Newb question about fine cuts

[TLFL]

I see a lot of pictures in the what have you done with your CP lately thread and many of them have really high fidelity cuts. I cannot seem to get my Razorweld 45 to do anything so fine. Is it that I need a smaller nozzle or what? Again, pretty new to this so just seeing knowledge.

Thanks

[Kwikfab]

I’m not familiar with the Razorweld machine but I still manage some “detail” with my large 65 amp nozzles

I’m a parts guy, I don’t care for signs cause I don’t like them and I’m not good at them but details are easy to do

[ChelanJim]

Here is some advice that might be useful:

@langmuir-daniel

To get the best angularity possible, be sure to use the lowest amperage nozzle that can still clean cut the thickness you are working with. For example, when i cut sheet metal with my 60 amp Hypertherm, i use a 30 amp nozzle for the best angularity (typically about 3 to 5 degrees).

@Simsworx

I would suggest running your RazorCut45 at 45A, as thats the settings for the nozzle. (Lower amperage may improve things, but I’ve yet to set it.) As far as speeds / feeds - We took the Hypertherm 45 chart and reduced it 66%. It provides a good starting place to adjust as needed.

@mechanic416

0.8 are 30 amp unshielded tips so you wouldn’t use them for 1/2". 1.0mm/50 amp tips and 1.1mm/60 amp tips can be shielded or unshielded. If your using 1.1mm/60 amp shielded tips with a CNC shield you need to measure the torch height between the tip and work piece not the shield and work. If the distance between the shield and work piece is more then .035" the torch height is way to high.

@langmuir-daniel

Let’s say you run two line tests. Both with THC off. On the first test you let IHS set the cut height. On the second test you manually set the cut height. If you get poor cut quality on the first test, it’s due to IHS setting the cut height too high or too low. You’ll need to compensate for this by either reducing or increasing the cut height in your g code.

IHS will set an incorrect cut height for two reasons. One is to compensate for spring back in the material. The torch and slide has weight which will cause the material to deflect (obviously worse for thin material). This has the tendency for the actual cut height to be lower than the programmed cut height. Second, there is some backlash in the z axis lead nut which must be compensated for. If it was not compensated for, it would have the tendency for the actual cut height to be lower than the programmed cut height. The backlash is the same whether you are working with sheet metal or thick plate and is built into the post processor of Sheetcam. I believe it’s .020”.

Let’s say that you program your cut height to .060”, but find that in reality your actual cut height is .080”. You need to set your cut height in Sheet CAM to .040” in order to guarantee a .060 cut height.

Make sure that you have the correct consumables for your torch purchased from either George or Bakers’ Gas or Langmuir. And verify that you have all the consumables in the stack and are in the correct orientation (I assembled my Hypertherm torch wrong once…don’t ask!).

And when in doubt, replace the nozzle. They will wear more quickly than the electrode.

[Knick]

@TLFL

I cannot seem to get my Razorweld 45 to do anything so fine

Material thickness? What settings are you using? Have you verified your cut height?
do you have a file that you had trouble cutting? Can you post it so we can see what it is your trying to cut?

[TLFL]

I have been cutting 16gauge sheet using the consumables that came with the RW45. Attached is the .nc file on the last thing I cut. They are some basic tools for something at work, but all of the holes came out terrible. I actually ended up cutting off the end with the holes because they were so poorly cut. As I stated in the beginning, I am definitely a newbie and trying to learn how to set up the CAM side of things. I use Fusion 360 and FireControl.
CO2-Tool-v2.nc (1.1 KB)

[ChelanJim]

It is not likely a single answer that is going to solve your cutting issues. Knick gave you some great questions and I listed multiple reading sources to help you start to narrow down your what “might” be the issue and what is more “likely” your issue.

Your sample gcode file is helpful as it has details of what was sent to the table:
G0 X0.5784 Y0.3647
G92 Z0.
G38.2 Z-5. F100.
G38.4 Z0.5 F20.
G92 Z0.
G0 Z0.04 (IHS Springback + Backlash)
G92 Z0.
G0 Z0.15 (Pierce Height)
M3
G4 P0.5
G0 Z0.063 (Cut Height)
H1

But it does not answer the major question: “Have you confirmed that the actual cut height is the cut height that the gcode is directing the table to produce?”

Among one of those suggested readings above in my previous post, you will find a very good example given by @langmuir-daniel titled “Cant get rid of heavy dross…” This is one of the most fundamental things after you have dry air and new consumables that you can count on being quality. If you have “crap” consumables you will get “intermittent” results at best.

We are all eager to help you get good results but you must do the work on your end by doing the leg work and reporting back. It is fine if you say you are ‘working on it’ or ‘will get time next week.’

Not trying to be bossy. I just want you to get your situation squared around and if you are anything like me, there is an expiration date on how long someone keeps something on the back burner. After awhile you convince yourself that you gave it a good shot and then bail on the entire project.

[Knick]

What did you have amps set at?
What was your speed (IPM)?
Did you slow the cut down for holes?

[Sticks]

@TLFL

I have been cutting 16gauge sheet using the consumables that came with the RW45

For how long?

Post a picture of the nozzle and electrode that is in your torch.

They are consumables, not lifetime. Bad cut height (including firing in the air with no metal to cut), moisture in the air supply, and well…age will end their service life and need replaced.

Worn out nozzles will result in bad cuts, dross, and bevel.

[TLFL]

All, this was a general question, I don’t have a lot of specific examples though I’ll pull together the images etc. and post them. Generally I was going with the default settings from multiple videos I have watched. ChelanJim’s point about cut height is a good one. I didn’t even know that was a thing, I assumed it was a standard setting. I do appreciate all of the responses and help and I’ll keep banging away at it. My challenge is that my work life is impacting my shop life so I am not getting out in the shop to do this as often as I would hope. Lately my time in the shop is pulling out the mower…