Compressed Air requirements

[HuguesP]

Hello,

i am planning to upgrade my DIY openbuilds router ( 16'' x 24'') . I was wondering about cool features that would make the build more challenging:

- Automatic tool changer with pressurized case spindle ( JGL-85 1.5kw 24000rpm ISO20 )
- Fog Buster or any DIY mist system
- Venturi and small suction plate ( pierson or DIY)
- tool sensor with blowdust

I was wondering if this could all be handle by one "quiet compressor", What would be the individual CFM and total CFM requirements
The sum of individual CFM might not be feasible but or knowing that they do no require their "High CFM" at the same time may reduce the overall CFM requirements.

Thanks.
Hugues.

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[__Britt]

Without datasheets for the specific items in question; I (obviously) can't come up with an actual worst-case-scenario air consumption figure; however just off of the top of my head:

The ATC spindle (if it's at all like the ones I'm familiar with the construction of) will only consume a significant amount of air during the tool-change operation; and compared to the other devices you mentioned, it's not very much.

The coolant system and the venturi vacuum pump are going to be the big air users. Exactly how much will depend on exactly which unit you get/make; and what it's settings are. I've seen mentions of consumption rates in the neighborhood of 4 to 5 CFM @ 90PSI; all the way down to less than 2 CFM.

The tool sensor, like the ATC spindle, will only use air while it's in operation; and depending on how you set it up, probably not that much.

With the air consumption of the coolant and venturi systems being the driving factor; I'm going to hazard a guess that you might be looking at a 220v compressor rated for continuous use... perhaps something like this:

https://www.californiaairtools.com/c...e/cat-15033cr/

It's not cheap, though... they want something in the neighborhood of $1500 for that one.



An idea that I just had - which means it may or may not be any good - is if you DIY the coolant system and venturi vacuum source; I'm wondering if they could be combined somehow? IIRC, the coolant system has a sort of venturi in it; for injecting the coolant fluid into the air stream; and the venturi vacuum source generates a stream of cold, high-velocity outgoing air - if you could just inject the fluid in the outgoing air of the vacuum ventiri; perhaps they could function on the same volume of compressed air from the compressor?

[HuguesP]

Thanks for your response, I understand your point.

I was more looking at real world experience than Calcs, Calcs tend to apply to industrial use with real High MRR and might be overkill from an "Hobby" standpointat low MRR.

If i could get my hand on a cheap Dental compressor, like this one
https://www.ebay.com/itm/FDA-550W-40...UAAOSwFPpdNVVL
I wounder how much I could do with it.

I agree that the tool change should not be an issue, because it it only used during tool change for a small period and the mist is shut off at this time.
the pressurized case however might only use low pressure, but it is consistent, i wounder the CFM requirement of this.

as for the Venturi, i have seen venturi really cheep that at 40-50 psi require really low CFM.
https://www.air-vac-store.com/mm5/me...egory_Code=AVR

of course i don't plan a vac table that would need to vac thru a mdf board and having multiple port open. but more like pierson work holding, aluminum or phenolic with gasket. if well done, it should not use to much CFM.

as for the double use f a single venturi, i would more aim at them working in parallel because most of the time i will probably use only one of them.

[nlancaster]

I use a mist coolant system, sort of like a fogbuster but DIY. 30PSI is the setting I use, and my 3CFM air compressor can just keep up with that.

The venturi vacuum systems consume an enourmous amount of air. I have seen between 6-10CFM at 90PSI which is alot for any home air compressor.

[GME]

Hello,

i am planning to upgrade my DIY openbuilds router ( 16'' x 24'') . I was wondering about cool features that would make the build more challenging:


- Venturi and small suction plate ( pierson or DIY)

I was wondering if this could all be handle by one "quiet compressor", What would be the individual CFM and total CFM requirements
The sum of individual CFM might not be feasible but or knowing that they do no require their "High CFM" at the same time may reduce the overall CFM requirements.

Thanks.
Hugues.

The supplier I use has venturi vacuum generators that require from 1.2 cfm to 14 cfm @ 90#, depending upon the model. The small one will handle up to 2' x 4' vacuum bags, while the 14 cfm model will handle up to 4' x 15' bags. I have the 14 cfm model and use an 80 gal 2 stage compressor. They are definitely air hogs while pulling the vacuum, but basically require no air, once the desired vacuum is reached. However, if you are contemplating drawing a vacuum on and MDF surface, it will probably run constantly, unless you seal the MDF very well.

There are advantages to having a large compressor. In addition to vacuum pressing, I spray finishes with professional HVLP guns (which are also air hogs). You prolong the life of a large compressor, especially 2 stage compressors, by dialing down the max pressure setting (typically 175# or so) to something lower. The compressor doesn't work as hard, with a lowered max pressure adjustment. My compressor is an Ingersoll Rand that's 25-30 years old and still running strong. I've only had to replace the pressure valve assembly once during that time. I think I also replaced the pressure relief valve once. It's 240V, so that can be an issue for some. I am able to do my own wiring, so it wasn't an issue for me.

In case you're interested, here is a link to the venturi I use: https://www.veneersupplies.com/produ...Generator.html

Also, if you go to Joe Woodworker, there are plans for building a complete vacuum outfit. I used a larger tank and made a few other modifications. It works great.

Here's link to the kit building process: https://www.joewoodworker.com/veneering/welcome.htm

I use a Noga Mini Cool mister. I run it between 30-40# most of the time. I don't pay much attention to air consumption, because my compressor tank (80 gals) is large enough that I can run the mister for about an hour + before the compressor kicks back on.

The dental compressor you linked to is 130 L, which translates to about 4.6 CFM. That's pretty small. You might be able to paint with it, but only wIith a low air consumption conventional gun or a quality low volume gun like an Asturo (Italian) WB gun. I don't believe the small compressor will deliver enough air to do everything you want it to. IMO 4 CFM compressors are best for low air consumption air tools on job sites. I don't know much about oilless compressors. I've never owned one. From what I've read, the oil free compressors have a shorter life expectancy. That makes sense to me.

Gary

[ger21]

I've got a few venturi's I use for veneering and my very loud 3HP compressor can't really keep up with them.

Looking at the ones you linked to, it appears that the ones that have low CFM requirements, also have very low vacuum flow. You may find these difficult to get the initial vacuum pull, and very susceptible to any leakage. I have a small GAST pump that I plan on using for hold down fixtures.

Not sure how much air pressurizing the spindle takes, but the drawbar and tool blast are minimal.

[HuguesP]

thanks for those complete answers,
Considering my CNC Space and my budget i ll probably investigate the mist coolant with an aquarium pump and the tool change with the Quiet compressor. Everything is far from being settled. I mostly uses the painter tape / CGlue method and to date it worked fine for me. i might continue with this method.

Just so you know how tiny is my cnc space