Author Topic: Titivating A CNC Plasma Table  (Read 11653 times)

Offline Spurry

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Re: Titivating A CNC Plasma Table
« Reply #125 on: January 16, 2017, 07:29:17 AM »
Luvverly job Andrew.  :thumbup: So, just the hole in the wall to do. Are you going to get the boys who did the Hatton Garden job along to assist?  :bugeye:
Pete

Offline awemawson

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Re: Titivating A CNC Plasma Table
« Reply #126 on: January 16, 2017, 07:47:25 AM »
It's only single skin 100 mm concrete blocks so I reckon they'd be over kill  :lol:

Current idea is to chain drill with my 50 mm diamond core drill, hopefully from both sides to avoid breakout. I do have 110 mm and 125 mm diamond tipped core drills, but the smaller diameter hopefully gets me nearer the circle that I want.
Andrew Mawson
East Sussex

Offline awemawson

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Re: Titivating A CNC Plasma Table
« Reply #127 on: January 17, 2017, 07:43:23 AM »
This morning I attacked the wall.

I'd thought long and hard the best way to space 2" diameter core drilled holes reasonably accurately to give a 12" 'wobbly edged' hole, and in the end I came up with the patented angular hole spacer. Simply a bit of wood with two holes spaced 5" apart, one being 2" from an edge. One hole was used as a pivot, on a screw in the centre of the hole, and the other was a guide for a masonry drill. Drill one hole, then rotate the spacer so that the edge of the gizmo lines up with the last hole, and drill another. Worked like a charm  :ddb:

I then drilled these hole out to the guide drill size for the diamond core drill, and drilled out the core - it went remarkably easily, with the expected conical break out on the far side.

Then it was just a case of fixing the inner wall plate and outer cowl, and connecting up the 12" heat resisting flexible air pipe to the extractor fan on the table.

Hopefully this afternoon I'll get a chance to use the table in earnest

Andrew Mawson
East Sussex

Offline PekkaNF

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Re: Titivating A CNC Plasma Table
« Reply #128 on: January 17, 2017, 09:00:20 AM »
"Scope Creep" -  uncontrolled changes or continuous growth in a project's scope. This can occur when the scope of a project is not properly defined, documented, or controlled. It is generally considered harmful.


Well it obviously happened on this project - I've just found myself ordering six 6003-2RS bearings - the assembly that holds the  gear wheels that engage with the racks on the machine each have two of these bearings - and at least one set feels notchy. Easy enough to change, silly not to really, but ...........  :scratch:

Luckily you haven't got feature creep!
https://youtu.be/aXQ2lO3ieBA

That happens to me at the end of design phase and then I need to weed extras out.

Pekka

Offline awemawson

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Re: Titivating A CNC Plasma Table
« Reply #129 on: January 17, 2017, 11:10:20 AM »
Well oddities abound - all excited I loaded up a sheet of 3 mm mild steel (zintec coated) and set it to cut out a 'bearing baffle' that I'd previously designed and cut on the table before I started updating it. It started off ok, measuring Z=0 and setting torch height, but when the actual plasma should have been initiated, movement stopped and the Hypertherm 45 displayed an error light showing 'loose consumables'

In the guts of the machine torch is a micro-switch that closes when the consumables are tightened onto the torch - I buzzed out the cables to the plug and everything was fine - closed when tight - open circuit when loose. Nothing to do with the CNC controller, this must be an internal issue with the Hypertherm - maybe something I disturbed when I remade the plasma voltage cable :scratch: . So I pulled the torch and cutter off the table, opened up the Hypertherm, and buzzed the switch all the way through to the main board - no issues. Put it back together and back on the CNC table, and tried again - same issue  :bang:

There is a button on the screen allowing me to trigger the torch on and off manually. Out of curiosity I clicked it, and initially there was a very weak release of compressed air - I did this several times then the torch fired up, no errors and full air discharge. I've come to the conclusion that the air solenoid in the Hypertherm was perhaps sticky and has now cleared, but why that should make it report loose consumables is a mystery  :scratch:

After that everything worked as it should - very odd. So here is a video of it cutting, and a picture of the result. Not surprisingly the cut quality hasn't improved since I did the re-build, but that's due to worn consumables and non-optimal cutting conditions controlled by program. Also there is an issue with the cut not ceasing fast enough at the end of a feature - I need to tweak the post processor to stop the arc marginally before the end of the feature to eliminate the nick it's producing.


