Fine Cut Consumables Clarification

[BanksAg]

We have a plasma table on order along with a 45XP, but I could use a little clarification on the fine cut consumables. The manual I downloaded shows the deflector (220955) being used with the standard retaining cap, and the shield (220948) being used with the ohmic retaining cap. On Hypertherm's website it shows that the shield can be used with either retaining cap. The shield seems like it would provide more protection for the nozzle, so is it okay to use the 220948 shield with the standard retaining cap on a machine torch?

Also, does anyone have recommendations on ratios of electrodes/nozzles to shield, swirl ring, & retaining caps to start with? We're buying the table & plasma cutter through a grant, so I set some money aside to purchase a bunch of consumables up front. I've been told that you will typically change the electrode & nozzle together, but any recommendations on the other parts would be helpful. My goal is start with enough of everything so that it doesn't cut into my typical shop budget until at least next school year.

Thanks in advance.

Tim
Banks High School

[motoguy]

I'll let Jim handle the first part, though I suspect his answer is "yes, the shielded application is the way to go with a CNC application". As far as I know, the only difference between the Ohmic and standard retaining cap is the metal band which contacts the shield, and has a tab for a spade connector.

I've been cutting a little less than a year, but I've yet to replace my swirl ring or retaining caps (though I have spares of both). Though I have a handful of shields, I pretty much still use the same 2 (finecut, non-finecut) on them, too. I keep them wiped down with anti-spatter, and make sure the exterior/holes/interiors are clean, and they seem to work fine. Once or twice when they've gotten particularly nasty, I've dropped them in the acid bath for a little bit to clean them up. I also have a bunch of o-rings for the retaining cap, which I've never used. I lube the one on the torch up every other time the cap comes off, though.

When learning, I went through FAR more nozzles than electrodes. Early on, it seemed like I was ruining a nozzle every time I fired the machine. Every time I pierced too low, didn't have enough pierce delay time, THC settings wrong, forgot to change my cut settings (forgot to change from 14g settings when cutting that 10g plate), didn't zero off the material, etc... IMO, the nozzles are the components abused during the learning curve. I would start with a 3:1 ratio of nozzles:electrodes, though it will ultimately depend on you and the learning curve. The good news is, it's not wasted money. You'll use them eventually, you just may not have to reorder for a while.

[Shane Warnick]

You want to cut shielded, so use 220948 with EITHER 220953 or 220854, depending on whether or not your table uses ohmic sensing to find the plate. If it's a plasmacam, use 220953. The deflector is for un-shielded cutting, and while I have never cut un-shielded, I was told it wasn't the way to go. I know where maps come from (some poor SOB went down that road and came back and told us what was there) so I chose to go shielded, since the source was reliable (Jim Colt).

Shane

[jimcolt]

I recommend using the shield (220948) for all cutting applications with Finecut consumables....mechanized and hand held, ohmic plate sensing or not. The shield is electrically isolated from the nozzle and minimizes the chance of the nozzle shorting to the material.....which will cause very short nozzle life.

Both retaining caps cut exactly the same......the ohmic cap just has a wire connector that allows the ohmic surface sensing function to operate.....assuming your cnc has that capability.

Here are the general ratios that we sell (millions of parts!) that pertain to Hypertherm air plasma (Powermax ) systems for mechanized cutting applications assuming that you use 100 nozzles:

Nozzle 100
Electrode 100
Shield 2
Swirl ring 2
Retaining cap 1

This is a good starting point, but certainly will vary with use! Jim Colt Hypertherm

We have a plasma table on order along with a 45XP, but I could use a little clarification on the fine cut consumables. The manual I downloaded shows the deflector (220955) being used with the standard retaining cap, and the shield (220948) being used with the ohmic retaining cap. On Hypertherm's website it shows that the shield can be used with either retaining cap. The shield seems like it would provide more protection for the nozzle, so is it okay to use the 220948 shield with the standard retaining cap on a machine torch?

Also, does anyone have recommendations on ratios of electrodes/nozzles to shield, swirl ring, & retaining caps to start with? We're buying the table & plasma cutter through a grant, so I set some money aside to purchase a bunch of consumables up front. I've been told that you will typically change the electrode & nozzle together, but any recommendations on the other parts would be helpful. My goal is start with enough of everything so that it doesn't cut into my typical shop budget until at least next school year.

Thanks in advance.

Tim
Banks High School