Messages

111

General Mach Discussion / Re: Rigid Tapping

« on: March 06, 2010, 03:41:53 AM »

Dom

The problem with rigid tapping lies with slowing down to zero, reversing and coming back out maintaining position

This is doable with a servo motor but there is probably a reason Mach cant do the threading cycle

Phil

112

General Mach Discussion / Re: Trying to get the analog out to work on a c11g

« on: March 06, 2010, 03:25:36 AM »

Are you using a smooth stepper ?

Phil

113

General Mach Discussion / Re: Trying to get the analog out to work on a c11g

« on: March 05, 2010, 06:56:04 PM »

First thing you do is disconnect the 10v to the VFD

Set the trim pot to the centre position

Set up a pulley, now you are aiming to get 10v out when the VFD is at it's max speed but it must have a minimum speed.

The actual figures don't matter it could be 1000 max 200 min

I have a pic of 100 min 500 max you will never have a zero speed, so if we get 10v at 500 when the speed is set to 100 we should get 2v

You are after a ratio in this instance of 5, 2, 1.

My setup is metric so the figures may be out for you, but it is trial and error and nothing can be damaged

Setup CONFIG/PORTS N PINS/SPINDLE SETUP you need to tick the two boxes

Now go to CONFIG/MOTOR TUNING see my setup pic you can adjust all you want you cannot damage anything, but you are just making up the numbers to get 10v when you have 500 set and 2v when you change to 100 DON'T FORGET TO SAVE THE SETTINGS

When you get as close as you can to the ideal voltage you then use the trim pot to fine tune the voltage

When you get the correct voltage on the output then you can connect it to the VFD to test

Phill

114

General Mach Discussion / Re: Newbie Problems

« on: March 05, 2010, 06:19:10 PM »

No wonder you're so good at Mach.  Thanks for the help!! It's working good now. I was able to work through the issues and am now happily cutting away, making lots of dust. Thanks again.

RB

If you ask him nicely he will tell you how much power his lathe spindle has.

Phil

115

General Mach Discussion / Re: Trying to get the analog out to work on a c11g

« on: March 05, 2010, 12:33:16 PM »

I have searched the site to find a similar problem with all the posts concerning this, they are all incomplete, with no real answer..

I have followed the directions from the cnc4pc site. it is an old board but I bought new and just now getting to use it..


I can get the pin14 on the 5vdc side to work, but not the 0-10vdc?


Anybody got any ideas?

Having followed the instructions you have forgotten to add 12v this is needed to get out 10v

Phil

116

General Mach Discussion / Re: Tool offset problem

« on: March 05, 2010, 11:02:19 AM »

Christo you can do no better than learn gcode 

G40 cancels offset
G41 offsets to the left
G42 offsets to the right

You should start the offset at the beginning of your tool and cancel at the end of the tool

There is a button in Mach that gives most of the codes and an explanation

Phil

117

PoKeys / Re: Pokeys Disabled ?

« on: March 05, 2010, 08:09:20 AM »

Not sure who that is meant for, I am certainly not a gentleman and Phil is English so definitely not him

Hood

I'll ave you Butler.

Phil

118

General Mach Discussion / Re: Fixtures, Offsets, Origins & Suchlike

« on: March 04, 2010, 07:43:06 AM »

Dom you could do nothing better than spending time in your mates machine shop A LOT OF TIME

There are lots of ways to find the centre of a hole DTI, probe, pointer, to putting a taper point in the collet and bringing it down into the hole.

It all depends on the accuracy you require.

As for holding the wheel, if it was fairly strong you could hold it in a chuck clamped to the table.

MDF would not be the best material for making jigs/fixtures a better bet would be PVC plastic in sheet form this is available from RS components & is easy to machine and is waterproof unlike MDF 

Phil

119

General Mach Discussion / Re: Fixtures, Offsets, Origins & Suchlike

« on: March 03, 2010, 07:58:47 PM »

How does one go about machining a pre existing component rather than just a flat sheet of metal?

Just imagine you are working on a 2D plane

To give an example: - say I bought a cheap plastic injection moulded wheel from my local DIY store with a round hole in the centre with plenty of plastic around the edge of it. Now lets say I wanted to machine a hex into the centre so I could drive the wheel from a motor/gearbox with a corresponding shape on the output shaft. I've got the wheel and stuck it in the vice of my machine, and I've got gcode for the hex shape. Now how on earth do I tell mach 3 how to machine my hex in the right place so that the centre of the hex is in the centre of the wheel ?

Well if you put a plastic wheel in a vice you are gonna break it.

It's a lot easier with Cad/Cam, but expensive.

So i have a part with a hole in it that i want to turn into a hex shape.

I draw the hex in cad with the centre of the hex at X0 Y0

I fix the wheel so that i can machine the hex

I then find the centre of the wheel

I then set the machine to X0 Y0

Now the when i machine the hex it is in the centre of the wheel matching the cad drawing

As a second example, immagine i have a machined a simple shape from a thick piece of steel and I then want to drill holes through the piece at 90 degrees. So I remove the part and flip it round so what was the side is now on the top. I've loaded up my new gcode program but again, how do I ensure it starts cutting the holes in the right place ?

This is something I really need to understand as much of the work I want to do will involve machining things on multiple sides and/or machining onto pre made parts.

Well to make things simple you have a square with a hole in the centre it is 150mm square x 25mm thick

See above procedure to make the square

Then on the side the same principle applies you will make another cad file to match what you want to do

You just set the machine DRO's to match the cad drawing positioning

Now there are wizards for making  Gcode in Mach but it is gonna be much harder to make complicated stuff that way but cheap.

With the expense of Cad/Cam comes built in simulation this allows you to fine tune your machining with minimal breakages.

If you had a collision with a stepper based system it is more forgiving so not too much damage, but not the case with a more powerful servo system

Phil

120

PoKeys / Re: Pokeys Disabled ?

« on: March 03, 2010, 06:34:28 PM »

Thanks to Scott as well, keep your head down mate.

Phil