Author Topic: engraving lines too wide  (Read 418 times)

donwatson

  • Full Member
  • ***
  • Posts: 118
    • View Profile
engraving lines too wide
« on: December 27, 2018, 07:25:25 AM »
I have just upgraded my laser engraver with an EleksMaker 2.5mW laser module and an EleksMaker Mana SE v3.2 board.
My first burns are shown in the attached pic.

The engraved line looks to be too wide, how do I get it thinner ???
The laser flashes at very odd moments how can I stop that happening ??

Thanks again
Don W


ggallant571

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 2531
    • View Profile
Re: engraving lines too wide
« Reply #1 on: December 27, 2018, 10:15:15 AM »
Do you have the pull-down resistors on the TTL PWM signal line? Is the host computer entering/exiting sleep mode at the time of the odd pulse?
SARCASM - Just one more service we offer here.

donwatson

  • Full Member
  • ***
  • Posts: 118
    • View Profile
Re: engraving lines too wide
« Reply #2 on: December 28, 2018, 02:59:51 AM »
Sorry ggallant571,
I have not got the resistor yet. I have ordered a 0.25W/1KOhm resistor.
The computer state Iam not sure about but it doesn't go into sleep mode. I think it was when I went to 'Laser Controller' mode.


Don W

ggallant571

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 2531
    • View Profile
Re: engraving lines too wide
« Reply #3 on: December 28, 2018, 05:59:11 AM »
You can use a terminal emulator such as teraterm to issue g-code commands. If it occurs when you connect to the USB then I would assume it is related to resetting of the controller during enumeration and the pull-down will fix the problem. I think T2 and BCL have similar features. Any 1K to 5K resistor will do. I prefer the 1/8W as they are smaller.

In the mean time, keep the 12V power to the controller OFF until you have established communications.
SARCASM - Just one more service we offer here.

Zax

  • T2Laser
  • Global Moderator
  • Hero Member
  • *****
  • Posts: 6397
    • View Profile
    • T2Laser
Re: engraving lines too wide
« Reply #4 on: December 28, 2018, 08:44:03 AM »
The pulse should only happen during USB boot up, if itís happening at random times it suggests the USB is going into power save mode (not the same as your computer sleeping). When this happens the Nano loses power as it relies on the 5V from the USB and not the 12V power supply (used for laser and motors).

The pull down resistor would stop the flashing but you will experience other issues if the USB is disconnecting.

donwatson

  • Full Member
  • ***
  • Posts: 118
    • View Profile
Re: engraving lines too wide
« Reply #5 on: December 29, 2018, 02:44:01 AM »
Thanks for the replies guys.
I will get on to this when my grandson leaves (later today).
Don W
EDIT I have had a quick look before I get the soldering iron out and ran a couple of burns.
I am happy with the way they have turned out with no extraneous burn marks/blobs or uncontrolled flashes.
I am happy to mark this one as solved as I will be going to BCL threads to set up with that.
I will be back when it all goes haywire again, thanks for the help so far.

Don W
« Last Edit: December 29, 2018, 05:40:35 AM by donwatson »

Troth530

  • Newbie
  • *
  • Posts: 14
    • View Profile
Re: engraving lines too wide
« Reply #6 on: December 29, 2018, 09:29:22 AM »
Did you refocus after installing the new laser. 
Took me a while to figure out how to focus properly because most surfaces just scatter the light and it's difficult to determine when you have the smallest beam.  You need a piece of black anodized aluminum and try to get it at the same height as your material.


On the laser module there is a 3 pin connector and next to it are some extra plated through holes for GND and PWM. 
You can just solder your resistor there.  I'll post a picture later.

