Air cooling/SWARF removal

[m.marino]

Okay running into the cooling/SWARF problem and looking at options and they are as follows:

Designing a plate to go on the machine to allow SWARF being directly sucked up and hoping the air flow provides some indirect air cooling (not the best option but gets swarf out of the way).

Getting input on designing a compressor based (type to be determined within a budget) for putting a directed jet of air on the tool tip to remove swarf from the cutting area and directed cooling.

Using a combination of the two above to put air on the tip while sucking up the swarf with some form of area pick up.

My head is done in at the moment with client work and getting ready for a convention in the US, so any information or ideas would be greatly welcomed.

Michael

[Tenson]

Off-topic, but where can I buy a coolant nozzle? The snake looking type for flood milling.

[Jonathan]

The cooling due to the air flow from sucking up the swarf will be negligible. I've found the compressed air method to be effective at clearing the swarf when milling Nylon (which is not the plastic you're cutting if I recall correctly), but didn't actually notice any change in the finish since with a single flute tool there's plenty of room for the swarf anyway.

Bear in mind the duty cycle rating on the air compressor you get as you will want to run it continuously, otherwise you will overheat and ultimately break it. Expect to buy a compressor rated for a much higher power / capacity to compensate for having to run it continuously.



Off-topic, but where can I buy a coolant nozzle? The snake looking type for flood milling.

Here:
http://www.arceurotrade.co.uk/catalogue/results.aspx?search=hose

Or:
http://www.ebay.co.uk/sch/Business-Office-Industrial-/12576/i.html?_from=R40&_nkw=coolant%20(pipe%2C%20hose)&_sop=15

[m_c]

Micheal, I'd go for a combination of both. Small jet aimed at the cutter to keep things cool, and a vac to try and control the swarf.
The main thing I suspect you need to aim for is to get the swarf away from the cutting area, so the cutter isn't re-cutting swarf and clogging itself.

And I know how you feel. I thought I had finaly got some time to catch up with a few of my own projects, however the paying job list has just grown :-/
(if anybody can magically weld a crankshaft back together without dismantling anything, there's a tractor sitting outside with said problem...)


Tenson, the brand name stuff is Loc-Line, however there are a good few cheaper versions around. The last stuff I got was from Arc Euro Trade, but most engineering type suppliers have it in some form.

[JAZZCNC]

Micheal I'm with M_C on this.! Keep the air to a minimum other wise you'll need a large CFM compressor and tank. Low direct pressure is all thats needed to clear the chips enough to stop re-cutting then good vacuum will do the rest.
Re cooling the spindle (which is what I think you mean when you say "indirect cooling") then I'd forget the compessed air route has the volume required would be large, the electricty alone of running a big compressor would pay for a water cooled spindle given time.!!
Maybe design some outer rap-around water cooled jacket type affair.??? Bit like an hot water bottle in reverse. .:emmersed:

[m.marino]

Okay,

Now comes the fun of designing something that will work and getting the materials. That and going back and remembering everything I forgot from almost 20 yrs ago with pneumatics. Thanks will design a bracket that includes both so that everything will work together. Luckily have the triton Cyclonic vacuum trap and that is helping out in the shop massively.

M_C if you need any cutting done let me know as not that far up the road from you (we live about a mile off the bypass). Any help you need just give me a bell.

So Looking at either a 24 liter tank and low pressure with an outside storage unit for the compress next to the shop or looking on ebay for a used hydrovane (lots of luck on that one) in good condition (need even better luck on that) and getting a brace in the roof to put a track on so the hoses can follow (decreasing the amount of hard angles is a good thing with vacuum).

Thanks folks and have a great day and weekend.

Michael

[Jonathan]

So Looking at either a 24 liter tank and low pressure

That's what I tried with my cheap 24L compressor from a car boot sale...with the minimum flow rate for it to be useful I still could not run it continuously. However if your part doesn't take too long (hard to say how long) to cut then that may not be a problem.


decreasing the amount of hard angles is a good thing with vacuum

Good thing with either really... most important is to use as big conduit/tube as you can.

[m_c]

Okay,
So Looking at either a 24 liter tank and low pressure with an outside storage unit for the compress next to the shop or looking on ebay for a used hydrovane (lots of luck on that one) in good condition (need even better luck on that) and getting a brace in the roof to put a track on so the hoses can follow (decreasing the amount of hard angles is a good thing with vacuum).


I've got a 25litre compressor in somebody elses garage if you want to try that option. I think it's only a 1.5 or 2 hp though. I bought it several years ago just to get a job done, somebody borrowed it as a temporary solution and it's sat gathering dust since. You can have it for a minimal fee.

I've got a couple engine driven hydrovane compressors needing collected. They're likely of 80's/early 90's vintage, but will of seen little work. I just want the engines, so you're welcome to the compressors if they're any use.


That's what I tried with my cheap 24L compressor from a car boot sale...with the minimum flow rate for it to be useful I still could not run it continuously. However if your part doesn't take too long (hard to say how long) to cut then that may not be a problem.

It's all in the nozzle size.



Good thing with either really... most important is to use as big conduit/tube as you can.

