and Bkkcoins use and/or what i can get a good price on.
4) some sort of plastic and not a good heat transfer medium, chip is designed to shed head though the base into the vias in the pcb
5) multi layer boards both
6  Bitcoin / Hardware / Re: DIY water block to suit Klondike K16 and Burnins 20 (Bitburner?) on: June 24, 2013, 09:04:45 AM

I have an update on my project.

I have been looking at doing away with the welding and using ABS plastic caps and clips.

In the images below is what I intend to 3d print. There will be a 40x40 square tube running inside the block to supply water to the other side off the 200mmx50mm rectangular tube (water block) so hoses are connected at same end.
The 6mm flat bar will be held in place by the clip and a 16x16 channel either side clamped together with M8x110mm bolts, I figure 1 clamp set every 3rd PCB. Flat bar to be drilled and tapped and PCB secured by M4x10mm nylon screws.

7  Bitcoin / Hardware / Re: Klondike - 16 chip ASIC Open Source Board - Preliminary on: June 24, 2013, 08:36:35 AM
I am an engineer with a background in aerodynamics/fluids and am capable of performing Heat/CFD simulations. Is there any way I can contribute to the heat sink/dissipation design. I can't promise anything but I can try if I had more understanding of what the goals/design are.

Awesome! :-)
Quick question about watercooling:
How about building a simple aluminum "box" from 5mm aluminum, no fins or similar, and screwing the K16s on that? We could use both sides of the cooler and it would be pretty easy to build.
I guess even with a low waterstream it should cool the board enough?
Cooling the water with a big radiator and a fan, outside, 35C outside-temp worstcase.
With a few dozen watt per 100cm this should be a piece of cake for the actual cooler?

Your gut-feeling is enough for me now :-)
(Else we might migrate to the K16 DIY thread)


I am working on something here. I will update soon as I have been working on doing up 3d printed ends and clamps.

8  Bitcoin / Hardware / Re: [Work in progess] Burnins Avalon Chip to mining board service on: June 23, 2013, 03:13:38 AM

Test Jig:

Awesome soldering skills \o/

9  Bitcoin / Hardware / Re: [Work in progess] Burnins Avalon Chip to mining board service on: June 21, 2013, 10:35:36 PM
Nice one burnin, you're nailing it.
Just 2 questions:
 -Do you provide standoffs, or should i get them:
  And if so, how high should they be?
 -The CAN cable, do you provide, or must we build one? I searched for a DIY one but found no easy to do ones.

The CAN cable is easy. Just ask for IDC Header 10 pin.
10  Bitcoin / Hardware / Re: [Work in progess] Burnins Avalon Chip to mining board service on: June 13, 2013, 06:58:55 AM
Just got my PSU, how is that for grunty connectors Cheesy

11  Bitcoin / Hardware / Re: [Work in progess] Burnins Avalon Chip to mining board service on: June 10, 2013, 09:16:08 AM
Hi Burnin,

I plan on stacking these boards side by side on a water block. The horizontal CAN-Bus would be a bit messy.
If possible could the board layout be modified so I could use a vertical 10 pin connector instead of the right angle one?
Looking at the renders there seems to be a few components in the way. If this is easy fix could you please consider it otherwise don't worry as I can work around it if need be.

Fantastic job so far  Grin

12  Bitcoin / Hardware / Re: DIY water block to suit Klondike K16 and Burnins 20 (Bitburner?) on: May 27, 2013, 08:54:25 AM
nice design, I like the idea.

what kind and size of fan/radiator are you planning to use for dissipation of 1,2kW?

I have reconditioned radiator out of a V8 and as for the fan I have not decided yet. If I had a backyard I would hire a trenching machine and dig a 10mx10 square 1 meter deep and bury a couple of loops of PEX piping.
13  Bitcoin / Hardware / Re: DIY water block to suit Klondike K16 and Burnins 20 (Bitburner?) on: May 27, 2013, 08:43:43 AM
The design could be easily lengthened for the K16 to create a longer block right?

