WOW These parts are big!! Toledo, OH

[Father-of-Ash]

Thanks Kelly,

Pete, I did use your calculator and got the same number(also parallel connection). I was just concerned about the pk296 because it requires less voltage, just wasn't sure if the calculator compensates for that. So feeding my geckos 56VDC is optimum? just wanted to confirm that. And if not, then would a step down regulator work or would that introduce too much noise?

[pblackburn]

You only need a different current limiting resistor if you are concerned with the heat of the stepper. I have a conglomeration of steppers on mine so I can give you a rough idea. I have the three steppers from the PK296A2A-SG7.2, one PK296-F4.5A and one PK299-F4.5A. I had to lower the values on the A2A resistors. If you are concerned, get the 48 or 50V. It will work well also. I started out with one in the 30 to 40 volt range. With the changes, I needed to upsize but I should have gone with a larger power supply in the beginning.

[Father-of-Ash]

Thank you Pete.

[Father-of-Ash]

I have most of the electronics ordered, just need to pick out all the din rail items and i should be able to start on kitchen table soon.

Is "Metalhead" Mike on vacation? its been almost a week haven't heard back from him yet. maybe my 2 PM's didn't go through, my "sent" folder is empty.

[MetalHead]

I am back - sent you a PM

[Father-of-Ash]

Hello all,

Some components have come in. I know the size of some of them will make you laugh. The capacitors, I had no idea were that big, never paid attention to dimensions, and I think I was falling asleep when I ordered the heat-sink, 2" too wide and a Gecko too long. Used push-button stations are more massive then my assumptions as well.

[Father-of-Ash]

edit: trying to get pic to attach.

[Father-of-Ash]

Hello all,

I have a simple question about the on/off switch for the front panel. I think I ordered the wrong one, part# GCX1152 from automationdirect.com. the contactor blocks dont stay engaged when pushed, so would I need some type of relay setup to make this work or just get a different switch?

I almost have all the electrical components and will soon post some pics of progress.

[MetalHead]

You need one that is not "momentary" - G is correct in the next post as usual - I miss read the specs when I reviewed that one !!

[Gerald D]

Bilal, your contactor block should have an Aux. set of smaller contacts to the one side. It is very normal practice, for safety reasons, to wire your switch with the aux. contacts to "latch" the contactor. Then, if mains power fails, and is reconnected, your contactor will stay off.

If you did use non-momentary switches, you would have a dangerous system.

[Father-of-Ash]

Thanks Gerald, the simplicity of it makes perfect sense now.

Here's more info for other newcomers.

Haven't had much time to look through PMDX diagrams, just wanted to ask if the start/stop buttons can use the same ground? only 3 wires can be used?
I would like to order my cable now so I can use some in the box, have many people used the cable calculator? is it reliable? cant find the link for it ATM.

[Gerald D]

There is a discussion following, and diagrams from here:
http://www.mechmate.com/forums/showt...4&postcount=55

[Fox]

I did my own cable calculating..
Walking along the machine.. max extended at every axle (can also be done in cad) and adding half a meter with every corner, and one at the control box (mounted at the machine) then I rounded the numbers up... and it was spot on.. Had a meter spare.

Mind you... walking along the machine while thinking of cable doubling trough e chains.

[darren salyer]

You could always run a string for length too.

[Father-of-Ash]

Thanks guys,

I don't have any part of the machine together yet, I'll just wait till it is together to be on the safe side.

On another thought, does anyone know if you can go bigger then 4kw spindle for 230v single phase america? or if there is anything bigger even available in 230v? and is 10awg shielded suitable?

[pblackburn]

For the VFD load output yes but not for the supply if using only single phase. I only know of Hitachi that makes a 3 phase VFD capable of running a 4 kW that may be wired single phase even though it is listed at 3 phase. Info is on cnczone.

[KenC]

4000W/230V= 17.4Amp.

You sure you want to run higher than 4kW on single phase?

[alan254]

I am running a 5HP Colombo spindle on single phase but you need to double the size of the VFD I am running 10 HP Lenze drive. All running fine

Al

[Father-of-Ash]

Pete, this is what I originally had in mind. In the end, if budget allows I will shoot for the Hitachi XJ200-075LF.

No, I guess not Ken, Thanks.

Al, what model is your Colombo? and what did you pay for the Lenz, if you don't mind me asking?

Another E-stop question, is it recommended to run it as a separate 2-core shielded cable or can it be part of a 7-core shielded? my e-stops will be 220v since my contactor coil is 220v. I think I will be running 2, 7-core cables other then the 4-core motor cables.

I plan to be using an air drill as well, can you guys give me some pointers as to what kind I should look for. there are a few Desoutters and Atlas copcos on ebay, going to need holes in aluminum, acrylic and some steel sheet.
And how much longer should the X rails be for the second cutter?\

Thanks again guys,
Bilal

[pblackburn]

I would advise against high voltage coils. Besides the higher risk of electrocution and arc flash potential (if not properly done) while troubleshooting, insurance companies don't like high voltage coils here in the States.

[KenC]

If it is possible, don't use magnetic contactor. I changed to SSR which has zero-crossing ability, i.e. it will only turn on AC is at 0V of the sinewave and only switch off when the cycle is complete. this will reduce/eliminate the EMI burst from the transformer. with a 24V latching circuit, you can still salvage your existing on/off push button, light and the E-stop circuit.

[Father-of-Ash]

Noted Pete.

Thanks Ken, is there a diagram of that in the forums?

I just found some Helukabel JZ-602-CY #82982 for $.44 per foot. is this good enough for the motors or should I look for double shielding? seems like an excellent price, no?

[KenC]

I derive my circuit from similar circuit.

[alan254]

Hi Bilal, my spindle is a RS90 CPE25 240Volt that I bought new from Blurry Customs, and the VFD Lenze MC1000 I picked up at an auction for $100. just lucky no one there knew what it was .

Al

[Father-of-Ash]

Ken, Thanks for that diagram. I will implement what you have done. for now just gonna get the controls running.

Ok Al, Thanks. lucky indeed.

What do you all think of that cable? would you use it?

[MetalHead]

Call Helukabel and ask if that cable is CNC rated. I always find if your cheap in the wire department it usually comes back to haunt you at some point sooner than later !!!

[james burrus]

Good to see you getting started

[Father-of-Ash]

Thanks James,

I should hopefully be posting some progress soon.

[Father-of-Ash]

Hi All,

I just had a couple quick questions to get in while I am at work. As to the bipolar parallel wiring. since its parallel does it matter where either A phase pairs go on the driver? /A or A? same for the B phase?

since I am using the pmdx-133 boards, do we use the grounding pin on the board for the shield drain or just put it to the aluminum plate? or both?

The table is going to be a fairly big table, 7x14', would it be recommended to go with 16awg for the motors instead of the typical 18awg?

I plan to have motors turning this weekend...I hope ...I think Ive already said that once, pictures to come.

[KenC]

on the phase,
It does, follow the manufacturer's specsheet and you should be ok.
if you don't have one, its impossible to tell the correct pole without expensive equipment or trial and error. the good news is you won't fry anything if the poles are connected wrongly.