<a href="http://www.youtube.com/watch?v=NMHk7ua96l8" target="_blank">http://www.youtube.com/watch?v=NMHk7ua96l8</a>

Andrew Mawson
East Sussex

Offline hermetic

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Re: Titivating A CNC Plasma Table
« Reply #130 on: January 17, 2017, 12:14:18 PM »
Excellent work Andrew, teething problems, you will soon sort them and have it humming! I could just do with it to cut a 24" circle in 1.5 galv , when can you deliver it to Yorkshire?
Phil.

Offline DMIOM

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Re: Titivating A CNC Plasma Table
« Reply #131 on: January 17, 2017, 12:34:49 PM »
Bravo Sir - good to follow proper refurb and see it working.

....I've come to the conclusion that the air solenoid in the Hypertherm was perhaps sticky and has now cleared, but why that should make it report loose consumables is a mystery.....

Well, the air is a sort of consumable isn't it?  :coffee:

What you found does remind me of the travails I had when I got my first machine with TNC155 - it would NOT start as the E-Stop was triggered. No matter what I traced and belled out I could not find the problem - axis final limit switches were all closed, E-Stop button wasn't activated.  Eventually found that the float switch in the Bijur auto-oiler was wired in series with the E-Stop  :bang:

Thanks for taking us along on another well-told adventure.

Dave

Offline RobWilson

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Re: Titivating A CNC Plasma Table
« Reply #132 on: January 17, 2017, 01:27:05 PM »
 :thumbup: Nicely done Andrew  :clap: :clap: :clap:


I wish I had the room for one  :(


Rob

Offline howsitwork?

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Re: Titivating A CNC Plasma Table
« Reply #133 on: January 19, 2017, 01:05:52 PM »
Looks good Andrew

Was the bucket outside in case you"felt a bit pale when you'd finished" :lol: :lol: :lol:

Ian

Offline awemawson

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Re: Titivating A CNC Plasma Table
« Reply #134 on: January 19, 2017, 02:10:14 PM »
Bucket was carrying away the spoil from knocking the 12" hole in the wall.

Been playing today trying to improve cut quality. If you can imagine the plasma flame being shaped like the picture below, the correct height setting of the plasma torch dictates the edge shape of the cut. It will always have curve, but you want it to be symmetrically placed about the depth of the plate.

To achieve this you need to know precisely where you are in the Z axis. Now this plasma cutter like many others, has a "floating Z axis slide" where by the Z axis can be slowly ramped onto the work by a probing cycle, the main axis carrying on travelling and the floating one stopping (as the torch has touched the work), until the Z axis limit switch is tripped, whereupon the controller raises Z by the switch and slide backlash amount and the Z axis is now on a true Z=0 position. This value is input to the software for accurate positioning. Measurement this evening implies mine is 2.5 mm or there abouts, however it was set up to 2.0 mm in software.  Meaning that any Z positioning commands would be out by 0.5 mm. Yet to repeat this a few times to get a good average value to work with.
Andrew Mawson
East Sussex

Offline mattinker

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Re: Titivating A CNC Plasma Table
« Reply #135 on: January 19, 2017, 02:29:37 PM »
How's the extraction?

Regards, Matthew

Offline awemawson

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Re: Titivating A CNC Plasma Table
« Reply #136 on: January 19, 2017, 02:35:27 PM »
A major improvement Matthew  :thumbup:

No longer does the welding shop fill up with a noxious fumes. Not sure about that pile of bodies accumulating outside though  :lol:
Andrew Mawson
East Sussex

Offline awemawson

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Re: Titivating A CNC Plasma Table
« Reply #137 on: January 22, 2017, 05:24:09 AM »
I'm loving this plasma cutter  :ddb:

This mornings exercise - try it out on 1.2 mm Zintec mild steel. I'd done a little trial yesterday to optimise cut speed, and this morning the idea was to make a little simple box.

- Draw it in Autocad - save as a DXF file

- Import into SheetCAM and produce a G code TAP file

- Import into Mach3 and make a flat box !

- Bend it on the Edwards Box & Pan folder

Absolutely straight forwards - it took less than an hour including taking the pictures and writing up this thread - magnificent - and no laying out bend lines, or having to make corner notches that go squiffy

--- I love it  :clap: :clap:
Andrew Mawson
East Sussex

Offline mattinker

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Re: Titivating A CNC Plasma Table
« Reply #138 on: January 22, 2017, 06:37:53 AM »
Andrew, you got the over cutting problem sorted! The 29mm hole can't be far away!

