Plasma cutter flow rate requirement
Bart Killam
I am buying a plasma cutter, and my welding supplier is pushing the Miller 375.
Very light, small machine, but it does cut nicely on 1/4". I wanted to go up to
a Thermal Dynamic 52, with double the cut. It was only about $400 more (about 1400 vs. 1800).
My old Cambell Hausfeld compressor is rated at 5.7 CFM @ 90psi; it is old and
probably has some small leaks with put the CFM number lower.
The 52 has a flow requirement of 6.7 @75psi; if I am doing the math correctly,
this corresponds to (75/90)*6.7 = 5.6, which my compressor can handle.
Is this correct ? Any advice is appreciated.
--
Bart Killam Work: (612) 349-9187 x1283
SAS Institute Inc. Fax: (919) 677-4444 (Fax)
Minneapolis Regional Office Email: sas...@wnt.sas.com
800 Nicollet Mall, Suite 2800
Minneapolis, MN 55402
--
Our Mission: To deliver superior software and services that give people
the power to make the right decisions.
Pete C.
Advice:
Hypertherm Powermax
Harbor Freight refrigerated air dryer
New compressor
Ernie Leimkuhler
Pete C. <aux3....@snet.net> wrote:
I second the vote for Hypertherm.
They are the leader in plasma cutters now.
I am trying to sell my Thermal Dynamics Pak38XL so I can buy the new
Hypertherm Max30.
I don't really need a new plasma cutter, but the Max30 is just so much
smaller and more powerful.
The Hypertherm Max30 and the Miller 375 Xtreme are very similar, and
both use Hypertherm torches, but the Max30 has the newer nicer torch,
and comes with a full kit of accessories.
Martin H. Eastburn
have beautiful cut through 1/2" AR 400F. That is hardened to 400 BHN
and Abrasion Resistant - the F is even more resistant.
The consumables are lower cost when with Powermax (so I read) and the
refrigerated air dryer really saves more. It is 220V.
I have a good filter before the air dryer to keep it clean as well.
Martin
Randy
Killam) wrote:
>
>
> I am buying a plasma cutter, and my welding supplier is pushing the Miller 375.
>Very light, small machine, but it does cut nicely on 1/4". I wanted to go up to
>a Thermal Dynamic 52, with double the cut. It was only about $400 more (about 1400 vs. 1800).
>
> My old Cambell Hausfeld compressor is rated at 5.7 CFM @ 90psi; it is old and
>probably has some small leaks with put the CFM number lower.
>
> The 52 has a flow requirement of 6.7 @75psi; if I am doing the math correctly,
>this corresponds to (75/90)*6.7 = 5.6, which my compressor can handle.
>Is this correct ? Any advice is appreciated.
>--
>Bart Killam Work: (612) 349-9187 x1283
>SAS Institute Inc. Fax: (919) 677-4444 (Fax)
>Minneapolis Regional Office Email: sas...@wnt.sas.com
>800 Nicollet Mall, Suite 2800
>Minneapolis, MN 55402
How much continuious cutting will you be doing? the compressor can
catch up between cuts. seems like you're close enough.
I have a Hypertherm Max 70, has to be 10 years old. works great, the
newer ones are smaller.
Thank You,
Randy
Remove 333 from email address to reply.
Martin H. Eastburn
is tripped. And is the low level above the working pressure ?!
I have a dual cylinder cast iron on a large verticle tank. I drive air tools
without problems. I drive my Hypertherm 600 at flow and pressure - and cut
without interrupt. My compressor can, upon trip, deliver more than I use and
thereby fill the tank back up to high pressure as I continue to cut.
On large sheet cuts and hundreds of inches on the CNC table - it might cycle
on a time or two.
Post the tank and preliminary pressure sensing and regulation I have a
particle/water filter - then a refrigerator unit - then another filter on my
plasma input. I put cold air out the nozzle.
Martin
Bart Killam
Just a hobby welder, very short cutting times, typically under a minute, never
over five minutes. Mainly concerned about damaging the machine if the flow rate
was less than required.
Mainly was wondering if the flow rate computation was correct. Decided on the
Hypertherm 45, the spec sheet gives a flow rate, but not a pressure. Need to
contact Hypertherm. After spending about $1500, do not want to buy a new
compressor. The high flow rate models can get expensive.
