Messages

251

General Mach Discussion / Re: Newbie In Need Of Help On Where To Start

« on: April 30, 2018, 02:46:55 PM »

DaveK,

We are still looking into plasma sources, hypertherm caught our eye the most so we are likely to go with them.
What type of spare consumables would for the torch would be recommended to stock up on in the beginning?
You seem like you have a good grasp on these things, is there any tutorials or places online that have helped you when you were in the process of learning your table?

Thanks for the information!

Hi

I would certainly go with Hypertherm if at all possible, I have the PM45 unit.

You would do well to have a good supply of electrode/Nozzle kits, a spare shield plus a spare swirl ring, all common parts but specific to each torch so make sure to get right parts. I would get a couple of kits plus a shield and ring, that should cover most things until you get going.

It will seem like you are eating nozzles at first, don't panic - it gets better But they are very easy to blow - that is why i  stress pierce height being bang on as that is a prime offender of blown nozzles.

Without going into detail now, many will quote "book specs" for cut height,pierce heght etc, as you read up, you will see that term over and over. Forget it The books are only correct in the lab, in the real world things are not so black and white. What you CAN take from the book are pierce height, cut height and pierce dwell - the missing data is cut speed and this is really best found by doing what are called straight-cut-tests on your material and machine.

It is a steep curve but once you see how it works it gets easier.

I got a lot of help from here and also here- http://www.plasmaspider.com/index.php?sid=6e4f2e280e6e93d9d1a5ba9fb4582aa2

252

General Mach Discussion / Re: wait action in macros

« on: April 29, 2018, 03:02:31 AM »

I have boiled my macro waits down to these two options...

IF the macro causes a physical axes move then I use

While IsMoving()
Sleep(10)
Wend

If I am updating a DRO then I use

Sleep(100)

Thats it, and it makes a big difference.

"Sleep" is very similar to "DoEvents" in visual basic, it yields program operation to the processor in order that it can catch up with other things that may or may not be important, without it, the program takes 100% of the CPU and the rest can go to hell

Sleep only needs short delays 10-100ms as all it does is yield more often which is good as it gives the macro the impression that it is still fast acting but also allows CPU time for other stuff. It just means "go check for other tasks every 10ms then come back" In CPU time 10ms is a long time.

I would never use sleep(1000) as it will make the macro very lumpy and slow.

253

General Mach Discussion / Re: Bridgeport Knee Mill Conversion?

« on: April 28, 2018, 11:24:32 AM »

The tool path display - is there a reason the path is so small compared to my display???



The material is only 5mm beyond the path shown.

254

General Mach Discussion / Re: REF All home

« on: April 27, 2018, 05:02:01 AM »

On a plasma the Z is rarely referenced at all, usually they have floating heads and will detect the top-of-material every pierce or two, thats all that matters to a Z on plasma.

255

General Mach Discussion / Re: Problem to setup a belt driven 4th axis

« on: April 26, 2018, 02:09:07 AM »

Simple - use pulleys with that ratio of teeth?

20 on one, 80 on the other etc

256

General Mach Discussion / Re: Newbie In Need Of Help On Where To Start

« on: April 25, 2018, 07:50:35 AM »

What is the plasma source - I use Hypertherm which is widely regarded as one of the best plasma generators out there.

I also use SheetCam for my CAM and various apps for the design, anything which can output a DXF file is good - InkScape, Illustrator, most CAD packages, and plenty of others.

You will need spare consumables for the torch - you WILL need these as they can be damaged by something as simple as a low pierce, pierce height - the point at which the torch sits the moment before starting a cut IS VITAL, get that right and repeatable before even plugging in the plasma source and it will save you $$$$$$

You WILL need a lot of scrap or other steel to practice on - don't go too thin, if you intend cutting say 3mm then practice on 3mm from the off - different thicknesses and types of steel WILL affect all of your settings.

There are a million and one other things to learn - it's taken me about 4 years and i'm still learning but can now churn out saleable parts in no time

Have you got a water table or downdraught table - different ways of dealing with terrible and dangerous fumes plasma tables can make, stainlesss steel in particular is bad, also aluminium, steel will just give you a sore throat and coat the workshop in black grime in no time at all

257

General Mach Discussion / Re: Bridgeport Knee Mill Conversion?

« on: April 24, 2018, 03:19:08 PM »

All back together, runs smoother now and a bit quieter without the back-gear belt.

258

General Mach Discussion / Re: Bridgeport Knee Mill Conversion?

« on: April 23, 2018, 02:45:15 PM »

Total bend was 1.2mm so pretty bad.

Using my press and some patience, I now have it down to 0.04mm which i think is far enough.

Going to remove the back-gear as well as it gets hot at full speed and makes a racket too, not been used since going CNC anyway.

259

General Mach Discussion / Re: Bridgeport Knee Mill Conversion?

« on: April 21, 2018, 12:28:29 PM »

Need to find an approved method first, I don't have much in the way of surface plates etc, do have a 20T press though.

Certainly a PITA though.

QC30 spindles are very rare and it cost a lot too.

260

General Mach Discussion / Re: Bridgeport Knee Mill Conversion?

« on: April 21, 2018, 09:13:45 AM »

Ok so the project is still going on

I now have a custom screenset, probe, probing macro's etc all working well.

Today I was bothered by some odd vibration I had since fitting the BT30 spindle, here's a short video of the top...

https://youtu.be/MJAr941aL-U

So I blamed the DIY drawbar, made another one, just as bad?

Tipped the head over and had a look and the splined portion of the spindle is clearly bent

https://youtu.be/jEhYINbUgzI

The tool section runs very true so not sure how you bugger a spindle like this??

It was like it when i got as i have had no crashes.

Now, not sure what to do really, it took ages to find that spindle, they are not that common. I have sold all my R8 tooling and only have BT30 now.

Can they be straightened?

I could push it out in the garden and torch it - it seems every time i get ahead she kicks me in the 'nads

Any ideas?