automatic water change

[Sacohen]

Maybe it's an issue with the motors then?

I have had the same issue with 2 motors and rsp3 has experienced the same thing as me with his set up.

 

[flamron]

I'm gonna try to get some all thread from HD tomorrow and some wing nuts so I can wire mine up and see if we hit the trifecta.

 

[Tickle]

I have had the same issue with 2 motors and rsp3 has experienced the same thing as me with his set up.

I would find it hard to believe 4 motors are bad and that mine have the same problem yet they came from a different source. I haven't had time to put more amperage to it

 

[Sacohen]

I know I tried both of my motors.
As far as rsp3 I don't know if he tried both or not, but still that is 3 motors.

Tickle you are having the same problem? I don't remember reading that.

 

[zachts]

Is this is the post you were Telling about?

If so you will notice that these are all for peristaltic pumps.

That looks about like the one, I seem to remember from the labs I worked in at college that they told us Tygon was not soft enough or tough enough for the peristaltic pumps in the lab but that could have been some different run of tubing but I thought all PVC was similar.

Never mind, my memory must be fading.

 

[Tickle]

Yup same thing not turning without help. They actually kind of pulse and only give like a 16th or a 8th of a turn

 

[zachts]

I'll have to skim back thru the last few pages but do your pumps work fine with only One head attached? Could be they can't produce the torque to operate two heads reliably especially if you seem to have to kick start them manually, I would guess this could be the case. Correct me if I'm wrong again but you bought two pumps and combined the heads right?

 

[Sacohen]

I do remember that know. Sorry. I'm getting confused between people and a little caught up in my own issue.

A couple of post back I just saw that you asked if I'm sure that my power supplies are putting out the correct amperage.

First of all I don't really have a way to test that, my mutlimeter only test up to 200ma and I think the fuse is blown anyway.

It's been a while since I was in electronics class in high school with Mr. Citrin, but if I remember a power supply does not put out amperage it is how much it is rated to handle or pulled before it fails.

 

[zachts]

Yup same thing not turning without help. They actually kind of pulse and only give like a 16th or a 8th of a turn

Way different but I have one of those old medical pumps with double runs of tubing on it for dosing 2 part and at low RPM it does this (PWM controlled i belive, it just doesn't get enough power to turn under the load of extra tubing that it wasn't designed for)

 

[Sacohen]

I'll have to skim back thru the last few pages but do your pumps work fine with only One head attached? Could be they can't produce the torque to operate two heads reliably especially if you seem to have to kick start them manually, I would guess this could be the case. Correct me if I'm wrong again but you bought two pumps and combined the heads right?

I don't remember, but I think I tried 1 pump only on the motor and it worked fine.

That is correct we bought 2 pumps and motors and stacked the pumps onto one motor.

These are multihead pumps and are designed to be stacked up to 4 if I remember what I read.

Dread240 has 3 (I think) of them running fine, but he has been misleading us with his power supply. He says it's 12v 1amp.

 

[zachts]

I do remember that know. Sorry. I'm getting confused between people and a little caught up in my own issue.

A couple of post back I just saw that you asked if I'm sure that my power supplies are putting out the correct amperage.

First of all I don't really have a way to test that, my mutlimeter only test up to 200ma and I think the fuse is blown anyway.

It's been a while since I was in electronics class in high school with Mr. Citrin, but if I remember a power supply does not put out amperage it is how much it is rated to handle or pulled before it fails.

Ah, don't suppose you happen to have a 10 or 20 watt 1ohm audio resistor laying around? you can use that to measure current via voltage accross the resitor........ (common trick for LED builds)

The reason I asked is that if you 1 amp supply can turn it there is absolutely no reason the 4 amp supply will not (save for a bad power supply, or the pump trying to draw more start up voltage or current then the supply can produce) That's why I asked.

I need to get back thru the last few pages to make sure I didn't miss something important but really a DC motor is pretty simple, it will draw current and voltage up until it reaches it's limit or until it starts to spin freely. At some point it will draw too much and either not turn, heat up and burn out, or just not turn. It may be that the 1 amp supply your trying could provide something briefly that the 4 amp supply could not due to internal design.

 

[flamron]

I tested mine singly and both turned fine with brand new norprene and a 500ma power supply.