All the best, Matthew

Offline awemawson

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Re: Titivating A CNC Plasma Table
« Reply #139 on: January 22, 2017, 06:50:51 AM »
Matthew, I'll cut you a range of holes and you can keep them in stock for when you need them  :lol:
Andrew Mawson
East Sussex

Offline mattinker

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Re: Titivating A CNC Plasma Table
« Reply #140 on: January 22, 2017, 06:54:37 AM »
Just hang 'em on a sky hook for me and I'll pick them up next year!!

Offline awemawson

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Re: Titivating A CNC Plasma Table
« Reply #141 on: January 23, 2017, 09:23:28 AM »
So what's all this box making all about  :scratch:

Well I decided that although bits nicely drop into the collection area at the bottom of the down drought extractor 'funnel', it would be much easier if there was a removable 'ash pan' in there that could come out for cleaning etc.

Ideally it would be the same size as the bottom of the drop box, but in reality it has to be able to pass through the door opening. In my enthusiasm to get it as tight as possible my first attempt ended up about 3 mm too big  :bang:

Never mind - it takes 65.06 seconds (according to sheetCAM !) to cut another slightly smaller one - I'm sure that the bigger box will come in handy for storing things  :lol:

I spot welded the fold tabs as I think it is neater than pop rivets. If too much falls at the periphery and hence misses the box, I can always fix deflectors further up the drop box.
Andrew Mawson
East Sussex

Offline awemawson

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Re: Titivating A CNC Plasma Table
« Reply #142 on: January 31, 2017, 03:22:58 PM »
Oh this Plasma Table is GREAT fun  :clap:

I've been trying to learn Inkscape, which is a very versatile but not very intuitive graphics program that let's me grab images, trace and manipulate them and do things with text that are difficult in other programs.

Here are a few things I've done recently - firstly a sign for the farm (*), then some name stencils to entertain grand children who are invading at the weekend  :bugeye:

(* sorry the pig is skewered by a red screw driver, I couldn't find anything else to hang it on ! )
Andrew Mawson
East Sussex

Offline mattinker

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Re: Titivating A CNC Plasma Table
« Reply #143 on: January 31, 2017, 04:34:37 PM »
Nice to see! The weather's got warmer, so the welding shed is accessible again. Your having fun! A 29mm hole soon?

All the best Matthew

P.S. Progress on the Warco, slow, but progress!!

Offline Pete W.

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Re: Titivating A CNC Plasma Table
« Reply #144 on: February 01, 2017, 05:21:33 AM »
Hi there, Andrew,

I can understand your pleasure at the new capability afforded by the plasma table.

Reading your mention of Inkscape reminded me of a post (here or elsewhere, I forget which) from someone who was trying to identify the font used in someone's logo so he could make a replica ID plate.  Sounds like Inkscape would be just the tool for that job. 
Best regards,

Pete W.

If you can keep your head when all about you are losing theirs, you haven't seen the latest change-note!

Offline awemawson

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Re: Titivating A CNC Plasma Table
« Reply #145 on: February 01, 2017, 07:55:40 AM »
Pete I think it was ME  :lol:

I was trying to replicate the FANUC logo for replacement reels for my wire eroder !


http://madmodder.net/index.php/topic,10211.msg115074.html#msg115074


With my new found knowledge of INKSCAPE it would be a doddle !!!!
Andrew Mawson
East Sussex

Offline Pete W.

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Re: Titivating A CNC Plasma Table
« Reply #146 on: February 01, 2017, 10:28:30 AM »
Pete I think it was ME  :lol:

I was trying to replicate the FANUC logo for replacement reels for my wire eroder !


http://madmodder.net/index.php/topic,10211.msg115074.html#msg115074


With my new found knowledge of INKSCAPE it would be a doddle !!!!


OK, you get off with a light sentence for handing yourself in and pleading guilty!!   :lol:   :ddb:   :lol:   :ddb: 

And we'll also take into consideration your record of community service!!   :D   :D   :D   :D   :D   :D   
Best regards,

Pete W.

If you can keep your head when all about you are losing theirs, you haven't seen the latest change-note!

Offline PekkaNF

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Re: Titivating A CNC Plasma Table
« Reply #147 on: February 03, 2017, 05:39:23 AM »

Offline awemawson

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Re: Titivating A CNC Plasma Table
« Reply #148 on: February 03, 2017, 06:16:38 AM »
 :lol:

.... happens down the farm all the time  :ddb: :ddb: :ddb:
Andrew Mawson
East Sussex

Offline PekkaNF

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Re: Titivating A CNC Plasma Table
« Reply #149 on: February 03, 2017, 06:25:10 AM »
Once my wife said that she is pretty sure I would not mind that punishment from famous BR movie.

Pekka