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#1
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7 core cable to junction boxes
hey All,
I am at the stage of buying electronics and doing my homework at the kitchen table. I think I have pretty much everything under control in understanding how wires are going to be routed, AWG sizes of each wire etc... However, I am lost on the following items: A) On the gantry and the z-slide I see in total 3 control boxes. all 3 have a big stop button (the e-stop). I have the following questions 1) The other two buttons, are they buttons or lights? 2) If they are buttons, are they going to the PMDX? 3) I can only imagine they are to manual control the Mechmate for correct positioning, is that correct? B) The E-Stop as in the schematic 10-70-155 CA just kills the power, but I was also reading about the e-stop on the PMDX. Do I also need to write that one? Through a extra relays properly? C) Any threads known about this feature, I was searching but couldn't find the correct threads yet... Ries |
#2
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Ries you are correct with the other 2 buttons. They are there for moving the gantry, but I do not use it. I control everything from my keyboard....with a long lead into the computer. Most of the setup is from the computer station, but sometimes I use my extended keyboard to zero the bit to my starting point somewhere else on the table.
Therefore only my E-stop is wired from the gantry to the BOB (PMDX). This e-stop is the same as the e-stop in Mach-3 |
#3
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Hey Kobus,
thank you for your response! So I wasn't wrong afterall... Just confused ![]() I am going to ask the price of the 7 core cable here, but I expect some high price... If it's high, I will leave it alone for now... And first get the machine roling and learn how I am going to work with it. RIes |
#4
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Small correction Kobus and Ries. The extra buttons next to the big red E-stop on the gantry ends and Y-car front are usually used for "Pause" and "Program Run" not for jogging the machine.
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#5
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Quote:
That makes perfectly sense now Going to order the buttons and cable then ![]() Thanks Alan, I was about to go to the shops and buy the cables.. I don't think I can buy any of the nice cables some people have, but I am hoping to find at least shielded. Ries |
#6
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Thanks Alan, just to show I have not used them.
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#7
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Well,
I got my cables today... But with my stupid head I forgot to buy the 7 core cable ![]() One thing though, ALL my cables are UN-shielded. The reason for being un-shielded is simply because shielded couldn't be found here. All people tend to say 'Ahhh yes.... imported cables!!, no seņor, we don't have them....' We will see how that goes.... Ries |
#8
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Ries,
You could still get the shielded cable for the 7 core, which will be your control stuff correct? I would definately want shielded on the control stuff at a minimum. The motors will not care about the noise but the control stuff will act erratic if noise gets in there. |
#9
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Quote:
The 7 core I didn't buy yet because I simply forgot in driving to and from each company. But I was thinking to use some audio sort of cable, there are a magnitude of audio companies here and they have shielded multi-core cable that will do for my control cable well. And you are right, since they are connected to the bob to run on high-impedance, I believe I did read the pull-up/down was 100K. Ries |
#10
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Ries,
An unused wire is not a shield. A shield must cover the other wire for it to be effective. The shield on the motor power wires is not to keep noise out, but rather to keep it in. Think of a shield as a blanket, if it is not covered by the blanket, whatever is not covered is unshielded. You might be fine with just the control wires shielded. I would not run them unshielded though. |
#11
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Heathm,
you are right there... I was just thinking since high frequencies generated from the pulses will go a bit to the middle core, it just might help a bit... Anyways, I will try with 4 cores first and see how that goes... Called again today to different electronics suppliers.. and they all found 500VA quite big.. even 250VA was big for them and can only be made (non standard they tell me and can only be made, google tells me different though....) ![]() Ries |
#12
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Ries, if you cannot get a 500VA toroid transformer in Quito, then consider a standard (non-toroid) type mounted outside your control box.
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#13
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Hey Gerald,
thank you for your response! I don't think even that they make toroid here (may be good business then?) and I am working my way to throughout suppliers for transformers (2 so far in whole quito) So far all suppliers consider it as special and need to be made on spec, it's hard to believe, but they say they only have 12, 24 and 48V up to around 150VA, anything else is special in Ecuador. Current price is 135USD for a 35V/500VA transformer. Kobus told me he uses a 42V/300VA for 4 steppers, and he has the same steppers as me, however I am planning to add the lathe to it early next year so I would like to have a bit of extra juice for the 5th stepper, although I don't really needed it I think. But come to think of it.. since they need to make it I will ask them a price for a 350VA/42V transformer and see what the price is... My mayor problem with letting somebody make on is that I already ordered one audio transformer and the first one I got did run hot without load and was dimensioned to small for the spec I needed. The second transformer I ordered was bigger, but still runned warm and is actively cooled in my amp.. So my worry with this transformer is that I go through the same troubles. I am going to make a decision next week, today is kitchen table day (not helping my wife with peeling potatoes though....) and assembling the bits and pieces. Ries |
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