Air Source Questions: Spectrum 625 and 375 Extreme.

[SundownIII]

Dave,

Like you, I read portable, but nowhere did I get the impression he was planning to "go mobile".

Frankly, the whole post made little sense. Maybe because the OP provided so little information.

On one hand we have the stated purpose for a cutter as cutting off a few strips, then we're talking 16ga-1/4" sheet material, to punching holes in 3/8" aluminum and steel??? All this with the intent of "making boxes".

Unless the OP has "unlimited resources" (lots of money), then, there's a lot of other tools that need to be acquired before he worries about "any" plasma cutter.

Sorry to be blunt, but this type posting just seems to "bring out the best in me".


Dave,

Going back to your original post in this thread, you also need to consider the post flow of the plasma when computing cut time. This varies between machines, but my 1250 has substantial post flow regardless of the duration of the cut. In other words, for a small cut (say a cutoff of 4") my machine will use a lot more air for postflow than it does in making the original cut. This would further reduce his "cut time". Use of nitrogen for other than the exotics or specific field use just doesn't make much sense to me.

[davedarragh]

"Post Flow"

Sundown: Very Good Point. To be honest with you, I didn't even consider it, as I use mine 99.9% of the time off the compressor. Post flow time would definetly shorten the life of a bottle of gas!

Yeah, sometimes people don't know what they want, and just bounce things off of others.

Thanks

Dave

[Bly]

I have been out of town and just got back. I read all of the posts and want to thank everyone for the help. Well, based on the posts here, I’ve decided that a plasma cutter is not for me right now. I guess I just got caught up in Miller’s advertising and was thinking that this could be an all around solution for my needs.

I gave the box making scenario as just an example of what I plan to do but in reality I have a bunch of projects in mind.

Thanks for the suggestions Desertrider. I have a drill press but just wanted something to make fast holes that don’t need to be clean and was trying to avoid a torch. I also have a chop saw, sawsaw and angle grinder but never thought of using a cut off wheel. I’ll try that. A shear is something I need though and never crossed my mind as the ones at HD only cut 18 ga. However, after researching a little more I found some that will cut up to 14 ga and nibblers that would do 10 ga.
Sundownhill, I have a Millermatic 252 and Passport and I’ve never used a plasma. After see some videos though, it does not look like I’ll be able to get the straight cuts I want with ease. I’m looking to try a cut off wheel and nibbler or shear.

Sundownhill, you are correct. I wanted to be portable not mobile. I’m back and forth between to properties and was hoping to load my Passport, Spectrum Plasma and a small compressor to travel between the 2. That is why I’m trying to avoid a 5-6’ tall compressor.

Thanks again for the help. I’ve saved a lot of money and now I can get a spoolgun!!! By the way, which would you guys recommend: A nibbler or shears for cutting sheet metal 16 ga – 12? I’ve never used either and don’t know where to start.

[Bly]

By the way, why does Miller push the portability factor on the Spectrum 375 and 625 when you need a monster compressor to run it. I know the reason why, I'm just venting. Or does someone actually make a high powered portable compressor that can run a plasma or one that can fit in that Blue case?

[Bodybagger]

Get one of these:


And one of these:


And you'll be set. All for less than 10% of a plasma/compressor/generator.

[SundownIII]

Bly,

Now that we have a little more info, regarding intended use, we may be able to make some better recommendations.

You may want to check out the Porter Cable Model Job Boss C3151 compressor. It's a double tank, low profile, oil less compressor.

Specs:
7.1 SCFM @ 40 PSI
5.3 SCFM @ 90 PSI
4.5 Gal Tank

Based on these specs, it barely meets minimum requirements for the extreme 375. I wouldn't recommend it for sustained cutting, but would probably do the small jobs you're talking about. You could "help it along" by installing a spare, 20 gal or so reservoir, in the air line. Won't give you any more capacity, but would allow a little more drawdown.

Don't get any of us wrong, a plasma is a great tool to have in the shop. I use one of my two units all the time. Best way I've found to cut stainless sheet in the shop. However, if I ever had to choose between the air compressor and a plasma cutter, the air compressor would stay.

In the absence of a shear, you may want to try a Bullet Industries metal cutting blade (7 1/4") on your skilsaw. When used with a angle guide, they produce extremely straight cuts. Make sure though that you wear leather gloves and full face protection. They will throw hot schrads.

The next step up for cutting sheet/plate to 3/8" or so, is the Milwaukee 8" Metal Cut saw. Got one, works great. Get my blades from Morse. They have an 8" thin metal blade (more teeth) as well as a standard blade which I use for 1/4" and up. 1/2" and thicker steel/SS, I use the Hypertherm PM 1250 plasma cutter with a guide (or I take it to my buddy's shop and shear it).

Sounds like you've got your welders covered (nice equipment).