 

[zachts]

I don't remember, but I think I tried 1 pump only on the motor and it worked fine.

That is correct we bought 2 pumps and motors and stacked the pumps onto one motor.

These are multihead pumps and are designed to be stacked up to 4 if I remember what I read.

Dread240 has 3 (I think) of them running fine, but he has been misleading us with his power supply. He says it's 12v 1amp.

Could be but it may be able to supply much more than that for a brief second to over come the needed torque to spin the heads. Not all supplies are created equal. It is also possible his have a different motor as these were second hand and not all that well labeled it seems.

I doubt the issue lies with the pump heads, they are mechanical and given enough tourque they should run. The issue will most likely be with the motor's capability and or the power supply. Remember you bought these used so the motors may not be up to snuff and could be weak. It's possible you could find a different motor cheap that could be used, but some further testing is in order before giving up.

 

[zachts]

yea... I think I just mislead you guys, because the adapter I'm using is definitely labeled 12vdc 1A, but it seems it's a mule and carrying way more then what it's rated for... doesn't even get hot really, it's kind of impressive

Would you mind measuring the current and voltage your pumps are drawing from this supply both at start up and during operation? I think it may solve a lot of mysteries!

 

[zachts]

On the 1amp I didn't have to turn it, but there was not tubing in it.
Once I put a load on it (tubing) I have to kick start it.

On the 4amp it runs the same if there is a load or not.
It does not speed up just stays at that barely moving speed the whole time.

I did try a 12v 2amp afterwards with tubing in it and it will start on it's own, but runs slow, not as bad as the 4amp, but slow.

I'll try to get a video of that too.

Does the motor get hot running with the tubing using the 4amp supply or 2 amp? If it does after a few minutes it is pushing it's limits, but higher current supply might do the trick for short bursts and or with some heatsinking for the motors (think RC cars ) It may need slightly more than 12 volts under this load possibly a small adjustable power supply would work? Lots of supplies can exceed their rated voltage depending on load and internal design.

 

[Sacohen]

The motor will not turn with the tubing in using the 4 or 2 amp power supplies.
The only one that will run the 2 pumps is the 1 amp power supply and that does not get hot.

I'm sure the 4 and 2 amps are hot because that are fighting to try to turn the motor and not getting anywhere.

I'll check them tomorrow.

 

[zachts]

The motor will not turn with the tubing in using the 4 or 2 amp power supplies.
The only one that will run the 2 pumps is the 1 amp power supply and that does not get hot.

I'm sure the 4 and 2 amps are hot because that are fighting to try to turn the motor and not getting anywhere.

I'll check them tomorrow.

Sorry I was asking about the motor getting hot not the supply, I doubt the bigger supplies are getting hot, I'm concerned about the motor if it is struggling to turn it will just convert power into heat until it fails. I've seen fan motors catch on fire when the get stuck. Best case failure it has an internal sensor to shut it down or it just melts the coil insulation, shorts and dies quietly with a small puff of smoke.

that tiny little medical pump I mentioned gets darn hot when the head gets stuck at low rpm, it has a sensor and shuts down and flashes an angry warning but......

 

[dread240]

whew I missed alot while I was gone for a bit.

zachts.. my amp clamp is in my other truck at work... which is broke down and I'm in a temporary work van so I don't have everything in it. I also don't have any resistors big enough laying around to test it that with voltage drop

I can say though... watching my eb8 current monitoring.. I'm picking up .3 amps when this turns on

120 * .3 = 36W
36W/12VDC = 3A

My power supply is pretty clearly listed as a 1A on the back of it, but the numbers I'm seeing are telling a different story just off of that. This is also an old school power supply I had sitting around, not some cheap china ebay one that is bubble gummed together and covered up with a pretty sticker, so probably playing a part in it as well too.

 

[Sacohen]

Sorry I worded that wrong.

The power supply on the 1amp will get warm after about 15 min. This tells me that the motor is pulling more that 1 amp and the PS can't last much longer.

As for the motor of the pump when it is connected to the 2 or 4 amp power supply, I'm sure it is getting hot (although I have not checked) because the motor is struggling to turn and not getting anywhere.

I'll check tomorrow to see if the motor is getting hot when connected to any of the power supplies I have.

 

[dread240]

I know they're used parts, but I seriously doubt all of you guys got bad motors with these things.