Laing DDC (Swiftech MCP350/355) Names & Info

[Borgod]

I didnt look at the colour of the impeller.

I just chucked it back in it's box.

[sbrehm72255]

I've got a simple question for Petra, will your top fit/work properly on this version of the DDC pump??

[Nikos]

Hello, during my R & D tests I have also tried the outlet position on the other side as your request and the results was very intresting: the pumps doesn't works at all!

That's why all the TOPs have had the outlet barb on the left side, because of the impeller geometry that implies it.

just wondering, this is the OClabs top here but all tops are very similar is design.

wouldn't it make more sense if outlet was on the right hand side as it looks like impeller spins clockwise. wouldn't it be better with the outlet on the other side??

There is only two ways to increase/reduce the absolute pressure of the DDC pump: 1. change the internal geometry of the impeller (impossible for us but not for laing) 2. change the geometry of the TOP (the only way for us).

I think it gets a lot less pressure that way.

Kind regards, Nikos

[Nikos]

I've got a simple question for Petra, will your top fit/work properly on this version of the DDC pump??

Hi, the positive probabilities are 99%, if you have this pump there you can verify very quickly if other TOPs fits well.

Kind regards, Nikos

[Petra]

2. change the geometry of the TOP (the only way for us).

3. Reverse engineer the motor and make modifications (maybe... I have yet to fully delve into the matter, but it's hypothetically possible and well within our means)

The performance capabilities of the DDC pumps are, primarily, motor-limited (especially if you start talking about the 9W DDC-3.1 and 18W DDC-3.2).

[Borgod]

Well I returned my 2nd MCP355. Before my store sent back a replacement he checked that also - he had 2 more in stock and they BOTH had the same problem.

W.T.F.

Petra would you be able to test an MCP350/355 before sending one to Australia?

[Nikos]

3. Reverse engineer the motor and make modifications (maybe... I have yet to fully delve into the matter, but it's hypothetically possible and well within our means)

The performance capabilities of the DDC pumps are, primarily, motor-limited (especially if you start talking about the 9W DDC-3.1 and 18W DDC-3.2).

Hi Petra

I didn't spoke about motor modifications as there will be warranty lost for the end users and also because we're not the manufacturer, so we can't change the motor. Perhaps laing will decide to apply some modifications on the DDC motor in the near future but as we've already saw untill now, all comanies try to optimise the production costs and the example in this case is the same motor either for 10 and for 18watt.

About the impeller geometry, perhaps, there is another physical limit on the machine capabilities, otherwise I think that they already made a new impeller and they didn't change only the inlet hole from 12 to 8mm.

Kind regards, Nikos

[JeffnWV]

I received my replacement MCP355 yesterday that has the exact same problem as the first.

It sounds like there is sand inside the pump. It works fine and there is plenty of pressure, but honestly it's like I put a handful of sand inside the motor.

Two MCP355, same problem, different retailer.

Not ing happy.

my replacement does that too...stopped after running it for several hours.

[Yozzman]

Mine died
Just wont start any more...
Just a little movement when it wants to start and thats it...

[Hellemyr]

I got my new pump today, whit blue impreller

But the pictures in that greman gude posted on previus page is gone

Anyone have another guide?

[MotF Bane]

If I were to walk into a retail store and find two Swiftech MCP355 boxes or two Danger Den DDC-Plus, is there any way to tell from the boxes whether it really is a DDC-2 or actually a DDC-3.2? If not, is there a way to tell just from looking at the pumps WITHOUT opening the top?

[elfy]

yeh check the screws iirc. the 3s have your normal philips screws the older ones have extra grooves

[mukmaster]

Nice Info , Very usefull

Mine want a fake but it was good being assured

[gabe]

Ok guys, let's talk about reliability.

In preamble, let me apologize in advance as I am not at liberty to release thorough statistical data because I have to respect the factory directives on the subject matter. So please read between the lines on some of the basic facts below:

90% of the pumps that we receive in RMA are not defective (we test every single one of them).

There is little if no difference in reliability between D5 (MCP655) and DDC1 (MCP350), and the number of actual failures is incredibly low (far better than any other pump manufacturer IMO). Stupid mistakes like inverting the wires in the D5 Molex connectors is arguably not counted as a failure.

Yes, one can normally expect somewhat less reliability from a pump that spins faster and heats up more (DDC2/MCP355).

[ranker]

Ok guys, let's talk about reliability.

In preamble, let me apologize in advance as I am not at liberty to release thorough statistical data because I have to respect the factory directives on the subject matter. So please read between the lines on some of the basic facts below:

90% of the pumps that we receive in RMA are not defective (we test every single one of them).

