my diy needle wheel dart pump

[WZHANG]

Hey, I got the exact same pump lying in my closet. If I have time I'll take it apart and see if it has a silicone carbide seal.

 

[smjtkj]

Cool Won digity! Post some pics of it apart so we can evaluate the possibilities!
Mike

 

[spazz]

im sure it dont have the silicone carbide seal but the case might be able to be modified to accept a new seal in it. when you post a pic can you see it the impellor screws on? if it is threaded it should have a slot in the end of the shaft right in the middle of the fan housing on the back of the motor. i like this pump already and will look into it further. the biggest problem i see righ now is the seal and the inlet and outlet sizes. but if i can convince the manufacture to make some bigger openings on the case we might be able to convert these to needle wheels. if the opening on the output was as big as the union fittings then it would flow tones of bubbles into a skimmer body.

also can you take a pic of the inside of the casing where the impellor rotates?

 

[ChemE]

spazz,

I keep wondering how long it takes until you break down and make your own housings on that CNC router. Then we could really get down to business.

 

[spazz]

<a href=showthread.php?s=&postid=7112430#post7112430 target=_blank>Originally posted</a> by ChemE
spazz,

I keep wondering how long it takes until you break down and make your own housings on that CNC router. Then we could really get down to business.

well i could do it if i could find a cheap supply of plastic to use for cutting. it wold have to be super thick stuff to make the 2 pieces out of. right now i couldnt make housings for less than $200 a set and we all know that dont fly. the best way to build a needle wheel pump is to injection mold the parts. and the molds for that can cost up to $5000 for each part of the casing. its super expensive to make the molds and almost nothing to injection mold it.

 

[ChemE]

<a href=showthread.php?s=&postid=7112578#post7112578 target=_blank>Originally posted</a> by spazz
well i could do it if i could find a cheap supply of plastic to use for cutting. it wold have to be super thick stuff to make the 2 pieces out of. right now i couldnt make housings for less than $200 a set and we all know that dont fly. the best way to build a needle wheel pump is to injection mold the parts.

How about 2 or 3 parts glued together instead? Or maybe laminate 1/2" stock to get the thickness you need.

<a href=showthread.php?s=&postid=7112578#post7112578 target=_blank>Originally posted</a> by spazz
and the molds for that can cost up to $5000 for each part of the casing. its super expensive to make the molds and almost nothing to injection mold it.

Yeah, we already had this conversation a page or two back. Although Hahn thinks you and I are wrong and that it can be done cheaply.

 

[spazz]

well if i used acrylic it wouldnt work very well. acrylic is too brittle. it will crack and break with stress on it. i think abs or polypropylne would be a better choice for housings. even pvc would be a good choice but not acrylic. i have to look at getting some sheets of pvc for expermenting with. its cheaper than acrylic but more durable under stress. it will flex some if needed. but sheets of that 1" thick wouldnt be very cheap either. after some reasearch i still might try it though. i just have to find the time. im way too busy right now.

 

[Roland Jacques]

<a href=showthread.php?s=&postid=7111761#post7111761 target=_blank>Originally posted</a> by won digity
Hey, I got the exact same pump lying in my closet. If I have time I'll take it apart and see if it has a silicone carbide seal.

is thier some good reason it is in the closet?

 

[ronc98]

I have tried the laminate approach to making larger stock from smaller stock. Dont bother. I have tired polycarbonate, pvc and acylic not much luck with any of it. You can get sections to glue however it is near impossible to get the whole surfaces to glue equally.

 

[tinygiants]

ronc98,

When you tried to glue the lamination, was it with a vacuum press?

 

[WZHANG]

Ok boys and girls.

Heres the pics

First, the bad news:

top shot

Heres my little problem. I don't know how to remove the impellar. Do I have to remove the back part in order to unscrew it? I noticed the impellar had a little hex looking "thingy" molded in the middle of it.

I don't have a socket thin enough at my house to remove the back part (the black fan housing part) of the pump right now.

 

[WZHANG]

<a href=showthread.php?s=&postid=7113158#post7113158 target=_blank>Originally posted</a> by yourfishman
is thier some good reason it is in the closet?

yeah, the pump is a piece of crap.

Just kidding. No, I just changed my mind about upgrading my tank. I decided I'd hold on to it incase I do later on.

 

[hahnmeister]

won digity, are you sure that pump is saltwater safe?

 

[Roland Jacques]

<a href=showthread.php?s=&postid=7113527#post7113527 target=_blank>Originally posted</a> by won digity
yeah, the pump is a piece of crap.

Just kidding. No, I just changed my mind about upgrading my tank. I decided I'd hold on to it incase I do later on.

now that was funny:lol:

 

[Roland Jacques]

You donââ"šÂ¬Ã¢"žÂ¢t have to machine a whole housing look at the cover on that Mightââ"šÂ¬Ã¢"žÂ¢s impeller housing above. Now instead of using that cover, remake it, not the whole housing if thatââ"šÂ¬Ã¢"žÂ¢s to involved. Have that center section of that cover extend out another inch or so. Use that area to contain the needles from your impeller. Leave the outer impeller vanes, or all the vanes, on the impeller. Just add the now longer needles to that center section of the impeller to greet the incoming air and water. Let the vanes do what vanes do best, push water/bubbles out of the housing. Just an idea.

 

[spazz]

so far this is looking very good. i can work with that pump. like it was stated before it will need a rework on the input front plate. but thats not too big of a deal. then the existing impelolor might be able to be used to make the needle wheel impellor. it would need to be machined on the cnc to re surface it thinner and have the pin holes drilled in it. then there is the question of the seal. if we can get the right seal to work in there then we have it made.

 

[smjtkj]

Spazz the tech said the seal was ceramic. He also said he didn't see any reason why it would not be ok for salt water. He said there was a salt water fish store in Florida that used like 10 of these on his setup. All are still fine according to him!
Mike

 

[ChemE]

I guess I'm confused as to why the seal must be silicone carbide. What difference does it make so long as it forms an effective seal? Are you concerned about the shaft wearing the seal over time?

 

[spazz]

well things get better and better all the time with this pump. if its ceramic it will hold up to the salt water just fine. the biggest thing about seals is that tey will leak if there a standard shaft seal. the shafts are made of steel and start to rust out and then it gets to the seal area and will cause the pumps to leak. that is why you want silicon carbide or ceramic seals. either one will work. im not sure if ou ever heard about the fresh water pumps that sequence hakes. they are just a dart pump with a fresh water seal in it. the seal is alot cheaper than the salt water seal so it makes the pumps cheaper. there was an on line vendor that was selling the freshwater pumps as dart salt water pumps. bad news there. there was alot of customers that had leaks with in days or weeks of installing the pumps on there tanks.
im going to look into this pump some more and might buy one and test it out. you guys are going to make me build another test tube/skimmer out of this. man im going to go broke. lol

 

[zapata41]

that pump there with a NW would work great in my 12x30" skimmer. now hurry up before i go and buy a alita60 air pump to replace the loud and crappy medo that i have right now.

Tim