Questions on Fabrica's control box

[Gerald_D]

Fabrica has kindly posted the following pics in his personal thread (http://www.mechmate.com/forums/showthread.php?t=310)...

http://www.mechmate.com/Forum/messages/329/3388.jpg
http://www.mechmate.com/Forum/messages/329/3389.jpg
http://www.mechmate.com/Forum/messages/329/3392.jpg
http://www.mechmate.com/Forum/messages/329/3390.jpg
http://www.mechmate.com/Forum/messages/329/3391.jpg

..and already the questions are starting. We might learn more if we keep the ensuing discussion in the Control System topic.

Irfanulla asked:
"Good to see the machine work, probably u might post a video later.....Gerald u have details on teh mains wiring, or fabrica can u provide me the main wiring, cause though of topic teh controller I made using the UHU controller makes the MCB at home trip every time i try to put on the controller, probably there is a soft start switch for teh power supply, meaning the stuff next to your torroid transformer in picture 4 , what are those and how have you interfaced the proximity switches to teh Mach soft ware."

[Gerald_D]

Irfanulla, there is a good chance that you need to replace your MCB with a "slower" one. Over here we have a choice of MCB "curves" and I am sure you have those choices as well. (link (http://www.klockner.co.uk/ta_mcb_basics.htm) - scroll down to Trip Characteristics}

That circuit next to his power supply is the PMDX-135 Power Preparation Module (http://www.pmdx.com/PMDX-135/index.html)

Looks like Fabrica has not used proximity switches, but has used microswitches (http://www.mechmate.com/Forum/messages/329/3395.jpg) instead.

[reza forushani]

Vadeem - Congrats. Great job

Gerald

Is the PMDX-135 necessary?
Are these microswitches reliable enough to use? Do you recommend them?


Just one comment

I spend almost $200.00 getting dust proof control box and I see you hot a fan sucking in air. Does that not pull dust in also?

[fabrica]

Reza All suction fans will have dust filters. I will fix them and upload pics today. I used microswitches since I had them in stock. I will be placing orders for Proxies immediatly. Can some guy provide me with proper specs for a good quality proxy.

[Mike Richards]

Fabrica, you've built a great looking machine!

I posted some information a few months ago about proximity switches, along with part numbers. You can find the information by clicking on this link (http://www.mechmate.com/Forum/show.cgi?tpc=832&post=1566#POST1566).

[fabrica]

Thanks for your compliments Mike. I will follow your link up.

[Gerald_D]

Proximity switches: very difficult to wire in series to make limit/homing/e-stop circuit.
Microswitches: prone to dust and damage from bumps
There is no easy choice here. We don't use any switches (trust the software), but if I went that way I would probably get proxies with a small relay on each proxy. I don't think the spec on the proxy is too critical, but I'd suggest you buy the best that is in stock near you.

Fans/dust: We have been extremely successful with our sealed box that does not breathe outside air. But we only have a 300VA power supply in there which drives 2Amp motors. I think our size/design will cope with 500VA supply (3.5 Amp motors). If a sealed box works with a single fan, then why cut holes for multiple fans?

Is the PMDX-135 necessary? With our 300VA and 2Amp motors we have no reason to use something like the PMDX-135.

[Irfanulla]

Gerald, i am not talking about the circuit, it the relay sort of thing near the Power supply

and Daya the UHU contoller has its roots in the CNCZONE at http://www.cnczone.com/forums/showthread.php?t=14217

Ok eye sight error about the proimity switches, any how daya does mention that he will use them :-)

CYA soon......

[Gerald_D]

Fabrica, why did you use clamping plates for the Geckos's, on one side only? Hope you know that you can slide those connector blocks off the gecko to get to the screw holes underneath.

I see you took a lot of trouble to keep the mains volatage wires outside the box. This probably comes from the time you had those problems with a Mach setting that had symptoms like interference. We don't have a problem with mains voltage wiring inside the box. The screen plate around the power supply is a good idea in any case - we might add one to our box if we see symptoms that look like interference.

Generally though, a very good product. You have achieved the very essential objectives of minimum cost for a product which you fully understand and can support yourself.

[Gerald_D]

Irfanulla, that "relay sort of thing" is a ......relay! That style is more commonly called a contactor. I am sure that Fabrica uses it to switch off the power supply when any e-stop button is pushed.

[fabrica]

The AC supply is connected to the Contactor. The contactor is switched On and Off through the Red and Green Push buttons mounted on the front door of the Control Box.

The e-stop is connected to the PMDX-122 Card. When e-stop si pressed it knocks off the control signals to the Geckos.

[Gerald_D]

Your E-stop should kill the router as well. Does your PMDX-122 control your router?

[fabrica]

No Gerald, The router is controlled separatly. When we try to wire the router through control box it generates noices and makes the motors to behave abnormally.

[Gerald_D]

That is good news and that is bad news....

The bad news: For some reason, your circuit in the control box is susceptible to interference. It should not be like this and I think you need to try and reduce this susceptibility. It means taking a very careful look at earthing/grounding - not too much and not too little. This is a discussion topic all by itself..

The good news: You have a way of testing for it now, before you really go into production.

[fabrica]

One reason I switched over to a toroidal transformer was to overcome the noise problem. After doing this and rearranging the wires most noise problems were overcome. After switching over to new transformer I have not tried to wire the router through the control box. I will give it a try on Monday.

[Hugo Carradini]

¿Does the PMDX-135 Power Preparation Module eliminate the use of the capacitor? I don't see a capacitor close to the transformer.
Thanks

[Gerald_D]

For sure! those 5 capacitors are plenty of "capacity"

[fabrica]

The reason why I invested on the PMDX 135 was becaue it was dirt cheap. I I were to buy those five caps locally It would have cost me more. I assume that with this PMDX 135 card my system would never be short of electrical energy since the five caps provide enough storage.