Gaps at start and end of lines

[Tech_Marco]

Now, what happen when you hit Reset?
It should hit Home limit switch three times in total and will move to origin location.

[Vegaman_Dan]

I took a video of hitting reset and letting it home, sit for several minutes before trying to go to an origin location that is off the work space, resulting in the noise. I'm sure that is a simple work space setting though.

https://www.youtube.com/watch?v=OoDJC1tjpQM

[Tech_Marco]

You need to check your limit switch location. It seems that you may either have a faulty limit switch or the switch was set too behind of the contacting point (over 80% chance!). The DSP didn't get signal from the limit switch that's why it take minutes to reset itself. I usually move the limit switch at least 2mm to the front so that the gantry would get a good 'strike' on the switches. Who care of losing only 2mm XY space but run the risk of losing 'HOME'!


Marco

[Vegaman_Dan]

I shall check the limit switch. While it hasn't change physically in position, there is always the chance a wire got pulled loose. I will reply back when I can check the switch tomorrow.

Good to know why it is taking so long after getting to the home / machine zero location.

[Tech_Marco]

I know the switches are in the same location. But.... did you make sure that it strike well and changing stage from Open to Close when the gantry hitting on it? Do slowly and lightly on gantry strike see if can get continuity from the limit switch. If you have to push hard, chance is that you won't get the limit switch working in proper way. It suppose to work well even with very light touch.

Sometimes, the most simply things could cause the bigger problem and it is usually ignored by us. In this case, I bet on the limit switch. If I win, send me a cup of cappuccino! If I lost, I give you $10 coupon for next purchase!


Marco

[Vegaman_Dan]

I checked the limit switches and they are being engaged smoothly. I added some rubber bumpers on the carriage to increase the space where it is detected so they would trigger earlier and they did, but no change in operation.

I checked the connections and they are solid at the switch and at the DSP as well. I can manually move the head gently (power off) and I'm getting proper continuity at the DSP when the switch engages.

Hitting reset on the control panel sends it to home, where it does engage the switches, backs off slightly and sits humming a tune. Yes, I can hear audio frequencies from the stepper motors it sounds like. It is also ticking like a clock quickly. If I manually trigger the Y limit switch, the ticking drops to half the speed. If I trigger the X switch, it changes again, beeps and comes out of the reset state like I would expect.

If I don't do the manual triggering, it will take the full 4 minutes or so for it to eventually come out of this state.


Video: Reset with bumpers added to carriage head to trigger limit switches earlier than normal

https://www.youtube.com/watch?v=v6Y1PqSdz8M


Video: Manually triggering X Y limit switches after unit homes in the upper left corner:

https://www.youtube.com/watch?v=AFeImpbnZ_Q

[Tech_Marco]

I am still believing that it is limit switches issue

You can simulate it by pressing the XY limit switches 3 times like x y x or x y y. Wait till the laser head getting closer to the home.

Without home location registered, you can't move the laser head too far as it won't know where is the laser head located

Marco

[Vegaman_Dan]

I have tried hitting the switches manually as in the video and it does seem to make it shorten the restart time. I'm not sure about the noises it makes during this time or the long high pitch whine it makes when done, separate of the beep from the control panel.

I notice it initially goes to the upper left extreme where the limit switches top it and it returns back to the cutting area a few centimeters, then sits in that state for a while unless I press those limit switches manually again. At that point they are quite a distance from the switches.

I made extensions and moved the switches into the cutting area but it makes no difference. Once the carriage makes the initial touch to the two switches, it backs off a bit and sits there until it either times out in 4 minutes, or I manually trigger the limit switches. It is acting like it should be hitting those limit switches a second time before it takes notice.

[Tech_Marco]

When it home, the laser head must be moving out from the limit switch in a few mm to let the switches disengaged. It is absolutely normal. As I mentioned from my previous post, the DSP needs three momentary contact to complete HOME registration.

If you still can't get it work properly, send it back and let me do t3sting for you


Marco

[Vegaman_Dan]

So the carriage has to hit the limit switches three times to make sure it homes correctly before it moves out?

Right now it hits the limit switches, pauses a tiny amount and then steps back out a bit which clears and releases the limit switches.

If I manually trigger them in the same manner as it is trying to home while still out on the cutting area, it does the same thing.

If I manually trigger and hold the two limit switches closed for a full second to two seconds, which is longer than the carriage would stay there, then it stops, backs off a bit and the reset is complete.

You are right, it is definitely related to the limit switches. If the system could delay moving the head back just a second or two longer, it would not display this behavior.

I don't think changing the limit switches will make any difference as the unit will stop and reverse in the same manner too quickly for the limit switches to be recognized fully. It is a most curious situation. I wonder if am overlooking something basic.

[Vegaman_Dan]

Alright, back after some time away from the projects due to travel.

Marco: From what I'm reading, should I send you the DSP controller? I'm out of ideas at this point and am willing to ship it to you and back if you can verify the unit itself is good. I'm fully willing to believe the issue is still on my end, but maybe verifying the DSP is working is a good way to test this configuration.

Is there a special address or name to address this to?

-Vegaman Dan

[Tech_Marco]

LightObject
21 Blue Sky Ct
Sacramento, CA 95828
(attn: Marco)

Leave a note in the package and tell the issue. Once received it, I'll test the limit system for you
Make sure to buy tracking and insured.

Marco

[Vegaman_Dan]

Thank you! This level of support is why I chose to go with this service.

[Vegaman_Dan]

DSP controller confirmed delivered to your site on 2/26. I hope you are able to determine the condition of the unit and eliminate it as the cause. Please let me know how to pay for the shipping back when you're ready.

[Tech_Marco]

There is nothing wrong with the DSP and both limit switches worked as the way it should.
Somehow you set the Start speed to "0.035mm/s" when it should be 10 or 20mm/s on the "User parameter" setup menu.

Card already shipped out 3 days ago and you should receive it today


Marco