[SCzEngrgGroup]

This one doesnt break the bank!
I really only use it for an air blast, but all the necessary parts are there except the solenoid valves and pulse electronics.

Mist Coolant Mist Lubrication System Unit For CNC Lathe Milling Drill Machine Sale - Banggood.com

I think you will find those suck (not in a good way), especially for intermittent operation. They depend on siphon action to get the coolant/oil to the nozzle, which makes them VERY dependent upon the height of the reservoir, relative to the venturi, the height of the fluid in the reservoir, and the viscosity of the fluid. And they need considerable time to "prime" after the air is turned on. When used with mist coolant (which is 90+% water), the amount of mist ejected is VERY inconsistent. And, the venturi and needle valve are VERY prone to clogging, which will usually completely **** off the fluid flow. I used several such systems for a long time, and HATED them all. The FogBuster is 10X better, but flood, while messy, is absolutely trouble-free and dead-reliable. A good MQL system will usually use a pressure, or positive displacement, pump to feed the fluid, to ensure a consistent, highly reliable flow.

Regards,
Ray L.

[popspipes]

I think you will find those suck (not in a good way), especially for intermittent operation. They depend on siphon action to get the coolant/oil to the nozzle, which makes them VERY dependent upon the height of the reservoir, relative to the venturi, the height of the fluid in the reservoir, and the viscosity of the fluid. And they need considerable time to "prime" after the air is turned on. When used with mist coolant (which is 90+% water), the amount of mist ejected is VERY inconsistent. And, the venturi and needle valve are VERY prone to clogging, which will usually completely **** off the fluid flow. I used several such systems for a long time, and HATED them all. The FogBuster is 10X better, but flood, while messy, is absolutely trouble-free and dead-reliable. A good MQL system will usually use a pressure, or positive displacement, pump to feed the fluid, to ensure a consistent, highly reliable flow.

Regards,
Ray L.

My mist coolant absolutely does not contain any water............. water tends to rust fine machined surfaces........

We were discussing the cost of the systems Ray, not the theory of operation.........

It is Chinese Ray, they sell some cheap stuff........

I have one, I use it for air blast............... works fine for that........

[RCaffin]

I think you will find those suck (not in a good way), especially for intermittent operation. They depend on siphon action to get the coolant/oil to the nozzle, which makes them VERY dependent upon the height of the reservoir, relative to the venturi, the height of the fluid in the reservoir, and the viscosity of the fluid.

Well, you can see my unit. All I can say is that my unit works just fine. I don't know about the Chinese ones, but I am sure a little experimenting could sort them out.
Yes, I do have my reservoir slightly above the nozzle, so maybe that helps. This avoids having to pressurise the coolant tank, which is always chancy as I quickly found that small variations in pressure can have rather large effects.
In my system the venturi is at the final air nozzle, not inside the brass control block. There's a 1/16" PE tube taking the coolant to the nozzle. This may make it more reliable.
I agree about the viscosity, but with 3 parts kero to 1 part oil there are no problems.
Attachment 331774

And they need considerable time to "prime" after the air is turned on.

This is true IF you let the coolant line drain.I have a very small (pnuematic) solenoid valve in line on the coolant, and the line does not drain significantly from day to day. However, you will notice a clear tube at the front of the bottle: that is a priming line. Open the coolant valve by manual over-ride and blow.

When used with mist coolant (which is 90+% water), the amount of mist ejected is VERY inconsistent.

No water in mine - and no rust. And I have to say mine seems fairly consistent too. It just runs.

And, the venturi and needle valve are VERY prone to clogging, which will usually completely **** off the fluid flow.

I have never had a clogged venturi nozzle. What is going to clog it? OK, if you use 90% water you might get algae: so don't use water.
I don't use a needle valve on the coolant. I use a fine delivery tube (seen above), which restricts a fair bit, and vary the length of the on-pulse. 1/2 second is often enough.

A good MQL system will usually use a pressure, or positive displacement, pump to feed the fluid, to ensure a consistent, highly reliable flow.

I am sure some do, but that makes them very expensive. You don't have to do it that way.

Cheers
Roger

[jttoner]

Although this is tapping aluminum this video shows tapping blind holes using a Balax form tap in a Procunier 1E tap head on an 1100. Tapping 2-56 On Tormach Video by miltons_stuff | Photobucket BTW with the Procunier in blind holes almost never break a tap and I have tapped 10s of thousands using this set up. YMMV

Don

Don, what's your formula for determining the correct feed rate? I'm not sure how to calculate it since we have little more than a guess as to spindle RPM. I know I'm missing something. I've done a few 14x20 taps in 7075 w/o incident but I think it was just blind luck. Those were with a Procunier 1E.

