Messages

1

General Mach Discussion / Re: Speeds and Feeds with Micro end mills

« on: February 29, 2012, 06:14:22 PM »

Thanks Rich

Some useful info there.

Like you say at $20 to $30 per end mill i can't afford to make too many mistakes...

I checked for backlash and runout and am confident my machine is set up well enough for this operation.

The length of cut on the endmill is 1.2mm (0.05") So i'll probably only take it to 0.035" (0.9mm) depth

Your depth per pass suggestions sounds like a good starting point.

I know the feedrate needs to be slow but how slow...?

By the way which has more strength carbide or HSS...?

Thanks again.

2

General Mach Discussion / Speeds and Feeds with Micro end mills

« on: February 29, 2012, 03:24:32 PM »

Hi

I'm looking for some advice on typical spindle speed and XY feed rates when using micro end mills.

I know each manufacturer has slightly different specs so just ball park figures at this stage is fine.

I am cutting a 1 mm deep profile cut into hardwood using a 0.2mm square end mill.

What are typical feedrates for this type of cut....? Plunge rate....? and what depth for each pass...?

The end mills are too expensive to take the trial and error approach so any help is appreciated.

Thanks

Jason

3

General Mach Discussion / Re: Flat spot on circles

« on: February 12, 2012, 05:36:58 PM »

Thanks for the reply Hal.

I'll check for backlash and see if that cures it.

Jason

4

General Mach Discussion / Flat spot on circles

« on: February 12, 2012, 06:24:25 AM »

I have a problem when cutting circles about 25mm in diameter.

The problem is the circle has a small flat spot on one side.

I have tried slightly different size circles 20mm & 30mm and it appears on all of them.

I am using VCarvePro to generate my G Code to a Proxxon MF70 CNC controlled by Mach3.

Not sure whats causing it so any help is appreciated.

Thanks

Jason

5

General Mach Discussion / Y axis moving in the wrong direction

« on: February 05, 2012, 11:12:14 AM »

Sorry if my question is a stupid one, but i am new to CNC and hope someone can help.

I have a 3 axis Proxxon MF70 CNC, my Y axis runs in the opposite direction when G code program is run.

I have set up home switches with the following results.

Homing X - The table moves to the far right. (steps count negative)
Homing Y - The table moves away from you to the far back (steps count positive)
Homing Z - The Z drives up (steps count negative)

If i set the "reversed" to a cross on the homing / limits screen for Y axis. My G code runs OK.

But when i come to home the axes again it homes initially, but on the next command drives the wrong
way against the home switch.

I'm not sure if my Mach set up is wrong or i'm missing something in my G code.

Any help would be appreciated.

Thanks

Jason

Xml attached and the first few lines of the G code:

N100G00G21G17G90G40G49G80
N110G71G91.1
N120T0M06
N130 (End Mill {1 mm})
N140G00G43Z20.000H0
N150S14000M03
N160(Toolpath:- Profile 1)
N170()
N180G94
N190X0.000Y0.000F200.0
N200G00X11.000Y10.500Z6.000
N210G1X11.000Y10.500Z-1.000F200.0
N220G1X11.000Y26.500Z-1.000
N230G1X27.000Y26.500Z-1.000
N240G1X27.000Y10.500Z-1.000


[
 

6

General Mach Discussion / Re: New people welcome !! Come in here and introduce your self!

« on: February 02, 2012, 01:09:41 AM »

Hi, I'm Jason from Manchester in the UK.

I work as an electro-mechanical engineer in a semi-conductor plant making micro-chips.

I am new to CNC and like many on here will be scratching my head with more questions than answers.

I have a Proxxon MF70 CNC micro mill which i will be using to help make and engrave jewellry.

Most of my work will be miniature carvings and engravings using 0.3mm endmills and the like.

I must say from what i have read the site appears to be a great place for help and advice and its a credit to all those involved in setting this up.