[dinkyguitar]

HI All,

As a newbie, where is the best place to buy the whole package, G540 and 3 drives with everything I need?

I saw Keling $455, but I think I need to install the motors resistors and get longer motor wires (not sure where to get these wires)

Cnc Router parts, $519, looks good and has the resistors and motors wires. Not sure if the $64 extra over Keling is worth it.

DeepGrover1, $535. Comes with a case and everythng in it, but I think I'm going to make my oun case, plus the motors with this kit are 270oz-in as opposed to 381oz-in for keling and cnc router parts.

Can I buy all th parts individually for cheaper? And what other places are there?

dinky

[Lee DeRaud]

I went the CNC Router Parts route, mostly because I absolutely hate fabbing cables: not having to solder connectors was well worth the money to me. YMMV.

[dinkyguitar]

Thanks Lee DeRaud,

How was it dealing with them? How long after you ordered did you get your stuff?

dinky

[Walky]

Are you going to use cable carriers?, that might be a deciding factor since some connectors won't fit in some carriers (unless it's the kind that can snap open or similar).

I've had good experience getting G540s from Hubbard CNC (carolbrent on Ebay) and Keling / Automation Technologies. The latter might be a good alternative if you plan on getting their 381 oz/in motors too (which are very good).

I usually go with chinese switching power supplies (24V, 36V, 48V), I always use those and IMHO they are pretty good, at least none has failed me.

[Lee DeRaud]

How was it dealing with them? How long after you ordered did you get your stuff?

Shipping was Priority Mail, about 3 days IIRC (this was back in January). They're very easy to deal with and great after-sale support. Power supply had a broken fan (looked like it happened at the factory), replaced no questions asked.

[vtx1029]

Automation tech (kellings new website) sells the CRP cables

High-Torque Stepper Motor, Stepper Motor, Driver, Stepper Motor kit, DC Servo Motor, DC Servo Motor kit, Stepper Motor Power Supply, CNC Router, Spindle, and other Components. Automation Technology Inc

[adam_m]

I just bought a G540, motors and power supply from Keeling, package arrived in 3 days.

I purchased the cables from CNC Router parts, I also didn't want to fabricate cables... they arrived in 4-5 days.

Pricing was a little better from Keeling.. the motors are not the same so you can't compare them,

I would buy from either of them again without a doubt, no worries.

Adam,

[dinkyguitar]

Thanks adam_m,

The motors from Keling, did you have to wire the resistor and crimp the DB9 connectors?

dinkyguitar,

[adam_m]

I'm just getting ready to start my build so I haven't even un-boxed them yet... I did crack the lid to make sure it was there ;-)

My understanding is that the G540 resistors needed are built into the cables from CNC router Parts which is why I bought them from them (CNC Motor Cable | CNCRouterParts)

The motors themselves will need to have the connectors added, no big deal, in my opinion. However I wanted to buy a good quality communication cable which is what I think CNC Router Parts is selling, I've not been disappointed with anything from them yet. I think you will get the same response from those on the forum who has used them in the past, good quality products.

Can someone chime in who has purchased the same cables from CNC Router Parts to let me know if I am incorrect in my understanding of the built in resistor.

Adam,

[Lee DeRaud]

Can someone chime in who has purchased the same cables from CNC Router Parts to let me know if I am incorrect in my understanding of the built in resistor.

AFAIK, the resistors are in the DB9 connector on the motor pigtail, not the cables. Easiest way to tell is measure the resistance between pins 1 and 5 at either end of the cable.

That said, I had a problem with motor overheating on the Z-axis (the longest cable). Ahren of CNCRP said it was due to noise in the cable interfering with the G540's ability to read the resistor at the other end. He supplied a set of short stub cables to put at the G540 end that also had the resistors wired in. So it's possible they're implementing it differently in products shipped now.

[adam_m]

CNCRP has the following in the description:

"These cables also feature an overmolded 3.5 kOhm resistor between pins 1 and 5 on the drive (male) connector side, and a drain wire from the shielding to pin 2 of the cable. This sets the current on a G540 to 3.5A/phase to support our motors and popular motors from other vendors, and minimizes electrical noise both to the drive and other sensitive electronics."

