Do I Need A Coolant System?

[Al-Hala]

Al-Hala, thanks for the links. You posted while I was typing. Could it be that I can keep this thing under $3K?

Welcome. Heh, keeping costs down. That depends on your inventiveness and patience. In machining, the purchase of the machine is one thing; the tooling required can easily equal and exceed the cost of the machine. That was the advice I was given before I got started, and it has proven out without question.

It really is just a trade off between your or friends sweat equity and time vs. purchase. At some point you have to decide what your time is worth. For some people (myself included at one time), they want to USE the machine, not build it. Others I (like myself currently), want the (insert adjective here) of building the machine up.

When I total all my costs: machine, tooling, CNC items, enclosure, I blew past that figure quite quickly. However, I am a Canucklehead; My Petrodollar is worth a wee bit less than yours on average. Given the time period over the outfitting my dollar went from being worth more than the US to 40% less, I would still hazard I went over that figure by a fair amount (shipping costs from the US to Canada are ruinous via UPS or Fed Ex for a lot of sources; the mill added $300 in shipping alone). Others native to the US might have a better angle on answering that question.

For creative vs. purchase, my own CNC linear motion showed me (from cheapest to most expensive) the following solutions:
- Leaving the OEM leadscrews in place, machining motor mounts to fit them. The backlash is dealt with using backlash compensation in the motion controllers. The motors are sized to compensate for the inherent greater loss of efficiency in leadscrews.
- Others reduced cost via only automating two axis, and leaving the Z manual (that always struck me as a false economy; what is the point of CNC when you have to adjust an axis every few minutes)
- Purchasing Chinese sourced ballscrews, machining motor mounts to fit them. There are a couple of sources that several have used and recommend
- Purchasing a combination kit of the above
- CNCFusion LMS machine kit

I chose the CNCFusion kit due to a combination of USE the machine thinking and lack of faith in my ability to source and acquire parts and build the mounts. Today, I would probably have tackled the job, or risked the eBay route (since there are several others since claiming good results and I am more confident in my abilities as a hack machinist).

Edit: Sorry for the late edit, but I found another good example of thinking out of the box (there is a pun there if you watch the video) MacPod Toolbox Controller. Macpod.net is the website of a fellow who made a $50 tachometer for the LMS Seig style spindles. I have known of him for a while, but did not think to look him up on YouTube. The Video shows how he used a metal toolbox to house all of the control and power systems. Now, I am not certain I want to put power line level items (120V) that can dissipate some heat into that form factor or container, but it is a novel approach (he claims one off, so no plans).

 

[Al-Hala]

I built my original micro drop system for about $100 in parts if you buy everything new. It does not need to be fancy. Take my digital pump system, eliminate the pump, and it works just fine. I'm using my system without the pump right now, I need to make some pump modifications. No fancy mixing valves needed, just standard hardware items. But yes, you still need an air compressor.

I recently read through that writeup of yours, Jim. That was quite nice. I would not have thought about using a peristaltic pump, but upon reflection, it makes sense.

 

[jbolt]

My experience so far with flood coolant has not been as horrific as it has been made out to be but I can understand why some don't want to deal with it. In the hobby sized environment the only issue I run into with chip evacuation using a low pressure pond pump is when making full depth finishing passes in a slot or pocket and the long slender chips bunch up. For these tool passes I have the air come on in addition to the flood which helps a lot. In the two years I have been running the flood coolant it has never gone rancid or smelly. Yeah it can be messy to clean up. My only real grip with flood coolant is it's ability to strip paint but I'm not real sensitive to how my machines look. As long as they are well maintained and perform their intended function I could care less how it looks cosmetically.

 

[grepper]

Please prepare your self for stupid questions, cuz I'm going to embarrass myself and ask some !

Is there any coolant that evaporates so that chips can just be vacuumed up after it dries, or is it just the fate of CNCing that you have to wipe oily goop off everything?

I take it just plain water doesn't cut it.

I've read about some places using alcohol. That seems dangerous and would require some sort of forced ventilation.

Jim D. I notice you use WD40. Why choose that over all the coolants available? My experience with WD40 and drilling is that it is a stinky, smokey mess. I wouldn't think it would drain off well and would pile up in a gooky mess.

What coolant would be best with a Fog Buster?

At this point I can't really machine anything because I have no coolant system. Plus no experience. Currently I should probably be considering just scratching away at some balsa wood!

 

[Jim_Hbar]

Machining steel involves using some sort of cutting fluid - if you think WD40 is smokey and stinky, try some of the sulfide based cutting fluids .
To play around with your mill, get some scrap blocks of UHMW and have at it.. The biggest issue then is static cling.

 

[JimDawson]

One thing to note is that many times we use ''coolant'' and ''lubricant'' interchangeably, and just call it coolant.

I like WD-40 for cutting aluminum, kerosene works great also (or a 50/50 mix). A gallon lasts for days of steady work, months with just intermittent work. If you are cutting manually, an occasional squirt from a can works fine, but when running the CNC a steady mist is important to keep the tool lubricated so the aluminum doesn't weld to it. Steel and other materials are more forgiving and can be run dry or with brushed on coolant. Most times on tool steel I just run air with no lubricant at all. It's important to get rid of the chips so you are not recutting them, this is where the air come in. Most of my work is aluminum so I just keep WD-40 in the tank. Most times I machine plastics dry with an air blast, but sometimes use a detergent/water mix for acrylic or polycarbonate. UHMW and HDPE are always machined dry, they cut like grease anyway.

Cutting generates heat, so no matter what you use you are going to have some kind of vapor generated. I have a vent system with an in-line fan if I'm really generating a lot of vapors.

There are many commercial coolants available in just about any mix you can think of. Most mix with water, some are used as furnished. There both synthetics and natural types. I even have a gallon of soy bean based coolant for really small work and engraving. I don't like the water mix stuff, I would rather clean up oily chips and I don't have rust problems.

If I were using a FogBuster, I would use the recommended coolant. I killed my commercial mist system by ignoring the manufacturer's recommended coolant. That's when I started experimenting with my own system.
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[grepper]

OK. I get it. Thanks everybody for your help on this last (and unexpected) piece of my, let's make a CNC machine puzzle!!!. I may have some build questions later, but for now at least I think I'm good to go.

Interesting; well for me at least: It took me a month of research, a LOT of questions, and the seemingly endless, patient, and informed help from all of you guys to get a clue. Hmmm... Don't know if I should be admitting to that, at least publicly. What a trip!

 

[Al-Hala]

There is too much to learn in the world for one person to get it all in a lifetime, and no need. Ask away, make an effort to search out common answers to common questions, pass the knowledge forward to others lower on the learning curve than yourself, and it will all work out. Ignorance is not a sin, unless it is willful Then it is time for the Ban Hammah!

 

[chips&more]

Your air compressor(s) do not have to be in the same room. They can be in another room or even outside, if the noise from it is an issue.

 

[derf]

A coolant system should be the least of your worries at this point. Get the machine up and running first, then look for solutions after you find problems. Trust me, once you get that far, the coolant dilemma will be a no brainer.