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Messages - carolynsdad

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Z Axis / Re: Controlling Z axis
« on: April 24, 2017, 09:43:57 PM »
It looks to be a very tidy and effective design Ralph and no loss of area.

My only concerns are:
1. The thread pitch looks to be very coarse so isn't backlash an issue? It would have been nice if they had used fine pitch threaded rod giving the tidy 1mm movement per rotation.
2. Also, what is the free play in the sliding plate like; is it enough to cause issues when the the dives accelerate?


Projects / Re: Slate Baby!!!!!
« on: April 24, 2017, 05:12:37 AM »
I use satin. I had a bad experience with matte. It goes on looking like milk and then it didn't clear up everywhere and had a bunch of bubbles. It could have just been a bad application. I may try again one day

Sounds as if you applied too much; easy to do when the product is flat and you know you are not going to get runs. It just needs a sealing flash, perhaps a couple of very light coats not encapsulation  ;)

Projects / Re: Slate Baby!!!!!
« on: April 23, 2017, 11:08:31 PM »
It's not the best video, but here you go.
How to paint slate
An alternative - you are using spray poly so do what model makers do, spray a very light coat of matt varnish onto the painter's tape to seal the edges then spray your paint after a very short waiting time.  Note they would also cut the overlapping tape in the corners with a very sharp scalpel so it lays flat as the overlap is where the biggest chance of paint bleed is.

In fact, for finishing your nice work have you tried matt or satin poly instead of gloss; it might look even better?


Trouble Shooting / Re: Laser randomly lowering power (OPEN)
« on: April 14, 2017, 09:29:09 PM »
What is the square part with the round section at the back of the laser? A pot? An Inductor?
That is an inductor.


Projects / Re: Slate Baby!!!!!
« on: April 14, 2017, 09:25:08 PM »
Smart work ThothLoki, what settings did you use in T2L please?


General Discussion / Re: High end laser modules
« on: April 03, 2017, 01:41:13 PM »
Hello, sorry for late reply. We are quite busy here ;)

1. Beam shape depands on the focus distance. For short focus distance around 20-30mm the beam spot is around 0,1mm and it is round. Power is a little smaller because the lens are not catching whole light. At longer distance the beam is a stripe but properly set it can be used as a nice squre. We are working on our software and it will allow to engrave pictures with big pixels square sized in high speed. We did testing and made a 100x100 mm^2 picture in like 15 minutes only.

2. We do not have any graphs but the idea is that PWM is switching the diode to full power. The only condition is that the PWM should be higher frequency, for example 5-10kHz. This way the signal is averaged and power output is very linear. I mean if you use 1% fill you should obtain 1% power. This is happening thanks to our high speed driver which is able to work with 50-100kHz signal easily. We will be doing testings soon after we end our docking station, then some graphs should show up ;)

3. It will lase instantlly. 1% ~ 1% power. If you speak about analog input then situation is a little different. You need around 0,3-0,4V to start lasing action. It is connected with diode threshold current.

Many thanks for replying.

Interesting point about focus distance; yes you can compensate for it over quite a range by lens adjustment but the best method is to have the object close to capture all of the output from the laser.

The top end frequency of your controller is interesting; the 1.1e Grbl build is I believe set at 7.8kHz, right in the middle of the lower range you mention. I think it would be interesting to experiment with much higher frequencies on laser drivers that are not designed for PWM control.

In designing your controller please make sure that it has a pull down on the input as the PWM output from an Arduino goes high impedance when booting which causes other controller sto turn on as they have pull-up resistors on the imput; I advocate the removal of the pull-up by track cutting to overcome the problem. Use of an external pull-down resistor is also used by some but not my prefered method..


If you have a problem with the laser pulsing on for about a second when changing from the design to the laser screens in t2laser or at any other time you might like to carry out the small modification that I describe in this message:,1391.msg18049.html#msg18049

I see the assembly of the large components is as poor on your board as it was on mine. I desoldered most of them and re-fitted them correctly.


T2 Software Updates / Re: Updates
« on: March 30, 2017, 03:01:51 PM »
Yes, sorry but that's still necessary.

I looked at alternate installers but haven't made any decisions yet.

Thanks, just needed to know how much I had to tell my daughter to do to take on the upgrade.


T2 Software Updates / Re: Updates
« on: March 30, 2017, 02:42:10 PM »
v1.3z "Zambia" is released.

Many thanks for another upgrade Zax.
I have been meaning to ask if it is still necessary to uninstall a previous version before installing a new one?


General Discussion / Re: High end laser modules
« on: March 30, 2017, 02:36:23 PM »

It looks like you are writing about our laser heads Nice! ;). We are in a hurry to explain. ;)

Some questions about your kit:
1. Is the laser diode output circular rather then oblong when viewed defocussed onto a surface?
2. How linear is the power output with reference to the PWM percentage and is it repeatable from one diode to another? Can you show us some linearity curves?
3. At what PWM percentage do the diodes start to lase?


T2 Engraving / Re: What am doing wrong
« on: March 29, 2017, 12:02:40 AM »
Advice on current issues would be greatly appreciated.

Excessive slack in your drive belts I should think; could alos be over tight though. Test for about 12mm slack at the area between motor and wheel and adjust with the respective carriage at the opposite end of the track to where you are adjusting.


General Discussion / Re: New lens
« on: March 25, 2017, 02:33:23 AM »

might try that mine neve had a spring from the beginning

The spring I am now using has four turns and fairly thick, the original was quite fine so there is the slight downside that the lens will not screw in quite as far so thin objects may need a raised support.  I'll be interested to hear how you get on.


General Discussion / Re: New lens
« on: March 23, 2017, 11:43:14 PM »
MarcusJ, some of the higher powered diode lasers have rectangular beams.

"Is anyone else's spot more rectangular than round?  I'm wondering if I've got some foreign particles in the laser or lens body."

Yes when defocussed my 3.5W laser image is rectangular but when sharply focussed I can't see a difference in line width.


General Discussion / Re: New lens
« on: March 23, 2017, 03:05:16 PM »
I have a solution to the wobbly lens problem. I had an issue on the 3.5W laser head bought from Bangood with a TTL board.

The wobble manifested itself as a damped sinusoidal oscillation at the start of engraved lines when moving quite fast and immediately after a change of direction.
My solution is to fit an uprated spring behind the lens; the one supplied is just not strong enough. It came free from my salvaged spring box.


Laser Accessories / A Laser Lens Adjustment Solution
« on: March 23, 2017, 02:54:24 PM »
I have seen clever ideas for enhancing the way in which the lens focus ring can be turned more easily but they rely on having a 3D printer which I do not have. So here's my solution that only requires four holes to be drilled in the knurled ring (I took them to the same depth as the the thread) and four pins (I made mine from an unwanted indoor TV aerial!). I drilled the holes using a Dremel on a drill press and ensured the holes gave an interference fit.  I pushed the pins in using a gentle tap with a hammer to start them then pressed fully home in a vice.

The end result means you can have a fairly precise measure of how much to rotate the lens by for multiple cuts in plywood and if a very fine adjustment is want a tube of suitable dimensions can be slipped over a pin.  Of course I did fully tape up the lens both ends and the thread.

My engineering might not be the best but it works for this 3.5W laser, it took 30 minutes to achive and it is free.


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