New here. I have a couple questions about RazorWeld Cut 45 set up

In setting up my RazorWeld, the instruction manual says use an air compressor with a 6.7 CFM rating or higher. Any recommendations?

I have a 300 size industrial oxygen tank. Would this be a viable alternative to an air compressor? And if so, what should I set my regulator at?

I would say no it really won’t last long. And very expensive if you are buying oxygen.

If you are looking for a compressor buy as big as you can afford. You will have fewer issues with cfms


Thank you for replying! I already use oxy for another job. Just thought it might be a temporary solution.

I’m looking at compressors and I keep finding 5.6 or close to that. The 6.7 and above has been harder to come by. So just weighing all my options.

You need something like this 60 gallon compressor.

A proper air supply system for CNC plasma cutting will add $1000 - $2000 to the cost of getting set up. You need a good supply of clean, VERY DRY air.


You have to watch the plasma manuals that were specifically written for hand cutting. Normally for CNC operations you’ll want 50 to 100% more CFM than hand operations.

A lot of manuals for units that have factory CNC ports will specify a different CFM for CNC use.

Here’s an example from the Everlast 62i manual.

It goes from 4.5 to 5 CFM for hand cutting operations to a recommendation of 9 CFM for CNC operations


The manual I’m reading came with the Razorweld. I purchased the Razorweld as an add on, along with the table. It’s designed to fit together as a CNC system. Forgive me, I’m finding your answer a little confusing. Are you saying that I would be looking for a CFM 50-100% higher than the 6.7 recommended in the manual?

Great! Thanks for your recommendation.

You should be looking for a compressor that can produce 11-12cfm like the one @ds690 recommended. If you use a lower cfm model your compressor will run constantly, producing hot moist air that will be difficult to condition to the levels required for plasma cutting.

Can you cut with a lower cfm model, yes you can… but your cut quality and consumable life will suffer.

If you drop below the flow needed your torch will extinguish.

You will make up the cost of the larger compressor pretty quickly just with the shorter consumable life.


Is it this manual?

It’s more like they repurposed that cut 45 to be used on a CNC machine. They did add a connection on those machines so it could be used with the CNC machine.

I’m saying it is very likely in the manual the referencing hand cutting operation when they’re showing that CFM.

During hand cutting it takes a lot more time to set up in between cuts giving your air system time to catch up.

When cutting with the CNC machine the time between cuts is much faster than hand cutting so the compressor does not get any extra time to catch up, like in the example of hand cutting.

It’s likely this manual only reflects the CFM required for hand cutting in their testing and does not correctly show the CFM needed for mechanized or CNC cutting, which uses more air.



Okay, perfect. That totally makes sense. Thank you!

Thank you for taking the time to explain this all to me! It all makes sense now.

A 60 gal Single Stage realistically runs 10.9cfm at 40psi and Drops heavily at 90psi. You have so many variables depending on if Aluminum Head, Aluminum w/ Cast Sleeve, Cast Head or V-Twin Castiron Head. All cast iron will give you the best % of CFM per Stroke Ration because of heat. If you’re going to the Box store, I would minimally look at an 80gal 2-stage. If you have the Funds and can go for a quality unit that will last 20-30+yrs. you can go 60gal 2-stage if it produces 16cfm at 175psi. Most units do not like to tell you TRUE running CFM at max pressure. A few product lines do like FS Curtis, Max Air, Bell-Air/Chicago Pneumatic. There are a lot of good lines, but remember HEAT is not your Friend. Your 1st 8-15’ of linear run distance from the compressor down the line air cools from the head to room Temp. That is where condensation and water can affect your equipment. Creat water Trap Drops to minimize water in the lines and filter systems. Do not mount the Filter directly to the pump. Waste since the air is still hot at that point. Make sure to often drain the compressor and or put an auto drain plug in the bottom of the tank. They make manual and or Electronic versions. High Humidity can drastically effect water in your system. I strongly Do Not Recommend a Rotary version for small home use. They are designed to wind up and stay running. If you have a lot of start-stop it creates a ton of heat and then condensation which will take out your bearings and ruin a very expensive unit. A way around it is to create a natural Leak in the air system, but that is a waste of air and energy. Rotarys are not as power efficient as a lot of people think. Your Meeter on your power box will be spinning fast!!.

1 Like

Thank you! That’s a lot of great information! I appreciate you explaining some variables and reasoning. It gives me a lot to work with when shopping for the compressor that will work for me.

Just know if your going on the affordable side, you can double up tanks for VOLUME, but you will never get the performance out of a Harbor Freight or cheaper brand lines. They just can hold up to heat, or produce enough air in CFM.

1 Like

Quality and durability is always worth the investment.

This is what am running for my small shop, it is quiet and does a FANTASTIC job. Provides over 20cfm at 150psi, has a built in drier and can easily recover even at 70 psi running continuously. When plasma cutting, the compressor cycles on and off fairly normally providing constant flow. If I did not have this, plan B would have been a 60 gallon (+ plan C adding another 40 gallon tank in line) and then seeing how long I can cut before pausing for the compressor to catch up.

1 Like

Awesome! Thanks for your recommendation. And for the picture.