Troth530

  • Newbie
  • *
  • Posts: 14
    • View Profile
Re: engraving lines too wide
« Reply #7 on: December 29, 2018, 02:13:24 PM »
Here's the pulldown resistor installed.  I have one leg of the resistor installed through the bottom of the PCB, the other to the bottom of the PCB to ensure the legs do not touch.  Then I hot glued it for stability.  The PWM and GND labels are above through holes you'll be using.  Really easy mod.

donwatson

  • Full Member
  • ***
  • Posts: 118
    • View Profile
Re: engraving lines too wide
« Reply #8 on: December 30, 2018, 09:55:17 AM »
Hi All,
I have had a good try at BCL and have set up the focus as per Ralph's instructions on his Tutorial #3 and it all looks good now. I will attach a pic. of my 'doodling/tries'

@Troth530, I have refocussed using a piece of Orange coloured card and I will try some plywood later.
I have found the 2 holes you mention and have carried out the same mod as you. Will try it tomorrow as I have been for an eye test this afternoon and the old eyes are still playing up.

Don W

Troth530

  • Newbie
  • *
  • Posts: 14
    • View Profile
Re: engraving lines too wide
« Reply #9 on: December 30, 2018, 10:38:22 PM »
Don, I can only get it close by eye, but to really dial it in, I rely on a good old greyscale and burn tests.  I also have to make sure if I'm focusing on the top surface of whatever I'm engraving.  I don't attempt to cut 3mm plywood with my 2.5W laser, but it will sure engrave nicely and cut thinner stock.

To focus I find the min point size and get it close- at the point where the dot goes from large to small to large again.  This gets me close, but I still don't rely on only my eyes.  Then I back it out to the where it's starting to get bigger, then use 1/16 to 1/8 turns at the most and do a test burn looking for a dark burn.  Then I turn it a little more to make it smaller and retest. Eventually I find the optimum spot but I rely on getting the darkest burn.  If you rely on a technique looking for the best cut, the focus point below the surface a little.  I do mostly engraving.

I had to learn this on my own, can you point me to the tutorial, I always like to consider new ways to do things.

donwatson

  • Full Member
  • ***
  • Posts: 118
    • View Profile
Re: engraving lines too wide
« Reply #10 on: December 31, 2018, 03:58:30 AM »
Hi Troth530.
I have stuck the resistor in and hot glued it temporarily and it has worked. I can dodge about between screens and jog about and I don't get any flashes. Thanks for that.
I still don't have the new wheels fitted but I can wait for better weather to get to the shed and bore for the new holes.

Ralph has a series of tutorials on YouTube andit is well worth while going through them. He also does the trial package for free so you can actually use the correct screens etc. The tutorial #3 that I mentioned is here
https://www.youtube.com/watch?v=XW5lEQPb4mU&t=90s
I have been working my way through these tutorials and find them very interesting.

Don W

Troth530

  • Newbie
  • *
  • Posts: 14
    • View Profile
Re: engraving lines too wide
« Reply #11 on: December 31, 2018, 01:39:59 PM »
ok.  His basic approach is the same.  Get it close by eye, then fine tune by an engraving.  In his case he can better interpret the fineness of the lines, in my case I'm looking for the darkest greyscale.  His technique is more generic when the speed and power are not set, in my case I have the optics and speed/power dialed in.

donwatson

  • Full Member
  • ***
  • Posts: 118
    • View Profile
Re: engraving lines too wide
« Reply #12 on: January 01, 2019, 12:31:54 PM »
It's good you have a system that works for you.
I am still working my way through Ralph's tutorials.

Don W

Zax

  • T2Laser
  • Global Moderator
  • Hero Member
  • *****
  • Posts: 6397
    • View Profile
    • T2Laser
Re: engraving lines too wide
« Reply #13 on: January 01, 2019, 04:14:39 PM »
If you prefer to use a line for the adjustment you can setup a custom button in T2Laser to do this. I use the pulse method and adjust for the smallest dot / hole or you can use a low power setting and adjust as you watch the spot size vary.

pedwards2932

  • Sr. Member
  • ****
  • Posts: 310
    • View Profile
Re: engraving lines too wide
« Reply #14 on: January 01, 2019, 06:08:25 PM »
sorry to jump in on this but I saw where you can show custom button but how do you set them up....didn't see it in the manual.