There is little if no difference in reliability between D5 (MCP655) and DDC1 (MCP350), and the number of actual failures is incredibly low (far better than any other pump manufacturer IMO). Stupid mistakes like inverting the wires in the D5 Molex connectors is arguably not counted as a failure.

Yes, one can normally expect somewhat less reliability from a pump that spins faster and heats up more (DDC2/MCP355).

I figured as much. Thanks for the information Gabe.

[Riddlinkidstone]

I almost went for a DDC, but all this forum talk of unrealiability made me go with a MCP665.

I still wanted a DDC for its compact size though...which doesn't matter now because I got a huge case to compensate for it LOL

Thanks for the info, Mr. Swiftech. Btw, whats your warranty policy on the MCP665? Just curious. I never looked into it.

[kiikkuja]

I have question about the pump. I recently opened my mcp655 and to my eyes there seems to be aluminium inside the pump. Sorry for the lack of photos.

Am I right or wrong? If there's aluminium in the pump it makes the current AL waterblock corrosion debate quite moot if you must use glycol in your system anyway.

I haven't had problems with corrosion to date but before i took apart my loop i used 80/20 water/glycol so i think it did what it was supposed to do.

[jayhall0315]

MCP 355 Failure Problems
(or The Strange Case of the Stuttering Pump)


Okay, many of you experienced watercoolers that have been to the forums before or lurk here often know that the Liang/Swiftech MCP655 pump has a good reputation for reliability and low failure rates. Same for the MCP 350 (also known as the DDC). The problem has been the more powerful MCP 355 (also known as the DDC -2 or the DDC +) which puts out 19.5 feet of head, and is no longer being made (the DDC 3.2 has replaced it). I purchased one of these pumps from Petra's Tech Shop (great place BTW) with their top back in May to use for a series of Showdown articles that I have been releasing here at XS. Surprisingly the pump worked quite well for me for the first one month of testing, even though it was not in continuous daily use.
After about five weeks, I decided that I would put this pump in one of the three computers in my little lab room and everything went fine for about four days until I noticed the E6700 CPU heating up to 83 deg C one morning. Doing a few checks revealed that the MCP 355 was now not running or not running correctly. Well, after looking over all the simple fixes like jimming the molex connectors and making sure the PSU rail was fine, I quickly drained the loop, removed the MCP 355 and replaced it with a MCP655, so that I could take the smaller pump out for inspection.
Two weeks had passed before I had a chance to look at everything carefully and here is what I have now found:

1 – If you take the regular top that comes with the MCP 355 (or Petra's top) and turn it over, you will see the large circular well which is about 7.75 mm deep. (See Photo #2 below) (sorry, I do not have a micro-caliper at home) If you now look at the naked pump (with the top removed), you will see the impeller head sticks above its base by ~ 7.60 mm. (see photo #3 below) This leaves only ~ 0.10 to 0.15 mm difference between the top of the impeller head and the bottom of the screwed on top (or Petra's top, which has the same internal height). Normally, as the impeller spins this 0.15 mm will be filled with water (which at this location almost acts a lubricant).

2 – The 'motor' of this pump (and the MCP 350 and MCP 655) is an electromagnet which simply means that it is a looped coil of wire inside the housing that goes around the impeller base. When current is applied, the impeller will follow the consequences of the famous 'right-handed rule' of electromagnetics and spin. If it is spinning correctly, the thermal heat generated from the electromagnet (and the rotation of the impeller itself) will pass into the cool water flowing over the impeller. If the impeller is not spinning, the heat will be trapped in the pump and build up (quite quickly, I might add).

3 – As the impeller starts to spin, once current is induced, it will rise and pick up rotational acceleration and physically rise slightly (critically, this rise is determined by how strong the electromagnet in the base is and how much current is passing thru that electromagnet and is described in physics by an ancillary to the Maxwell equations (this takes the form of a triple integral that you would see in multivariable calculus).

4 – When Liang put out the stronger version of the MCP 350, which is now called the MCP 355 (also called the DDC-2 or DDC+), they simply increased the amperage from 0.75 amps to 1.5 amps (I suspect thru the printed circuit board (PCB)). They failed to take into account that this would now cause the impeller to rise even higher from the base and possibly touch the bottom of the supplied or Petra's top.

5 – Testing the PCB on the back of the pump with an oscilloscope reveals no problems. The PCB is not the culprit.