A doubling the resistance wouldn't be good...

[Lee DeRaud]

CNCRP has the following in the description:



A doubling the resistance wouldn't be good...

It wouldn't double, even if you matched that cable with an old resistor-equipped motor: if the resistor is at the drive end of the cable, there's no need to connect the pin 1/5 wires to the other end, so a resistor at the motor end doesn't do anything.

This implementation only has one potential problem that I can see: the cables are now motor-current-specific. Not an issue if you're buying a kit, but something to keep in mind if you're doing a mix/match with multiple vendors.

[dinkyguitar]

Just an FYI, I was reading the G540 manual and it says that if your using 3.5a motors you don't need a resistor....

"If your motors are rated below 3.5A you must use a current set resistor across PIN 1 and PIN 5. The resistor is calculated by taking the current in amps and multiplying by 1000. If your motor is rated at 2.8A per phase you will have to use a 2.8K 5% 1/4W resistor. If your motor is rated at 3.5A or above you can safely not use a current set resistor; however, your G540 will not go into current standby mode which will result in increased motor heating."

But what does this mean? And what resistor would you use on a 3.5a motor??

"however, your G540 will not go into current standby mode which will result in increased motor heating."

dinky

[dinkyguitar]

So I emailed Keling questioning if their kit

CNC Stepper Motor Kit: , Stepper Motor, Servo Motor, Power Supply Automation Technology Inc

comes with a resistor for their motors and their response was, "you may need a resistor which you can get from Radioshack".

That was just 1 of my questions, and me being a newbie, the fact that they don't even know that question puzzles me. Very short answer to someone who is interested in purchasing their product....Doesn't give me a warm and fuzzy feeling purchasing from them since it leaves me with questionable after purchase support...

dinky,

[Drools]

Hi Dinky, in the case of the Keling kit above. They are selling you the steppers and driver not the wiring that goes between them. The resistor is part of that wiring, the G540 has very good wiring documentation. The size of the resistor used may vary depending on the steppers used and what current the user wants to run his/her steppers at. For instance some users may not want to run the steppers at their max current and but rather run them at 80% current, this would require a different resistor than the one used for max current.
Just a note if you do not run the steppers at max current you will not get their max torque but in some instances that is acceptable.

[dinkyguitar]

Thanks drools,

I'm glad someone could help me....So, in my case would it be better for me to run the motors without resistors? Those motors are 3.5a max., what would you suggest? Since my machine will be similar to yours....BTW how's your machine w/ 620oz-in motors and 3k resistors?

dinky,

[Drools]

Hi Dinky, my large machine works great thanks, very solid and the cuts are very clean.
My CNCRP 620oz motors are working quite well on the 3K resistor off the G540, of course I do not get the full 620oz from them but I have not had any issues.
Since my experience is limited to my own builds I cannot really comment on what would be best for you. However there seems to be quite a few good reviews on this combination from Keling and changing or adding a resistor is a minor operation.

[IBBruin]

For service AFTER the sale, CNCRP simply CAN NOT BE BEAT. Good luck getting ANY information from Keiling.

[LazerBee]

Perhaps it's just me and I don't want to sound mean but if you are balking at putting in a resistor you may want to go with a ready built system. Part of the enjoyment does come from the "figuring it out" but if you are going to put it together yourself it can become a lot more complicated. Have you been to candcnc's site. They have electronics all ready to go and it sounds like pretty much plug n play. The g540 comes with excellent documentation on resistor selection and if whoever you purchase from does not include them they are very inexpensive at RS. I bought my G540 from modelshopcnc on ebay and as I recall they sent the resistors as well and had a good price. Hope this helps.

[dinkyguitar]

Thanks LazerBee,

Your not being mean....I just didn't understand what the resistors were for, so I asked questions to someone who supposed to deal with them and they didn't answer me, as if they didn't know...Now granted they may be getting hundred's of emails, but I didn't feel confident in them.

Anyway, with the help of the members on this forum, I got my questions answered...



dinky,