Inconsistent results when cutting material close to 10mm

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idank
Posts: 8
Joined: Mon Apr 16, 2018 3:32 pm

Inconsistent results when cutting material close to 10mm

Post by idank »

Hi all, Nova 35 80 watt user here.

I've been getting some inconsistent results when cutting for example 8mm MDF. Sometimes the cut will penetrate to the bottom just fine and other times it won't. Given the low speeds (I'm using 70% power, 3mm speed), it is extremely frustrating to discover after an hour long job that it didn't go all the way. The focal length is set to 6mm as instructed.

What's the reason for the inconsistent cut results and how can I avoid it?
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LINUS
Webmaster
Posts: 263
Joined: Tue Apr 28, 2015 3:55 am

Re: Inconsistent results when cutting material close to 10mm

Post by LINUS »

I think you need a high compressor
Because of major,be at ease so.
idank
Posts: 8
Joined: Mon Apr 16, 2018 3:32 pm

Re: Inconsistent results when cutting material close to 10mm

Post by idank »

LINUS wrote: Tue May 01, 2018 8:56 am I think you need a high compressor
I've been using the high pressure low noise compressor provided by Thunderlaser all along.
Ben
Posts: 137
Joined: Tue May 24, 2016 9:06 am

Re: Inconsistent results when cutting material close to 10mm

Post by Ben »

Please first check it according to the attachment.
Attachments
cutting problem 2.pdf
(193.31 KiB) Downloaded 544 times
idank
Posts: 8
Joined: Mon Apr 16, 2018 3:32 pm

Re: Inconsistent results when cutting material close to 10mm

Post by idank »

Ben wrote: Thu May 03, 2018 1:02 am Please first check it according to the attachment.
Hi, I followed the instructions. Both looks good. https://photos.app.goo.gl/PAqwYz9j78HLkAiT6

I also noticed that there is significant disparity between the suggested speed and power settings from http://www.thunderlaser.com/download/do ... P%20V2.pdf and the ones I need to get material to cut. For example 5mm acrylic, I need to use 70 power / 8 speed. For 12mm acrylic, I had mixed results with 70 power / 1 speed. Sometimes it cuts and sometimes it won't. I cannot go higher than 70 power because the laser tube was configured to not exceed 70% power even though the suggested parameters show 80 power.

I know the numbers shouldn't match exactly, but this much of a difference might suggest there is a deeper problem?
idank
Posts: 8
Joined: Mon Apr 16, 2018 3:32 pm

Re: Inconsistent results when cutting material close to 10mm

Post by idank »

Hi, any suggestions on how to get better cut results?
Ben
Posts: 137
Joined: Tue May 24, 2016 9:06 am

Re: Inconsistent results when cutting material close to 10mm

Post by Ben »

Hi Idan,

Sorry for my late reply.
For your cutting problem,sometimes it cut through just fine and other times it won't.
It seems that the setting is at the threshold between cut through or not.
We suggest to lower the speed a little bit just fine.
Besides,you should know that the MDF is more difficult to cut than other wood like plywood.
Some suggestions as following:
1.using 2mm nozzle laser head cone for cutting wood(6mm nozzle laser head cone in the toolbox for cutting acrylic)
2mm nozzle laser head cone.png
2mm nozzle laser head cone.png (32.26 KiB) Viewed 26449 times
2.Strong blowing will make wood easy to cut.
For big pressure compressor,please wait the tank to pressurize till the needle stop move,then start the job.
For water separator,please pull up two regulators then rotate them to "+" direction to release the air.
water separator.png
water separator.png (146.02 KiB) Viewed 26449 times
Above two step to make sure you have the most strong air blowing when cutting.
3.Make sure the working table is level,and use some strong magnet to flat the material.
http://www.thunderlaser.com/troubleshoo ... level.html
4.Make sure the focus lens and mirror are clean.
5.Make sure the vertical of laser beam are alright on four corner of working table.
http://www.thunderlaser.com/how-to-use- ... -path.html

About the laser power setting,we have limit the max power as 70%.
It's ok if you want get to 80% power,please refer to below picture.
But I recommend you don't set power over 90%,or it will affect the life span of laser tube.
Vendorsettingoflaser.png
Vendorsettingoflaser.png (275.07 KiB) Viewed 26449 times
idank
Posts: 8
Joined: Mon Apr 16, 2018 3:32 pm

Re: Inconsistent results when cutting material close to 10mm

Post by idank »

Hi Ben, I'll try the 2mm cone to see if that improves anything. I believe I've already verified the other things are OK.

Given the disparity between the suggested settings and the settings I need to use in practice to get things to cut, I'm starting to think there's a deeper problem here. Here's another example I just tried with 5mm acrylic: suggest settings are 60p/12s, while I need 65p/5s. I would say this is not some small difference you can chalk to the specifics of the material or variance in the laser tube.

When you test the laser tube, do you test how it behaves with respect to the advertised limitations? I was told the Nova 35 80W machine I bought can go up to 15mm acrylic and 10mm wood. So far I've hit a wall with 12mm acrylic and 8mm MDF. That's a 20% loss in terms of what the machine is capable of cutting.
Ben
Posts: 137
Joined: Tue May 24, 2016 9:06 am

Re: Inconsistent results when cutting material close to 10mm

Post by Ben »

Hi Idan,

If there's a lot of loss for the laser power,it's more about the problem from focus lens or laser beam path.
Please check them for sure,the focus lens is intact and clean and the laser beam goes down vertically to four corner of table.

If they are just fine,so it seems that the power of laser tube become weak.
Please click the link below to have a test.
http://www.thunderlaser.com/troubleshoo ... eaker.html
idank
Posts: 8
Joined: Mon Apr 16, 2018 3:32 pm

Re: Inconsistent results when cutting material close to 10mm

Post by idank »

Hi Ben, I spent most of the day on cleaning the machine and ran the laser power test both before and after.

First, here are pictures of the mirror and lens that seemed to accumulate a lot of dirt: https://photos.app.goo.gl/421weE32aJ6JyVwc2

I have no idea how it has so much dust on it, especially the lens which is tucked inside the nozzle. Cleaning the mirror was easy so I proceed to the lens. I take it out and try to rub it with the cloth and alcohol, but it's not coming off. So I use apply a tiny amount of force and it starts looking clean, but then I notice I had cracked the lens!

https://photos.app.goo.gl/Mn5jNOweBHebTsyF2

Well that's a bummer. I'm not sure what I did wrong as the dirt wasn't coming off just by rubbing it - it was almost like the lens was coated with something - and the little force that I used managed to break it. Anyhow, lucky there's a spare in the toolbox and it appears clean.

Results of cutting a 15mm circle from the 6mm acrylic (it was actually closer to 5.5mm) that was in the toolbox: both were run at 70 power and air compressor on. Before cleaning I needed 10 speed to get a clean cut. After cleaning 15 speed.

All in all a pretty solid improvement so that's good. Are these results inline with what you expect?

As a reference point http://www.thunderlaser.com/download/do ... P%20V2.pdf has 5mm acrylic at 60 power and 12 speed.
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