[Crevice Reamer]

Is there a formula to determine what size resistors i will require on the G540 as per the drawing in the case that i use different motors ?

Formula is one K of resistance per motor Amp. 2.8A motor = 2.8K resistor.

Formula for most efficient PSU Voltage for motor is 32 times the square root of incuctance in mH.

G540 can only accept <= 50V and 3.5A. Motor Voltage much over 50V results in less available torque at speed.

Any motor Amps over 3.5 will result in reduced available torque. EG, 282 oz 4.2A motor becomes a 235 oz motor.

There are as yet no perfectly matched motors for G540. The motors that I recommended for you are the best available that I have found.

CR.

[TheoOZ]

Thanks for the info

[roger g]

I only have used Hobbycnc's 3 axis controller, but I will look up other one probotix.

[thkoutsidthebox]

I selected HobbyCNC, but the Gecko was not an option on the list. I'd go with Gecko.

[dan dimock]

I did not have the money for gecko and was fed up with Hobby CNC, so I went with Probotix and I have been very happy. You can call if you have a problem and they will do all they can to help.They told me that I would get better service and power from my motors to run them with the four wire set up that you cannot do with hobby cnc.
I would look into it before i got any other.
Dan

[roger g]

Here is what I did and why.
I when with Hobby cnc because of the driver chip and the PWM, no load resistor needed. I took this one over the Xylotex.
the ad on the Probotx of there power supply being 4.x amps confused me.
each of my motors can draw up to 3 amp. 3 amp time 3 motors = 9 amps if all three motors where at full on.
the switcher is a regulated power supply. when exceeding it's rated power it could shut down.
my brute force un regulated supply will grown the voltage will drop, but current will still flow.
Look up PWM it explains how the current is on the motor and not accross a droping resistor.

[dan dimock]

The Probotix driver let me use my motors in the in parallel bipolar mode. From what I read that is the best way to get the most out of my motors.
My power supply is a 28 volt dc and 12 amps output.
I set each of my boards at 3.95 volts and that gives me a 2.5 amps and I am using the same motors I had on my HobbyCNC that was a 300 but now they run at a 425.
I am move than pleased with what I have now.
Dan

[roger g]

Dan:
There are more motor controller out there, they work differently
parallel the winding on the motor allows a lower voltage and higher current.
the bottom line is are you happy
Roger

[dan dimock]

George G

I am very happy with the set up that I have now.
For me, it works a lot better then it did when I was using the Hobby CNC drivers.

If I had the money I would have got the Gecko, but I am disable and on a very low set income. What I was trying to say is I would go with Probotix over HobbyCNC.

Dan

[D.L]

Man, everyone bags hell out of poor old Xylotex.
In a way, they are right.

Pro: They offer a complete set of motors, board, powersupply for the price of most others boards only. In Australia you cant find steppers anywhere, shipping it all in one go was desirable.

Con: They are attracting beginners and yet they give an awful set of instructions and web site information.
Hence, all these beginners are miss wiring there drives and presto, SMOKE and the bad rep from a stung customer.

Pick up your game guys, good product, crap sales/support/marketing.
I am happy with mine, does not miss a step when tuned proper like any other.

Gecko's got it sussed. Good product, sales, support. He deserves success.

[vlmarshall]

They offer a complete set of motors, board, powersupply for the price of most others boards only.

When I bought mine from them, they offered a relay board as well, which has been quite useful.

[dixter20]

I've developed an educational "video game" on CNC basics. It presents the user with an interactive 3D interface for exploring content on CNC and Tooling. The content is supported with graphics, pics, movies, 2D animations, and 3D animations.

The module would be of most use to those just beginning to explore CNC.

It's available for free download at: http://learncnc.org/

[wthierry]

I blew up 5 Hobbycnc kits and never got one to work.
The people at Probotix was supper nice, I got my motors and power supply from someone else and they even offered to wire it all up for me if I would send them the power supply and motors.
Each time I had a problem, they would go into details with pictures.
You may have had a bad deal, but for me I rate them a 10.
dan

I ordered one, it came within a week, havent put it together yet, but so far their customer service has been great

[grumpygeek]

I'll chime in as well, I added a Probotix SideStep to my xylotex 3 axis board to let me run dual screws on one axis. When I was wiring it together, I had some questions followed by some issues getting to work, so I sent a quick email to Probotix support on a Sunday mid-day expecting to get a reply sometime Monday. I had a reply within 30 minutes, and exchanged 2 rounds of email before figuring out what I had done wrong, they also offered to call and walk me thru the wiring, but I had figured it out by then. So in my opinion Probotix support rocks (this was all about 6 months ago).

