Potable lubricant or job for 3D printing

[RogerS]

We have a backwash filter as part of our water treatment plant.


It's a complicated device that has an In, an Out, a dosing port and a drain. Water flows in different directions depending on the control unit on top. It developed a fault whereby the drain was permanently leaking enough to lower the pressure enough for the pump to kick in until pressure was restored until the drain let enough out......you get the picture.

On investigation, this shaft wasn't turning.


Taking the top off showed a large disc with holes in that send the water in the right direction. And at the right time



in conjunction with the holes in this green disc.



The large black cogwheel was stuck but did free up. However, it is no longer a smooth fit but binds due to wear.

None of these items are available any more. So I was wondering if there was a thick potable grease I could pack into the required area to try and keep it running smoothly ?

Failing that, is this a job for 3D printing (which I don't have)

 

[Cabinetman]

Could it be fixed by putting the part on a lathe and “drilling” it out to fit a nylon bush? Or brass? What is the shaft made from Roger?

 

[AJB Temple]

https://www.zoro.co.uk/shop/power-transmission-and-flow-control/greases/fg-food-grease-4-00ml/p/ZT1036956X?utm_source=google&utm_campaign=pla%2B%7C%2BPower%20Transmission%20%26%20Flow%20Control&utm_term=ZT1036956X&utm_medium=pla_css_3&targetid=pla-1409374323014&loc_physical_ms=9045127&dev=c&gad_source=1

You can also buy (cheaper) tubs of food safe grease for bearings etc from the same place. The spray stuff is used routinely to grease the blade on meat slicers and also in coffee machines, and the tub stuff is used on the blade bearings etc and in planetary mixers and such like. Should be fine for water.

 

[RogerS]

Could it be fixed by putting the part on a lathe and “drilling” it out to fit a nylon bush? Or brass? What is the shaft made from Roger?

Perhaps but a lot of work, I think, as I have no lathe but do know a man who has !

https://www.zoro.co.uk/shop/power-transmission-and-flow-control/greases/fg-food-grease-4-00ml/p/ZT1036956X?utm_source=google&utm_campaign=pla%2B%7C%2BPower%20Transmission%20%26%20Flow%20Control&utm_term=ZT1036956X&utm_medium=pla_css_3&targetid=pla-1409374323014&loc_physical_ms=9045127&dev=c&gad_source=1

You can also buy (cheaper) tubs of food safe grease for bearings etc from the same place. The spray stuff is used routinely to grease the blade on meat slicers and also in coffee machines, and the tub stuff is used on the blade bearings etc and in planetary mixers and such like. Should be fine for water.

That's a cracking link, thanks, Adrian.

 

[Eric the Viking]

Wot Adrian said!

I rebuilt the DC's Kenwood Chef a few years ago, using a service kit and a new motor. The kit came with food-safe grease to re-pack the gearbox, which turned out to be just in time, as the old grease had the consistency of frozen lard.