Where a plasma shines is in cutting out non straight patterns. I actually do very little "freehand cutting" with the plasma. I'll generally just cut a pattern out of 1/8" masonite with the jig saw, and then use the plasma to cut the metal. I have made up a couple of square jigs for cutting SS with the plasma.

Lots of options out there. No such thing as "too many" tools.

[piniongear]

When Miller first came out with a plasma cutter they made one that had a built in air compressor and would cut up to 1/8 inch steel.
You picked this up like a small suitcase and it ran off 115V and was completely portable. The drawback was it's small power and high cost.
Don't they still make something like that?
pg

[Bly]

Sundownhill,

I’m definitely going with the angle grinder with the blades you mentioned first. This will obviously be much cheaper than the plasma route. But just for my future reference, which of these compressors do you think would work best for small jobs with the Spectrum 375:

1. Porter Cable Model C3151 you mentioned:
150 psi
Oiless
7.1 SCFM @ 40 PSI
5.3 SCFM @ 90 PSI
4.5 Gal Tank

2. Makita MAC5200:
140 psi
Oil lubricated
6.9 SCFM @ 40 PSI
6.5 SCFM @ 90 PSI
5.2 Gal Tank

3. Dewalt D55146:
200 psi
Oiless
5.2 SCFM @ 90 PSI
4.5 Gal Tank

They are all the same design and look. My guess would be the Makita but it’s 140 psi instead of 150 psi, or would the higher 200 psi on the Dewalt provide more useable air? By the way, could the Makita at 6.5 cfm be used on small jobs with the Spectrum 625 since it meets the 6.0 cfm minimum?

You mentioned that you use masonite as a guide. Do you think I could get the same straight cuts as with a saw if I used masonite as an edge on each cut?

[Desertrider33]

I had the Makita MAC5200 compressor. Gave it to pop for his handyman service. It did a better job than my Porter Cable pancake compressor did, but it's still not big enough to run the plasma's you're talking about effectively. It will get you by in a pinch, but that is all. I wouldn't buy one for that purpose.

Miller does make a plasma cutter with a built-in air compressor. I believe it's called the Spectrum 125C. Hypertherm also makes one very similar. They are small, light, easily portable units but are limited on cutting thickness. These could be a consideration for light jobs and intermittent use. They're not all that expensive.

All of the inverter plasmas are easily portable, you just need power and air to run them.

If you want to spend 9 G's, you can buy the Trailblazer Air Pak self generating welder/compressor, which has plenty of power and air to run bigger plasmas than you are considering. It puts out 12,000 watts of power and 30 cfm of air, if I remember right. Very cool machine for mobile work. A bit beyond most people's budgets though.

I don't have power hand shears, but I do have an air nibbler. It works ok, better for shapes than long straight cuts. For straight cuts on sheet steel, an angle grinder and cut-off wheel work good.

I like Sundown's suggestion of a metal cutting blade in a Skil saw. I have been thinking of getting one of those circular saws made specificaly for cutting metal. I keep seeing them at the welding shop and hear them calling my name when I walk down that aisle. I'll have to check one out some time.

A press shear is definately the best tool for cutting sheetmetal if you intend to do a fair amount of it. I'm seeing more and more of these for sale used lately. Alot of shops giving up the ghost and liquidating the bigger machines now.

[piniongear]

To sum it all up, in your original post you said the need for a plasma was related to your hobby work.
Your hobby is not going to give you much fun and pleasure if you find yourself struggling with trying to get a straight cut on some 1/16 inch steel.
And, without a plasma, that is the best you can expect...... a struggle!

So my suggestion is to save up and earmark the money needed to get this equipment, or perhaps find yourself another hobby. But, golf costs money too!
pg

[SundownIII]

Bly,

First, let me say that you've gotten some good advice here, and some advice that seems to come from posters who've never used the tools they're recommending. Guess it's up to you to decide who to listen to.

As far as the compressors, non of the smaller units are recommended for sustained cutting. If you go back to my previous post I said that the PC may meet your "minimum" requirements. In other words, it'll provide the necessary air in a pinch.

Can't comment on all the compressors. I have the PC that I mentioned and have been very happy with it (don't ask it to do too much). I have used it with my PM600 for short duration cuts. Just have to wait for it to build pressure back up. I've had excellent luck with Makita tools across the board. In fact, I don't think I've ever had a "bad" one. Got a couple of their sliding mitre saws, bout a half dozen drills, and half dozen grinders. Their 18v impact driver is the cat's meow. In other words, good tools.

I've been less impressed with the DeWalt tools of late. Got a grinder (free) when I bought the chop saw. Neither tool has been outstanding. Chop saw is just OK, and the grinder runs rough and hot.

It may just be me (spoiled by the cnc plasma cutting table at buddy's shop), but I've never been able to get a straight plasma cut (even with a guide) that compares to a saw cut in steel. When you go to aluminum, it's not even close. For SS, plasma is the tool of choice, since it just destroys a saw blade.