Some have plans to use the heat sinks to help give rigidity to the boards when they are daisy chained together.

Off the shelf here you can get the aluminum sq tube 200x50 in lengths of 6.5m
Cannot get flat bar that wide (that i could find) but you can cut sheet (was looking at nesting and getting it laser cut anyhow).

K16 is 100x100 so you could fit 2 across a 200m tube with no tolerances. So 2 mounted either side is 4 per 100mm. 6.5m length could in theory hold 260 boards. My concern here is 260x40w=10.4Kw can enough water flow through the block to cool that many boards?

I do not know how good the heat rejection on the tube will be yet but a am comfortable with my 38 x K16 on one block.

The K16 Modular Design is a 4x4 16 boards (400mm x 400mm no tolerances). You could stack two 200x50 water blocks one on top of each other?
14  Bitcoin / Hardware / Re: DIY water block to suit Klondike K16 and Burnins 20 (Bitburner?) on: May 27, 2013, 08:25:57 AM

Power supply and distribution. Just an idea so far.....

I estimate I am going to be using about 1.2kw@12v so have been looking how to supply and distribute it.

My current plan is to get this 1500w power supply and make a power rail to run along the top of the water block.
I don't have much experience with PCB software so was hoping someone could help out with this. The idea is to sort of staple a heavy duty cable onto a pcb using link wire and soldering it to the tracks. The pcb would just be a repeating pattern totaling about 600mm long so you can snap it off at the required length. The stripped cable would be 'stapled' to pcb both top and bottom.

15  Bitcoin / Hardware / Re: DIY water block to suit Klondike K16 and Burnins 20 (Bitburner?) on: May 27, 2013, 07:53:49 AM

Some new renders and sketches

K16 Heat Sink Plate

Idea for turning end plates into part of a case.

16  Bitcoin / Hardware / DIY water block to suit Klondike K16 and Burnins 20 (Bitburner?) on: May 25, 2013, 01:08:10 PM
Water cooling block for multiple boards

I am going to make a single water cooling block to cool either 30 Burnin or 38 Klondike K16 boards.
The strategy is to keep it simple KISS and use off the shelf parts. This is not built yet so any suggestions welcome.

The preliminary plans and CAD drawings below is for a 10 x Burnin board water block (for 30 board size it will be 3 x the length)
Aluminum rectangular tube 200mm x 50mm x 600mm x wall thickness 3mm
Aluminum flat bar (x2) 160mm x 560mm x 3mm
Aluminum flat bar (x2) 50mm x 200mm x 3mm
Aluminum weld in hose fitting (x2) TBA
Heat sink compound TBA
Heat transfer insulator TBA
Aluminum mesh 10-20mm mesh size.

End plates fully welded both ends of rectangular tube to make waterproof and then pressure tested - TIG weld.
Heat sink plates to be tack welded in place on both sides of rectangular tube - TIG weld

Heat sink materials
The plan is to put a heat sink compound between the pre-drilled and tapped heat sink plate and aluminum sq tube.
Heat transfer insulator material TIM between the plate and the boards. At this stage I have no idea what i am going to use and any suggestions would be welcome.

CAD files
I will post the CAD files when complete.

This is a consolidation of discussions in threads here and here.
Mesh will be stuffed into the aluminum sq tube to increase surface area and create turbulence.

Concept drawing

Heat sink plate render - fit Burning board

Heat sink plate CAD

Aluminum tube render

End plate render

17  Bitcoin / Hardware / Re: Sydney - Klondike assembly EOI on: May 22, 2013, 11:06:30 AM

I like your idea, it looks to have a lot of promise, particularly for cooling as many boards as mine.

Is there a u-bolt that would suit the holes on the klondike?
Also would the fact that there is a through hole component make it infeasible for the klondike?

I don't quite understand what you guys mean about surface area.
Are you talking about the interior surface area that is in contact with the water?

