Piercing question

Ok I have never really watched when piercing takes place. The other day I did and I have questions.
I have the razor 45 with a machine torch. So tell me if what I am seeing is correct.

The torch lights at pierce height and does not not until pierce time has completed.
Should the metal be pierced before torch moves down to cut height?
Or does it happen as its moving down to cut height?

So the amount of time we’re talking about is the tool head moving at 100 inches per minute. Moving a length of .09 in which would take about .054 seconds .

I think the important point is before the torch starts making any x or y movements the Pierce is completely through the material.

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It was through before any X or Y movement, but it seemed like it never pierced until it was almost at the cut height. I thought maybe it should pierce up higher to help with blow back into the torch.

How thick of metal was you cutting? What delay did you have?

1/4” I think I had .9 at 45 amps. I will double check

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I will look at my settings I had for My rw45. I didn’t cut a lot of 1/4 before I upgraded. My cut looked really good with it trying to remember how well it pierced.

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@Knick I looked at my settings for my rw45 I cut 1/4 at 45 amps 20 Ipm and 1 sec Pierce.
I got nice results at those setting using a hand torch. I know your thoughts wasn’t cut quality.

I can’t remember how that machine pierced. Food for thought though my hypertherm 65 calls for 240 percent higher pierce height higher than cut height up to 1/2. 1/2 is 300 percent then 5/8 is 400 percent. My wonder is what if you raised your pierce height a little.

I will need to look into this further. I use the same pierce height for everything. What got me wondering about this in the first place was watching the torch closely.

When I was watching it cut 1/4" it seemed like the torch had to get very close to the material to make the pierce, which seemed like a lot of blowback into the torch.
I was thinking maybe it needed a longer delay so it would pierce when it was at a higher in its travel downward.
Or is it maybe coming down to fast?

I was trying to find if what I have is normal or should the pierce happed at a point when the torch is not so close to the material.
I have a couple of projects I am wrapping up and will do some reading when done.

Thanks for your input

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I don’t know if it will help but one way to find out. The rw45 is a nice startup machine. After getting my ht65 I noticed it is way under powered compared the the hypertherm at 45 amps.
I would cut 1/4 plate at 20 inches with the rw 45and 50 with the hypertherm at 45 amps.

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I just looked and I am cutting 1/4" at 48 with the RW @ 45amps. The cut seems very good, other then it seems to have more bevel than what I thought it should.

Hmm I don’t know if mine could cut at that speed.

For 1/4" with the RW45, we’re at 32 ipm, 1.0 pierce delay, .15 pierce and .06 cut height. For our setup, this provides excellent results. (Almost no dross, clean cut edges)

And yes, under almost all situations, i expect the pierce to penetrate prior to any X / Y moves. (Exception being 1/2" and higher ramp & wiggle starts.)

I take it thats 45 amps?
The thing I wondered was, does the torch seem like its almost down to cut height before it pierces or maybe halfway down. My seems to be at cut height before it pierces.

45 Amp, correct.

We keep our water table full, so its obvious when the pierce occurs. (Usually sound) I expect the pierce to be complete right before the torch starts to drop to cut height. (Note - when I see the pierce occuring late, its time to check / change consumables.)

We’re also at 6000’ elevation for what its worth.

So you think the pierce is happing before the torch starts to drop, where mine is closer to the bottom of torch’s travel.

So how does that effect cutting?
I think were about 900’

I guess another thing I have never played with is at what speed the Z axis is set at.
Do you think the pierce time includes the time it takes the torch to go from pierce height to cut height?

@100fpm you a talking about 54 milliseconds. If you have a Pierce delay of 1 second is 1000milliseconds.

Adding or not adding it to the travel time of the z-axis makes plus or minus 5% to the total time at a second delay.