--
Bart Killam Work: (612) 349-9187 x1283
SAS Institute Inc. Fax: (919) 677-4444 (Fax)
Minneapolis Regional Office Email: Bart....@sas.com
800 Nicollet Mall, Suite 2800
Minneapolis, MN 55402
--
Our Mission: To deliver superior software and services that give people
the power to make the right decisions.
The Power to Know... SAS
In article <v01l35t8ofi1h0s3j...@4ax.com>,
--
Bart Killam Work: (612) 349-9187 x1283
SAS Institute Inc. Fax: (919) 677-4444 (Fax)
Minneapolis Regional Office Email: Bart....@sas.com
800 Nicollet Mall, Suite 2800
Minneapolis, MN 55402
--
RoyJ
you show. The operative word is STANDARD cubic feet per minute which is
measured at atmospheric pressure. The compressor takes in a certain
volume, compresses it to whatever pressure so that is the limiting
factor. Higher pressures and the compressor cannot output as much air on
the exhaust stroke so the CFM goes down working into higher pressures.
Martin H. Eastburn
My 600 did. I had ice in my refrig unit and it limited flow.
Martin
dan
sci.engr.joining.welding mine and will die if we don't mount a rescue
by Fri, 12 Jun 2009 00:27:52 -0700:
Third vote for the powermax30 very nice machine.
--
Dan H.
dan
sci.engr.joining.welding mine and will die if we don't mount a rescue
> Mainly was wondering if the flow rate computation was correct. Decided on the
>Hypertherm 45, the spec sheet gives a flow rate, but not a pressure. Need to
>contact Hypertherm. After spending about $1500, do not want to buy a new
>compressor. The high flow rate models can get expensive.
The machine will shutdown if the pressure gets too low. On my
powermax30, the internal regulator is set at 60psi. I don't know what
the pressure switch is set at, but you could just lower the pressure
until it gives you a low air fault without cutting to find out how low
it can go.
--
Dan H.
Randy
Killam) wrote:
>
> Just a hobby welder, very short cutting times, typically under a minute, never
>over five minutes. Mainly concerned about damaging the machine if the flow rate
>was less than required.
>
> Mainly was wondering if the flow rate computation was correct. Decided on the
>Hypertherm 45, the spec sheet gives a flow rate, but not a pressure. Need to
>contact Hypertherm. After spending about $1500, do not want to buy a new
>compressor. The high flow rate models can get expensive.
>
>--
On short cuts you will be running off the air in the tank, so the
pumping capacity of the compressor will not really come into play.
Bart Killam
I called Hypertherm tech support; the PowerMax 45 need a full 6.0 cfm @90psi. Any lower flow rate
would result in auto shutoff with error lights on panel.
I looked into compressors in that range. It seems that under 6.0 cfm,
compressors are inexpensive; under $300. The next step up was 7-9cfm, with prices
at minimum $800. And these are 220V machines, which would require rewiring
my garage for 220V/60A.
So while I can afford the powermax 45; the compressor and rewiring job is not
affordable right now. One has to be rich to be a hobbyist welder.
John Husvar
sas...@unx.sas.com (Bart Killam) wrote:
> I called Hypertherm tech support; the PowerMax 45 need a full 6.0 cfm
> @90psi. Any lower flow rate
> would result in auto shutoff with error lights on panel.
>
> I looked into compressors in that range. It seems that under 6.0 cfm,
> compressors are inexpensive; under $300. The next step up was 7-9cfm, with
> prices
> at minimum $800. And these are 220V machines, which would require rewiring
> my garage for 220V/60A.
>
> So while I can afford the powermax 45; the compressor and rewiring job is
> not
> affordable right now. One has to be rich to be a hobbyist welder.
Same with blacksmithing: You can make a small fortune -- if you start
with a big one.
Pete C.
Bart Killam wrote:
>
> I called Hypertherm tech support; the PowerMax 45 need a full 6.0 cfm @90psi. Any lower flow rate
> would result in auto shutoff with error lights on panel.
>
> I looked into compressors in that range. It seems that under 6.0 cfm,
> compressors are inexpensive; under $300. The next step up was 7-9cfm, with prices
> at minimum $800. And these are 220V machines, which would require rewiring
> my garage for 220V/60A.
>
> So while I can afford the powermax 45; the compressor and rewiring job is not
> affordable right now. One has to be rich to be a hobbyist welder.
