Messages

961

General Mach Discussion / Help with Threading Wizard

« on: February 04, 2010, 04:55:46 AM »

Hi,

I need to cut short threads on 20mm rings. The thread is 0.75mm pitch, 2.5mm long. It needs to stop exactly after 2.5mm and the tool pull out. In the threading wizard I used a pull out angle of 90 degrees, but the tool still doesn't pull at 90 degrees. There is still some angle, so that the last 1.5 taps are not cut to full depth and the nut that has to be threaded on it doesn't go all the way down the thread.

Is there any way to tell the wizard to cut the thread to full depth along the full length defined and only then pull out perpendicular? The wizard is a very convenient way to output the Gcode for cutting threads and it takes the angled in-feed in account, so I don't want to use the G32.

Thanks,
Daniel

962

Tangent Corner / Re: First time making shims-Advice please

« on: February 03, 2010, 03:09:48 PM »

HI John,

I am guessing you intend to cut the shim rings from a sheet metal. I would assume the diameters don't have to be accurate. There are many ways to do this, and I think you should go with the one you can handle best using your tooling and equipment.

The way you're suggesting is very good if you can adjust the fly cutter for the required diameters. On a CNC mill it would be much easier - just using an end mill to orbit the circles.

If you don't have a CNC mill, I'd prefer making it on a manual lathe. The way I did it was to attach the material to the lathe face plate using double sided type and cut the circles using specially ground tool, but with 0.2mm I think you can use almost any sharp tipped tool. You could mount a piece of sacrificial plate on the face plate, even MDF would be good for this. Worked well for me in cutting 150mm diameter circle from 10mm thick stock.

Hope it helps.

Daniel

963

Show"N"Tell ( Your Machines) / Re: 5 axis Spinning Lathe: machine and control panel in progress

« on: February 03, 2010, 02:51:44 PM »

Yes, also figured that spring loading the tool could help...

Daniel

964

Show"N"Tell ( Your Machines) / Re: 5 axis Spinning Lathe: machine and control panel in progress

« on: February 03, 2010, 02:36:49 PM »

Still don't understand it...  When spinning manually you feel the material and you know when it's already touching the form tool, but when jogging a CNC you don't have any feedback whether you reached the form tool. As I see it, you can easily stall the axis by pushing the tool too hard against the form.

The measuring technology is interesting. Thanks for the info.

0.6mm over 3 metre - WOW! Very impressive.

Daniel

965

Show"N"Tell ( Your Machines) / Re: 5 axis Spinning Lathe: machine and control panel in progress

« on: February 03, 2010, 10:25:14 AM »

Hi Scott,

Yes, I figured that was what he was doing, and that was why I was amazed by his ability to jog the machine such as to reproduce the form tool shape. The shape is not trivial at all... the curvature is parabolic or circular or something...

As to the accuracy he claims to achieve, I don't know how one can measure to such accuracy on a curved surface. May be he uses a kind of light reflecting measuring system to measure the part (since they reflect light very well), but I wouldn't think so... Also in 10 degrees difference there would be about 4 times more thermal expansion than the claimed accuracy.

Daniel

966

Show"N"Tell ( Your Machines) / Re: 5 axis Spinning Lathe: machine and control panel in progress

« on: February 03, 2010, 01:52:07 AM »

Amazing! How can one jog that accurate on a CNC machine...? More so when you don't feel the reaction forces (or does this system have servos on the MPGs to simulate the load?)

Daniel

967

Show"N"Tell ( Your Machines) / Re: My new project

« on: January 29, 2010, 01:46:07 AM »

You may have already tried it Monty, but since you didn't mention it - did you try setting a bigger debounce in Mach?

Daniel

968

Show"N"Tell ( What you have made with your CNC machine.) / Re: That is no moon.

« on: January 28, 2010, 10:14:10 AM »

I wish I never asked

Daniel

969

Show"N"Tell ( What you have made with your CNC machine.) / Re: That is no moon.

« on: January 28, 2010, 09:36:43 AM »

Looks impressive, Barry. If only we knew what it was supposed to be... Looks to me like a mock-up of some kind of a space shuttle launching system...

It's not an easy one for the first part I'd say, and it came out very well.

Daniel

970

Show"N"Tell ( Your Machines) / Re: My Balding Beaver

« on: January 27, 2010, 05:50:35 AM »

Hood,

Curious if you had already have the time to mount and test the new ball screws? Are they really what they claim them to be?

Thanks,
Daniel