Upgraded with X7 kit - issues with steppers

srkinard
Posts: 6
Joined: Sun Apr 30, 2017 10:21 pm

Upgraded with X7 kit - issues with steppers

Postby srkinard » Sun May 21, 2017 5:18 pm

Installed the X7 kit on my Chinese K40 laser and powered everything up...I thought I got the stepper motors wired correctly, but they move in the opposite directions.

If it hit the RIGHT button on the keypad, the gantry moves left.
If it hit the LEFT button on the keypad, the gantry moves right.
If it hit the UP button on the keypad, the gantry moves down.
If it hit the DOWN button on the keypad, the gantry moves up.

So when it powers on, the gantry heads for the right-front corner and grinds against the stops instead of moving to the upper left and hitting the installed limit switches.

Each stepper motor has a red, blue, yellow and white wire. I matched it this way to the schematic posted in the instructions PDF-
Red -> A+
Blue -> A-
Yellow -> B+
White -> B-

Any ideas on what I might have done wrong?

Thanks
Ross

Tech_Marco
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Joined: Mon Jun 15, 2009 3:00 pm

Re: Upgraded with X7 kit - issues with steppers

Postby Tech_Marco » Sun May 21, 2017 9:06 pm


srkinard
Posts: 6
Joined: Sun Apr 30, 2017 10:21 pm

Re: Upgraded with X7 kit - issues with steppers

Postby srkinard » Mon May 22, 2017 8:12 am

Ah..ok. I haven't connected it to a computer yet as I'm finishing up the actual installation. I was only using the controller pad to test.

I'll go ahead and install the software on the laptop I'll be using and connect it, then see if I can reset it all.

Thanks!
Ross

srkinard
Posts: 6
Joined: Sun Apr 30, 2017 10:21 pm

Re: Upgraded with X7 kit - issues with steppers

Postby srkinard » Mon May 22, 2017 3:19 pm

So I worked on this when I got home...LaserCad would not communicate with the device but RayCam would.

I set the parameters and the directions are now proper.

However the limit switches still do not stop the gantry...I check continuity and they are working as a N.O. switch should...when the head is in the upper left both X and Y switches are closed.

I hit reset and it promptly moved to the upper left corner and kept hammering away at it and before I could hit STOP it had pulled my X belt in half.

I'm beyond frustrated. Now I have to purchase more stuff and take the gantry back out completely to repair the belt. Is there a trick to making it recognize the limit switches?

Thanks
Ross
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Techgraphix
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Re: Upgraded with X7 kit - issues with steppers

Postby Techgraphix » Tue May 23, 2017 12:05 am

Sometimes all directions and plus / minus make it very confusing to get ALL directions right. When you have your key-direction right it can still be your product is mirrored.. That's why i think it might look at the wrong sensor.
Anyway you have 6 (homing) sensor-inputs. If you have 6 attached you can do the following:
Place the head, manualy, somewhere in the middle, Set all speeds to snail-speed so it will take a minute or so to have it moved to the homepoint.
Reset and in the meanwhile trigger all sensors sequencialy, When it stops moving in one of the directions or stats a movement the other way, Then you have found one of the appropriate sensors.. (just a guess: it's another one than you expected ;-) )

Making a temporary test panel with 6 switches can also help to sort these things out..

BTW this belt: isn't it just come loose from the fixing/tensioner... Tearing a belt in two with those tiny K40 steppers?? It must have been a very bad belt.. (for the record: i use tuned 3nM motors and i don't worry that they even could tear my belt.. Belts can lift at least (a few) hundred kilo's )

Kees

srkinard
Posts: 6
Joined: Sun Apr 30, 2017 10:21 pm

Re: Upgraded with X7 kit - issues with steppers

Postby srkinard » Wed May 24, 2017 7:23 pm

Thanks Kees...I realized I needed to walk away and take a few days to come back with a fresh approach and renewed patience.

Once I pulled the gantry out I saw how the belt is clamped up underneath the X carriage piece...it had pulled out from one side. The little oval washer they used to clamp it down seemed overtightened and flared, so I inverted it so the outer edges clamped down instead and then re-tensioned it.

I grabbed a few NO pushbuttons and wired them up with it slow and it worked setting the limits...I've redone the wiring and with the gantry outside the chassis the limit switches are working.

Since I've got it apart to this level still, I'm printing some brackets for a drag-chain to mount and a support for the air-assist hose.