Buy a second smaller compressor and manifold the two together. You'll
increase both the storage capacity with the two tanks, as well as the
CFM capacity with both compressors running. The only bad part is you
also increase the noise level.
Bob Engelhardt
> ...
> So while I can afford the powermax 45; the compressor and rewiring job is not
As has been pointed out previously, your demands on the compressor will
be intermittent. I.e., you will draw from the tank & it will catch up
while you're paused to reposition the work and/or yourself. If you're
not doing CNC, your duty cycle is likely to be quite low.
Even if you find yourself stopped & waiting for the compressor to catch
up, you're still getting work done and nothing's been harmed. And it
will happen infrequently.
Go for it! Worst case you'll find that you do need a bigger compressor
and you'll live with this one while you save up for the new one.
Bob
Ignoramus12074
With a little bit of patience and attention, you can buy a used
compressor for much less than the above prices.
The OP can also use a smaller compressor, as long as it has a big
enough tank to hold enough air to make his typical cuts. He would just
have to wait between recharges. A possibility to consider is to buy a
smallish compressor and a extra tank. Tanks cost next to nothing
used.
Some things are inevitable, such as getting at least a 5 HP compressor
and rewiring a garage for 220. You can postpone them, but in the end
it will be necessary.
Ditto on blacksmithing.
i
Martin H. Eastburn
connected it will deliver from the volume while the pump tries to catch up.
You have to have them stored with say 100 more pounds of pressure and regulate
it down. SO if you have an old one, put in line and as a storage and even pump
it to aid in re-pressuring. When you can replace what you have you might
want to keep the extra volume, but not pump.
A lot of time you can find various pumps and tanks for sale in estate sales
or simply moving. Using the tanks as a storage area will help a lot!
Think of water. If you have two 1/2" inlets and a 3/4" outlet - one won't
be able to keep up, but two will match the output. The volumes in the tanks
will deliver the flow as they drop in pressure being refilled by one or more
of the 1/2" inlets... So if you don't do 100% cutting for many minutes -
you might be ok. When you let go of the trigger, the pump starts overtaking...
Consider cutting right angles - cut 2" across one flat and then let go of the
trigger. Reposition and cut again.
You won't use it all of the time, it is best to have one rated higher than
needed in volume and pressure.
The one I have is a belt driven, double headed cast iron I bought at Home Depot
(as I recall) with all green on the front - meaning all air tools can be used.
The low trip is above my Hypertherm 600 trip point and the pump can generate
more than I use and fill the tank several times during long cuts. I cut some
1/2" AR400 pre-hard at 8-10"/minute. If it weren't so tense, I could fall asleep.
I cut thin stuff at 200+ in/min and that scares me as the CNC table goes into
action!
Martin
Pete C.
"Martin H. Eastburn" wrote:
>
> If you have a big tank that will help. If you have several smaller ones all
> connected it will deliver from the volume while the pump tries to catch up.
> You have to have them stored with say 100 more pounds of pressure and regulate
> it down. SO if you have an old one, put in line and as a storage and even pump
> it to aid in re-pressuring. When you can replace what you have you might
> want to keep the extra volume, but not pump.
>
> A lot of time you can find various pumps and tanks for sale in estate sales
> or simply moving. Using the tanks as a storage area will help a lot!
>
> Think of water. If you have two 1/2" inlets and a 3/4" outlet - one won't
> be able to keep up, but two will match the output. The volumes in the tanks
> will deliver the flow as they drop in pressure being refilled by one or more
> of the 1/2" inlets... So if you don't do 100% cutting for many minutes -
> you might be ok. When you let go of the trigger, the pump starts overtaking...
As I mentioned in another post, you don't have to replace the existing
compressor, you can supplement it. If the current compressor can do say
4 CFM you only need to parallel it with another that can do 2 CFM or
better to get your required 6 CFM to support continuous cutting.
>
> Consider cutting right angles - cut 2" across one flat and then let go of the
> trigger. Reposition and cut again.
>
> You won't use it all of the time, it is best to have one rated higher than
> needed in volume and pressure.
>
> The one I have is a belt driven, double headed cast iron I bought at Home Depot
> (as I recall) with all green on the front - meaning all air tools can be used.
>
> The low trip is above my Hypertherm 600 trip point and the pump can generate
> more than I use and fill the tank several times during long cuts. I cut some
> 1/2" AR400 pre-hard at 8-10"/minute. If it weren't so tense, I could fall asleep.
