The Dark Satanic Mill

[Chris J]

I thought it might be best to start a thread on my project here and try and keep my ramblings in one spot (easier for people to avoid) :-)

Anyway as some of you know I'm trying to get a machine to cut out brooch shapes in a 1-2mm thick sheet of copper to help my wifes jewellery making efforts.

I was hoping to get away with a cost of around £1500 so I seem to be limited in what I can get.
Decent off the shelf machines seem to go for a fair bit more than that so short of finding a half built project that someone is bored with (you know who you are) I am going to need to build something myself.

There seems to be a trap with self build as it is almost as if you need a workshop with a Mill to make your Mill !! If anyone near Great Yarmouth is out there please speak up :-)
So I'm thinking I need to buy something in almost a kit form that needs only a small amount of home workshopping.

I have had a number of emails and phone conversations with Gary at Zapp who has been very helpful and also one forum member is being driven to distraction behind the scenes - Big thanks due.

In a day or so I will put up a list of the kit I'm proposing to get so you guys can rip it to pieces :-)

Chris

[motoxy]

Do not worry about lack of mills etc. I have a router screwed under the bench, a hobby bench drill and a sliding mitre saw. You may need a bit more ingenuity and help from the forum but it can be done.

Bruce

[Chris J]

This whole thing is turning into a nightmare.

I only wanted to help my wife make a brooch !!

Now Im sucked in :-)

[mocha]

lol, too late now... you should've taken the Blue pill! :-)

Wait until you start lusting after a T shirt with the logo "There's no place like G74" !
:-)

[Chris J]

lol, too late now... you should've taken the Blue pill! :-)

Wait until you start lusting after a T shirt with the logo "There's no place like G74" !
:-)

I'm not that sad...........................am I ? Maybe a cap then. :-)

[John S]

Shouldn't that be G28 ?
Unless you live inside a drilling or tapping machine ?

[mocha]

Shouldn't that be G28 ?
Unless you live inside a drilling or tapping machine ?

I did think it should have been G28, but according to NC Programming as per ISO (DIN 66025) and RS274,http://www.machinemate.com/FullListCodes.htm it said 74... Is the difference because of "dialect" or is there another reason???

[John S]

God almighty that's an old list, half those codes won't run on a modern machine/.
No G28, no G30
G76 screwcutting has been allocated to something else.?

[mocha]

Now I am confused because Power Automation GmbH, the company that makes or sells the machines that those codes relate to seem to still be in business I think... Well, they are scheduled to be at a trade show in July...

Do you know of an up to date list of G-codes?

[John S]

Why not take the list that Mach uses ?
No good insisting that 'THIS' is the standard if your machine can't handle it.

Good book and really a bible is CNC Programming Handbook by Smid.
Bit pricey in 3rd edition but 2nd editions can be picked up cheaply and not a lot of difference in them.

Just checked and G74 is left hand threading on mills and drilling cycle on lathes.

[mocha]

Thanks for that John. LOL. Up to about an hour ago I thought that there were only minor dialect differences in G-code and those would only be found in the heady areas of Haas / Fanuc type territory. I also thought that the ISO standard would be the main one in use! :-) WRONG! ...and as I have no ambitions to purchase an 8 axis PA 8000 e2, I'll certainly wander over to Amazon grab the handbook, sounds like a useful read.

At the moment I'm not certain if I'll use Mach 3 or something else so I've only had a quick look through the Mach manual. If I do end up using Mach3 then I'll obviously use their G-code spec.

[JAZZCNC]

Good book and really a bible is CNC Programming Handbook by Smid.
Bit pricey in 3rd edition but 2nd editions can be picked up cheaply and not a lot of difference in them.

Better idea save your money and put it towards the machine getting done quicker because although like John says it's a good read and very informative it does relate more to industry standards and Mach doesn't exactly follow them to the letter(At the moment.!). . . . Can't beat hands on experience IMO so get bloody cutting ASAP and learn along the way.

[JAZZCNC]

At the moment I'm not certain if I'll use Mach 3 or something else so I've only had a quick look through the Mach manual. If I do end up using Mach3 then I'll obviously use their G-code spec.

To be honest Mocha if your using a decent Cam package you'll probably rarely touch the G-code and even then if you do it will most likely be simple stuff like changing a feed rate (F Code) in G1 move or some thing like Z height etc nothing special or unique and mostly standard G-code on Most controls.!!

It's idea good idea to learn G-code so you can monitor and understand or keep track of whats happening while cutting but it's getting less and less needed has Cam gets better and Post processors become more refined.

[Jonathan]

Better idea save your money and put it towards the machine getting done quicker because although like John says it's a good read and very informative it does relate more to industry standards and Mach doesn't exactly follow them to the letter(At the moment.!). . . . Can't beat hands on experience IMO so get bloody cutting ASAP and learn along the way.

Just what I was thinking.

A lot, if not most, of the 'hobby' CAM programs tend to do almost everything with G0,1,3 anyway presumably because there aren't many cases where it makes a difference. For instance V-carve doesn't even use G81 to drill, just uses G1 and G0.

Just yesterday I was chamfering some large rectangular aluminium parts, but due to the parts having taken so long to cut and the MDF bed the chamfers were uneven. Easily solved by measuring the actual width of the chamfer in the 4 corners and adding Z moves to those points to make the tool move on an inclined plane to compensate for the bed...didn't need any fancy codes, just a bit of common sense. Look them up if/when you need them.

[mocha]

To be honest Mocha if your using a decent Cam package you'll probably rarely touch the G-code and even then if you do it will most likely be simple stuff like changing a feed rate (F Code) in G1 move or some thing like Z height etc nothing special or unique and mostly standard G-code on Most controls.!!

It's idea good idea to learn G-code so you can monitor and understand or keep track of whats happening while cutting but it's getting less and less needed has Cam gets better and Post processors become more refined.

Thanks Jazz, I must admit that my thinking has been influenced by all the posts I've noticed where it's mentions something like, "...so I have to go and edit that (in/out/etc) in the G-code". I've almost accepted that some kind of tweaking will be required. (I even pulled down Notepad++ in readiness!) My experience with trying to get something useful out of TurboCAD / CAM did nothing to allay that belief! But from what you are saying, that's not as common a situation as I thought.

[Web Goblin]

The book would be handy as a reference but I doubt you would use it alot. I am learning G Code as I go along. At work we use custom ESSI and the only time I dig out the manual is when the machine does something wrong and I need to check the program or when the CAD/CAM guys want some advice on something.

Ian

[Chris J]

Well this isn't going to be much of a build thread as I've decided to buy one that someone else has built!!

June 10th delivery all being well :-)

Head is full of Cad stuff now !!