6 – It takes very little friction (or downward pressue) to keep the impeller from spinning when it first starts up. (Roughly, I gauge this at about 250 grams – see the experiment in Photo #4 below where I have 170 gram pliers on the impeller)

7 – This is likely causing the impeller at times to rise up off the base (or 'needle' it is almost resting on) and touch the bottom of screw down top (which also means you now how a quandary, because if you screw down the top very tight, you lessen this ~0.15 mm headroom and if you leave it looser, you risk a leak). When the top of the impeller touches the bottom of the screw on top, there is now enough friction to prevent the impeller from picking up speed and spinning properly, or to spin more slowly (which is causing the 'sand' sound that many of you are hearing). Many of you will also be able to see this as 'stuttering' if you look into the pump while you run it dry (just connect the pump to your PSU, but only for 1 ~ 2 seconds, any more and you risk damage to the PCB)

8 – This stoppage of the impeller is mitigated a tiny bit by the orientation that you have the pump in.

9 – Depending upon the viscosity of the coolant you are using, how tight you screwed on the top and several other factors, these impeller stoppages could start as soon as you buy the pump or take place months later (or perhaps never occur). That is the ghost in the machine and the reason why it has been so difficult to pinpoint the troubles with this specific pump (the MCP 355). I also increased the viscosity of the water pouring thru the pump with cooking oil (along a known viscosity curve to mimic those using this pump with zerex, hydrix, etc) and found it to be very, very sensitive and unpredictable to viscosity differences.

10 – I suspect, but am not sure (so please do not do this, until we hear back from someone in the know at Liang or Swiftech) that many of these problems would disappear if we were to grind off another 0.5 mm from the circular depression that is on the the bottom of the screw on tops.

11 – The reason why the failure rate for the MCP 350 pumps is so much smaller is that less amperage is being pumped thru the electromagnet, which causes the impeller to rise off its base less (and is within the 0.15 mm safety range). The MCP 350 impeller also spins slower and therefore, if it does occasionally touch the bottom of the screw on top, there is less friction, and less chance that the impeller will be stopped.

How sure do I feel that this is the correct answer to describe most of the problems that you are having or will be having; fairly sure. I do not work for Liang's QC unit and I do not have access to their engineering documents, but I feel the above statements are likely true, although I cannot be 100% sure. There have also been some cases where it looks to me like the heat buildup from the impeller being blocked has led the PCB to be damaged but this is a secondary effect. I will notify Gabe and Petra of this, and I hope this helps out anyone who may own these pumps.

Have a good evening,
Jay


Photo #1 – Taking a look at the MCP 355 to troubleshoot
Photo #2 – The 7.75 depth of the circular depression at the bottom of Petra's screw on top (although, the stock top from Liang has the same depth, so this is not Petra's fault)
Photo #3 – The ~ 7.60 mm that the impeller head rises above the base.
Photo #4 – The downward pressure needed to stop the impeller is being examined.

[Tony]

Awesome post and keenly waiting for an update

[jayhall0315]

Awesome post and keenly waiting for an update

Tony,
Follow the action here:
http://www.xtremesystems.org/forums/...d.php?t=153138

Jay

[iadstudio]

Here are some pics of the Watercool DDC Tank PRO..












It's not identical to the Alphacool Tank....

I haven't been able to find one of these or the Alphacool version in the US. Are there any retailers who ship these to the US?

[Seolfor]

I haven't been able to find one of these or the Alphacool version in the US. Are there any retailers who ship these to the US?

Alphacool version:

attachment
http://www.xoxide.com/alphacool-lain...ttachment.html
http://sharkacomputers.com/almoladdcre.html
pump with attachment
http://sharkacomputers.com/almoladdc12v.html

I can vouch for xoxide, but I've never heard of sharkacomputers. Hope this is what you were looking for.

[migueld]

Alphacool version:

attachment
http://www.xoxide.com/alphacool-lain...ttachment.html
http://sharkacomputers.com/almoladdcre.html
pump with attachment
http://sharkacomputers.com/almoladdc12v.html

I can vouch for xoxide, but I've never heard of sharkacomputers. Hope this is what you were looking for.

Add www.performance-pcs.com to the list, they have plenty of Alphacool options, and they currently have an amazing deal on the DDC 9W + alphacool top for $89, get it while it lasts

BTW, sharkacomputers is pretty good as well, they have good service and prices.

[MaxxxRacer]

Thread unstuck, but mentioned in DDC section of pumps guide

[Mike44]

Wow, I must say that this is an extremely informative thread!! I think it's made me change my mind from using an aquastream or eheim pump and use a DCC in the system I'd like to build. Sweet info too on the pump flow rates!! Thanks!!

One question though: do you need any EM shields for these pumps? Just asking because I know that the aquastream and eheim pumps do, and given that the mounting location for the DDC for me would be beside my hard drives I just want to make sure they would stay safe.

Thanks very much!!

Mike