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-   MechMates already cutting (http://www.mechmate.com/forums/forumdisplay.php?f=78)
-   -   First Cuts #108 - Willemstad,Netherlands (http://www.mechmate.com/forums/showthread.php?t=3761)

Tom Ayres Sat 24 May 2014 14:41

Sorry, I'll try not to say anything anymore.

dbinokc Sat 24 May 2014 15:05

I apologize if it seemed like I was chastising you. Just making a suggestion.

KenC Sun 25 May 2014 00:05

did you ground directly from board terminal to your chassis earth point.

Regnar Sun 25 May 2014 00:19

Have you tried grounding your dust collection? From the photos it looks like it isnt and if your Z axis proximity switch is anything like the rest of us it might be getting zapped. It also looks very close to the Z motor and X motor.

Just notice that the hose actually gets very close to all those wires on top of your Y car. I would seriously consider running copper wire around the whole thing and grounding it out.

smreish Sun 25 May 2014 07:11

Paulo,
I have had similar issues with my #28 that about drove me nuts.
Some of the detective work may take a while, but it's how I found it on my machine.

Check these things to isolate the issue:
- does it run without issues when spindle off and dust collection off?
- Disconnect the proximity circuit at the control box and check? If so, I had to make an isolated plastic mount to keep Z-axis sensor separate from machine ground.
- check if it runs without spindle physically touching machine...means barrier material between spindle case and z-axis (including mounting bolt)


How i fixed my machine.
- added plastic isolator bushings to my 12mm body proximity sensors
- added 12vdc relay to proximity circuit to put a "dry contact" between the proximity sensor and the PMDX board.


In summary...the proximity sensors have been the induction point for noise on all my machines. The only time I had an issue, was with the spindle machine. Router didn't have enough noise to make it an issue.

Good luck.

parrulho Sun 25 May 2014 22:17

Russell, you touch a good point, my dust pipe is not grounded. I fell already the static on my hands. I'll run a naked wire from outside, It should be OK. I have a bypass on the Z proximity switch, it's waiting for a bracket for long time:)... is why the static did not gave troubles, yet.

Sean, my machine is running without troubles since I grounded the 12V power supply, it's was floating... so far so good.

Ken, I did the same as the motors power supply, ground the negative black wire to the aluminium heat sink that is the common for all machine, and yes, directly from the board terminal.

Thank you to all.

KenC Mon 26 May 2014 00:55

Connect to the aluminum heat sink is not the correct thing to do. It should be connected directly to the chassis ground point. I do not have the ability to explain the whole concept in a few words, do read up on "Star ground".
Edit..
I know most will think "what wrong with connecting to a common conductor? Its a chunk of metal & they are suppose to act as one point in theory"" I used to think that way too. BUT that is correct ONLY when everything is peachy..
Ground loop always exist, like everything in life, we can live with it as long as it is not a nuisance. BUT when it cause problem. The easiest & least hassle to tame it is to further reduce the resistance by a low resistance (thick) copper wire to connect to the ground point instead of relying on the chasis or heat sink or other chunk of metal as conductor.

parrulho Mon 26 May 2014 06:21

Following the plan, that heat sink is acting as the "center of the star " and not a branch.

KenC Mon 26 May 2014 07:26

The heat sink is a good place for the noise. BUT not the best place to place any power supply ground on it.
Another place where think may went wrong without knowing. You house Ground went bad. This is a very common in my part of the world.

parrulho Mon 26 May 2014 09:36

While it's working, it will stay as is. If I have problems in future I'll come at it again... Thanks for your advice.

parrulho Thu 29 May 2014 23:32

I was a little reluctant to write this post because I could be misinterpreted. I don't want to prove anything, please see this post more like a disclaimer. Here at the forum, there are a lot of people much more capable than me that I admire and thank them all the help provided.

