Errant head movement on startup

Hardware settings, adjustments and fixes and other hardware discussion. This includes the "doHICky" Laser Power measurement system by Russ.
Post Reply
User avatar
Jeremy Willson
Posts: 5
Joined: Wed Jun 02, 2021 12:44 am
Location: Brisbane, Qld
Country: Australia
Nickname: wasteofspace
Laser Machine Make or Type: Red and Black Chinese
Laser Power: 80W
Laser Bed Size: 500mmx700mm
Home Position: TR
Control Software: LIGHTBURN
RDWorks Version: 8.01.48-20200417
Ruida Controller: RDC6442
Accessories: Air switch, internal surround lighting, Ammeter, Twin 12v air pusher fans in front (Russ made me do it)
Windows Version: 10

Errant head movement on startup

Post by Jeremy Willson »

I have a problem that sometimes occurs when I first turn the machine on.

I am using a China blue, faux 60w laser, with a Ruida 6442G controller (from memory, bevause I cannot see a number on the box).

When starting the machine, it will sometimes home, and then start slowly creeping along the X axis. It will continue with this aberrant behaviour until I manage to get it to accept something to cut - even with the laser itself turned off - it will then behave itself again and act like nothing happened.

It has done this for the last year or so. Any ideas, because it is really annoying? Just turning it off and then on again does not cure the problem.
Jeffrey Aley
Posts: 341
Joined: Fri Aug 11, 2017 1:08 am
Location: Folsom, California
Country: United States
Laser Machine Make or Type: Kehui
Laser Power: 50W
Laser Bed Size: 500mmx300mm
Home Position: TL
RDWorks Version: 8.01.24
Ruida Controller: RDC6442
Accessories: Spray bottle with water (for small fires)
Fire extinguisher (for big fires)
Windows Version: Win10 Enterprise

Re: Errant head movement on startup

Post by Jeffrey Aley »

Usually, when you power-on the machine, the head moves in the direction of "home" relatively quickly until the limit switch is triggered. Then it moves away from home very slowly until the limit switch shuts off.

Is it possible that your limit switch never shuts off? On my laser, the limit switch lights up (I think it has a red LED inside) when it is triggered, so I can easily see what is happening.

Regards,

-Jeff
User avatar
Gene Uselman
Posts: 1671
Joined: Thu Jul 07, 2016 3:18 pm
Location: Suburban Minneapolis, Minnesota, US
Country: USA
Nickname: Gene
Laser Machine Make or Type: AKL1318-2
Laser Power: 130W & 80W Reci
Laser Bed Size: 51 x 71
Home Position: TR
Control Software: LIGHTBURN
RDWorks Version: RDw .19 & Lightburn
Ruida Controller: RDC6445
Accessories: I have a combining lenses, pin tables [homebuilt], honeycomb tables , wireless remote, Modifed Ultimate Air Assist, home built non-powered rotary device, Prusa i3 MK3S and Mini Prusa printers.
Windows Version: Win 10 Pro

Re: Errant head movement on startup

Post by Gene Uselman »

There is also a setting for how far from the limit the head will move to the actual zero position. I am in Texas so I cannot look at my machine to tell where to set that.
If the Help and advice you received here was of VALUE...
Please consider making a donation to maintain the RDWORKSLAB Forum.

BT48 Alpha Shopbot and 1300x1800 130W Laser

The days that I keep my gratitude higher than
my expectations, Well, I have really good days.

Ray Wylie Hubbard
User avatar
Jeremy Willson
Posts: 5
Joined: Wed Jun 02, 2021 12:44 am
Location: Brisbane, Qld
Country: Australia
Nickname: wasteofspace
Laser Machine Make or Type: Red and Black Chinese
Laser Power: 80W
Laser Bed Size: 500mmx700mm
Home Position: TR
Control Software: LIGHTBURN
RDWorks Version: 8.01.48-20200417
Ruida Controller: RDC6442
Accessories: Air switch, internal surround lighting, Ammeter, Twin 12v air pusher fans in front (Russ made me do it)
Windows Version: 10

Re: Errant head movement on startup

Post by Jeremy Willson »

Jeffrey Aley wrote: Sat Jun 05, 2021 2:14 pm Usually, when you power-on the machine, the head moves in the direction of "home" relatively quickly until the limit switch is triggered. Then it moves away from home very slowly until the limit switch shuts off.

Is it possible that your limit switch never shuts off? On my laser, the limit switch lights up (I think it has a red LED inside) when it is triggered, so I can easily see what is happening.

Regards, -Jeff
Hi Jeff. Thank you for your interest.

I just went and tested the limit switch.

It turns on (lights) when the head reaches the far top left corner, then the head backs off a tad and then homes again, then the light turns off.

This is not to say that it always does this of course, but it does give me something to look at the next time it happens.
User avatar
Jeremy Willson
Posts: 5
Joined: Wed Jun 02, 2021 12:44 am
Location: Brisbane, Qld
Country: Australia
Nickname: wasteofspace
Laser Machine Make or Type: Red and Black Chinese
Laser Power: 80W
Laser Bed Size: 500mmx700mm
Home Position: TR
Control Software: LIGHTBURN
RDWorks Version: 8.01.48-20200417
Ruida Controller: RDC6442
Accessories: Air switch, internal surround lighting, Ammeter, Twin 12v air pusher fans in front (Russ made me do it)
Windows Version: 10

Re: Errant head movement on startup

Post by Jeremy Willson »

Gene Uselman wrote: Sat Jun 05, 2021 6:27 pm There is also a setting for how far from the limit the head will move to the actual zero position. I am in Texas so I cannot look at my machine to tell where to set that.
Hi Gene
Thanks for that, I look forward to checking that possibility.
User avatar
Jeremy Willson
Posts: 5
Joined: Wed Jun 02, 2021 12:44 am
Location: Brisbane, Qld
Country: Australia
Nickname: wasteofspace
Laser Machine Make or Type: Red and Black Chinese
Laser Power: 80W
Laser Bed Size: 500mmx700mm
Home Position: TR
Control Software: LIGHTBURN
RDWorks Version: 8.01.48-20200417
Ruida Controller: RDC6442
Accessories: Air switch, internal surround lighting, Ammeter, Twin 12v air pusher fans in front (Russ made me do it)
Windows Version: 10

Re: Errant head movement on startup

Post by Jeremy Willson »

Jeffrey Aley wrote: Sat Jun 05, 2021 2:14 pm Usually, when you power-on the machine, the head moves in the direction of "home" relatively quickly until the limit switch is triggered. Then it moves away from home very slowly until the limit switch shuts off.

Is it possible that your limit switch never shuts off? On my laser, the limit switch lights up (I think it has a red LED inside) when it is triggered, so I can easily see what is happening.

Regards, -Jeff
Hi Jeff
You were totally correct in your diagnosis, but the fault was intermittent.
I just checked again, and the limit switch stayed on this time, and now it doesn't turn off at all - even if I hit it with a hammer. Sigh, I have ordered another one on eBay, but it will take a few days to get here.
Rather than trying to thread the wires through the chains, I am just going to cut the old one off at the head and solder the new sensor onto the old wires.
Post Reply

Return to “General Hardware”