Compressor & Air Gun

[wcsg]

I'm looking to buy a compressor and air gun for the router bit. I have the 3hp spindle. I was looking at the vortex cool gun for $185 but I read somewhere that might be overkill and good compressed air at 35-40 psi is good enough. So my question is without being overkill what size dedicated air gum compressor is good? Oil Free? Oil Lube? I don't need it for anything other than a cooler and where is a good place to get a regular air gun as an attachement?

[Brady Watson]

Erik,
You can make your own for under $20.

http://www.bradywatson.com/Aluminum.htm

-B

[gwilson]

After looking at Brady's set up and if you have a compressor in your shop already, I would consider running a line to near your bot than have a pressure regulator before going to the tip. I airbrush and use a full size 125psi compressor and use my regulator (with water trap) to drop down to about 10 to 25psi depending on the paint.
Gerald Wilson

[wcsg]

Nice pic Brady. What do you use for a compressor?

[fleinbach]

Nice work Brady, Proper procedure and the bot can preform many wonders

[Brady Watson]

Erik,
For little stuff like that I use my PorterCable 'homeowner' style upright 25gal compressor. It is an oil-less high-RPM deal that does around 6-8 CFM at 90 PSI. Setting it to 25PSI it only cycled on about once every 10 minutes to fill the tank again. I didn't see the need to run my 25 CFM Ingersol for this. It doesn't take much air to cool the bit. I just used the compressor's built-in regulator to dial it down to around 25 PSI. Like Ron Popeil says: "Set it and forget it!"


I bought a Husky blow gun kit from Depot and took the 1/4" NPT nipple adapter that allowed the football inflator to screw into it and just threaded it into one of the 90° brass fittings. I used 2 brass fittings together to allow double adjustability. From there, I just screwed in a brass nipple and then a 1/4" compressor fitting. You'll notice the black electrical tape that I have wrapped around the football inflator. They put a hole in the side so that kids don't try to stab their friends with it and inflate their legs etc...Tape this off so that ALL of the air blows on the bit. This requires very low CFM from your compressor and very efficiently cools the bit only. Larger orifice tubes only waste CFM and reduce pressure/efficiency.

Although I didn't use it on the AL project I did, going forward, an automatic oil injector filled with denatured alky would probably put frost on the parts! A tiny bit in the air line is all that is needed to take advantage of the cooling by evaporation principle. The discharge should be dry to the touch and never dripping. It doens't take an expert to know that it is flammable, so keep that in mind.

-B

[wcsg]

what's the pros and cons of oil and oil free? Anyone know? Or am I putting to much thought into this,


Thx Brady

[olecrafty]

oil free (oil less) compressors are generally cheaper, and a lot louder than the conventional oil lube compressors. The oil free compressors are home owner type compressor or what we call throw away units. When it quits it cost more to repair than it is worth at that point.

I have a coleman 5 hp oil free that is 8 years old and still going strong. Just have to wear hearing protection when working close to it for a long period of time

[scottcox]

I recommend the oil-filled for the noise reason alone. I also have a Coleman 5hp oil-less and it startles me everytime it kicks in. It's really, really loud. It's about to go in the shed out back with the air hose through the wall.

That'll be 2 cents, please. ;-)

[wcsg]

OK, glad I asked, noise is a factor for me

[Brady Watson]

Yep...mine is pretty loud too & now that it has some mileage on it, I can hear the tell-tale signs of piston slap when it is cold.

-B

Every time the compressor kicks on, the dog comes blasting in the shop (no matter where he is) looking to get a muzzle full of compressed air
So yeah...the Porter Cable oil less "6HP" <---(Yeah right!) is pretty loud...

[olecrafty]

Loc-line and Cederberg (sp) are 2 brands of quick hook up air and coolant lines. Use the smallest nosal opening. Also install a needle valve before the nosal. This will create a temperature inversion and cool the air as it comes out of the nosal. The air will not be quite as cool as the $185 vortex cool gun, but it will be cool enough for the job. Plus you keep the money in your pocket where it belongs. We have used this setup for years and it has save hundreds of dollars on over heated bits and bit sharpening.

