[Pplug]

I've been doing some looking around for a laser focuser for my retrofit. I haven't seen any info on them or where to buy them. Can anybody clue me in as to what they are, how they work and where to purchase one or at least where to get the parts to make one?

I'm using the lightobject Dsp Awc-608 and I would like to automate the height of my z table.

Thanks!

[Melody-gweike]

I've been doing some looking around for a laser focuser for my retrofit. I haven't seen any info on them or where to buy them. Can anybody clue me in as to what they are, how they work and where to purchase one or at least where to get the parts to make one?

I'm using the lightobject Dsp Awc-608 and I would like to automate the height of my z table.

Thanks!

Hi, It is something like this one. It works to keep a fixed focial length. Here is a video to show how that works.


[ame=http://www.youtube.com/watch?v=7xwz-ADo-lo]Auto focus of laser - YouTube[/ame]








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Melody
Sales Manager of G.Weike
E-mail: [email protected] [email protected]
Skype: melody.gweike

[Pplug]

I was looking for something that does not make contact with the material. If I used that touch sensor on a piece do paper on my honeycomb cutting table, it could go throught the material.

Thank you.

[atv2]

WK has a version that does not make contact with the material, basically you place the included block of aluminum under the sensor, and once it gets close enough (never actually making contact) it will stop moving the z axis. It works great and is very accurate. Unfortunately, on some machines, the z axis is driven by a single motor, and sometimes the table binds up as the motor tries to move too quickly. The fix is pretty simple: slow the motor down.

[TechGraphix]

With a proximity-sensor just beside the lens-shaft and a certain block of metal (for each focal length anothe block) this auto-focus thing is a piece of cake.
Just move the tabel down sofar that the block can be placed on top of the material and under the sensor. select autofocus and enter.. the table moves up till the sensor is activated. now take away the block and your ready to go.

I will make a little film soon how to replace the lens and adjust the sensor in a minute or so..

Kees

[Pplug]

Very nice! This is exactly what I was looking for! Now I have to see if it will work with the awc-608 dsp controller.

[TechGraphix]

I'm quite sure it will work with that controller. connect to Z+ of U/Z limit (pin 5)
for more info, just request

Kees

another view on the proxy:

[Pplug]

Great! Now, where do I get one?

This has been some excellent help! Thank you!!

[TechGraphix]

You can buy them on ebay for just a couple of dollars. There are plenty of them but what should you look for?:
A smaller sensor is lighter, so a 8mm diameter is preferred (mine's 12mm)
the detection distance should be as small as possible: the reproductive measured distance is a percentage of that detection distance.. try to get 2 or 1.5mm
The output should be NPN type. When the sensor is activated this output is drawn to GND
There are two types: Flush and Non-Flush. I prefer Flush types as they only "look" in front of them (With non-flush types you see the plastic part coming out of the metal shield)
Find a type DC6-3xV, Although this should work from 6 to 30-somwhat Volts it works fine at 5 Volts too.
The right proximity sensor has three wires: Brown (+), Black (output) and Blue (-)

I think this one is nice but there are many others..
LJ8A3 2 Z BX 2mm Inductive Proximity Sensor Switch DC 3 Wire 6 36V NPN No | eBay

Here a little film i made How i change the lens and at the end the whole autofocus procedure..
http://youtu.be/EnaLNZPRrwo

[Pplug]

Thank you sooo much! Do the reference plates need to be made from a ferrous metal or can I just use an aluminum block?

[TechGraphix]

Aluminum is possible but the detection distance is much smaller than ferrous metal (iron or steel). Ferrous material is prefered.
This doesn't need to be a solid block: a small disk of, say, 10mm round and 2mm thick, placed on a wooden or plastic column will work too. As long as it stands quite solid on the material during the autofocus-procedure.
The other referenceblock i use for adjusting the sensor during a lens-change is just a block of aluminum 10mm thick. This 10mm is exactly the distance between the nozzles tip and the focal point (in my case, i made it that way..)

Kees

[Pplug]

The laser tip we have is not designed that way. Ours is fixed in place and does not move up and down. That is good information on the ferrous metal height plate. I might make the body from al and the top from epoxied sheet steel. I ordered 4 of those sensors and they should be here in about 2 weeks. I also have to fabricate a means to hold one on the laser. If the height gauge works out then I might replace several of the other limit switches with these as well.

[speedythinker]

The laser tip we have is not designed that way. Ours is fixed in place and does not move up and down. That is good information on the ferrous metal height plate. I might make the body from al and the top from epoxied sheet steel. I ordered 4 of those sensors and they should be here in about 2 weeks. I also have to fabricate a means to hold one on the laser. If the height gauge works out then I might replace several of the other limit switches with these as well.

I know this post was a little outdated. But see what we have done so far. See our new RTAF (Real time auto focus)
https://www.youtube.com/watch?v=rjhTnPCnJMo

Marco
LightObject