Before I bought the Milwaukee 8" Metal Cut Saw (similar to a skilsaw), I went to Lowes and bought a cheap skilsaw (about $50) along with the extended warranty ($5.00). Ordered a couple of the 7 1/4" Bullet metal cut blades and went to town cutting. Use a piece of 1"x1/8" angle as a guide. Did a good job on up to 1/4" plate. Biggest complaint was the flying slivers. Cut quite a bit of 1/8" and 1/4" material with that setup. Ironically, the saw still survives.

The 8" Milwaukee is definitely a step up. Cleaner cut. More powerful (faster) and more blade options (thin cut steel, regular steel, aluminum). I get my blades from M.K. Morse. Not cheap but good/excellent quality. Last time I checked Lowes handles a Lennox 7 1/4" metal cut blade (about $50) that works well in both the skilsaw and the Milwaukee.

Either of these two options (with a proper guide) will give you a cleaner/straighter/better edge cut than a hand held plasma. Anyone who tries to tell you different is "huffing and puffing".

When it comes to aluminum, there's no comparison. A saw cut edge will blow a plasma cut edge away any day. I don't care if it's cut with a skilsaw, jig saw, sawsall, etc, they're all better than plasma. With the plasma cut, the edge still has to be ground to remove the oxides created by the heat of the cut (I normally use a carbide burr to trim the edge in curved cuts), whereas a saw cut is ready to weld (other than surface oxides).

Thin stainless, I normally cut with a grinder and a cut off wheel. If the job is large or the material is thick, I take it to my buddy's shop and either shear it or cut it on the water jet.

For mild steel angle, bar stock, etc. I normally either use the Porter Cable Dry Cut Saw or the Wilton bandsaw.

For cutting SS angle, rounds, etc (cut off type jobs), I use the Wilton bs.

The plasma cutters excell at making non-straight cuts in thicker material. Best tool I've found for making inside cuts (no way to get to them with a bandsaw for instance). I use them for making holes in thicker stock (motor mounts, support braces, etc) where drilling would be a pain. Here I generally use a pattern made from 1/8" aluminum stock. The 1250 is also an excellent tool for gouging out old welds. Lot more convenient than the torch.

For "out of shop" work, I generally carry a chop saw, a grinder with a cut-off wheel, and a 18v sawsall (Makita). Gets the job done 95% of the time.

Personally, I'd recommend talking to your LWS about setting up a demo on a plasma cutter. If that's not possible, ask if they have anyone you could talk to that could possibly show you how they operate. If you post up your location, there maybe a member close by who will speak up. If you're near VA, I'd be happy to set up a demo for you and let you "get a feel" for what they do best and don't do well. A good plasma cutter (the only type to have) is a major investment. You need to understand what they are capable of. They're great machines to have but not always the "best" option.

For instance, I can't imagine trying to get a "clean cut" on an 1 1/2" SS boat shaft. I can sever it with the 80A machine (would look like a gopher chewing on a tree) but that's about it. On the other hand the bandsaw will lob off 1/16" thick slices like they were scalloped potatoes.

Sorry for the book. Lots of options.

[SundownIII]

piniongear,

Obviously, you've never seen the cut made by a Milwaukee 8" Metal Cut Saw, with a thin metal cut blade (comparable to a shear).

In fact, a 4 1/2" grinder with a cutoff blade (in trained hands) does an excellent job. (comparable to a plasma but slower).

A while back I had to cut a new face for a stainless steel refrigerator we had on a boat in the yard. With all the tools I had available (to include two plasma cutters), I went with the grinder and a cut off wheel. Sandwiched the edge to be cut between two pieces of 1"x1/8" aluminum angle (to pull heat away and not warp the stainless), and cut the SS with the grinder. Perfect cut with no blueing of the SS.

Been cutting/forming metal for a "little while".

[Bly]

Sundownhill,

Would you happen to have the model #'s of the MK Morse blades you use? Thanks.

[Desertrider33]

I just saw the Evolution Rage Saw 7-1/4" metal cutting circular saw. $160 msrp with blade. I have the Evolution Rage 3 metal cutting miter saw and I like it. Built very well. I might get that little circular saw to keep on the truck.

http://www.evolutiononlineshop.com/E...age_Saws~x.cfm

[SundownIII]

Bly,

The M.K. Morse blades I use on the 8" Milwaukee Metal Cut saw are as follows:

All 8"

CSM840SC 40 Tooth 5/8" Arbor Steel
CSM868TSC 68 Tooth 5/8" Arbor Thin Steel
CSM860AC 60 Tooth 5/8" Arbor Aluminum

These are called the Morse Metal Devil Blades.

This info can be found at www.mkmorse.com or www.metaldevil.com

I also use their sawsall blades and their holesaw blades (for notching pipe)