>
> I cut thin stuff at 200+ in/min and that scares me as the CNC table goes into
> action!
I fired up the CNC plasma table I've been building for the first time
this past weekend :) I did my test cuts on 14 ga steel at 150 IPM and it
is amazing the time dilation effect that occurs. The gantry moving at
150 IPM during testing seems pretty slow, but that same 150 IPM seems
like a rocket when there is a plasma stream going.
Martin H. Eastburn
I have one and there are groups in Yahoo. I have PlasmaCam myself.
Martin
Pete C.
"Martin H. Eastburn" wrote:
>
> What kind of table do you have ?
> I have one and there are groups in Yahoo. I have PlasmaCam myself.
>
> Martin
I built it to match my needs. Basically compact to not take up my whole
shop and fully enclosed and with water table to not mess up my whole
shop. Powermax 1000, CANDCNC Dragon Cut DTHC controls, Mach3, SheetCAM,
TurboCAD.
http://wpnet.us/first_plasma.wmv
Winston
> "Martin H. Eastburn" wrote:
>> What kind of table do you have ?
>> I have one and there are groups in Yahoo. I have PlasmaCam myself.
>>
>> Martin
>
> I built it to match my needs. Basically compact to not take up my whole
> shop and fully enclosed and with water table to not mess up my whole
> shop. Powermax 1000, CANDCNC Dragon Cut DTHC controls, Mach3, SheetCAM,
> TurboCAD.
>
> http://wpnet.us/first_plasma.wmv
Yeah! I actually jumped when it lit off!
Very cool!
--Winston
Pete C.
Yes, nice to see it up and running finally. I've been working on it
since December or so intermittently.
Martin H. Eastburn
One thing I noticed was the return clamp on top!
At least you were not near.
I put mine on the bottom with a magnetic twist on attachment.
I use a high percentage of a plate and when possible, I cut out
circles, and rectangles - various shapes - to have steel around.
I cut a lot of AR400 steel and get chunks that the scrap man wont.
I'll make something out of them. The circles I like to use as
steel pads on machine feet.
Spreading the weight over a wider surface.
Looked like a large cane knife being cut.
I can't find a knife man around here - he'd love some of the scrap
I have for his forge.
Martin
Pete C.
"Martin H. Eastburn" wrote:
>
> Nicely done.
Thanks, it seems to have come out nicely. It only occupies a 3x4
footprint and is designed so I can move it with the forklift or palette
jack if I need to. The water table and enclosure seem to do a good job
of containing any mess. The other plasma torch for cutting down the
sheet to fit the table makes a nice mess on the floor of course.
>
> One thing I noticed was the return clamp on top!
I'm going to put a basic lug connection to the support frame that holds
the slats and use the frame for the return, since I clamp one corner of
the sheet to that frame to eliminate any wiggle in the slats.
>
> At least you were not near.
>
> I put mine on the bottom with a magnetic twist on attachment.
>
> I use a high percentage of a plate and when possible, I cut out
> circles, and rectangles - various shapes - to have steel around.
>
> I cut a lot of AR400 steel and get chunks that the scrap man wont.
> I'll make something out of them. The circles I like to use as
> steel pads on machine feet.
> Spreading the weight over a wider surface.
I'll have to put a few more sheets of material on my next steel order. I
need to order some more tube and angle, going to add a perimeter rail to
the roof of my camper, also looking at building a back porch for the
truck / camper combo.
>
> Looked like a large cane knife being cut.
Actually, it was a support slat. The slats that were in the frame in
that pic were just pieces cut from a roll of steel anchor strapping. The
first cutting task was to cut "real" support slats out of 14ga sheet.
Gunner Asch
<lion...@consolidated.net> wrote:
>
>I can't find a knife man around here - he'd love some of the scrap
>I have for his forge.
Gunner raises his hand........
"Lenin called them "useful idiots," those people living in
liberal democracies who by giving moral and material support
to a totalitarian ideology in effect were braiding the rope that
would hang them. Why people who enjoyed freedom and prosperity worked
passionately to destroy both is a fascinating question, one still with us
today. Now the useful idiots can be found in the chorus of appeasement,
reflexive anti-Americanism, and sentimental idealism trying to inhibit
the necessary responses to another freedom-hating ideology, radical Islam"
Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno