I went to use my Chinese Laser Engraver to make a label only to find that it was reporting an error on the water circulation. Now these things come as standard with a small immersible pond pump, and you provide a bucket to put it in
Now I have to use anti-freeze as my laser is next to the roller shutter, and I didn't want an open bucket of poisonous antifreeze on the floor in case the dogs took a sip, so I got an enclosed 'Chiller Unit'. These things are essentially very simple - they have a reservoir tank, and a circulating pump that pumps coolant through the laser tube, and returns it via a pair of aluminium tube radiators. There is a thermostat controlling a fan cooling the radiators, and a flow sensor coupled to an alarm sounder. Finally there is a thermometer display showing tank temperature. They are quite expensive for what they are, but I was fortunate enough to pick a used one up for less than half price on eBay. It has served me well for a year or so until this incident.
Examining it it was obvious that the pump wasn't running. It's a brushless 24v DC 25 watt jobby. The exact identical item is available on various Chinese web sites, but at quite a price and a very long lead time.
Time to see what else will fit. Several small 24 V pump available in the UK on ebay - but with different mountings and different inlet pipe diameters, but I was sure that could be overcome
Ordered one and the postman delivered it this morning so here goes :
First remove the old pump. Mounted nicely on a rubber vibration mount, but the wet side was intriguing to say the least. It seems they've used soft silicone tube with silicone sealant and tywraps to hold it all together