Plasma Cutter

Just remember that most of the small cheap plasma cutters tend to overstate their cut and sever range. Also It won't cut as thick on aluminum. I don't know what "plot arc" is. A quick search didn't tell me.

Oh! Duh! I'm not normally that slow. I promise. I bet you meant pilot arc. YES. Its it helps with interrupted cutting and cutting dirty(ish) material. Some claims are that the pilot arc may burn through paint, rust, and other gunk, and the main arc will come on when the "current starts to flow."

One thing I would strongly suggest if you buy one of those inexpensive low price import machines is stock up on consumables just in case they aren't available later.

Yeah , I missed that one when I proofread . I thought it would probably be a feature I'd need , most of my stock is stored outside and it's not too clean . And I figure they will fudge on the capabilities , but I think I'll be cutting 3/8" and under mostly - if it's heavier than that there's always the OA torch . Most of my aluminum projects are pretty small , I seldom need anything bigger than the 4X6 bandsaw . And aluminum I can cut with my woodworking saws and the proper blades .

I have read about the difficulty of getting consumables . They list a torch model though I don't know how standardized that is between vendors . Probably be a good idea to stock up as you suggest . I have found a 50 amp unit with the pilot arc for 225 bucks that I think will fit my needs . It's first job might be cutting those OCS's into knife blanks ... I'm already thinking of ways to warm up the shop better this winter so I can spend some Quality Time with my forge and anvil .

Um... am I missing something again? LIGHT THE FORGE! LOL.

I'm shopping for one now ... and I'm wondering if the plot arc feature is worth the extra cost . I'm looking at the bottom of the price range , around 200-250 bucks - I'm not going to be using this thing all day every day . I'm basically looking at one for irregular cuts and more efficient cutting on things too big for my bandsaws . I don't do much OA cutting since I'm operating on small bottles - a "B" tank for Acetylene and a 20 CF oxygen tank . And since the wife has no objection ... she's always been pretty flexible with me on buying tools , she knows I save much more on repair costs than the cost of those tools .

My plasma cutter, which is a nice (and expensive) Thermal arc, has a feature that you set for cutting stuff like expanded metal or dirty metal. I believe it is what is now called a pilot arc. I dunno what Thermal Arc calls it. It does, on my machine, wear the consumables faster, but when needed it sure is handy. Eric

P.S. Yer a bad influence. I started looking at plasma cutters again today.

They are incredibly handy at times. Much easier and faster than pretty much every other cutting method except for a shear.

The only problem with lighting up a gas forge (or torpedo heater) is the several hundred pounds of cold iron machine tooling ... the forge will warm the place quite nicely , but I end up with flash rust on the lathe and mill . I have a small pot belly stove that might work out , I just need to find the time to repair it and rearrange the whole shop to accommodate it .

They're getting quite reasonable now . The one I bought is one of the cut50 variants with pilot arc . 225 bucks plus taxes , free shipping . My wife didn't even ask what I wanted it for , she's a gem when it comes to me buying tools .

__________________________________

My 1/2 HP air compressor couldn't keep up with a 30A plasma cutter.

__________________________________

I think my 60 gal/6hp unit might be able to keep up with the duty cycle on this one . It wants around 4 1/2 CFM @ 75 PSI . I'm still studying these things , but if I understand it correctly you need less air pressure at lower amp settings ... I got plenty of stuff to practice on . I'll need to buy more consumables , right after the first of the month when my monthly transfer to the shop account happens .

On 10/28/2020 5:35 AM, Jim Wilkins wrote: ..... My 1/2 HP air compressor couldn't keep up with a 30A plasma cutter.

__________________________________

I think my 60 gal/6hp unit might be able to keep up with the duty cycle on this one . ... Snag

=======================

Yep, it should be enough. I don't even turn on my newer 60 gal one for small jobs like sandblasting rust spots, the air in the tank is plenty.

Torpedo heaters (& any open-flame heater) are really, REALLY bad in a shop. Because each pound of fuel burned produces more than a pound of water vapor*!! Water vapor + cold steel = flash rust, as you found.

• - the reaction is very straightforward, but I'm too lazy to work out the details. Basically it's hydrocarbon plus oxygen gives CO2 & H2O.

My 40A plasma cutter runs fine on my 2hp compressor.

My 40A plasma cutter runs fine on my 2hp compressor.

=======================

Thanks, that's a useful data point. I wasn't looking for such a large compressor but couldn't pass up the deal, $75 unused but missing the pump (handling damage?). The 3HP Harbor Freight air pump works fine on it.

On 10/29/2020 9:22 PM, Snag wrote: > On 10/28/2020 8:16 PM, Bob La Londe wrote: >> On 10/27/2020 7:31 PM, Bob La Londe wrote: >>> On 10/27/2020 5:42 PM, Snag wrote: >>>

Whelp! I done went gone and ordered one. Didn't get quite the deal you did, but I went with the CUT60P (60 amp) unit at just under $300.

I've got a piece of 3/4" steel plate laying out in front of the shop that I have wanted to break down for various projects for a while now. I hope this will cut it without to much slag.

==============

I've encountered a tool-dulling hard layer at the CNC plasma cut in hot rolled steel. Fortunately the tool that dulled was an easily resharpened HSS lathe bit instead of an endmill or bandsaw blade.

Double up on the air tanks if your little compressor can't keep up. That said, plasma cutting is pretty quick, and you may not need it unless you're cutting 100' of 3/4 plate. ;)

I'm late here, but heard that the Lotos brand was a step above most imports. 50A $409 vs $259 for others on Amazon.

Double up on the air tanks if your little compressor can't keep up. That said, plasma cutting is pretty quick, and you may not need it unless you're cutting 100' of 3/4 plate. ;)

========================================

I did that to help my 1/2 HP compressor keep up when sandblasting vehicle rust spots. I also hung up an 8" wall gauge to monitor the tank pressure from where I was working, to show if I should wait a little before starting.

It was barely adequate for sandblasting and cost me some plasma consumables because I couldn't as easily pause to check the gauge.

My "3HP portable" air compressor matched the draw of my small Hypertherm plasma cutter (about 10mm max cut), for continuous running.