I did my machine following the plans an directions of the forum. That part of ground/earthing with the heatsink as the central ground point is explained here: http://www.mechmate.com/forums/showthread.php?t=4

But it is not the principal reason of this post, the reason is that: http://www.mechmate.com/forums/showt...6&postcount=23

here you can see clearly that I should NOT have connected the negative of the small power supply to the heatsink, it breaks the isolation of the board.

Maybe put line filters on power input of the VFD to see if I can remove that wire... or check my house ground as pointed by Ken. If somebody has any idea where I can connect the power supply ground without break the isolation of the board, please let me know.

Meanwhile I will keep that ground at my own risk. I do not advice nobody to do it.

KenC Fri 30 May 2014 09:14

Think Sewage pipe in your house, (done correctly,) the Panel ground point is the last/lowest point of your all drain pipes before it leaves your house. Connecting the Board PSU ground to this point will keep your board isolated from other parts of the circuit. It sounds weird, but that is how its done.

parrulho Fri 30 May 2014 23:37

3 Attachment(s)
just to freshening up air :) some V-Bit work done

sierra347 Sat 31 May 2014 00:23

Very cool, Paulo did you draw the artwork yourself?

Robert M Sat 31 May 2014 04:27

Nicely done.....& like finishing too ;)

darren salyer Sat 31 May 2014 07:07

Very Nice!!

pblackburn Sat 31 May 2014 07:19

Awesome.

racedirector Sat 31 May 2014 08:52

Wow, cool mirror surrounds, they really pop with the finishing. Well done Sir!

Alan_c Sat 31 May 2014 10:49

Brilliant, would you mind documenting the paint effect process?

tnarch Sat 31 May 2014 11:10

wow! did you paint the silver then rub on black stain?

parrulho Sat 31 May 2014 12:20

Sure... Practically I designed the artwork but not from scratch. The client bring me the idea with a jpeg drawn. Then, after vectorize it and clean the vectors I play with it: copy, past, mirror, tweaking etc until get the size needed... Also she wanted the two models sharing the design of one of the corners.

the finish was very simple, almost no sanding. Used a very dark stain, 2 hands and finish with rust oleum silver with a brush almost dry, passing very light brushstrokes only on top. the result is like very old metal frames.

tnarch Mon 02 June 2014 23:20

thank you for sharing your techniques.

parrulho Sat 21 June 2014 14:30

5 Attachment(s)
Finally got my spindle controlled by Mach3 using brains and Modbus. The VFD is a Mitsubishi FR-D720 but it should work with almost all Mitsubishi drivers. For communications have used a rs-485 PCI card with 4 wires but is possible to use only two wires. The cheap chinese converters did not work. no signal of noise yet :)

Attached are screenshots and the "brain" I'm using.

parrulho Sat 21 June 2014 14:31

The Brain did not pass... if you want it, just ask.

parrulho Sat 21 June 2014 14:32

1 Attachment(s)
Screenshot of the brain.

parrulho Mon 21 July 2014 16:41

1 Attachment(s)
Nice companion for my machine: a mini wireless keyboard. all you need to do is setup shortcuts as you like and you own a full mechmate remote control. Best $14 dollars spent...:)

racedirector Mon 21 July 2014 17:30

Thats neat :) Looks like one of those used on HTPC machines? Where did you buy that? I have seen similar locally for about A$26.00

parrulho Mon 21 July 2014 20:08

Yes, it's more used in media centers. That one I bought from ebay:
http://www.ebay.com/itm/321422647882...84.m1439.l2649

racedirector Mon 21 July 2014 22:03

Cool, I'll grab one for my Raspberry Pi HTPC and my machine at the same time :)

parrulho Thu 13 November 2014 13:54

2 Attachment(s)
Hello people,

No noise, no troubles on my machine. Still going strong. I have replaced the pmdx 122 just to get all inputs working (old board was missing one).

A simple yet good looking, sign for myself. PVC board with no finishing.

Regards,
Paulo


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