The mirrors and lens on this thing are so discolored (with barely a few hours use on it) it's just not worth fooling with at the moment. I've gotta order a new mirror and lens to fit the Lightobject head that came with the kit, so I'll just order the other 2 mirrors at the same time and swap out all the optics at once.

With all the work I've done pulling it out and changing parts out, I'm concerned with everything lining up when it goes back together. Most importantly the up/down alignment between the 1st mirror at the tube and the fixed mirror on the X-axis. As it moves towards the front of the machine how much have I altered the vertical alignment...I'm thinking the laser is broad enough to handle the changes since the lens actually collects and focuses the wider pattern down.

I also need to get some NO switches for the top & bottom of the Lightobject Power Z table...I printed a mount for them I found on Thingiverse.

Last thing...has anyone here installed a beam-combiner and put a pointer inline?

Thanks
Ross

Techgraphix
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Re: Upgraded with X7 kit - issues with steppers

Postby Techgraphix » Thu May 25, 2017 2:05 am

srkinard wrote:has anyone here installed a beam-combiner and put a pointer inline?

I had experimented with it but took it out again. To be honest, i think it's more a fancy gadget than a real practical solution:
- The red dot on your work can have a minimal diameter but because of the light intensity it can be appear 1 to several mm's in diameter.
- Alignment and keeping te alignment over time is an issue. Prior to lasering you Always have to check if the red dot is exactly on the lasers focuspoint.
- Every extra device (lenses, mirrors, combiners, expanders etc) in the laserbeam reduces the laserpower.. this can be something form 5-25% reduction for every single device.

I prefer to work more acurate when placing engravings on items (like text on black-anodized frontpanels for amplifiers for instance). For that i fix a piece of cardboard on the bed, focus to that and have the outline of that panel lasered on the cardboard (low power high speed) so i can exactly place the panel to the right spot. Focus on the top of that panel and engrave all figures and text at exactly the right spot.
Advantage of this methode is that i'm sure that the panel is aligned.
When i have to engrave multiple items, i fix the same cardboard and cut the outline of those items out of the cardboard so i have an acurate mold to place them in, at the exact right place and orientation..

Try to do that with a reddot... goodluck ;)

So i don't see any usefull application for a reddot, but of course you are free to place a reddot-combiner if you want it, just for wanting it..

Oh something else.. If you configured it right, you only need TWO sensors: HomeX and HomeY.. For the Z-table the upper-level is determind by your focussing-sensor and the lower-level is so far down there that you probably won't get there.. You don't have to include the Z in the reset-procedure.
Just leave it where it is. Manually lower the bed (by pressing Z- on the panel) place your object and select autofocus when you have a focussensor installed..
This focus sensor can be a microswitch, a proximityswitch or, like i have, a programmable Ultrasonic sensor (this works really great! except on material like felt, but a piece of paper on it solves this)

Kees

srkinard
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Joined: Sun Apr 30, 2017 10:21 pm

Re: Upgraded with X7 kit - issues with steppers

Postby srkinard » Tue May 30, 2017 4:03 pm

So I got everything assembled almost...still need to mount the Z-axis limit switches and screw the Power-Z table down.

Aligned the mirrors and set the UM/Pulse with some test measurements...now I can drop a shape in, cut and measure and it's accurate.

Cutting works...I've adjusted laser power and speed and gotten expected results so that's cool.

Engraving...so far I have not gotten ANY engraving to work. Every single attempt made gives "Engrave Beyond border limit!" on the X7 panel.

I know I've gotta be missing something basic...any ideas to try?

Thanks
Ross

Techgraphix
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Re: Upgraded with X7 kit - issues with steppers

Postby Techgraphix » Wed May 31, 2017 6:23 am

srkinard wrote:Every single attempt made gives "Engrave Beyond border limit!" on the X7 panel.

When engraving the laser has to start somewhere left or right from the engraving to gain the requested speed.
This implicates that if the speed is high and the accelleration is quite low, you need quite a distance to ramp up the speed.
If this distance falls beyond the programmed mechanical borders of your laser, you will get this message.
How to solve?:
place your object somewhere in the middle, not too close to the sides (also set your origin right ofcourse)
Increase the acceleration to a level that the machine can handle without getting lost steps.
Decrease de engraving speed (and power)
If you configured it all right, you should be able to engrave with ~500mm/sec and have overshoots of less than 1 or 2 cm. Keep your object at least this overshootdistance away from the mechanical (and programmed) limits.

Kees


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