16 ga steel: oddball dross

[_Ogre]

cutting 16ga mild steel cr. have some weird dross issues. near edge and 2 legs of this cut are perfect, no dross top or bottom. back edge and 3 leg of the cut has bottom dross in opposite directions. dross comes off easily. my bulltear table doesn't like 315 ipm speeds so i had to slow it down a bit.

what variable do i adjust to minimize dross?

[rikduk]

What consumables are you using?
On 16 ga, i use 45 or 50 amp Hypertherm consumables, and the manual says 255 ipm.
I have a Bulltear as well, and it cuts that fine, with the exception of Inside sharp corners being a little round.(decel/accel).

[BTA Plasma]

It looks like you went slower but never dropped your amperage. Amperage and cut speed are relative to each other. Also you machine will cut those corners at 315ipm it is all laid out in your topic area as well as discussed on the phone. If you dont feel comfortable changing settings for that kind of speed then you will have to change cut speed and drop amperage not just drop speed.

[jimcolt]

The same.....higher speed gets rid of dross. Since you don't mention what plasma, it is hard to give good advice on the best way to cut 16 gauge at lower speeds. If you have a Hypertherm Powermax65 or 85, I would suggest using the FineCut consumables and operating off the "Low Speed" FineCut charts just as the operators manual suggests. This chart is for cutting 10 gauge and thinner materials all at under 150 ipm, there will be slight dross on some materials, but easy to remove.

Keep in mind that the condition of the consumables can affect quality, and the setup and operation of your height control system as well.

Jim Colt Hypertherm

[_Ogre]

@jc: i have pm65 in my signature. i used the slowcut setup for finecut nozzle. just thought it was strange that 2 edges were clean, crisp, dross free and the 3rd edge would have that much dross.

@bta: we talked cv settings and the resulting overburn that it would cause stopping at turns. plus i'd have to change the settings for each material. i'm trying to set this up for a less skilled operator to run; aka anyone in the shop but me
i've been adjusting volts to try to accommodate slower speeds, i'll have to work on the amps vs speed. i'm new and learning, as you know.
setting up slow rotary head speeds should have taught me that relationship. at this point what is obvious to you is not so obvious to me.

@rikduk: finecut consumables. had to slow down to keep the radius under .25''
you are correct with the 255ipm not 315 as i stated. that was for 24 ga that really cut off the radius's

i do like this table and use the 10'' z axis clearance to do things that shouldn't be possible on a lesser table. like tube fixtures for cutting pre bent 3'' exhaust tubing for production exhaust systems. i'll post some pics later.
thanks for the feedback folks

[BTA Plasma]

You should easily be able to cut at 400ipm with that machine. We just outlined more processes for that cut speed in the forum. The dross got worse and worse on your cut so that could mean you weren't travelling fast enough so with the right info you should hit those cut speeds for your amperage without an issue. Your table will accelerate and cut at those speeds for all materials no need to turn anything off from the modification.