Messages

31

Show"N"Tell ( Your Machines) / Re: New Build 6 axis CNC first timer

« on: May 11, 2009, 07:33:23 AM »

If the Gecko's are just sitting on the metal cabinet sheet metal, then you will need a heat sink on the back. They do become warm and hot is a bad thing.
With gecko's I do not use a Breakout Board as the Gecko's are already opto insulated. What Software are you planing to use to generate the 5 axis toolpath?
Are you planing to 5 axis index machine or 5 axis continuous machine?
Rainer

32

Feature Requests / Re: Support for Mesa 5i20/7133Cards

« on: May 02, 2009, 12:13:59 PM »

Would not work. All you get out of Mach3 is step and direction signals. No direct servo control. The only device right now is the smooth stepper from warp9 which is comparable. It's a proprietary solution and still in beta.  Works well however and I could not use my large machine without it as Mach3, depending on MS windows, is struggling to create something resembling a smooth pulse sequence.
Cheers
Rainer

33

Show"N"Tell ( Your Machines) / Re: New Build 6 axis CNC first timer

« on: April 19, 2009, 04:53:34 PM »

I buy my power supply here:
http://www.antekinc.com/PS-10N63R.pdf

Take a close look at the 5V power supply section. if it's only regulated with a 7805 or similar chip then it's garbage.
Go get a couple of those: http://tinyurl.com/d7c7k2
They are switching power supplies with superior noise levels compared to the cheaply regulated ones.
If you would connect an oscilloscope to the simply regulated power supplies then you will see noise which can lead to steps or direction switches which will be all but impossible to debug later. The switching power supplies linearity is dead flat. That's where the switching power supplies lead. And for a BB you do not need power. A single amp usually is enough. aving 12 V as well is nice as some breakout boards also allow you to controll the spindle speed and for that you need the 12V to drive the VFD of the spindle from 4 to 10 Volts. aprox 7-18000RPM....

PS:I am not sure... but this might be Kelling's source ))

Lemo


PPS: Spindle VFD's with great service http://www.dealerselectric.com/


And yes, i bought those power supplies from China. Two weeks later a fun little box arrives with all sorts of cool stamps on it. No sweat and for $3.... I don;t even get the shrink tubing from the local electronics store for that amount...

34

Show"N"Tell ( Your Machines) / Re: New Build 6 axis CNC first timer

« on: April 19, 2009, 04:21:09 PM »

Don't worry. The watt's are fine once you are above or at the demand of the motors. Anything more will cost you copper, money, and weight but that's it.
I use a 900Watt power supply for 4 1KW servo's. I limited the current in the drives so I won't kill the power supply. With the pulsed characteristics of the drives I never exceeded 800 Watts.
Don't worry, you'll be fine. And yes, Bipolar Parallel has the best torque for your application.
It's all good.
Lemo

35

Show"N"Tell ( Your Machines) / Re: New Build 6 axis CNC first timer

« on: April 19, 2009, 03:44:06 PM »

1300 Watt, wow!
I didn't see you mentioning welding  ...
Make sure that this power supply will be on it's own breaker. It will pull a LOT when being switched on and a transformer based power supply.
20Amps slow on 120V would do...
No need to cool it as the motors will not use more than 4-500 of them 1300 Watt's.
But in case of failure you have reserves to run the tool through the floor 
Keep us posted.
Lemo

36

Show"N"Tell ( Your Machines) / Re: New Build 6 axis CNC first timer

« on: April 18, 2009, 09:09:30 PM »

You're off your rocker

Take a close look at how the cabling should look like according to the manual....

I have a bad cold, so I will not dare to give you a cookbook here with my stuffed head and smoke coming out of my ears... But here is a list of things you have to check and set accordingly and you are on your way!

1. Check the winding of your stepper. Parallel Bipolar gives the best oompffff and look up that voltage for that type of wiring for both motors. There are two other ways to connect the winindgs and they are not as powerful. Check that!

2. Take the lowest Voltage of the motor e.g. 3.5Volt and multiply that by something between 15 and 20. Till you get a result you can actually buy.... Like 40-50 Volts.
Consider that higher Volts are fine but it also becomes much much unsafer to operate.... DC is worse then AC to touch and be really really careful with anything above 5-15Volts...
Really!

3. Take the highest AMPS like 4amps and multiply with the volts you need. e.g. 70Volts times 4amps is 280 watts. Thats what one motor can pull. I know... that is not correct as it is less because the gecko drive is pulling with 20KHz and bla bla bla but I don;t want to scare the good man.... Soooooooo something like 5-600 watts will heat that flock of motors well.
Considering not all axis are moving at the same time.

4. Switching power supplies are not good. Use a Toroid transformer. Antec.... New Jersey... My Chinese Neighbor... Good Stuff and very affordable. People will try to get into an argument about toroid's and switching power supplies. Tell them I'll meet them behind the gym and show them their split diode!
5. The Gecko's resister does limit the ampere NOT the voltage. You are a tad lost there.... aehhh of the rocker .
6. The Spindle will use a VFD Device which will supply the 300 to 400 Hz to drive the RPM high. Do not let the Manufacturer talk you into some horrendous sum. Your size should not cost more than a couple hundred dollars. Check Dealers Electronic with their fabulous VFD's and great service. I have 4 from them, all quality manufacturers like Westinghouse and one fried after a year and a half and I got it exchanged for free and upgraded to the latest model...

So.... check your setup again and the best of luck. And for all.... keep it safe. This is not harmless stuff....
Just in case, give your wife my email address.... I can use that 5th axis head 
Again.... best of luck and the best wishes for a un-toasted experience
Lemo

37

General Mach Discussion / Re: z axis problems

« on: April 14, 2009, 08:05:34 AM »

Include the description of noise and all sorts of observations. The matter is complex enough that a behavior meaningless to you might be the key to the root of the problem for someone else. Also go to the geck drive website and read the essay about steppers. There are a few critical issues with stepper motors like mid band resonance and things alike which at first sound esoteric but then once manifested and observed in your own machine become a very real and understandable. The size of the machine does not really mater, all the principles are alive and kicking in a gantry crane to lift containers or your small router. So go, try to adjust and then let us know how things go.

Another hint.... if you calibrate your machine, then do not calibrate the amount of steps with a caliper for starters. Calibrate the amount of steps with the maximum distance you can move. If you calibrate that within an inch only or a couple, then the slight error you will have multiply along the larger distance. If you calibrate over a few feet and you are off maybe 5/1000th then you will have a fraction of that error within smaller distances. However, checking for accuracy with a caliper or dial is useful, just not really for the initial calibration.

Good luck
Rainer

38

General Mach Discussion / Re: z axis problems

« on: April 13, 2009, 10:59:57 PM »

Check the motor tuning section and do not forget to select the axis before adjusting parameters as one can easily mess up the x axis as it is the default... Mach3 is currently not the most intuitive piece of software.

Run the z axis manual with the highest jog speed and make sure that it does not stall. When it stops and rattles and hums then the motor tuning parameters are set incorrectly. Every machine is different so there are no settings I could give you.

Don;t be afraid to set the acceleration to high. The steppers will stop moving while cursing you out with the sound of a hornets nest if settings are to high. For short test you cannot ruin anything. Just don;t let them sit and scream while you go and have a beer.

So... try to tune the motors. Looks like you have a clean little machine. All should work well.

Lemo

39

Show"N"Tell ( Your Machines) / Re: Finished my 4th axis

« on: April 11, 2009, 10:26:53 AM »

It's a start! I'm a big step forward to my 5th axis and that will do it. Next week the software will be finished to generate the tool path.
It's a scary part
Rainer

40

Show"N"Tell ( Your Machines) / Re: New Build 6 axis CNC first timer

« on: April 09, 2009, 05:13:47 PM »

Be careful with the cut's. Anything above 1Hp will bend that setup. And 1HP is already beefy.
Rainer