Not for something carrying solids/fluids you don't!
You need to keep the air speed up, or it'll drop the solids and clog!

[Jonathan]

Good thing with either really... most important is to use as big conduit/tube as you can.



Not for something carrying solids/fluids you don't!
You need to keep the air speed up, or it'll drop the solids and clog!

Ok, clearly I was generalising too much as obviously it has to be a balance between the two. This site explains a lot:

http://billpentz.com/woodworking/cyclone/DCBasics.cfm#DuctingSize

[cropwell]

Bear in mind that I have an A4 machine and am only cutting small parts...

I am thinking about trying a fridge compressor to provide a continuous stream of air to the tool and using a vacuum cleaner to remove chips. I am mainly going to machine acrylics and I know I have a lot to learn about, but with thermoplastic materials I understand that build-up on the tool will ruin work very quickly and easily.

The Vac is a Wickes workshop vac and I am thinking of making a holster with a microswitch in it to switch it of when the nozzle is put in it.

My view is against any shrouding round the cutter as I like to see what's going on.

[cropwell]

Arc Euro near Leicester


090-080-10500



Any good ?
350mm Coolant Hose - Flat Spout - Plastic Tap - 1/4"BSP
£4.90

[Jonathan]

using a vacuum cleaner to remove chips...
My view is against any shrouding round the cutter as I like to see what's going on.

Unfortunately those two statements don't really belong together. The flow rate from a standard household vacuum cleaner is very low compared to even a small proper dust extractor - roughly 10 times less. I tried a couple of vacuum cleaners and they were completely useless as the tool threw the the chips out at such a high speed that the vacuum could not catch them. The only way to get it to work was to add a shroud to intercept the chips, giving them time to be caught. Still it's not a good solution, so I got one of these, which was cheaper at the time:

http://compare.ebay.co.uk/like/180429249351?var=lv&ltyp=AllFixedPriceItemTypes&var=sbar&adtype=pla

I was intending to make a cyclone for it, but since I almost exclusively cut aluminium it only really gets used when I surface the MDF bed it's hardly worth it. I leave it to surface the bed on it's own as I don't trust it to filter the fine MDF dust properly.

[John S]

At the shows we run a vacuum pump piped up as a compressor to blow air onto the tool with a drop of cutting fluid bled in as we are usually cutting steel or alloy.
These run continuous from 10am until 5:00 pm and even though they get quite warm they don't give ant trouble.

Add to this they are 3 phase units rewired in delta with a capacitor across the dead phase so we can run them on single phase.

[cropwell]

In the days when I had money, I had the Clarke two bag dust extractor, but never found it much use. The problems were different for me then. I was woodworking using a sawbench and I wanted to keep the workshop (garage) dust down.
Now I have a small CNC setup in my den and it is on a bench with shielding all round. I have posted a couple of pics in my "Hi Y'all" thread. Chasing the tool with a vac keeps dust down and pulls a lot of the swarf into it. After the job any further mess is confined to the bench. Bear in mind that what I do will be small scale and mainly acrylic, aluminium or circuitboard, with the occasional jig cut out of that mixture of wood dust and glue, MDF.
The fridge compressor is yet an idea I have to try out, and I want to experiment with cutter cooling and directing the swarf towards the back of my bench where it can be easily cleaned up.

[JAZZCNC]

Bear in mind that I have an A4 machine and am only cutting small parts...

I am thinking about trying a fridge compressor to provide a continuous stream of air to the tool and using a vacuum cleaner to remove chips. I am mainly going to machine acrylics and I know I have a lot to learn about, but with thermoplastic materials I understand that build-up on the tool will ruin work very quickly and easily.
Fridge compressor will work better if you can send to a small storage tank so it's got a slight head start but should work fine.
Like I said to Micheal who is also cutting mostly acrylics you don't need much air to clear chips from recutting, which is what you mostly want to avoid for both cutter life and finish quality. The nozzle size is key here like M_C says, I find the flexi Loc-line type pipe/nozzle that you find most Engineering suppliers offer that the nozzles are to large and mostly designed for coolant. My cheap and dirty solution is to use car brake pipe and solder main jet from motorcycle on end, it's simple and easy but accurate jet and controlable. (or simpler still just nip end with pliers, just can be a bit random on direction!!)


The Vac is a Wickes workshop vac and I am thinking of making a holster with a microswitch in it to switch it of when the nozzle is put in it.

My view is against any shrouding round the cutter as I like to see what's going on.

This would work good and if you used the M codes M8/9 for coolant turning outputs on/off controlling relay turning vac on/off the microswitch could be put in line with relay so it only comes on when pipes in it's holster. . . . Theres other ways but this would be easiest.!!

I'm the same with wanting to see cutter but to have that and still clear the crap you need plenty of Vacuum with a large pipe sucking up everything not nailed down.!!
The shroud helps slow power vacs but comes with the price of lower visabilty.!! I've seen some good shrouds made with clear acrylic but I'm sure it's only short lived affair before they get frosted by the shot blast affect.?

My solution is to just blast every thing out the way and hope my 6" pipe grabs most of it.!!:emmersed: