Messages

111

Tangent Corner / Re: Denford Orac Auto Chuck

« on: February 10, 2008, 09:59:28 AM »

Hi Graham, Ok Thanks for your advice.



Cheers
John

112

Tangent Corner / Re: Denford Orac Auto Chuck

« on: February 09, 2008, 04:56:31 PM »

Thanks for your quick reply Graham, I was more concerned about the extra weight of the chuck compared to the 4" 3 jaw chuck the Orac has. Also the extra length of the collet chuck will be 1.5" more once I fit a backplate than the Orac chuck and I was concerned if there would be any extra load on the spindle bearings or would that not make much of a difference to worry about.


Cheers
John

113

Tangent Corner / Denford Orac Auto Chuck

« on: February 09, 2008, 03:38:19 PM »

Hi, I have been using my Orac for some time now and would really like to have an auto chuck for bar feeding. I recently aquired a Burnerd collet chuck which takes the EC collet range. These are usually fitted to Colchester lathes and the outer diameter is about 5 inches and the length about 4", Fitting it to the Orac is not an issue but will I encounter other problems like the motor not capable of driving it or the force of closing the collet lever putting strain on the headstock/lathebed mountings or other issues.


Your advice greatly appreciated.




Cheers

John

114

General Mach Discussion / Re: Servo system

« on: February 08, 2008, 12:52:57 PM »

I'm building a servo system and using Gecko G320's. They are said to be the best as long as your power supply is below 80 volts (70 is best). Use these with 500 line encoders, most people say they have had good results.

If you can wait a bit Gecko are bringing out a new drive called the G380. They say it has overvoltage protection and motor short circuit protection and also raised the 128 count fault limit to something over 1000.

There's lots of other things different, I cant remember. Have a look on CNCZone in the Gecko forum for G380.

Cant wait to get mine going, still working on the mechanics though. I need 2 other drives so I'm in the queue for the new G380's.


Hope this helps

115

General Mach Discussion / Re: Can VB Buttom Code make calls to subroutines in other files ?

« on: February 07, 2008, 05:37:12 PM »

Hi, I havn't tried this but it's an idea, If you put in each button ( Code "M111") and check the execute G-code, each button should run a macro called M111 (you can give the macro any number of your choice this is just an example) place the Macro in the Mach3 Macro folder and write your VB code in the macro.

Hope this works for you, let us know how you get on.

116

General Mach Discussion / Re: Fast Jog but it skips on G-Code

« on: February 06, 2008, 03:30:41 PM »

Hi Clint, I seem to have more questions than answers, let me get this straight. Your rapid speed is now set to 45 with accel set to 5, so your ramp-up time is 0.15 secs. At this setting you have run it without skipping.

Does it skip when on feed or rapids?

If the answer is at the very beginning of rapid moves during the ramp up period then you'll have to reduce the acceleration number. This is ok it'll just take a bit longer to get up to speed.

If it skips during the middle of a rapid move then basically the stepper cannot go that fast, you'll have to reduce the velocity.

A stepper motor on an axis can be made to go faster by,

Raising the drives voltage (make sure your drive can handle the voltage increase)
More powerful stepper motor. (If your existing motor is struggling to provide enough torque to overcome mechanical friction)
If your drive is uni-polar then changing to a bi-polar drive will increase the existing motors torque and speed.

If it skips during feeds then the problem could be,

Your computer is too slow (Computer's resources are at a minimum and has to do other tasks) I recommend no slower than 1200Mhz
Electrical noise (All your step and direction cables should be sheilded with only one end of the sheild connected to 0v)
A problem I havn't thought of. (Others chip in please to help this guy out)


Hope this helps.

117

General Mach Discussion / Re: Fast Jog but it skips on G-Code

« on: February 05, 2008, 05:24:24 PM »

Hi, i'm not familiar with your setup but the voltage should be ok, try an accel value of 3, see what happens and if you get a good result increase in small increments.

118

General Mach Discussion / Re: Fast Jog but it skips on G-Code

« on: February 05, 2008, 01:26:50 PM »

Hi, Try increasing the drives acceleration time. The same thing happened when I set my machine up and this cured it.

If it doesn't, Try posting info on your power supply voltage and mechanical setup to help diagnose your problem.

Hope this helps.

119

General Mach Discussion / Re: setting up a reflective object sensor for dummy's

« on: February 03, 2008, 03:15:29 PM »

Hi, I just did a quick look on Ebay and there is a large difference in price but all you'll need is a simple one so try bidding for this one Ebay item no 130193806388. If not, be patient and a cheap one will come along eventually.

120

General Mach Discussion / Re: setting up a reflective object sensor for dummy's

« on: February 03, 2008, 01:50:58 PM »

Yep, Chris is nearly there, The capacitor I was referring to is a non polarity type (eg can be connected any way round). As to shortening the leads maybe I wasn't clear enough. It isn't necessary to do that, only to make the connection near the sensor/switch end of the cable and not near the end of the cable that connects to the breakout board.


Hope this helps.


PS: I've just read through this thread and I just wondered if you had use of an oscilloscope you could have tracked the problem down in 5 minutes.
I have one and found it invaluable just for problems like this. I looked on US Ebay and one could be had for less than $20 and learning the basics of how to use them is not that hard, it's just like using a multimeter.

Just a thought!