1 oho all, oh

As halloween approaches, I have been trying to repair a fog machine that quit on me two years ago. I didn't get it fixed last year, but I have tried to get it up and running this year.

I believe the pump has failed, but because I lack some basic knowledge, I can't confirm this. I'm hoping you all can help me.

I've cleaned the mechanical elements within and reassembled, but it still doesn't function. I'm confident that the mechanisim that whould slide back and forth within the brass pipe because I've cleaned it and there is little friction.

So, I'm convinced the issue is within the winding on the pump. I have looked for continuity across the two leads that emerge from the winding, but cannot get a tone from my multimeter. I do measure resistance at 291 ohms. Does that sound high?

The housing specs it as 120V, 60Hz.

At this point, I am more interested in understanding why it doesn't work than I am in actually fixing it. At about $35.00 I can replace this machine entirely, but I still want to know why it doesn't work.

Can anyone explain how this pump works and what to test for to determine why it no longer does?

Thanks!
B

 

When it is assembled and connected to the mains does it buzz?

 

Are these two parts supposed to be joined together?
Can you tell by looking at the ends?

 

Hi Albert,

Thanks for the quick response!

The unit does buzz slightly. I actualy connected it directly to 120v via thread nuts and and an appliance cord I had.

The piece you circled slides within the brass tube. I believe it move rapidly back and forth drawing the fog liquid in from the right and moving it left. I had reassembled it it after cleaning it. There was quite a bit of residue from the fog liquid over the last several years. However, it still doesn't vibrate or move that "slug" back and forth in the barrel..

 

Here is another image. Note that the exploded view includes the metal rings that insert into each side of the winding "carrier" (white plastic). The rings are separated by a band of plastic, each rests flush with the exterior of that plastic winding carrier with plastic between the bands..

 

Are you missing an O-ring? If I've guessed correctly how this thing works I would expect to see 2 O-rings on the brass cylinder to keep the pole pieces (the 2 silver rings) spaced slightly apart.

 

You need two valves for this pump to work.
The little spring with the rubber bit on the end and the white plastic bit it is near looks like one of them.
Does the other little white plastic bit have a valve inside it?

 

Thanks you guys for all the feedback. This is kind of a stupid little exercise, I admit, but thank you for going through it with me!

I really think the mechanical elements of the pump are in working order. Per your question AH, yes, there are two valves. The first is easier to identify than the second. I've marked the first on the right side of the image below. Alec, I don't think I lost any parts during disassembly.



The other, is harder to see. The chrome colored shaft is actually a tube with a very small plate at the end of it (A). There is a spring that runs from the right side of the assembly to the left such that it provide resistance to the plate moving to the left. I assume that when in operation, the small plate moves to the left to allow the liquid to pass from right to left (flow indicated by green arrows). there is a small stopper backed with a spring (B) that prevents fluid from going upstream.

Because I've cleaned all the mechanical parts and did not loose any when I took it apart, I am interested to know if there is a way to test the coil.

As I said previously, I can not get a tone from my multimeter when looking for continuity. Is this normal for a coil? I do measure resistance across the leads from the coil.

Any way to confirm the coil works?

 

Any way to confirm the coil works?

If you want to test it with the pump disassembled you risk frying the coil, if full mains voltage is applied to it, because the plunger and housing would be absent from the magnetic circuit. You could try connecting a mains-rated incandescent bulb in series with the coil to limit the current, then inserting the plunger in the coil centre and feeling for vibration.

 

Thanks, I'll try that