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I've been playing with various solutions to combine air and lube/coolant and have been having some success with gravity feeding the lube using a drip style machine oiler.
With the lube delivered at the air nozzle there is negligible airborne droplet creation but it's a bit of a pain to get the feed exactly right.
This is my latest metering system, now I just need to case the PSU and build the new nozzle system.
Attachment 25019
Attachment 25020
Interesting. I was considering how best to do mist coolant so will watch this post. Best option to me seemed to be the pressurised coolant tank arrangement when the coolant is forced into the air flow under pressure rather than drawing it Venturi style with a partial vacuum which I guess this is similar to. But I don’t have an air compressor so no rush to go any route just yet.Quote:
Originally Posted by magicniner
A peristaltic pump with a stepper gives you positive and predictable fluid delivery, no pressurised containers with pressure settings, needle valves, fluid viscosity and so on to upset the balance of perfect lube volume delivery.
It's all completed and connected up, right this minute it's lubing, with just enough air to clear chips from the cut, a job cutting parts from 2mm D2 Tool Steel plate with a 2mm 4 flute EM, seems to work nicely :D
Attachment 25029Quote:
Originally Posted by magicniner
Couldn't have put it better myself :smile:
We really need a "Like" button! :DQuote:
Originally Posted by johnsattuk
A couple of years ago I started a thread about printing my own peristaltic pump. The intention was to follow through with a controller for coolant and air. The project was shelved through illness and now I am better I am picking up on unfinished projects.
I have all the kit I need to make a step programmer that at each step delivers air, coolant or both. I thought about 16 steps at first, but that is way OTT so 8 channels.
I will carry on with it one day, but I have other projects to clear first.
The reservation I have is that peristaltic pumps need a soft silicone tube. I have been informed that silicone tube is not oil resistant _ any advice please !
Cheers
Rob
Sounds good ! I have a spare stepper and driver plus I think there is a psu somewhere. I guess a variable pulse generator is a pretty cheap module to buy ?Quote:
Originally Posted by magicniner
Silly question but does the drip feed into the last part of the nozzle inside the tube or does it drip into the air flow?
I'll let you know about Oil and the Silicone Tube.
On oil introduction, the oil is introduced into a sleeve concentric around the air tube, the oil sleeve is shorter than the air tube and it's position can be adjusted to tune oil delivery but essentially the oil is always introduced after the air leaves the nozzle.
This is the nozzle I bought https://www.aliexpress.com/item/New-...1-dc8fbff7776eQuote:
Originally Posted by routercnc
It has liquid fed to the centre and air around it. The airflow atomises the coolant. I am not sure, but I think it also generates a venturi vacuum to pull the coolant into the air stream.
I think this is the one that Nick used, but there are more pulse generators than you can shake a stick at on AliExpress.
https://www.aliexpress.com/item/8-24...4-a44ab6a74f1d
You don't want Atomised coolant, you want the drops to be large enough to drop out of the air, Atomisation is easy with any Scent-Spray type arrangement but it will bugger your respiratory system unless you use truly massive extraction, enough to negate the heating in any shop on a cold day!
Exactly right Nick! That is why I was thinking of the step system so that you delivered coolant without air or air without coolant (or both or neither) at each step of the 8 step sequence. The mister nozzle I bought was to experiment with, if you used it as designed you would get a fog in the workshop.