Coolant with a mill

[cfellows]

My DRO's were mounted at the back and under the side with perspex anti splash covers, but because I couldn't see them I used a 3 axis display box designed for these cheapo linear scales, just plugged the leads in and mounted it where it could be seen.
You can see it on this post
http://freeforums4u.com/viewtopic.php?t=137&mforum=homemodelengine

John,

I see from another thread that you have a mill / drill that looks exactly like mine (Enco)? What have you found the benefits of using coolant to be? Is it pretty easy to control the splatter of coolant around the immediate area?

Thx...
Chuck

 

[Tin Falcon]

C F:
From what I have seen most home shop guys tend to shy away from the coolant at lease flood. The main benefit from coolant is increased feeds speeds and therefore production rates. the downside is it can be messy and left sitting it tends to grow things and get smelly . Most home shop guys will tend to just dab a little cutting fluid on , use a drip system or possibly a mist system . I tend to dab with an acid brush most of the time.
Tin

 

[Bogstandard]

Chuck,
I use it mainly when I am doing serious heavy stuff not related to making these little engines. For these I do what Tin does and use a brush or a washing up liquid bottle with a bit of silicon tube on the end to get the liquid in close but safely.
To answer your question fully, it allows me to machine at much higher feeds and speeds, plus I find I get a better finish because it is flushing the chips away from the cutter so you don't get secondary cut and scratch marks
If I do use the suds pump, I do a clean up of the surrounding area for about 4ft and drape catch cloths over everything. I have made perspex guards with magnets on to place around the job, but it still flies everywhere, and a shower afterwards is compulsary.
Having friends in the aerospace industry helps when it comes to coolant. A small soda bottle full of the coolant they use, mixed with the correct amount of water, lasts for ages and it doesn't go 'sour' like the normal machine coolant, plus you don't get any funny looking things growing in it.

John

 

[macona]

Flood coolant is a mess and unless you are running cnc its really not necessary.

Mist or spray coolant is great though. There is a guy in ebay selling the Bijur brand spray mist unit. for $80. New old stock. I picked one up from him about a year ago and it works real nice. Unlike the Kool-mist units it pressurizes the coolant tank so it does not rely on venturi effect to pull coolant out of the tank. This means you can totally control air and fluid volume and get a nice wet spray, not a mist the clouds the air. I do use a coolmist with my table saw.

He only has the tanks though. You can make the nozzles and he does supply plans for the nozzles. Not too hard to make.

Mist coolant is actually recommended by carbide manufacturers over flood unless you have enough PSI to totally envelop the mill while running. Often when running the flutes will keep the coolant from getting to the cutting edges constantly and cause thermal shock and create microfractures. This makes the bits die sooner.

Other options are to run dry which is fine for steel or use one of those vortex guns that blow cold air from a compressed air source. There are plans to make those out there. Only drawback is they use a LOT of air.

The guy with the $80 Bijur NOS:

http://cgi.ebay.com/BIJUR-Spraymist...goryZ633QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

 

[cfellows]

Thanks for all the feedback. I'm really interested more from the finish standpoint than for speed. I don't mind going slow.

Chuck

 

[Bogstandard]

Chuck,
For what you are doing, you don't need any of this fancy stuff.
Just use a brush or squeezy bottle, thats all you need.
If you have a compressor a blowgun will do the job as well, just keep the swarf away from the cutter, but do wear eye protection all the time when machining not just when blowing the swarf away.

John

 

[macona]

With aluminum WD-40 is a good cutting fluid. Actually the Stoddard solvent in it. Buy it by the gallon and put it in your own sprayer. Much cheaper that way.

Good ole Sulfer Cutting Oil is good for most things steel. I use an old hair gel bottle for mine.

Use air to keep from recutting chips. This is the biggest problem for surface finish when milling. You only need 20 PSI or so. Or use a shop vac mounted near the spindle.

I have found that inconsistent application of cutting fluids is what creates the the biggest surface finish issue. Thats whats nice about the Bijur unit. Set it and forget it...