I bought the Xylotex 3 Axis board off of ebay with motors from someone who have never got around to making their cnc machine. After reading the manual and researching how to connect the particular motors, I had no issues with the board. I contacted them to see if they still had any single axis boards to sell so I could drive the 4th motor, they responded within a day and said 'no' but that I should be able to find a single axis board based on the same chip for sale elsewhere, which lead me to Probotix. This is the level of support I expect from most companies on the internet, it is adequate and works for most people.... though it would have been nice if they had mentioned Probotix, but I guess it is a competitor.

I have been tempted by some of the really cheap driver boards on ebay, and as long as you can find a source of support on the internet (usually thru boards like this) you should be fine, but I wouldn't do it on your first build.

I guess I have been lucky, just about every person and company I have bought parts from has been great, but this may be because I always research the heck out of most things before I buy. If I could afford just to buy the good stuff I would, but usually I am looking for the cheapest stuff I can get without hosing myself

As in all things, buyer beware I guess.

[wthierry]

im looking for a cheap way to learn the ins and outs. still havent begun assembly, but will next week. anyway I bought the prebuilt motor control unit, hoping to hook that up and test it this weekend.

wes

[kolias]

I will also vote for Probotix, best service you can find out there

Nicolas

[cncnoel]

I am on my second CNC machine now, both home built. I went for HobbyCNC in the first instance based on price & "completeness" of the kit. With HobbyCNC you DO have to assemble it all yourself, but it was easy, in my opinion, and it just "worked". I am using 305 oz-in steppers, and have a 2kg (4pound-ish?) router to lift on the Z axis. I for one am happy with HobbyCNC boards. The Gecko oned do look nice, and are pre-built, so if electronic assembly is not your thing, go for them. However if you're handy with a soldering iron & want to save some dolleiros - go for the HobbyCNC.

[Woodenspoke]

Here is my two cents for what its worth. My Sieg X2 conversion using the Xylotex complete system and the CNC fusion kit.

It worked for 3 plus years until I blew up the Xylotex board just a month ago. Then I found out the hard way I was stuck with a dead board and no way to get it fixed. The 90 day warranty should have been a clue as to after sale support they provide. The motors were OK and enough to do what I needed at the time. The inside of the the box was a mess as everything was glued down to the plastic. I had to drill holes in the box to remove the PS board cover just to check the fuse.

The Xylotex board is really way too expensive these days (at the time there was not much to choose from) as there are so many other choices these days.

I wound up going with a Gecko Board and complete Gecko Drive G540 system from Cantronics.com and Dan Mauch. I cheaped out on the plastic box and now regret it as it has no relays (flood coolant and spindle control) and is too Small to add any to the box. Plus a set of 385oz steppers. The G540 is great except for the connectors, wish it was a screw on and I didn't have to splice on 3 feet to get the DB9 out side of my flood coolant box (the reason I toasted the Xylotex).


First the difference in the performance compared to the Xylotex board and Z steppers was off the charts. Like a new machine and I was moving at almost twice the speed I was before without feeling I was pushing the machine too far past its limits. That is from 12ipm to 24ipm. A similar Z axis access acceleration. I was under the impression my X2 moor was the limiting factor, it was the driver board.

The bottom line for what you get with the G540, A warranty, Board repair (after the fact possibly), Blowup protection on the board for people like me and an isolated breakout board. It is really cheap. Plus 10 steps per rotation and you are putting out 48V to the motors and not 24V. Probably the biggest performance improvement. Again you can directly control a sieg X2 motor speed and a flood coolant with this board (which I have not done yet)

If I looked at the two complete systems I bought Xylotex Vs Cantronics it was only $100 more for the G540 system but you get so much more.

[Crevice Reamer]

Thanks for the well-spoken report Woodenspoke. Glad it all worked out for you.

I now recommend the Keling KL23H2100-35-4B381 motors as the current best match for G540 on all axes:

http://kelinginc.net/NEMA23Motor.html


For very large routers and heavy heads like X3 or G0704, I recommend the KL34H295-43-8B Keling N34 906s with G540:

http://kelinginc.net/NEMA34Motor.html

CR.

[embguru]

Probotix offers $200 for 3 axis kit. Best price out there. Just need to assemble it. Got it working with a Sherline 5000 bought on ebay. Excellent Customer service as well.