[patricktoomey]

I'm cutting lots of 3/4" plywood with a 1/4" compression spiral and I've been having an issue with the chips staying down in the cuts. My dust collector will pickup everything on the surface of the sheets and nothing is flying around the shop but it's not powerful enough to suck the chips up out of the cuts. Does anyone using air jet cooling know if it may be enough airflow to loosen the chips to make dust collection more effective?

[Brady Watson]

I thought about this & it seems that blowing air in the kerf would be more trouble than it is worth...same with using dust collection AND compressed air when cutting AL sheet. You don't need both. The air nozzle would more than likely get in the way with either the dust foot or tool changing operations. It's hard to get around not leaving chips in the kerf no matter how strong your DC is.

I made a routine that moves the tool (with no bit in it) like the CR command that vacuums up the table after I have removed the parts and scrap. You might want to try the same thing yourself. Since there is no cutting force present, you can run the routine max speed to vacuum up the swarf/chips. It doesn't take long on an Alpha or 4G.

-B

[olecrafty]

We used both dust collection and blowing air in the kerf. This works well with the old style foot on the PRTs. Using Cederburg or loc line you can easily adjust the nosal where it is needed and move it out of the way for bit changes. You do put more chips on the table than with just dust collection. But it saves $$ on bits and by reducing heat you can speed the cut a little too.

For removing the dust from the table we added a wye and a gate in the dust collector line. On this line we added a hose from an old shop vac with a ground wire inside. We use the wide sweep attachment for large area clean up and the small nosal for smaller apps.

[wcsg]

After much thought I went ahead and ordered the Vortex cool gun from Http://arizonavortex.com

$175.00

Also I got a small 3 gal oil compressor from grizzly for $99.00

Thx all for our input

[trakwebster]

What I'd like to know is why not use an electric drill gun? They're relatively cheap, sturdy, easy to replace, run off electricity which you already have right there on the carriage (at least I do).

Why would you go to all the trouble of using a compressed air drill?

[wcsg]

were not talking about drills, but cool guns and compressors

[trakwebster]

I get that you're talking about compressors, but what's a mystery to me is ... why?

What is this thing you are hooking up? Why is it desireable? (I thought a cool gun was a drill.) From re-reading your initial post, I see that this is something to hold a router bit. But I'm still ignorant and would like to know the answer of why it would be a good thing to use compressed air to drive a router bit instead of just using a router.

Fill me in?

[scottcox]

Arthur,

They're using a compressor and air gun to COOL a bit with a flow of air across it while cutting.

[ckurak]

Arthur,

Try this link for a picture of a "cold air gun."

http://www.vortec.com/cold_air_guns.php

[patricktoomey]

I have a question for anyone using these... If the output temperature is -30F, are there any condensation or icing problems? I'm in a very high humidity area and it would seem to me that the end of this thing would be dripping water and turning into a block of ice within minutes but maybe the engineers have found a way around that?

[Brady Watson]

The output temp is typically 30° F less than ambient temperature...So if your shop is 70°, then output will be 40°. Personally, these cold guns are too expensive to justify. Add a little alky to an automatic oil injector resivoir and use compressed air...It will outperform a cold gun any day of the week...and it will cost you less than $40 to do right.

-B

[patricktoomey]

Brady, that sounds more reasonable. The Vortec site says they have a 100F drop from input temp which would scare me but it is adjustable so keeping it above freezing would probably help. I like the idea of the alchohol in the injector except for potential fire. I guess the mix would be low enough to not be an explosion hazard? I've never had a problem with bits overheating since I work primarily in wood and Corian and I just make sure my chiploads are good. I would like to use compressed air to help keep the chips clear though and I like the idea of being able to turn on a little alky when cutting Corian as I could keep the bit really cool and maybe get some higher feedrates and/or longer bit life.

[Brady Watson]

Pat,
You should not be able to see/feel any droplets of alky...It should already be evaporated by the time it reaches the tip of the nozzle. If you are concerned with it being a fire hazzard, you can use isopropyl & water @ 50/50 mix, with a reduction in cooling ability and increased moisture/fogging potential.

-B

[wcsg]

Here's an update pic

http://www.thesignsyndicate.com/forums/index.php?showtopic=1394