[SCzEngrgGroup]

Don, what's your formula for determining the correct feed rate? I'm not sure how to calculate it since we have little more than a guess as to spindle RPM. I know I'm missing something. I've done a few 14x20 taps in 7075 w/o incident but I think it was just blind luck. Those were with a Procunier 1E.

RPM for tapping is not in any way critical, as long as you know what the ACTUAL RPM is, and don't go crazy. Typical tapping speeds are 200-1000 RPM, with the higher end generally being for softer materials. Some tapping heads are more forgiving of spindle speed errors than others. The Procunier has no ability to "absorb" excess travel if the downfeed is too fast compared to the actual (not commanded, but ACTUAL) spindle RPM, so if your spindle speed runs higher than commanded (which is not at all uncommon on an open-loop spindle, you will almost certainly break the tap, and could damage the Procunier. For that reason, when I use my Procunier, I either make sure I KNOW the actual spindle RPM, and still down-feed at 90% feed. If downfeed is slower than it should be, the Procunier clutch will simply release briefly, until the downfeed "catches up". With a closed-loop (i.e. - servo) spindle, you can safely downfeed at 100% feed.

Downfeed is calculated based on RPM and thread pitch as:

FEED = RPM/TPI

So, if tapping 1/4-20 threads at 200 RPM, you would feed at 5 IPM.

Regards,
Ray L.

[SCzEngrgGroup]

Also, be sure to use the correct tap drill size. Many charts only give the correct size for a 70% thread, which is suitable for wood, plastic and aluminum. For harder materiais, you must drop down to 50% thread, which means a larger tap drill. For example, a 1/4-20 70% thread (e.g. in 6061) requires a 0.201" tap drill, while 1/4-20 50% thread (e.g. in 303SS) requires a 0.2188 tap drill. Using a 0.201" drill in steel is MUCH more likely to break the tap. In Titanium, I would think 50% thread would be required.

Regards,
Ray L.

[jttoner]

Thanks Ray,

It was blind luck. I fed maybe 6% slower then calculated using the RPM I measured with a cheapo Chinese laser device. It's readings tend to vary according to some combination of the continental drift times the phase of the moon, all divided by the Julian date. I reasoned that feeding too fast would not end well and hoped the Procunier would tolerate feed that was somewhat slow. I lucked out. Again, thanks

[Don Clement]

Don, what's your formula for determining the correct feed rate? I'm not sure how to calculate it since we have little more than a guess as to spindle RPM. I know I'm missing something. I've done a few 14x20 taps in 7075 w/o incident but I think it was just blind luck. Those were with a Procunier 1E.

Not blind luck but rather blind holes. I feed at 100% with the Procunier tap 1E head. Worked for me in tapping 10s of thousands of blind 4-40 and 2-56 holes in 6061-T6 aluminum on my Tormach 1100 using a Balax form tap. BTW with the Procunier 1E I don't use form taps in anything greater than #8. The largest tap I use with aluminum with the Procunier 1E is 1/4 or M6. I do tap 1/4-20 or M6-1 in aluminum with the Procunier 1E using cutting taps but still feed at 100%. Procunier recommends 100% feed rate http://www.rockford-ettco.com/Downloads/Pro-QuikTap.pdf YMMV but 100% feed using a Procunier worked really well for me as I almost never break a tap using the Procunier on my Tormach 1100 over the last 8 years unless I do something like forget the manual feed override setting. Also for tapping Aluminum Relton A9 cutting fluid works well for me with both cutting and form taps. For small taps in aluminum with the Procunier I use the fastest rpm for the feed rate available. I have a series 1 Tormach so my feed is limited to about 60 ipm. The Procunier retracts at twice the infeed which limits my RPM to 1200 for a 4-40 tap.

Don

[jttoner]

Don, thanks. I knew you've done a huge amount of tapping and I really appreciate you sharing your experience with a novice such as I. I believe I've had my machine 3 or 4 years now, but I don't use it that often. Worse, as seems common with many other novices, I'm afraid to go fast. Now that I have more time on my hands I need to take some scrap metal and try recommended speeds & feeds. When I look at HSM's recommendations I shudder in fear. On my Lagun I could feel and hear if I was too aggressive. It's a massive machine and rigidity has never been an issue. Anyway, I'm just rambling, but thanks again.