Limit Switches

[jlauzon]

I ordered these today from GearBest.com; $3.48 each.

[Administrator]

I have these on my 3D Printer but not on my laser machine. I don't know how you would mount these on the laser frame. In the 3D Printer world, there are a lot of 3d printed end stop brackets available (in .stl file form) so you can print your own parts.

Let us know what you come up with for mounting brackets. You have the aluminum frame?

[jlauzon]

I have these on my 3D Printer but not on my laser machine. I don't know how you would mount these on the laser frame. In the 3D Printer world, there are a lot of 3d printed end stop brackets available (in .stl file form) so you can print your own parts.

Let us know what you come up with for mounting brackets. You have the aluminum frame?

Astute point in the mounting. I was staring at my frame (yep, same extruded aluminum as most) for a long time thinking about that.

I'll likely just wait until they get here and do my usual hack job. If I come up with anything that's not too embarrassing, I'll post pics.

[BritVic]

I bought these ...   https://www.amazon.co.uk/gp/product/B00D021STW/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1
8 x Sub-min micro switches for £2.22 inc shipping seemed a pretty good deal to me, and I have 2 left over as spares (inc Z axis)
All I have to do now is wait for the tiny 2.2 x 10mm self tapping screws to mount them with, and they are also coming from Amazon!
I will be mounting them directly on the lower part of the alloy frame, since I believe "safety" devices should be kept as simple as possible.
Not certain yet which pin to use on the shield yet, probably "abort" or the equivalent.
Will send a pic when done.
Vic

[ROSS]

Will send a pic when done.
Vic

and a wiring diagram!! 

[BritVic]

Yep ok Ross, I'll let you know which pin I Superglued the hot lead to


(joke!)

[ROSS]

Yep ok Ross, I'll let you know which pin I Superglued the hot lead to


(joke!)

[dindunuffin]

Can you set hard limits via the software? T2Laser or in grbl?  I have trouble with running into the stops sometimes and have to hit the emergency stop and make adjustments before starting over. 

I'm still having trouble finding the etch boundaries.  I tried drawing a box around the workspace of the T2laser sketch and burn that, but it still exceeded the limits, and I used the A5 workspace setting which matched my kit.

[Zax]

Grbl supports home and limit switches. The basic L1/L2 Eleks boards don't have an input but you can easily add a wire to the Nano socket (it has internal pull up resistors so it's as easy as a direct wire and then to ground).

If you home your machine then software can prevent over travel, but physical limit switches are always a better option.

The actual travel distance varies slightly by machine, depending on your assembly but most won't achieve the size they state.

[Administrator]

>The basic L1/L2 Eleks boards don't have an input...

So, if we wanted a controller board that does have the input, we'd have to step up to at least an L3?

[Zax]

All the Eleks board does is provide a header socket for the connection to the Nano, but yes, if you want plug and play the L5 or L6 would be the answer (not sure about an L3).

[Administrator]

Thanks @Zax, I'm thinking ahead...hey wait a minute, that hurts my head...I will probably want to add limit switches to my laser machine at some point in the future so I guess I'll keep my eye open for an L5 or L6 board.

[n1te]

Hello,
maybe a dumb question but why we should stick with these elecs boards?

For example, this board fully support grbl 9.x, arduino (not nano), and many other things.
http://www.ebay.it/itm/281670664172?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I'm not really happy to know my machine run on some board that can disappear from market in a couple of months or so, and I am looking for alternatives.

n1te

[Administrator]

That looks like a shield for an Ardunio Uno microprocessor board...you either have to already have a spare Uno laying around to use with it or you have also buy one...this is just for the shield. I just read further down, it is for the Uno board. I also see the driver boards are not included so you have to buy those too. How funny, I have some spare Uno boards laying around and I also bought some spare driver boards...I have everything to make this work except for the shield itself.

Having said all that, this looks like an excellent setup...however, a little pricey after buying everything needed to make it work, but this looks like it would be a good alternative to what we have now, if the L2 controller boards were no longer available. I'm assuming there isn't anything there that would not make it work with our laser machines.

Perhaps @Zax can comment here too?

[Zax]

As Ralph pointed out, this is just a "shield" or daughter board for an Arduino Uno.

It doesn't offer anything more than an Eleks L6, and isn't as compact. You could use it as a replacement if needed.