Also instead of the nozzle, maybe you could consider something like this:
Doesn't have to be that one, I'm sure there's standard ones you can get from a hardware store
All you would need to do is weld the cap on the end, then drill a suitable hole and tap a thread inside it.
I would trust a screw in, more than hoseclamps, even though the pressure probably isn't that high so it may not matter.
Also you could place the holes on the top rather than either end which tom_o was suggesting.

I have given up on u bolts. The boards would have to extend 10mm past the area that needs cooling and neither board layout is doing that.
My work around is to use 3mm thick flat bar, drill and tap mounting holes then tack weld the flat bar to the rectangular tube.

The take offs could be a threaded fitting or anything for that matter. I prefer the clamp fitting over threaded as aluminum is not the most durable material and I would not trust the thread in so far as me accidentally stripping it. Using a more durable material is also out due to galvanic series.

Mounting the take off at the top. The positioning is not a big deal once the air is out but I was planning mounting on top to make it easier to bleed anyhow. Drawings are just to get the idea across not technically accurate yet Smiley

The surface area was for the inside. The more surface area you have in contact with the water the more heat is exchanged, The idea of the mesh inside was to increase surface area and turbulence.

This is a sketch of my latest plan so far, I plan on having the boards line both sides and that is another good reason to dump the u bolt idea:

18  Bitcoin / Hardware / Re: Sydney - Klondike assembly EOI on: May 21, 2013, 01:54:36 PM

Thanks for the input, everythings still very tentative till the design is finalised then I can start to shop around.
It'll be interesting to see how fast we can get these boards put into action.
I can't imagine the components being too much cheaper than mouser but would love if they were.
Hopefully the through hole components don't affect the overall assembly price too much.
If anybody knows any good assemblers or a place to get the heatsinks domestically I think we could all benefit.

I am going to be water cooling mine, I have not worked all the details out yet but it will be simple using off the shelf parts.
I have an avalon now and it puts out a lot of heat and noise.

Here is my initial idea. Its looking like I will need to make an adapter plate from flat bar and will mount broads both side of the tube.

19  Bitcoin / Hardware / Re: Sydney - Klondike assembly EOI on: May 21, 2013, 08:08:36 AM
Best price I can gather right now is as follows:
machine setup (per unique part): 25 parts (pls correct me if I'm wrong) = $100
PCB Load : $4 per board = $2500 (just for my boards, will be more including others)
Component placement fee, $0.05 per part x 307 parts = $15.35
Assembly Price per board = approx $20 per board + parts
would love to hear corrections or better offers...

Hi emanymton

I can think of a few items:
The solder paste stencil
Through hole components
Cost/supply of components, the assembler should be able to supply all of these and depending on what their turnover is they could have good buying power. Tubed components we could supply and will for the avalon chip also they load one for one. Reel components on the other hand can add up on short runs, they are a bit like staples in that when separated from the tape are useless and depending on the machine a number are wasted when loading up.

I think we really need the PCB file and BOM for a comparative quote, what one company charges for assembly, another might make up in supply, and other in short lead times.

20  Bitcoin / Hardware / Re: [Work in progess] Burnins Avalon Chip to mining board service on: May 20, 2013, 12:42:39 PM

Have you any idea of the thermal specs of what you're proposing? i only ask as I used to be into PC watercooling years ago and helped with the design of a couple of peltier/TEC blocks. A flat tube would possibly be the worst solution as it has minimal surface area, the only design with less surface would be a circular pipe!

My main concerns are that a flat tube design could suffer from many hotspots partially due to the height of that tube, thermal pockets and laminar flow along the surfaces you actually want to be cooling. In decent waterblocks turbulence is actually quite desirable up until a the point it seriously impedes the water from flowing, a restrictive waterblock is an generally an effective one, making up for the loss in flow with far better thermal characteristics.

At the very least you'd want those in/outlets to be on the top pointing at the board. Is thinner bar available? Just seems way too tall!

Hi tom_o, not really the plan at this point was to over engineer. As for turbulence and surface area I was thinking of stuffing it full with 10mm aluminum wire mesh. Another issue was heat distortion of the tube when the ends and take offs are welded on, the outside needs to be a nice flat surface. 
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